Tin is a chemical element with the symbol Sn (from Latin: stannum) and atomic number 50. It is a post-transition metal in group 14 of the periodic table of elements. Tin is obtained primarily from the mineral tin ore containing tin dioxide SnO2. Tin has chemical similarities to its two neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has the highest number of stable isotopes on the periodic table (with 10 stable isotopes), thanks to its "magic" number of protons. Tin has two main allotropes: at room temperature, the stable allotrope is β-tin, a silvery-white, malleable metal, but at low temperatures, tin changes to the less dense gray α-tin, which has a diamond-like cubic structure. Tin metal is not easily oxidized in air. The first alloy used on a large scale was bronze, made from tin and copper, beginning in 3000 BC. e. After 600 BC e. pure metallic tin was produced. A tin-lead alloy of 85-90% tin, usually consisting of copper, antimony and lead, was used to make tableware from the Bronze Age until the 20th century. Nowadays, tin is used in many alloys, most commonly in soft tin/lead alloys, which typically contain 60% or more tin. Another common use for tin is as a corrosion-resistant coating on steel. Inorganic tin compounds are rather non-toxic. Because of its low toxicity, tinned metal has been used to package food using tin cans, which are actually made primarily of steel or aluminum. However, overexposure to tin can cause problems with the metabolism of essential trace elements such as copper and zinc, and some organotin compounds can be almost as toxic as cyanide.
Characteristics
Physical
Tin is a soft, malleable, ductile and highly crystalline silvery-white metal. When a tin plate is bent, a cracking sound known as "tin crack" can be heard from the twinning of the crystals. Tin melts at a low temperature, around 232 °C, the lowest in group 14. The melting point drops further to 177.3 °C for 11 nm particles. β-tin (metallic form, or white tin, BCT structure), which is stabilized at room temperature and above, is malleable. In contrast, α-tin (the non-metallic form, or gray tin), which is stabilized at temperatures up to 13.2 °C, is brittle. α-tin has a cubic crystal structure similar to diamond, silicon or germanium. α-tin has no metallic properties at all because its atoms form a covalent structure in which electrons cannot move freely. It is a dull gray powdery material that does not have any widespread use beyond a few specialized semiconductor applications. These two allotropes, α-tin and β-tin, are better known as gray tin and white tin, respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C and pressures above several gigapascals. Under cold conditions, β-tin spontaneously transforms into α-tin. This phenomenon is known as the "tin plague". Although the α-β transformation temperature is nominally 13.2 °C and impurities (eg Al, Zn, etc.) below the transition temperature are below 0 °C and, with the addition of Sb or Bi, the transformation may not occur at all, increasing the durability of tin. Commercial grades of tin (99.8%) resist transformation due to the inhibitory effect of small amounts of bismuth, antimony, lead and silver present as impurities. Alloying elements such as copper, antimony, bismuth, cadmium, silver increase the hardness of the substance. Tin quite easily forms hard, brittle intermetallic phases, which are often undesirable. Tin does not form many solid solutions in other metals in general, and several elements have appreciable solid solubility in tin. Simple eutectic systems, however, are observed with bismuth, gallium, lead, thallium and zinc. Tin becomes a superconductor below 3.72 K and is one of the first superconductors to be studied; The Meissner effect, one of the characteristic features of superconductors, was first discovered in superconducting tin crystals.
Chemical properties
Tin resists corrosion from water, but can be attacked by acids and alkalis. Tin can be highly polished and is used as a protective coating for other metals. A protective oxide (passive) layer prevents further oxidation, the same as that formed on tin-lead and other tin alloys. Tin acts as a catalyst when oxygen is in solution and helps accelerate chemical corrosion.
Isotopes
Tin has ten stable isotopes with atomic masses 112, 114, 120, 122 and 124, the largest number of any element. The most common of these are 120Sn (almost a third of all tin), 118Sn and 116Sn, while the least common are 115Sn. Isotopes with even mass numbers have no nuclear spin, while isotopes with odd numbers have a spin of +1/2. Tin, with three common isotopes 116Sn, 118Sn and 120Sn, is one of the easiest elements to detect and analyze using NMR spectroscopy. This large number of stable isotopes is believed to be a direct result of atomic number 50, the "magic number" in nuclear physics. Tin also occurs in 29 unstable isotopes, covering all other atomic masses from 99 to 137. Apart from 126Sn, with a half-life of 230,000 years, all radioisotopes have half-lives of less than a year. Radioactive 100Sn, discovered in 1994, and 132Sn are among the few nuclides with a “double magic” nucleus: although unstable, having a very uneven proton-neutron ratio, they represent endpoints beyond which stability declines rapidly. Another 30 metastable isomers were characteristic of isotopes between 111 and 131, the most stable being 121mCH with a half-life of 43.9 years. Relative differences in the abundance of stable tin isotopes can be explained by their different modes of formation in stellar nucleosynthesis. 116Sn through 120Sn inclusive are formed by the s-process (slow neutrons) in most stars and are therefore the most common isotopes, while 122Sn and 124Sn are not only formed by the R-process (fast neutrons) in supernovae and less commonly. (The isotopes 117Sn through 120Sn also benefit from the r-process.) Finally, the rarest proton-rich isotopes, 112Sn, 114Sn, and 115Sn, cannot be produced in significant quantities in the s- and r-processes and are considered to be among the p-processes. nuclei, the origin of which is not fully understood. Some proposed mechanisms for their formation include proton capture as well as photodisintegration, although 115Sn can also be partially produced in the s-process, both at once, and as a “daughter” of long-lived 115In.
Etymology
The English word tin (tin) is common to the Germanic languages and can be traced to reconstructed Proto-Germanic *tin-om; cognates include German Zinn, Swedish tenn and Dutch tin. The word is not found in other branches of Indo-European languages, except as a borrowing from Germanic (for example, the Irish word tinne came from English tin). The Latin name stannum originally meant an alloy of silver and lead, and in the 4th century BC. e. it came to mean "tin" - the earlier Latin word for it was plumbum quandum, or "white lead". The word stannum appears to have been derived from the earlier stāgnum (same substance), the origin of the Romanesque and Celtic designation for tin. The origin of stannum/stāgnum is unknown; it may be pre-Indo-European. According to Meyer's Encyclopedic Dictionary, on the contrary, stannum is considered to be a derivative of Cornish stean and is evidence that Cornwall was the main source of tin in the first centuries AD.
Story
The extraction and use of tin began in the Bronze Age, around 3000 BC. BC, when it was noted that copper objects formed from polymetallic ores with different metal contents have different physical properties. The earliest bronze objects contained less than 2% tin or arsenic and are therefore believed to be the result of unintentional alloying by tracing the metal content of the copper ore. Adding a second metal to copper increases its strength, lowers its melting point, and improves the casting process by creating a thinner melt that is denser and less spongy when cooled. This made it possible to create much more complex forms of closed bronze objects. Bronze objects with arsenic appeared primarily in the Middle East, where arsenic is often found in association with copper ore, however, the health risks associated with the use of such objects soon became clear, and the search for sources of much less dangerous tin ores began early Bronze Age. This created a demand for the rare metal tin and formed a trade network linking distant sources of tin to the markets of Bronze Age cultures. Cassiterite, or tin ore (SnO2), an oxide of tin, was most likely the original source of tin in ancient times. Other forms of tin ores are less common sulfides such as stannite, which require a more active smelting process. Cassiterite often accumulates in alluvial channels as placer deposits because it is heavier, tougher, and more chemically resistant than granite. Cassiterite is usually black or generally dark in color, and its deposits are easily visible in river banks. Alluvial (placer) deposits can be easily collected and separated by methods similar to gold panning.
Compounds and chemistry
In the vast majority, tin has an oxidation state of II or IV.
Inorganic compounds
Halide compounds are known for both oxidation states. For SN(IV), all four halides are well known: SnF4, SnCl4, SnBr4, and SnI4. The three heaviest elements are volatile molecular compounds, while tetrafluoride is polymeric. All four halides for Sn(II) are also known: SnF2, SnCl2, SnBr2 and SnI2. These are all polymeric solids. Of these eight compounds, only iodides are colored. Tin(II) chloride (also known as stannous chloride) is the most important tin halide commercially. Chlorine reacts with tin metal to create SnCl4 while the reaction of hydrochloric acid and tin produces SnCl2 and hydrogen gas. In addition, SnCl4 and Sn combine with tin chloride through a process called co-proportionation: SnCl4 + CH → 2 Sncl2 Tin can form many oxides, sulfides and other chalcogenide derivatives. SnO2 dioxide (cassiterite) is formed when tin is heated in the presence of air. SnO2 is amphoteric in nature, which means it dissolves in acidic and basic solutions. Stannates with the structure Sn(OH)6]2, like K2, are also known, although free stannous acid H2[CH(on)6] is unknown. Tin sulfides exist in both +2 and +4 oxidation states: tin(II) sulfide and tin(IV) sulfide (mosaic gold).
Hydrides
Stannan (SnH4), with tin in the +4 oxidation state, is unstable. Organotin hydrides, however, are well known, for example tributyline hydride (Sn(C4H9)3H). These compounds release transient tributyltin tin radicals, which are rare examples of tin(III) compounds.
Organotin compounds
Organotin compounds, sometimes called stannanes, are chemical compounds with tin-carbon bonds. Of the tin compounds, the organic derivatives are the most commercially useful. Some organotin compounds are very toxic and are used as biocides. The first known organotin compound was diethyltin diodide (C2H5)2SnI2), which was discovered by Edward Frankland in 1849. Most organic tin compounds are colorless liquids or solids that are resistant to air and water. They adopt tetrahedral geometry. Tetraalkyl and tetraaryltine compounds can be prepared using Grignard's reagents:
4 + 4 RMgBr → R
Mixed alkyl halides, which are more common and have greater commercial value than tetraorganic derivatives, are prepared by repartitioning reactions:
4Sn → 2 SnCl2R2
Divalent organotin compounds are rare, although more common than divalent organogermanium and organosilicon compounds. The greater stabilization that Sn(II) has is attributed to the “inert pair effect.” Organotin(II) compounds include both stannylenes (formula: R2Sn, as seen for singlet carbenes) and distannylenes (R4Sn2), which are roughly equivalent to alkenes. Both classes exhibit unusual reactions.
Emergence
Tin is formed in the long-term s-process in low- and medium-mass stars (with masses from 0.6 to 10 times the mass of the Sun) and, finally, during the beta decay of heavy indium isotopes. Tin is the most abundant 49th element in the earth's crust, at 2 ppm compared to 75 mg/L for zinc, 50 ppm for copper, and 14 ppm for lead. Tin does not occur as a native element, but must be extracted from various ores. Cassiterite (SnO2) is the only commercially important source of tin, although small quantities of tin are recovered from complex sulfides such as stannite, cypindrite, frankeite, canfieldite and tillite. Tin minerals are almost always associated with granite rock, usually at the 1% tin oxide level. Due to the high specific gravity of tin dioxide, about 80% of mined tin comes from secondary deposits recovered from primary deposits. Tin is often recovered from granules washed downstream in the past and deposited in valleys or the sea. The most economical methods of mining tin are scooping, hydraulics or open pits. Most of the world's tin is produced from placer deposits, which may contain as little as 0.015% tin. World tin mine reserves (tons, 2011)
Indonesia 800000
Brazil 590000
Bolivia 400000
Russia 350000
Australia 180000
Thailand 170000
Others 180000
Total 4800000
China 1500000
Malaysia 250000
Approximately 253,000 tonnes of tin were mined in 2011, mainly from China (110,000 tonnes), Indonesia (51,000 tonnes), Peru (34,600 tonnes), Bolivia (20,700 tonnes) and Brazil (12,000 tonnes). Estimates of tin production have historically varied depending on economic viability dynamics and developments in mining technology, but at current rates of consumption and technology, it is estimated that the Earth will run out of tin mining within 40 years. Lester Brown suggested that tin could run out within 20 years based on an extremely conservative extrapolation of 2% growth per year. Economically recoverable tin reserves: Million. tons per year
Recycled or scrap tin is also an important source of this metal. Tin recovery through secondary production or recycling of scrap tin is growing at a rapid pace. While the United States has not mined tin since 1993 nor smelted tin since 1989, it has been the largest secondary producer of tin, processing nearly 14,000 tons in 2006. New deposits are found in southern Mongolia, and in 2009 new tin deposits were discovered in Colombia by Seminole Group Colombia CI, SAS.
Production
Tin is produced by carbothermic reduction of oxide ore using carbon or coke. Reverberatory furnaces and electric furnaces can be used.
Price and exchange
Tin is unique among other mineral commodities due to complex agreements between producing and consuming countries dating back to 1921. Earlier agreements tended to be somewhat informal and sporadic and led to the "First International Tin Agreement" in 1956, the first of a permanent series of agreements that effectively ceased to exist in 1985. Through this series of agreements, the International Tin Council (ITC) had a significant influence on tin prices. MCO supported the price of tin during periods of low prices by purchasing tin for its buffer stock and was able to contain the price during periods of high prices by selling tin from this stock. This was an anti-market approach designed to ensure a sufficient flow of tin to consuming countries and profits for producing countries. However, the buffer stock was not large enough, and for most of those 29 years, tin prices rose, sometimes sharply, especially from 1973 to 1980, when rampant inflation plagued many of the world's economies. In the late 1970s and early 1980s, US government tin inventories were in an aggressive sales mode, in part to take advantage of historically high tin prices. The slump of 1981-82 was quite harsh for the tin industry. Tin consumption dropped sharply. MCO was able to avoid a truly drastic reduction by accelerating purchases for its buffer stock; these activities required MCOs to borrow on a large scale from banks and metal trading firms to increase their resources. MCO continued to borrow funds until the end of 1985, when it reached its credit limit. Immediately after this came the great “tin crisis”, and then tin was excluded from trading on the London Metal Exchange for a period of three years, the MCO soon collapsed, and tin prices, already in a free market, fell sharply to $4 per pound (453 g) , and remained at this level until the 1990s. The price increased again by 2010 with a rebound in consumption following the 2008–09 World Economic Crisis, accompanying renewed and continued growth in consumption in the developing world. The London Metal Exchange (LME) is the main trading platform for tin. Other tin markets are Kuala Lumpur Tin Market (KLTM) and Indonesia Tin Exchange (INATIN).
Applications
In 2006, about half of all tin produced was used in solders. The remaining uses were divided between tin plating, tin chemicals, brass and bronze alloys, and niche uses.
Solder
Tin has long been used in alloys with lead as solder, in quantities ranging from 5 to 70%. Tin forms a eutectic mixture with lead in the proportion of 63% tin and 37% lead. Such solders are used to join pipes or electrical circuits. On 1 July 2006, the European Union's Waste Electrical and Electronic Equipment Directive (WEEE Directive) and the RoHS Directive came into force. The lead content in such alloys has decreased. Replacing lead comes with many problems, including higher melting points and the formation of tin whiskers. Tin plague can occur in lead-free solders.
Tinning
Tin bonds take well to ironing and are used to coat lead, zinc and steel to prevent corrosion. Tinned steel containers are widely used for food preservation, and this forms a large part of the tin metal market. In London in 1812, the first tin canister was made for preserving food. In British English these are called "tins", but in America they are called "cans" or "tin cans". The slang name for a can of beer is "tinnie" or "tinny". Copper cooking vessels such as pots and pans are often lined with a thin layer of tin, since the combination of acidic foods with copper can be toxic.
Specialized alloys
Tin combines with other elements to form many useful alloys. Tin is most often alloyed with copper. Tin-lead alloy has 85-99% tin; Bearing metal also contains a high percentage of tin. Bronze is primarily copper (12% tin), while the addition of phosphorus produces phosphor bronze. Bell bronze is also a copper-tin alloy containing 22% tin. Tin was sometimes used in coins to create American and Canadian pennies. Because copper was often the base metal in these coins, sometimes including zinc, they may be called bronze and/or brass alloys. The niobium-tin compound Nb3Sn has been commercially used in superconducting magnet coils due to its high critical temperature (18 K) and critical magnetic field (25 T). A superconducting magnet weighing just two kilograms can create the same magnetic field as electromagnets with normal weight. A small proportion of tin is added to zirconium alloys for cladding nuclear fuel. Most metal pipes on an organ have varying amounts of tin/lead, with 50/50 alloys being the most common. The amount of tin in the pipe determines the tone of the pipe, as tin gives the instrument the desired resonance. When a tin/lead alloy cools, the lead cools slightly faster and produces a mottled or mottled effect. This metal alloy is called spotted metal. The main benefits of using tin for pipes are its appearance, performance and corrosion resistance.
Other Applications
Perforated tinned steel is a craft technique that originated in Central Europe to create household items that were both functional and decorative. Perforated tin lanterns are the most common application of this technique. Candle light passing through the perforations creates a decorative light pattern. Lanterns and other perforated tin items have been created in the New World since the earliest European settlements. A famous example is the Revere lantern, named after Paul Revere. Before the modern era, in some areas of the Alps, goat or ram horns were sharpened and metal was punched through it in the shape of the alphabet and numbers from one to nine. This teaching tool was known simply as the "horn". Modern reproductions feature motifs such as hearts and tulips. In America, wooden cabinets of various styles and sizes were used for cakes and food before refrigeration, designed to repel pests and insects and keep perishable foods from dust. These were either floor or hanging cabinets. These cabinets had tin inserts in the doors and sometimes on the sides. Window glass is most often made by placing molten glass on molten tin (float glass - sheet glass produced from molten metal), resulting in a perfectly smooth surface. This is also called the Pilkington process. Tin is also used as the negative electrode in modern lithium-ion batteries. Its use is somewhat limited by the fact that some tin surfaces catalyze the decomposition of carbonate electrolytes used in lithium-ion batteries. Stann(II) fluoride is added to some dental care products (SnF2). Tin(II) fluoride can be mixed with calcium abrasives, while the more common sodium fluoride gradually becomes biologically inactive in the presence of calcium compounds. It has also been shown to be more effective than sodium fluoride in controlling gingivitis.
Organotin compounds
Among all the chemical compounds of tin, organic tin compounds are the most commonly used. Their global industrial production probably exceeds 50,000 tons.
PVC stabilizers
The main commercial use of organotin compounds is in the stabilization of PVC plastic. In the absence of such stabilizers, PVC would otherwise rapidly degrade when exposed to heat, light and atmospheric oxygen, resulting in a discolored and brittle product. Tin scavenges labile chloride ions (Cl−), which would otherwise cause HCl to be lost from plastic. Typical tin compounds are carboxylic acid derivatives of dibutyltin dichloride, such as dibutyltin dilaurate.
Biocides
Some organotin compounds are relatively toxic, which has its advantages and disadvantages. They are used for their biocidal properties as fungicides, pesticides, algaecides, wood preservatives and anti-rot agents. Tributyltin oxide is used as a wood preservative. Tributyltin was used as a marine paint additive to prevent the growth of marine organisms on ships, although use decreased after organotin compounds were recognized as persistent organic pollutants with extremely high toxicity to some marine organisms (eg, scarlet grass). The EU banned the use of organotin compounds in 2003, while concerns about the toxicity of these compounds to marine life and damage to the reproduction and growth of some marine species (some reports describe biological effects on marine life at concentrations of 1 nm per liter) led to a worldwide prohibited by the International Maritime Organization. Currently, many states restrict the use of organotin compounds to vessels longer than 25 m.
Organic chemistry
Some tin reagents are useful in organic chemistry. In its most common application, stannous chloride is a common reducing agent for the conversion of nitro and oxime groups to amines. The Style reaction links organotin compounds with organic halides or pseudohalides.
Lithium-ion batteries
Tin forms several intermetallic phases with lithium metal, making it a potentially attractive material for battery applications. The large volumetric expansion of tin upon lithium doping and the instability of the organotin electrolyte interface at low electrochemical potentials are the greatest challenges for use in commercial cells. The problem was partially resolved by Sony. Tin intermetallic compounds with cobalt and carbon are marketed by Sony in its Nexelion cells released in the late 2000s. The composition of the active substance is approximately Sn0.3Co0.4C0.3. Recent studies have shown that only certain crystalline facets of tetragonal (beta)Sn are responsible for undesirable electrochemical activity.
Soft white metal - tin - was one of the first metals that man learned to process. Scientists believe that tin began to be mined much earlier than iron was first discovered.
Some archaeological finds confirm that tin mines in what is now Iraq were in operation four thousand years ago. Tin was traded: merchants exchanged it for precious stones. In nature, tin is found in the oxide tin ore cassiterite, a mineral whose deposits are found in Southeast Asia, South America, Australia, and China.
From the history
According to historians and archaeologists, tin was first discovered, most likely by accident, in alluvial deposits of cassiterite. Ancient furnaces containing waste slag have been found in the south-west of Great Britain. Among the discovered objects from the era of Ancient Rome and Greece, tin items are very rare, which confirms the assumption that this metal was expensive.
Tin is mentioned in works of Arabic literature of the 8th-9th centuries, as well as in medieval works describing travel and great discoveries. In Bohemia and Saxony, tin began to be mined in the 12th century. 
It is interesting that long before people began to mine pure tin, they invented bronze - an alloy of tin and copper. According to some sources, bronze was known to man as early as 2500 BC.
The fact is that tin exists in ores together with copper, so when smelting they obtained not pure copper, but its alloy with tin, that is, bronze. Tin can be found as an incidental impurity in copper utensils of the Egyptian pharaohs made in 2000 BC.
Chemical properties of tin
Tin is inert to water and oxygen at room temperature. The metal also tends to become coated with a thin oxide film when exposed to air. It was the chemical inertness of tin under normal conditions that made the metal popular among manufacturers of tin containers. 
Sulfuric and hydrochloric acid in a diluted state act on tin extremely slowly, and in a concentrated form they dissolve it when heated. When combined with hydrochloric acid, tin chloride is obtained, and when combined with sulfuric acid, tin sulfate is obtained.
When reacting with dilute nitric acid, tin nitrate is obtained, and with concentrated nitric acid, insoluble tin acid is obtained. Tin compounds are of great industrial importance: they are used in the production of electroplating coatings.
Applications of tin
This silvery-white soft metal can be rolled out into a thin foil. Tin does not rust, so it is widely used in various fields. Most often, containers are made from this metal. If tin is applied in a thin layer to another metal, it will give the surface a special shine and smoothness.
This property of tin is used in the manufacture of tin cans. Tin is often used as an anti-corrosion coating. More than a third of all tin mined in the world today is used in the production of food and beverage containers. Tin cans, familiar to everyone, are made of steel coated with a layer of tin no more than 0.4 microns thick. 
Another third of the mined tin is used to make solders - alloys with lead in different proportions. Solders are used in electrical engineering for soldering pipelines. Such alloys can contain up to 97% tin, copper and antimony, which increase the hardness and strength of the alloy.
Utensils (primarily frage) are made from tin mixed with antimony. In industry, tin is used in various chemical compounds.
The chemical element tin is one of the seven ancient metals known to mankind. This metal is part of bronze, which is of great importance. Currently, the chemical element tin has lost its popularity, but its properties deserve detailed consideration and study.
What is an element
It is located in the fifth period, in the fourth group (the main subgroup). This arrangement indicates that the chemical element tin is an amphoteric compound capable of exhibiting both basic and acidic properties. The relative atomic mass is 50, so it is considered a light element.
Peculiarities
The chemical element tin is a plastic, malleable, light substance of silvery white color. As it is used, it loses its shine, which is considered a disadvantage of its characteristics. Tin is a dispersed metal, so there are difficulties with its extraction. The element has a high boiling point (2600 degrees), a low melting point (231.9 C), high electrical conductivity, and excellent malleability. It has high tear resistance.
Tin is an element that does not have toxic properties and does not have a negative effect on the human body, therefore it is in demand in food production.
What other properties does tin have? When choosing this element for making dishes and water pipelines, you will not have to fear for your safety.
Finding in the body
What else is tin (a chemical element) characterized by? How is its formula read? These issues are discussed in the school curriculum. In our body, this element is located in the bones, promoting the process of bone tissue regeneration. It is classified as a macronutrient, therefore, for full life, a person needs from two to ten mg of tin per day.
This element enters the body in larger quantities with food, but the intestines absorb no more than five percent of the intake, so the likelihood of poisoning is minimal.
With a lack of this metal, growth slows down, hearing loss occurs, the composition of bone tissue changes, and baldness occurs. Poisoning is caused by the absorption of dust or vapors of this metal, as well as its compounds.
Basic properties
The density of tin is average. The metal is highly corrosion resistant, which is why it is used in the national economy. For example, tin is in demand in the manufacture of tin cans.
What else is tin characterized by? The use of this metal is also based on its ability to combine various metals, creating an external environment resistant to aggressive environments. For example, the metal itself is necessary for tinning household items and utensils, and its solders are needed for radio engineering and electricity.
Characteristics
In terms of its external characteristics, this metal is similar to aluminum. In reality, the similarity between them is insignificant, limited only by lightness and metallic luster, resistance to chemical corrosion. Aluminum exhibits amphoteric properties, so it easily reacts with alkalis and acids.
For example, if aluminum is exposed to acetic acid, a chemical reaction is observed. Tin, on the other hand, can only react with strong concentrated acids.
Advantages and disadvantages of tin
This metal is practically not used in construction because it does not have high mechanical strength. Basically, nowadays it is not pure metal that is used, but its alloys.
Let us highlight the main advantages of this metal. Malleability is of particular importance; it is used in the process of making household items. For example, stands and lamps made of this metal look aesthetically pleasing.
The tin coating significantly reduces friction, thereby protecting the product from premature wear.
Among the main disadvantages of this metal, one can mention its low strength. Tin is unsuitable for the manufacture of parts and components that involve significant loads.
Metal mining
Melting of tin is carried out at a low temperature, but due to the difficulty of its extraction, the metal is considered an expensive substance. Due to the low melting point, when applying tin to the surface of a metal, significant savings in electrical energy can be achieved.
Structure
The metal has a homogeneous structure, but depending on the temperature, its different phases are possible, differing in characteristics. Among the most common modifications of this metal, we note the β-variant, which exists at a temperature of 20 degrees. Thermal conductivity and its boiling point are the main characteristics given for tin. When the temperature decreases from 13.2 C, an α-modification called gray tin is formed. This form does not have plasticity and malleability, and has a lower density because it has a different crystal lattice.
When moving from one form to another, a change in volume is observed, since there is a difference in density, resulting in the destruction of the tin product. This phenomenon is called the “tin plague.” This feature leads to the fact that the area of use of the metal is significantly reduced.
Under natural conditions, tin can be found in rocks in the form of a trace element, and its mineral forms are also known. For example, cassiterite contains its oxide, and tin pyrite contains its sulfide.
Production
Tin ores with a metal content of at least 0.1 percent are considered promising for industrial processing. But at present, deposits in which the metal content is only 0.01 percent are also being exploited. Various methods are used to extract the mineral, taking into account the specifics of the deposit, as well as its variety.
Tin ores are mainly presented in the form of sands. Extraction comes down to its constant washing, as well as the concentration of the ore mineral. It is much more difficult to develop a primary deposit, since additional structures, construction and operation of mines are required.
The mineral concentrate is transported to a plant specializing in smelting non-ferrous metals. Next, the ore is repeatedly enriched, crushed, and then washed. Ore concentrate is restored using special furnaces. To completely restore tin, this process is carried out several times. At the final stage, the process of cleaning rough tin from impurities is carried out using a thermal or electrolytic method.
Usage
The main characteristic that allows the use of tin is its high corrosion resistance. This metal, as well as its alloys, are among the most resistant compounds to aggressive chemicals. More than half of all tin produced in the world is used to make tinplate. This technology, associated with applying a thin layer of tin to steel, began to be used to protect cans from chemical corrosion.
The rolling ability of tin is used to produce thin-walled pipes from it. Due to the instability of this metal to low temperatures, its domestic use is quite limited.
Tin alloys have a significantly lower thermal conductivity value than steel, so they can be used for the production of washbasins and bathtubs, as well as for the manufacture of various sanitary fittings.
Tin is suitable for the production of minor decorative and household items, making tableware, and creating original jewelry. This dull and malleable metal, when combined with copper, has long become one of the most favorite materials of sculptors. Bronze combines high strength and resistance to chemical and natural corrosion. This alloy is in demand as a decorative and building material.
Tin is a tonally resonant metal. For example, when it is combined with lead, an alloy is obtained that is used to make modern musical instruments. Bronze bells have been known since ancient times. An alloy of tin and lead is used to create organ pipes.
Conclusion
The increasing attention of modern manufacturing to issues related to environmental protection, as well as to problems related to maintaining public health, has influenced the composition of materials used in the manufacture of electronics. For example, there has been increased interest in lead-free soldering process technology. Lead is a material that causes significant harm to human health, which is why it is no longer used in electrical engineering. Soldering requirements became more stringent, and tin alloys began to be used instead of dangerous lead.
Pure tin is practically not used in industry, since problems arise with the development of the “tin plague”. Among the main areas of application of this rare scattered element, we highlight the production of superconducting wires.
Coating contact surfaces with pure tin allows you to increase the soldering process and protect the metal from corrosion.
As a result of the transition to lead-free technology by many steel manufacturers, they began to use natural tin to cover contact surfaces and leads. This option allows you to obtain high-quality protective coating at an affordable cost. Due to the absence of impurities, the new technology is not only considered environmentally friendly, but also makes it possible to obtain excellent results at an affordable cost. Manufacturers consider tin to be a promising and modern metal in electrical engineering and radio electronics.
Tin is one of the few metals known to man since prehistoric times. Tin and copper were discovered before iron, and their alloy, bronze, is, apparently, the very first “artificial” material, the first material prepared by man.
The results of archaeological excavations suggest that even five millennia BC people knew how to smelt tin itself. It is known that the ancient Egyptians brought tin for the production of bronze from Persia.
This metal is described under the name “trapu” in ancient Indian literature. The Latin name for tin, stannum, comes from the Sanskrit "sta", meaning "solid".
Mention of tin is also found in Homer. Almost ten centuries BC, the Phoenicians delivered tin ore from the British Isles, then called the Cassiterides. Hence the name cassiterite, the most important of the tin minerals; its composition is SnO 2. Another important mineral is stannin, or tin pyrite, Cu 2 FeSnS 4 . The remaining 14 minerals of element No. 50 are much less common and have no industrial significance. By the way, our ancestors had richer tin ores than we do. It was possible to smelt metal directly from ores located on the surface of the Earth and enriched during the natural processes of weathering and leaching. Nowadays, such ores no longer exist. In modern conditions, the process of obtaining tin is multi-stage and labor-intensive. The ores from which tin is now smelted are complex in composition: in addition to element No. 50 (in the form of oxide or sulfide), they usually contain silicon, iron, lead, copper, zinc, arsenic, aluminum, calcium, tungsten and other elements. Today's tin ores rarely contain more than 1% Sn, and placers contain even less: 0.01...0.02% Sn. This means that to obtain a kilogram of tin, at least a hundredweight of ore must be mined and processed.
How is tin obtained from ores?
The production of element No. 50 from ores and placers always begins with enrichment. Methods for enriching tin ores are quite diverse. In particular, the gravity method is used, based on the difference in density of the main and accompanying minerals. At the same time, we must not forget that those who accompany them are not always empty breeds. They often contain valuable metals, such as tungsten, titanium, and lanthanides. In such cases, they try to extract all the valuable components from the tin ore.
The composition of the resulting tin concentrate depends on the raw materials, and also on the method by which this concentrate was obtained. The tin content in it ranges from 40 to 70%. The concentrate is sent to kilns (at 600...700°C), where relatively volatile impurities of arsenic and sulfur are removed from it. And most of the iron, antimony, bismuth and some other metals are leached with hydrochloric acid after firing. After this is done, all that remains is to separate the tin from the oxygen and silicon. Therefore, the last stage of rough tin production is smelting with coal and fluxes in reverberatory or electric furnaces. From a physicochemical point of view, this process is similar to the blast furnace process: carbon “takes away” oxygen from tin, and fluxes transform silicon dioxide into slag, which is light compared to metal.
There are still quite a lot of impurities in rough tin: 5...8%. To obtain grade metal (96.5...99.9% Sn), fire or, less commonly, electrolytic refining is used. And the tin needed by the semiconductor industry with a purity of almost six nines - 99.99985% Sn - is obtained mainly by the method of zone melting.
Another source
In order to get a kilogram of tin, it is not necessary to process a hundredweight of ore. You can do it differently: “rip off” 2000 old tin cans.
There is only half a gram of tin per jar. But multiplied by the scale of production, these half-grams turn into tens of tons... The share of “secondary” tin in the industry of capitalist countries is approximately a third of total production. There are about one hundred industrial tin recovery plants operating in our country.
How do you remove tin from tinplate? It is almost impossible to do this by mechanical means, so they use the difference in the chemical properties of iron and tin. Most often, tin is treated with chlorine gas. Iron does not react with it in the absence of moisture. Tin combines with chlorine very easily. A fuming liquid is formed - tin chloride SnCl 4, which is used in the chemical and textile industries or sent to an electrolyzer to obtain metal tin from it. And the “whirlwind” will begin again: they will cover steel sheets with this tin and get tinplate. It will be made into jars, the jars will be filled with food and sealed. Then they will open them, eat the cans, and throw away the cans. And then they (not all, unfortunately) will again end up in “secondary” tin factories.
Other elements cycle in nature with the participation of plants, microorganisms, etc. The tin cycle is the work of human hands.
Tin in alloys
About half of the world's tin production goes into cans. The other half goes to metallurgy, to produce various alloys. We will not talk in detail about the most famous of the tin alloys - bronze, referring readers to the article about copper - another important component of bronzes. This is all the more justified since there are tin-free bronzes, but there are no “copper-free” bronzes. One of the main reasons for the creation of tin-free bronzes is the scarcity of element No. 50. Nevertheless, bronze containing tin continues to be an important material for both engineering and art.
Equipment also requires other tin alloys. However, they are almost never used as structural materials: they are not strong enough and are too expensive. But they have other properties that make it possible to solve important technical problems with relatively low material costs.
Most often, tin alloys are used as antifriction materials or solders. The former allow you to preserve machines and mechanisms, reducing friction losses; the latter connect metal parts.
Of all antifriction alloys, tin babbits, which contain up to 90% tin, have the best properties. Soft and low-melting lead-tin solders well wet the surface of most metals and have high ductility and fatigue resistance. However, their scope of application is limited due to the insufficient mechanical strength of the solders themselves.
Tin is also included in the typographic alloy garta. Finally, tin-based alloys are very much needed in electrical engineering. The most important material for electric capacitors is staniol; this is almost pure tin, turned into thin sheets (the share of other metals in staniol does not exceed 5%).
By the way, many tin alloys are true chemical compounds of element #50 with other metals. When fused, tin interacts with calcium, magnesium, zirconium, titanium, and many rare earth elements. The compounds formed in this case are quite refractory. Thus, zirconium stannide Zr 3 Sn 2 melts only at 1985°C. And not only the refractoriness of zirconium is to blame here, but also the nature of the alloy, the chemical bond between the substances that form it. Or another example. Magnesium cannot be considered a refractory metal; 651°C is far from a record melting point. Tin melts at an even lower temperature - 232°C. And their alloy - the Mg 2 Sn compound - has a melting point of 778°C.
The fact that element No. 50 forms quite numerous alloys of this kind makes us critical of the statement that only 7% of the tin produced in the world is consumed in the form of chemical compounds (Concise Chemical Encyclopedia, vol. 3, p. 739). Apparently, we are talking here only about compounds with non-metals.
Compounds with non-metals
Of these substances, chlorides are the most important. Iodine, phosphorus, sulfur, and many organic substances dissolve in tin tetrachloride SnCl 4. Therefore, it is used mainly as a very specific solvent. Tin dichloride SnCl 2 is used as a mordant for dyeing and as a reducing agent in the synthesis of organic dyes. Another compound of element No. 50, sodium stannate Na 2 SnO 3, has the same functions in textile production. In addition, it makes silk heavier.
Industry uses tin oxides to a limited extent. SnO is used to produce ruby glass, and SnO 2 is used to produce white glaze. Golden-yellow crystals of tin disulfide SnS 2 are often called gold leaf, which is used to “gild” wood and gypsum. This, so to speak, is the most “anti-modern” use of tin compounds. What about the most modern?
If we keep in mind only tin compounds, then this is the use of barium stannate BaSnO 3 in radio engineering as an excellent dielectric. And one of the isotopes of tin, 119 Sn, played a significant role in the study of the Mössbauer effect, a phenomenon that led to the creation of a new research method - gamma resonance spectroscopy. And this is not the only case where an ancient metal has served modern science.
Using the example of gray tin, one of the modifications of element No. 50, a connection was revealed between the properties and the chemical nature of the semiconductor material. And this, apparently, is the only thing for which gray tin can be remembered with a kind word: it brought more harm than good. We will return to this variety of element No. 50 after talking about another large and important group of tin compounds.
About organotin
There are a great variety of organoelement compounds that include tin. The first of them was received back in 1852.
At first, substances of this class were obtained in only one way - in an exchange reaction between inorganic tin compounds and Grignard reagents. Here is an example of such a reaction:
SnCl 4 + 4RMgX → SnR 4 + 4MgXCl
(R here is a hydrocarbon radical, X is a halogen).
Compounds with the composition SnR 4 have not found wide practical use. But it is from them that other organotin substances are obtained, the benefits of which are undoubted.
Interest in organotin first arose during the First World War. Almost all organic tin compounds obtained by that time were toxic. These compounds were not used as toxic substances; their toxicity to insects, molds, and harmful microbes was used later. Based on triphenyltin acetate (C 6 H 5) 3 SnOOCCH 3, an effective drug was created to combat fungal diseases of potatoes and sugar beets. This drug turned out to have another useful property: it stimulated the growth and development of plants.
To combat fungi that develop in the apparatus of the pulp and paper industry, another substance is used - tributyltin hydroxide (C 4 H 9) 3 SnOH. This greatly improves the performance of the equipment.
Dibutyltin dilaurate (C 4 H 9) 2 Sn (OCOC 11 H 23) 2 has many “professions”. It is used in veterinary practice as a remedy against helminths (worms). The same substance is widely used in the chemical industry as a stabilizer for polyvinyl chloride and other polymer materials and as a catalyst. The reaction rate of the formation of urethanes (polyurethane rubber monomers) in the presence of such a catalyst increases by 37 thousand times.
Effective insecticides have been created based on organotin compounds; organotin glasses reliably protect against x-rays, polymer lead and organotin paints are used to cover the underwater parts of ships to prevent mollusks from growing on them.
All these are compounds of tetravalent tin. The limited scope of the article does not allow us to talk about many other useful substances of this class.
Organic compounds of divalent tin, on the contrary, are few in number and have so far found almost no practical use.
About gray tin
In the frosty winter of 1916, a shipment of tin was sent by rail from the Far East to the European part of Russia. But what arrived at the scene was not silver-white ingots, but mostly fine gray powder.
Four years earlier, a disaster occurred with the expedition of polar explorer Robert Scott. The expedition heading to the South Pole was left without fuel: it leaked from iron vessels through seams soldered with tin.
Around the same years, the famous Russian chemist V.V. Markovnikov was contacted by the commissariat with a request to explain what was happening with the tinned teapots that were supplied to the Russian army. The teapot, which was brought into the laboratory as an illustrative example, was covered with gray spots and growths that crumbled even when lightly tapped with a hand. The analysis showed that both the dust and the growths consisted only of tin, without any impurities.
What happened to the metal in all these cases?
Like many other elements, tin has several allotropic modifications, several states. (The word “allotropy” is translated from Greek as “another property,” “another turn.”) At normal above-zero temperatures, tin looks so that no one can doubt that it belongs to the class of metals.
White metal, ductile, malleable. White tin crystals (also called beta tin) are tetragonal. The length of the edges of the elementary crystal lattice is 5.82 and 3.18 Å. But below 13.2°C the “normal” state of tin is different. As soon as this temperature threshold is reached, a restructuring begins in the crystal structure of the tin ingot. White tin is converted into powdered gray or alpha tin, and the lower the temperature, the greater the rate of this conversion. It reaches its maximum at minus 39°C.
Gray tin crystals of cubic configuration; the dimensions of their unit cells are larger—the edge length is 6.49 Å. Therefore, the density of gray tin is noticeably lower than white: 5.76 and 7.3 g/cm 3, respectively.
The result of white tin turning to gray is sometimes called "tin plague". Stains and growths on army teapots, carriages with tin dust, seams that have become permeable to liquid are the consequences of this “disease”.
Why don't similar stories happen now? For only one reason: they learned to “treat” the tin plague. Its physicochemical nature has been clarified, and it has been established how certain additives affect the susceptibility of the metal to the “plague”. It turned out that aluminum and zinc promote this process, while bismuth, lead and antimony, on the contrary, counteract it.
In addition to white and gray tin, another allotropic modification of element No. 50 was discovered - gamma tin, stable at temperatures above 161°C. A distinctive feature of this tin is its fragility. Like all metals, tin becomes more ductile as temperature increases, but only at temperatures below 161°C. Then it completely loses its ductility, turning into gamma tin, and becomes so brittle that it can be crushed into powder.
Once again about the deficit
Often articles about elements end with the author’s speculations about the future of his “hero.” As a rule, it is drawn in pink light. The author of the article on tin is deprived of this opportunity: the future of tin - a metal undoubtedly the most useful - is unclear. It's unclear for one reason only.
Several years ago, the American Bureau of Mines published calculations from which it followed that proven reserves of element No. 50 would last the world for at most 35 years. True, after this, several new deposits were found, including the largest in Europe, located on the territory of the Polish People's Republic. And yet, the shortage of tin continues to worry experts.
Therefore, finishing the story about element No. 50, we want to once again remind you of the need to save and protect tin.
The shortage of this metal worried even the classics of literature. Remember Andersen? “Twenty-four soldiers were exactly the same, and the twenty-fifth soldier was one-legged. It was the last to be cast, and there wasn’t enough tin.” Now the tin is missing quite a bit. It’s not for nothing that even two-legged tin soldiers have become rare – plastic ones are more common. But with all due respect to polymers, they cannot always replace tin.
Isotopes
Tin is one of the most “multi-isotopic” elements: natural tin consists of ten isotopes with mass numbers 112, 114...120, 122 and 124. The most common of them is 120 Sn, accounting for about 33% of all earthly tin. Almost 100 times less than tin-115, the rarest isotope of element No. 50. Another 15 isotopes of tin with mass numbers 108...111, 113, 121, 123, 125...132 were obtained artificially. The lifetime of these isotopes is far from the same. Thus, tin-123 has a half-life of 136 days, and tin-132 only 2.2 minutes.
Why is bronze called bronze?
The word "bronze" sounds almost the same in many European languages. Its origin is associated with the name of a small Italian port on the Adriatic Sea - Brindisi. It was through this port that bronze was delivered to Europe in ancient times, and in ancient Rome this alloy was called “es Brindisi” - copper from Brindisi.
In honor of the inventor
The Latin word frictio means friction. Hence the name anti-friction materials, that is, materials “against friction”. They wear out little and are soft and ductile. Their main application is the manufacture of bearing shells. The first antifriction alloy based on tin and lead was proposed in 1839 by engineer Babbitt. Hence the name of a large and very important group of antifriction alloys - babbitts.
Tin for canning
The method of long-term preservation of food products by canning in tin-plated jars was first proposed by the French chef F. Appert in 1809.
From the bottom of the ocean
In 1976, an unusual enterprise began operating, which is abbreviated as REP. It stands for: exploration and exploitation enterprise. It is located mainly on ships. Beyond the Arctic Circle, in the Laptev Sea, in the area of Vankina Bay, REP extracts tin-bearing sand from the seabed. Here, on board one of the ships, there is an enrichment plant.
World production
According to American data, world tin production in 1975 was 174...180 thousand tons.
Metal tin, mining and tin deposits, production and use of metal
information about the metal tin, properties of tin, deposits and mining of tin, production and use of the metal
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Tin - definition
Tin is an element of the main subgroup of the fourth group, the fifth of the periodic table of chemical elements D.I., with atomic number 50. Denoted by the symbol Sn (Latin Stano). Under normal conditions, the simple substance tin is ductile, malleable and fusible, shiny silver-white in color. Tin forms several allotropic modifications: below 13.2 °C, α-tin (gray tin) with a cubic diamond-type lattice is stable; above 13.2 °C, β-tin (white tin) with a tetragonal crystal lattice is stable.
1.1 Tin Stano Sn
Tin is one of the metals that had a decisive influence on: (from 4 to 1 thousand years BC) is named after the alloy of tin and copper.
Tin is a soft white metal that can be alloyed with copper to create bronze, one of the first metals mastered by man.
Tin is one of the seven metals of antiquity, which is capable of preserving the taste and smell of drinks.
Tin is metal of Jupiter, which was often used to predict the future. This metal is strongly associated with prosperity and abundance, with obtaining some benefits necessary for a person, which are given to a person for fulfilling; for example, a person may serve society or religion. This is the metal of hierarchs, priests and social leaders.
Tin is a substance belonging to the group of light metals. At normal (room) temperature it does not react with either oxygen or water. Over time, it can be covered with a special film that protects the metal from corrosion.
The Tin Story
The first mentions of tin, which, as people previously believed, even had some magical properties, can be found in biblical texts. Tin played a decisive role in improving life during the Bronze Age. At that time, the most durable metal alloy that man possessed was bronze, which can be obtained by adding the chemical element tin to copper. For several centuries, everything from tools to jewelry was made from this material.
The Latin name stano, related to the Sanskrit word meaning "steady, durable", originally referred to an alloy of silver, and later to another alloy imitating it, containing about 67% tin. By the 4th century this word was used to refer to tin itself.
The word tin is common Slavic, having correspondences in the Baltic languages (cf. Lit. alavas, alvas - “tin”, Prussian alwis - “lead”). It is a suffix from the root ol- (cf. Old High German elo - “yellow”, Latin albus - “white”, etc.), so the metal is named by color.
Tin was known to man already in the 4th millennium BC. This metal was inaccessible and expensive, since products made from it are rarely found among Roman and Greek antiquities. There are mentions of tin in the Bible, the Fourth Book of Moses. Tin is (along with copper) one of the components of bronze, invented at the end or middle of the 3rd millennium BC. BC. Since bronze was the most durable metal and alloy known at that time, tin was a “strategic metal” throughout the “Bronze Age”, more than 2000 years (very approximately: 35-11 centuries BC).
Finding tin in nature
Tin is a rare trace element; tin ranks 47th in terms of abundance in the earth's crust. The Clark content of tin in the earth's crust ranges, according to various sources, from 2·10−4 to 8·10−3% by mass. The main tin is cassiterite (tin stone) SnO2, containing up to 78.8% tin. Much less common in nature is stannin (tin pyrite) - Cu2FeSnS4 (27.5% Sn).
Prevalence in nature is shown in the following table
In unpolluted surface waters, tin is found in submicrogram concentrations. In groundwater its concentration reaches several micrograms per dm³, increasing in the area of tin ore deposits, it enters the water due to the destruction primarily of sulfide minerals, which are unstable in the oxidation zone. PDKSn = 2 mg/dm³.
Tin is an amphoteric element, that is, an element capable of exhibiting acidic and basic properties. This property of tin also determines the characteristics of its distribution in nature. Due to this duality, tin exhibits lithophilic, chalcophilic and siderophilic properties. Tin in its properties is close to quartz, as a result of which the close connection of tin in the form of oxide (cassiterite) with acidic granitoids (lithophilicity), often enriched in tin, is known, up to the formation of independent quartz-cassiterite veins. The alkaline behavior of tin is determined by the formation of quite a variety of sulfide compounds (chalcophilicity), up to the formation of native tin and various intermetallic compounds known in ultrabasic rocks (siderophilicity).
Forms of location
The main form of occurrence of tin in rocks and minerals is scattered (or endocript). However, tin also forms mineral forms, and in this form it is often found not only as an accessory in acidic igneous rocks, but also forms industrial concentrations mainly in oxide (cassiterite SnO2) and sulfide (stannine) forms.
Solid phase. Minerals
In general, the following forms of tin occurrence in nature can be distinguished:
Scattered form; the specific form of tin in this form is unknown. Here we can talk about an isomorphically dispersed form of tin occurrence due to the presence of isomorphism with a number of elements (Ta, Nb, W - with the formation of typically oxygen compounds; V, Cr, Ti, Mn, Sc - with the formation of oxygen and sulfide compounds). If tin concentrations do not exceed certain critical values, then it can isomorphically replace the named elements. The mechanisms of isomorphism are different.
Mineral Form: Tin is found in concentrating minerals. As a rule, these are minerals in which Fe+2 is present: biotites, garnets, pyroxenes, magnetites, tourmalines, etc. This relationship is due to isomorphism, for example, according to the scheme Sn+4 + Fe+2 → 2Fe+3. In tin-bearing skarns, high concentrations of tin are found in garnets (up to 5.8 wt.%) (especially in andradites), epidotes (up to 2.84 wt.%), etc.
In sulfide deposits, tin is included as an isomorphic element in sphalerites (Silinskoye deposit, Primorye), chalcopyrites (Dubrovskoye deposit, Russia, Primorye), and pyrites. High concentrations of tin were detected in pyrrhotite from greisen from the Smirnovskoe deposit (Russia, Primorye). It is believed that due to limited isomorphism, solid solutions decompose with micro-precipitates of Cu2+1Fe+2SnS4 or tillite PbSnS2 and other minerals.
Actually mineral forms
Native elements, alloys and intermetallic compounds
Although the concentrations of these minerals in rocks are very low, they are distributed in a wide range of genetic formations. Among the native forms in place with Sn, Fe, Al, Cu, Ti, Cd, etc. were identified, not counting the already known native ones, gold and silver. These same elements also form various alloys with each other: (Cu + Sn + Sb), (Pb + Sn + Sb), etc., as well as solid solutions. Among the intermetallic compounds, stistaite SnSb, atakite (Pd,Pt)3Sn, shtumyrlite Pt(Sn,Bi), zvyagintsevite (Pd,Pt)3(Pb,Sn), taymyrite (Pd,Cu,Pt)3Sn and others were identified.
The following forms of occurrence of tin and other elements are found in various geological formations:
A group of intrusive and effusive igneous rocks: traps, picrites of the Siberian platform, hyperbasites and gabbroids of Kamchatka, kimberlites of Yakutia, lamproites of Aldan, etc.; granitoids of Primorye, Far East, Tien Shan.
A group of metasomatically and hydrothermally altered rocks: copper-nickel ores of the Siberian platform, gold deposits of the Urals, the Caucasus, Uzbekistan, etc.
Group of modern ore formation: pelagic sediments of the Pacific Ocean, products of the Great Fissure Tolbachik eruption, Uzon hydrothermal system in Kamchatka, etc.
A group of sedimentary rocks of various origins.
Tin oxide compounds
The most famous form is the main mineral of tin - cassiterite SnO2, which is a compound of tin with oxygen. According to nuclear gamma resonance spectroscopy, the mineral contains Sn+4
Cassiterite (from the Greek kassiteros - tin) is the main ore mineral for the production of tin. Theoretically contains 78.62% Sn. It forms separate secretions, grains, continuous massive aggregates, in which the grains of the mineral reach a size of 3 - 4 mm and even more.
1. density 6040-7120 kg/m³ (lowest for light-colored cassiterites);
2. hardness 6½;
3. shine - matte, on the edges - diamond;
4. imperfect cleavage;
5. conchoidal fracture;
The main forms of cassiterite isolation:
1. microinclusions in other minerals;
2. accessory mineral deposits in rocks and ores;
3.solid or disseminated ores: needle-shaped radial aggregates (Primorye), colomorphic and cryptocrystalline segregations and accumulations (Primorye); The crystalline form is the main form of cassiterite isolation. In Russia, cassiterite deposits are found in the Northeast, Primorye, Yakutia, and Transbaikalia; for - in Malaysia, Thailand, Indonesia, China, Nigeria, etc.
Hydroxide compounds
A secondary place is occupied by tin hydroxide compounds, which can be considered as salts of polytin acids. These include the mineral succulite Ta2Sn2+2O; solid solution of tin in magnetite of the type Fe2SnO4 or Fe3SnO3 (Brettstein Yu. S., 1974; Voronina L. B. 1979); “varlamovit” is a product of stannine oxidation; it is believed to be a mixture of amorphous and semi-amorphous Sn compounds, metatinic acid, a polycondensed phase and a hydrocassiterite phase. Hydrated oxidation products are also known - hydromartite 3SnOxH2O; mushistonite (Cu,Zn,Fe)Sn(OH)6; copper hydrostannate CuSn(OH)6, etc.
Silicates
A large group of tin silicates is known, represented by malayaite CaSn(SiO5); pabstite Ba(Sn, Ti)Si3O9, stocasite Ca2Sn2Si6O18x4H2O, etc. Malayaite even forms industrial accumulations.
Spinelids
Among other oxide compounds, spinels are also known, for example, the mineral nigerite Sn2Fe4Al16O32 (Peterson E.U., 1986).
Tin sulfide compounds
Includes various tin compounds with . This is the second most industrially important group of mineral forms of tin. The most important of these is stannine, the second most important mineral. In addition, frankeite Pb5Sn3Sb2S14, herzenbergite SnS, berndtite SnS2, tillite PbSnS2 and kesterite Cu2ZnSnS4 are noted. More complex sulfide compounds of tin with lead, silver, and copper, which are mainly of mineralogical significance, have also been identified. The close connection of tin with copper determines the frequent presence of chalcopyrite CuFeS2 deposits in tin ore deposits with the formation of the cassiterite - chalcopyrite paragenesis.
Stannine (from Latin pewter - tin), tin pyrite, a mineral from the class of sulfides with the general formula of the form Cu2FeSnS4. It follows from the chalcopyrite formula by replacing one Fe atom with Sn. Contains 29.58% Cu, 12.99% Fe, 27.5% Sn and 29.8 S, as well as impurities of Zn, Sb, Cd, Pb and Ag. A widespread mineral in tin ore deposits of the Russian Federation. In a number of deposits in Russia (Primorye, Yakutia) and Central Russia (Tajikistan), it is an essential element of sulfide minerals and often, together with varlamovite, makes up 10-40% of the total tin. Often forms impregnations in ZnS sphalerite and chalcopyrite. In many cases, stannine decomposition phenomena with the release of cassiterite are observed.
Colloidal form
Colloidal and tin-silicon compounds play a significant role in the geochemistry of tin, although it has not been studied in detail. A significant place in the geology of the element is played by colomorphic compounds and the products of its crystalline transformations into cryptocrystalline varieties. Colomorphic cassiterite is considered as a form of expression of viscous gel-like solutions.
Independent studies have revealed an abnormally high solubility of SnO2 in chlorine-silicon solutions. Maximum solubility is achieved at the ratio.
Analysis of the properties of the Sn(OH)4 compound and their proximity to the Si(OH)4 compound reveals its ability to polymerize, ultimately forming the compounds H2SnkO2k+1, SnkO2k−1(OH)2. In both cases, it is possible to replace the (OH) group with the F and Cl anions.
Thus, the polymerization of Sn(OH)4 molecules and their combination with Si(OH)4 molecules leads to the formation of a gel (colloid) and the appearance of HmSn2nSinOp chains, with m ≤ 8, or Hs (Nekrasov I. Ya. et al., 1973 ).
Available evidence suggests that the colloidal form is a natural intermediate in the precipitation of tin from hydrothermal solutions.
Forms of tin in the liquid phase
The least studied part of the geochemistry of tin, although cassiterites in the form of prisoner minerals have been established in gas-liquid inclusions (Kokorin A. M. et al., 1975). There are no works on the analysis of specific tin-containing natural solutions. Basically, everything is based on the results of experimental studies, which speak only about the probable forms of tin in solutions. A significant role in the development of the methodology for these studies belongs to Academician V. L. Barsukov
The entire set of experimentally established forms of tin in solutions is divided into groups:
Ionic compounds. These compounds and their structure are described in terms of classical valence and stereochemical concepts. Subgroups stand out:
Simple ions Sn+2 and Sn+4 are mainly found in magmatic lavas, as well as in hydrothermal solutions with low pH values. However, in existing hydrothermal systems, reflected by the composition of gas-liquid inclusions, such conditions have not been established.
Salts of halide acids - SnF2, SnF40, SnCl40. The role of chlorine in the transport and deposition of tin and associated metals is believed to be more significant than that of fluorine.
Hydroxyl compounds of tin. Under alkaline conditions, the starting compounds are H2SnO2, H2SnO4, H2SnO3. These forms are often established based on known mineral forms. Some of these forms are of both artificial (CaSnO3, Ca2SnO4) and natural (FeSnO2, Fe2SnO4) origin. In acidic environments, these compounds behave as weak bases such as Sn(OH)2, Sn(OH)4. It is believed that one of the forms of manifestation of such compounds is varlamovit. According to experimental data, Sn(OH)4 is deposited only at T< 280°C в слабокислых или нейтральных условиях при рН = 7 - 9. Соединения Sn(OH)4 и Sn(OH)3+ устойчивы при рН= 7 - 9, тогда как Sn(OH)2+2 и Sn(OH)+2 - при рН < 7.
Quite often, (OH)-1 groups are replaced by F and Cl, creating halogen-substituted modifications of hydrotin compounds. In general, these forms are represented by the compounds Sn(OH)4-kFk or Sn(OH)4-kFk-nn. In general, the Sn(OH)3F compound is stable at T = 25 - 50 °C, and Sn(OH)2F² at T = 200 °C.
Sulfide compounds. According to experimental data, the solution contains SnS4-4 or SnS3-2 compounds at pH > 9; SnS2O-2 (pH = 8 - 9) and Sn(SH)4 (pH = 6). There is mention of the existence of a compound of the Na2SnS3 type, which is unstable in an acidic environment.
Complex tin compounds have been studied during the dissolution of cassiterite in fluorinated media. These compounds are highly soluble. Compounds obtained in chloride solutions have the same properties. The main forms of complex compounds known from experiments include Na2(Sn(OH)6), Na2(SnF6), Na2(Sn(OH)2F4), etc. Experiments have shown that the complex Sn(OH)4F2-2 will prevail at T = 200 °C.
Colloidal and tin-silicon compounds. Their existence is evidenced by the presence of colomorphic cassiterite deposits in many deposits.
Industrial types of tin deposits
The geochemical features of tin described above are indirectly reflected in the formational formation of tin ore deposits proposed by E. A. Radkevich with subsequent additions.
A. Formation of tin-bearing granites. Cassiterite is found in the accessory part of granites.
B. Formation of rare metal granites. These are granites of the lithionite-amazonite-albite type (apogranites according to A. A. Beus). Cassiterite in the accessory part together with columbite-tatnatlite, microlite, etc.
B. Formation of tin-bearing pegmatites. Tin mineralization is characteristic of Be-Li-, Be-Ta-, F-Li- types.
D. Feldspar-quartz-cassiterite formation. Iv is highlighted. F. Grigoriev. These are quartz-feldspar veins with cassiterite and other minerals.
D. Quartz-casterite formation. Extended to the NE USSR. These are vein zones, greisens with quartz, muscovite, wolframite, cassiterite, etc.
E. Cassiterite-silicate-sulfide formation with tourmaline and chlorite types. One of the main productive formations of Primorye Russia.
J. Cassiterite-sulfide formation. Also the main tin-producing formation. It identifies the main types:
stockwork tin-tungsten mineralization;
ore bodies of quar-cassiterite-arsenopyrite type;
productive quartz veins of sulfide-cassiterite-chlorite type;
Z. Tin-skarn formation.
I. Woody tin formation (rhyolite formation).
K. Formation of basic and ultrabasic rocks (according to I. Ya. Nekrasov)
Tin dioxide is a very effective abrasive material used to “finish” the surface of optical glass.
A mixture of tin salts - the "yellow composition" - was previously used as a dye for wool.
Tin is also used in chemical current sources as an anode material, for example: manganese-tin element, mercury-tin oxide element. The use of tin in a lead-tin battery is promising; for example, at the same voltage as a lead battery, a lead-tin battery has 2.5 times greater capacity and 5 times greater energy density per unit volume, its internal resistance is much lower.
Tin is a chemical element
Tin is one of the few metals known to man since prehistoric times. Tin and copper were discovered before iron, and their alloy, bronze, is, apparently, the very first “artificial” material, the first material prepared by man.
The results of archaeological excavations suggest that even five millennia BC people knew how to smelt tin itself. It is known that the ancient Egyptians transported tin for the production of bronze from.
This metal is described under the name “trapu” in ancient Indian literature. The Latin name for tin, stano, comes from the Sanskrit word “sta,” meaning “solid.”
Mention of tin is also found in Homer. Almost ten centuries BC, the Phoenicians delivered tin ore from the British Isles, then called the Cassiterides. Hence the name cassiterite, the most important of the tin minerals; its composition is SnO2. Another important mineral is stannin, or tin pyrite, Cu2FeSnS4. The remaining 14 minerals of element No. 50 are much less common and have no industrial significance. By the way, our ancestors had richer tin ores than we do. It was possible to smelt metal directly from ores located on the surface of the Earth and enriched during the natural processes of weathering and leaching. Nowadays, such ores no longer exist. In modern conditions, the process of obtaining tin is multi-stage and labor-intensive. The ores from which tin is now smelted are complex in composition: in addition to element No. 50 (in the form of oxide or sulfide), they usually contain silicon, iron, lead, copper, arsenic, calcium, tungsten and other elements. Today's tin ores rarely contain more than 1% Sn, and placers contain even less: 0.01...0.02% Sn. This means that to obtain a kilogram of tin, at least a hundredweight of ore must be mined and processed.
How is tin obtained from ores? The production of element No. 50 from ores and placers always begins with enrichment. Methods for enriching tin ores are quite diverse. In particular, the gravity method is used, based on the difference in density of the main and accompanying minerals. At the same time, we must not forget that those who accompany them are not always empty breeds. They often contain valuable metals, such as tungsten, titanium, and lanthanides. In such cases, they try to extract all the valuable components from the tin ore.
The composition of the resulting tin concentrate depends on, and also on how this concentrate was obtained. The tin content in it ranges from 40 to 70%. The concentrate is sent to kilns (at 600...700°C), where relatively volatile impurities of arsenic and sulfur are removed from it. And most of the iron, antimony, bismuth and some other metals are leached with hydrochloric acid after firing. After this is done, all that remains is to separate the tin from the oxygen and silicon. Therefore, the last stage of rough tin production is smelting with coal and fluxes in reverberatory or electric furnaces. From a physicochemical point of view, this process is similar to the blast furnace process: carbon “takes away” oxygen from tin, and fluxes transform silicon dioxide into slag, which is light compared to metal.
There are still quite a lot of impurities in rough tin: 5...8%. To obtain grade metal (96.5...99.9% Sn), fire or, less commonly, electrolytic methods are used. And the tin needed by the semiconductor industry with a purity of almost six nines - 99.99985% Sn - is obtained mainly by the method of zone melting.
In order to get a kilogram of tin, it is not necessary to process a hundredweight of ore. You can do it differently: “rip off” 2000 old tin cans.
There is only half a gram of tin for each. But multiplied by the scale of production, these half-grams turn into tens of tons... The share of “secondary” tin in the industry of capitalist countries is approximately a third of total production. There are about one hundred industrial tin recovery plants operating in our country.
How do you remove tin from tinplate? It is almost impossible to do this by mechanical means, so they use the difference in the chemical properties of iron and tin. Most often, tin is treated with chlorine gas. Iron does not react with it in the absence of moisture. Tin combines with chlorine very easily. A fuming liquid is formed - tin chloride SnCl4, which is used in the chemical and textile industries or sent to an electrolyzer to obtain metal tin from it. And the “whirlwind” will begin again: they will cover steel sheets with this tin and get tinplate. It will be made into jars, the jars will be filled with food and sealed. Then they will open them, eat the cans, and throw away the cans. And then they (not all, unfortunately) will again end up in “secondary” tin factories.
Other elements cycle in nature with the participation of plants, microorganisms, etc. The tin cycle is the work of human hands.
Tin in alloys. About half of the world's tin production goes into cans. The other half is in, to obtain various alloys. We will not talk in detail about the most famous of the tin alloys - bronze, referring readers to the article about copper - another important component of bronzes. This is all the more justified since there are tin-free bronzes, but there are no “copper-free” bronzes. One of the main reasons for the creation of tin-free bronzes is the scarcity of element No. 50. Nevertheless, bronze containing tin continues to be an important material for both engineering and art.
Equipment also requires other tin alloys. However, they are almost never used as structural materials: they are not strong enough and are too expensive. But they have other properties that make it possible to solve important technical problems with relatively small materials.
Most often, tin alloys are used as antifriction materials or solders. The former allow you to preserve machines and mechanisms, reducing friction losses; the latter connect metal parts.
Of all antifriction alloys, tin babbits, which contain up to 90% tin, have the best properties. Soft and low-melting lead-tin solders well wet the surface of most metals and have high ductility and fatigue resistance. However, their scope of application is limited due to the insufficient mechanical strength of the solders themselves.
Tin is also included in the typographic alloy garta. Finally, tin-based alloys are very much needed in electrical engineering. The most important material for electric capacitors is staniol; this is almost pure tin, turned into thin sheets (the share of other metals in staniol does not exceed 5%).
By the way, many tin alloys are true chemical compounds of element #50 with other metals. When fused, tin interacts with calcium, magnesium, zirconium, titanium, and many rare earth elements. The compounds formed in this case are quite refractory. Thus, zirconium stannide Zr3Sn2 melts only at 1985°C. And not only the refractoriness of zirconium is to blame here, but also the nature of the alloy, the chemical bond between the substances that form it. Or another example. Magnesium cannot be considered a refractory metal; 651°C is far from a record melting point. Tin melts at an even lower temperature - 232°C. And their alloy - the Mg2Sn compound - has a melting point of 778°C.
The fact that element No. 50 forms quite numerous alloys of this kind makes us critical of the statement that only 7% of the tin produced in the world is consumed in the form of chemical compounds (Concise Chemical Encyclopedia, vol. 3, p. 739). Apparently, we are talking here only about compounds with non-metals.
Compounds with non-metals. Of these substances, chlorides are the most important. Iodine, phosphorus, sulfur, and many organic substances dissolve in tin tetrachloride SnCl4. Therefore, it is used mainly as a very specific solvent. Tin dichloride SnCl2 is used as a mordant for dyeing and as a reducing agent in the synthesis of organic dyes. Another compound of element No. 50, sodium stannate Na2SnO3, has the same functions in textile production. In addition, it makes silk heavier.
Industry uses tin oxides to a limited extent. SnO is used to produce ruby glass, and SnO2 is used to produce white glaze. Golden-yellow crystals of tin disulfide SnS2 are often called gold leaf, which is used to “gild” wood and gypsum. This, so to speak, is the most “anti-modern” use of tin compounds. What about the most modern?
If we keep in mind only tin compounds, then this is the use of barium stannate BaSnO3 in radio engineering as an excellent dielectric. And one of the isotopes of tin, 119Sn, played a significant role in the study of the Mössbauer effect, a phenomenon that led to the creation of a new research method - gamma resonance spectroscopy. And this is not the only case where an ancient metal has served modern science.
Using the example of gray tin, one of the modifications of element No. 50, a connection was revealed between the properties and the chemical nature of the semiconductor material. And this, apparently, is the only thing for which gray tin can be remembered with a kind word: it brought more harm than good. We will return to this variety of element No. 50 after talking about another large and important group of tin compounds.
About organotin. There are a great variety of organoelement compounds that include tin. The first of them was received back in 1852.
At first, substances of this class were obtained in only one way - in an exchange reaction between inorganic tin compounds and Grignard reagents. Here is an example of such a reaction:
SnCl4 + 4RMgX → SnR4 + 4MgXCl
(R here is a hydrocarbon radical, X is a halogen).
Compounds of the SnR4 composition have not found wide practical application. But it is from them that other organotin substances are obtained, the benefits of which are undoubted.
Interest in organotin first arose during the First World War. Almost all organic tin compounds obtained by that time were toxic. These compounds were not used as toxic substances; their toxicity to insects, molds, and harmful microbes was used later. Based on triphenyltin acetate (C6H5)3SnOOCCH3, an effective drug was created to combat fungal diseases of potatoes and sugar beets. This drug turned out to have another useful property: it stimulated the growth and development of plants.
To combat fungi that develop in the pulp and paper industry, another substance is used - tributyltin hydroxide (C4H9)3SnOH. This greatly improves the performance of the equipment.
Dibutyltin dilaurate (C4H9)2Sn(OCOC11H23)2 has many “professions”. It is used in veterinary practice as a remedy against helminths (worms). The same substance is widely used in the chemical industry as a stabilizer for polyvinyl chloride and other polymer materials and as a. The reaction rate of the formation of urethanes (polyurethane rubber monomers) in the presence of such a catalyst increases by 37 thousand times.
Effective insecticides have been created based on organotin compounds; organotin glasses reliably protect against x-rays, polymer lead and organotin paints are used to cover the underwater parts of ships to prevent mollusks from growing on them.
All these are compounds of tetravalent tin. The limited scope of the article does not allow us to talk about many other useful substances of this class.
Organic compounds of divalent tin, on the contrary, are few in number and have so far found almost no practical use.
About gray tin. In the frosty winter of 1916, a shipment of tin was sent by rail from the Far East to the European part of the Russian Federation. But what is replaced is not silver-white ingots, but mostly fine gray powder.
Four years earlier, a disaster occurred with the expedition of polar explorer Robert Scott. The expedition heading to the South Pole was left without fuel: it leaked from iron vessels through seams soldered with tin.
Around the same years, the famous Russian chemist V.V. Markovnikov was contacted by the commissariat with a request to explain what was happening with the tinned teapots that were supplied to the Russian army. The teapot, which was brought into the laboratory as an illustrative example, was covered with gray spots and growths that crumbled even when lightly tapped with a hand. The analysis showed that both the dust and the growths consisted only of tin, without any impurities.
What happened to the metal in all these cases?
Like many other elements, tin has several allotropic modifications, several states. (The word “allotropy” is translated from Greek as “another property,” “another turn.”) At normal above-zero temperatures, tin looks so that no one can doubt that it belongs to the class of metals.
White metal, ductile, malleable. White tin crystals (also called beta tin) are tetragonal. The length of the edges of the elementary crystal lattice is 5.82 and 3.18 Å. But below 13.2°C the “normal” state of tin is different. As soon as this temperature threshold is reached, a restructuring begins in the crystal structure of the tin ingot. White tin is converted into powdered gray or alpha tin, and the lower the temperature, the greater the rate of this conversion. It reaches its maximum at minus 39°C.
Gray tin crystals of cubic configuration; the dimensions of their elementary cells are larger - the edge length is 6.49 Ǻ. Therefore, the density of gray tin is noticeably lower than white: 5.76 and 7.3 g/cm3, respectively.
The result of white tin turning to gray is sometimes called "tin plague". Stains and growths on army teapots, carriages with tin dust, seams that have become permeable to liquid are the consequences of this “disease”.
Why don't similar stories happen now? For only one reason: they learned to “treat” the tin plague. Its physicochemical nature has been clarified, and it has been established how certain additives affect the susceptibility of the metal to the “plague”. It turned out that aluminum and zinc promote this process, while bismuth, lead and antimony, on the contrary, counteract it.
In addition to white and gray tin, another allotropic modification of element No. 50 was discovered - gamma tin, stable at temperatures above 161°C. A distinctive feature of this tin is its fragility. Like all metals, tin becomes more ductile as temperature increases, but only at temperatures below 161°C. Then it completely loses its ductility, turning into gamma tin, and becomes so brittle that it can be crushed into powder.
In a popular form, the author introduces a very ancient metal - tin. This metal and its salts are used in many national economies. Organotin coatings are used as protective coatings. Organotin preparations are widely used in agriculture and medicine. Nowadays, it is impossible to do without tin powder, foil and other alloys and salts.
Who is he? Soft in its properties, it gives others hardness. Low-melting by nature, it becomes refractory when combined with other metals. For centuries it was used to cast bells and cannons, monuments, statues and jewelry that still fascinate us today.
Today we will see it in typographic fonts, in tin cans, and in bearings. One of its isotopes helped scientists develop a new research method, which is currently widely used by chemists, physicists, and biologists (gamma resonance spectroscopy).
Recently, he “made friends” with hydrocarbons, and chemists began to prepare substances with remarkable properties - pesticides, catalysts, stabilizers, plant growth stimulants, medicines and paints.
When you see sparkling toys on the Christmas tree, you will recognize our acquaintance in the “gilding”. He does not “live” in a separate apartment, but always in a “communal apartment”, with different neighbors. Most often he chooses his home in the mountains - in granite cliffs and rocks. It often “settles” along river banks and on the coasts of seas and oceans. And sometimes it lives deep underground. Therefore, it is not easy to force it to “come out” to the surface, and even more difficult to “disconnect it from its neighbors.” That is why it causes a lot of trouble for enrichers and metallurgists.
First meeting.
How did people in ancient times become acquainted with this silvery-white metal, and where and when did they first become acquainted?
Having received fire, people learned to use it - they burned clay, smelted metals from ores. It was then, according to the beliefs of the ancient Greeks, that man became acquainted with tin. So says a beautiful poetic myth.
How does modern science answer this question?
There is still no consensus among scientists, and there is no clear answer.
“Five to six thousand years BC, much earlier than man learned to smelt and process iron, he already knew how to smelt tin,” wrote academician A.E. Fersman1. But not all scientists share this point of view. Some believe, citing archaeological excavations, that this event occurred almost a thousand years later. Until now, the most ancient tin products are considered to be a ring and a flask found in one of the Egyptian pyramids. They were apparently made in the middle of the second millennium BC.
1 Fersman A. E. Entertaining geochemistry. M.-L.: Detgiz, 1954, 174 p.
However, these finds cannot yet serve as sufficiently strong evidence of the fact that tin in its pure form was not used before. It is possible that many ancient tin products simply did not reach us due to the low resistance of this metal to air and moisture. In addition, there were few tin deposits in the Ancient East. They met in Mesopotamia, Northern, and Iran. Egypt did not have its own tin; it was imported from Iran.
In ancient Indian literature - in the Vedas, Mahabharata - tin is called trapu. At the same time, the Latin name stannum comes from the Sanskrit “sta” - persistent, “solid, durable. This also suggests that tin was known as far back as four thousand years BC. The word stano also has another meaning - “still water”, pond, lake. In the middle of the century, tin was considered a type of lead and was called white lead (Plumbum album), while ordinary lead was called black lead (Plumbum nigrum). The Russian name “tin”, according to the famous professor N.A. Figurovsky, comes from the ancient Slavic word “tin” - an intoxicating drink. The ancient Slavs stored it in lead vessels and, apparently, began to call the metal (lead) that way. “The word tin,” writes N. A. Figurovsky, “is also in connection with the name of another liquid body - oil (oleum)... words related to tin - tin (lead lamp) and tin (tin vessel).”
Even earlier, people became acquainted with copper, approximately 6.5-7 thousand years ago. Some archaeologists believe that man became acquainted with this metal at an earlier period.
In the 60s, layers of pre-ceramic Neolithic were found in Çatalhayük. Analysis of these layers showed that they date back to the 7th-6th millennium BC. Copper awls were found during these excavations. Therefore, some scientists began to argue that man’s acquaintance with the world occurred 9 thousand years BC. However, subsequent studies did not confirm this assumption.
Copper ores were often contaminated with various impurities. It is possible that black pebbles of tin ore were among them. The tin-containing ore, entering the smelting furnace, was mixed with copper to form an alloy - bronze (from the Persian word “brontsion”, which means “alloy”).
Even in ancient times, it was well known that the addition of certain minerals to copper ore facilitates the smelting of metal from it.
It is likely that the pieces of tin stone were added to the copper ore as flux.
Bronze, obtained by chance during the smelting of copper, quickly gained recognition among people in those distant times. The new alloy, golden-yellow in color, was much harder than copper, was perfectly forged, was perfectly cast, and was well processed.
“We don’t know how this wonderful alloy was discovered by man,” writes academician A.E. Fersman. “It can be assumed that a person smelted copper ore with an admixture of tin many times (such “complex” deposits of copper and tin occur) and eventually noticed the result of joint smelting and understood its significance.”
The remarkable qualities of bronze helped almost everywhere to displace copper from the use of prehistoric man. Weapons began to be made from bronze - axes, swords, daggers, tips, arrows, jewelry - bracelets, pendants. The Bronze Age played a significant role in human culture.
The ancient metallurgists, noticing that pieces of tin ore had such a beneficial effect on copper smelting, probably tried to smelt black stones without copper ore. Drops of silvery-white metal - tin - appeared in the melting furnace.
In the Bronze Age, however, this metal in its pure form did not find wide use. Craftsmen made decorations on weapons and vessels from tin. One of the ancient Greek myths tells how the god of fire and blacksmithing, Hephaestus, forged a shield for the hero Achilles and decorated it with an ornament made of tin. The author of the Iliad, Homer, mentions this.
Having appreciated tin and learned how to smelt it from ore, the ancient ore miners began searching for this ore. They did not then have such a rich arsenal of various instruments and methods that science and technology provided modern geologists with.
Several years ago, geologists had a new original device in their arsenal - a gamma resonance tin detector. With its help, you can determine the metal content in ore with an accuracy of hundredths.
Like tracker hunters, ore miners were very observant, and this often helped them uncover the secrets of underground treasures. In the same way, water and trees often told ore miners the location of ore. They knew from experience that certain types of trees, bushes, and mushrooms often grow in places where ores occur. For example, in some places, kachim (a grass, less often a subshrub from the clove family) almost always grows above copper ore deposits; in others, oak grows.
There are many other signs by which ore miners found tin ores. On cold autumn nights, frost lightly dusts the ground and silvers the tops of the trees. It has been noticed that with the rays of the sun, frost melts most quickly where some ore lies. This happens because in the places where the ore vein occurs, the earth warms up faster (after all, metal oxides have a higher heat capacity than soil). Back in the Middle Ages, the famous metallurgist Agricola explained the faster melting of frost over ore deposits by the fact that dark objects heat up faster.
Without any advanced instruments, ancient miners, using vines, explored various metal ores, including tin. Some considered hazel branches to be the most suitable for searching for ores. Others found copper using ash vines, lead and especially tin using pine branches.
Some modern scientists consider this amazing art of wielding a “magic rod” as simple charlatanism or consider it an echo of ancient superstitions.
Other scientists, marveling at the extraordinary skill of ancient ore miners in finding placer and vein metals, are ready to attribute to them a special susceptibility to magnetic fields and weak electrical currents generated by ore deposits. And there are those who are ready to believe in the supernatural senses of Bronze Age people, for example their ability to “see” with their fingers. Of course, such speculation is not true.
At the beginning of their acquaintance with tin, ancient people mined tin ore from placers, mainly in river sediments. In those days, they were already familiar with the technique of washing it off. Later, tin began to be mined from deep-lying tin ore.
Ores were mined by open-pit mining. In open workings, bridges (pillars) were made to protect miners from rubble and death under the rubble, although accidents often occurred. Until now, during archaeological excavations of ancient workings in Siberia, Kazakhstan, Altai and other places in our country and in many where copper and tin were mined already in the Bronze Age (in England, China and Peru), skeletons of dead miners are found.
Pillars were also left in underground adits to protect against possible collapses. But these were already pillars or columns made of rock that supported the arch of the adit. Such fastenings are found in many ancient workings where copper and tin were mined. Often such supports were made of stone slabs or blocks, and in places where there was a lot of forest, wooden posts were often used. In those distant times, people descended into the underground galleries along steps carved into the rock or wooden stairs. Most often these were logs with notches or trees with thick branches cut off. In the Urals, in one of the ancient mines, such a staircase was found. Using such primitive stairs, miners not only descended into adits and workings, but also lifted ore in troughs, leather bags, and wicker baskets.
Initially, tin ore was smelted over a fire. The flame of the fire was enough to extract the low-melting metal (after all, tin already melts at 232 degrees). Later, tin began to be smelted in pits, the walls of which were coated with a dense layer of clay to protect it from seepage of groundwater and leakage of molten metal into the ground. Firewood and pieces of ore were placed in layers in the pit.
The technology for smelting tin from placers was somewhat different. First, a fire was made in the pit, and when the wood burned, ore was poured onto the burning coals.
In both cases, the liquid metal formed during melting accumulated at the bottom of the pit. It was scooped out with special ladles and poured into molds.
Later, to improve the process of fuel combustion in the pit, they began to use bellows to supply air. This small improvement made it possible to increase the capacity of the pits; they began to be made wider and deeper. But over time, the swimming trunks became large, and it was difficult to get the metal from the bottom of the pit.
What helped us out, as we now say, was work ingenuity. One of the ancient metallurgists came up with a new “unit” for smelting ore - a large wooden barrel coated inside with refractory clay. This “lining” reliably withstood high temperatures. soon replaced the pits (furnaces). It turned out that smelting metal in barrels, into which coal and ore were poured layer by layer, and also blowing air with bellows, was no worse than in pits, but much more convenient.
Centuries passed and metal smelting techniques improved. The barrels were replaced by small handicraft shaft furnaces (such homemade furnaces were used in China for tin smelting at the beginning of the 20th century). Such a furnace, made of brick or stone, was first heated with wood and coal, and then tin ore and charcoal (and later coke) were loaded into it layer by layer. Air was also blown by bellows, but since much more of it was required than before, the blower was driven by horses. Later, horse traction was replaced by drainage wheels.
However, when smelting tin ore in primitive shaft furnaces, it was not possible to reach a temperature at which the slag would also melt. The waste rock remained in the furnace in the form of a sintered dense mass. Therefore, upon completion of melting, the furnace had to be dismantled to remove slag.
Over time, tin was smelted in much larger shaft furnaces and at higher temperatures, which produced molten slag. But simultaneously with the recovery of tin, the recovery of iron also occurred. The result was a large number of different refractory iron-tin alloys (metallurgists call them “Hartlings”). They significantly reduced the yield of pure tin. Another disadvantage of shaft furnaces was that they could only smelt tin ores that consisted of large pieces. But there were few such ores. Later, metallurgists learned to process ores and concentrates in such furnaces, which were obtained by simple washing. They were pre-sintered on special gratings.
Tin smelting technology improved slowly. Only at the beginning of the 18th century, for the first time in England, shaft furnaces were replaced by reverberatory furnaces with grate fireboxes. Pulverized coal was used to heat them, and later.
Reverberatory furnaces had many advantages over. mines, so they began to quickly displace them. However, in reverberatory furnaces it was not possible to raise the heating temperature of ore during smelting above 1300-1350 degrees. To completely extract tin from slag, you have to add a lot of lime, which increases the melting point to 1400-1500 degrees.
In the 30-40s, tin was extracted from steel slag in electric furnaces, in which higher temperatures could be obtained. Now, in such furnaces, concentrates rich in tin are melted (if they do not contain iron impurities), that is, metal is smelted without additional processing of slag. In addition, the productivity of electric furnaces (per unit area) is much higher than that of reflective furnaces. The use of electric furnaces made it possible to improve production standards and improve working conditions for metallurgists.
Despite advances in mining and smelting techniques, tin is still an expensive metal.
Devil's cry. For many centuries, alchemists in different countries tried unsuccessfully to obtain gold from base metals. Alchemists taught that nature always strives to create perfect objects, such as gold, but unfavorable circumstances prevented this, and instead of gold, inferior metals were formed - copper, lead, tin. But in order to turn lead or tin into gold, you must first prepare the "philosopher's stone" or elixir.
Alchemists persistently and persistently searched for this miraculous elixir.
Alchemists, using the teachings of the ancient Greek philosopher and naturalist Aristotle, argued that all metals consist of two carrier elements - sulfur and mercury. They consist of pure mercury - the basis of metallicity, and base metals have an even greater admixture of sulfur - the beginning of variability. Therefore, to get gold, you need to be able to remove sulfur.
However, all their efforts were in vain. They did not find an existing "philosopher's stone" and were unable to turn base metals into gold.
Despite the complexity of their teaching, alchemists made significant contributions to the further development of chemistry. In search of the mythical elixir, they discovered many salts and acids and developed methods for their purification.
Testing various metals in order to transform them into gold, alchemists paid great attention to tin. They were attracted primarily by its mysterious properties. Tin, one of the softest metals on our planet, when alloyed with copper gave it hardness.
But what struck the alchemists even more, perhaps, was the crackling sound that was clearly heard when bending a tin stick. “This is the voice of the devil who has entered metal,” they said.
Alchemists called a phenomenon incomprehensible to them (which was noticed by the famous alchemist Haber) “tin cry.” In our time, this name has been preserved, but now it is not associated with the sounds made by the devil, but comes from the English word creak - creak, crunch. The reason for this crackling sound (not observed in other metals) has now been solved. The tin stick “crunches” because its crystals move slightly and rub against each other.
Tin, a malleable and fusible metal, has good malleability, second only to noble metals and copper, and therefore thin sheets of foil (staniol) can be easily obtained from it. Silvery-white, with a faint bluish tint, they turn brown in transmitted light. Like other metals, tin forms salts with some non-metals (chlorine, sulfur, fluorine, bromine), which are used in the national economy. Tin does not interact directly with either carbon or nitrogen. It is also “indifferent” to direct contacts with hydrogen and silicon. However, tin hydrides and nitrides can be obtained indirectly.
If you throw a piece of tin into a dilute solution of hydrochloric or sulfuric acid, it will take a very long time to dissolve. This metal will react just as slowly with aqueous solutions of other strong acids (nitric, hydrobromic); tin is practically insoluble in organic acids (acetic, oxalic). What is the reason for this behavior of tin? It is explained by a slight difference in the values of the normal potential of tin and hydrogen, in the series of voltages in which all metals (and hydrogen) are located according to their chemical activity. The further to the left in this row and the farther from hydrogen the metal is, the faster it displaces hydrogen from acids. Tin in this series is located in close proximity to hydrogen.
Tin dissolves not only in acids (diluted and concentrated), but also in alkalis, forming, depending on the reaction conditions, two groups of compounds - stannites and stannates.
Chemists have obtained various compounds of tin with acids - phosphates, nitrides, sulfates. All of them are crystalline solids. In contrast, tin nitrate Sn(NO3)2 is a mobile liquid, highly soluble in water. And one more unusual property of this tin derivative is that it melts at a temperature of minus 20 degrees. In industry, tin compounds with sulfur and chlorine are most often used.
Both the potter and the dyer. At the end of the 15th century, the alchemist Vasily Valentin, in the vain hope of obtaining a miraculous elixir, began to calcinate a mixture of table salt, alum and iron sulfate. The elixir did not work out, but a new, previously unknown liquid formed in the vessel. She smoked in the air. When inhaled, this smoke caused severe coughing. If the liquid was tasted, it burned the tongue. Droplets of liquid that fell on the fabric burned through it, it corroded and dissolved the metals. It was hydrochloric acid. The alchemist called this liquid “sour alcohol.” Almost half a century later, another European alchemist, Andrei Libavius, became interested in “sour alcohol.” He repeated the experiment of his predecessor and obtained exactly the same caustic liquid. First of all, he decided to find out how “acid alcohol” acts on metals. Copper, iron, zinc dissolved in this caustic liquid. Having dissolved tin in “acid alcohol,” Libavius evaporated the resulting solution and obtained white rhombic crystals. What kind of substance was this? Now we call it stannous chloride. At that time, no one had any idea about chlorine. This element was first discovered in 1774 by the famous Swedish chemist Scheele and later by the English scientist Davy (1810). We do not know what the alchemist called the salt he received, but he began to conduct various experiments with it. First of all, I decided to test the effect of the new substance on tissues. Will this salt destroy them as well as acidic alcohol? It turned out that tin chloride is by no means the worst enemy of textile materials.
Even in ancient times, people learned to dye wool and fabrics with dyes that were extracted from flowers, fruits and roots of various plants. At that time, some paints of animal origin were also used. The ancient purple, which was once used to dye the togas and robes of the Persian kings, was obtained from one of the species of mollusks. In South America, Indians have long dyed fabrics scarlet using carmine, a dye obtained from cochineal, aphids collected on cacti.
Ancient dyers were well acquainted with mordants - substances that strengthen the color of fabrics. Most often they were obtained from natural minerals. Thus, Greek and Roman dyers widely used alum when dyeing fabrics. The Greek historian Herodotus, who lived in the fifth century BC, called them "aluminum", and four hundred years later the ancient Roman scientist Pliny the Elder called them "alumene".
Tin chloride also turned out to be a good mordant. Once Libavius dipped a piece of brightly colored fabric into its solution, the color not only did not fade, but became even brighter.
However, it took several more decades before the alchemist's discovery found practical application. One of the first to use tin mordants in dyeing was the Dutch chemist Drebbel. Soon this discovery gained wide recognition among dyers in many countries.
In Europe at that time they did not yet know how to process and produce cotton fabrics. They were brought from the countries of the Middle East and India. At that time, thin cotton calico fabric (later called calico), which was brought from the Indian city of Calcutta, was widely used in Europe. This fabric attracted me with its original colors. Dyers used tin mordants to apply red patterns, flowers, and simple designs to the fabric. Over time, dyers began to use tin mordants for dyeing wool and silk fabrics.
For more than a hundred years, tin chloride has been helping chemists create durable organic paints that do not fade in the sun. It is also used in many other industries, since stannous chloride is a strong reducing agent and is highly soluble in water, alcohol, ether and many other organic solvents.
A close “relative” of tin chloride, tin tetrachloride, also has many valuable qualities that are widely used in some industries. It is obtained by passing a stream of dry chlorine into liquid tin. Like tin chloride, it dissolves well in water and various organic solvents, but unlike it, it can itself dissolve sulfur, phosphorus, and iodine.
Already more than two hundred years ago, we learned how to make beautiful printed calicoes in our country, which enjoy constant success among women. A clear and durable printed pattern or ornament on chintz is obtained thanks to tin tetrachloride. Textile workers also use it as a finishing agent (from the French apprêter - to finally finish fabrics). Sodium stannate (Na2SnO3) is also successfully used in the textile industry for the same purposes. Stannates are easy to obtain - just fuse tin dioxide (SnO2) with some alkali or dissolve freshly prepared tin dioxide hydrate in alkali solutions. Stannats are used not only by textile workers, but also by radio technicians. Thus, barium stannate is widely used in various radio engineering devices - it is an excellent dielectric.
Tin dioxide has long been used in pottery. We do not know the name of the person who was the first to fashion a pot or jug from clay dough thousands of years ago and begin to burn it on fire. But since then, pottery has been in demand among the population in all countries of the world. At first, the products of ancient potters had an ugly appearance. But the most important drawback of pottery is the porosity of the inner walls. Such dishes were, as it were, penetrated by many capillaries - tiny channels through which water seeped. It was not possible to preserve water or other liquid in such clay vessels even for several hours.
For a long time they could not find a way to make the surface of clay products non-porous. But, as often happened in the history of great discoveries, chance helped. Somehow a little mixture of sand and soda fell on one of the clay pots prepared for firing. Imagine the potter’s surprise when, having pulled his pots out of the kiln after firing, he saw on one of them a smooth, shiny film covering the entire inner surface of the pot.
Thus, chance helped the ancient potters to close the pores in their products with a reliable glassy film. It was called glaze. Later they began to add lime to the glaze, and in some places where there was tin ore, cassiterite. Gradually we learned to make multi-colored glazes by adding different substances to the mixture of sand and soda.
The accidental discovery of the glaze subsequently led to an equally accidental discovery of the glass. Once a potter applied a layer of glaze to one of his pots very carelessly. After firing, instead of an even, smooth film of glaze, a small shiny lump of glass was found in the pot. This was the beginning of glass making.
Already the first glassmakers knew that with the help of tin dioxide it was possible to obtain a beautiful white glaze. Therefore, with a small addition of cassiterite, beautiful milky white glass can be prepared. This glass was beautiful, but opaque. Light rays passed through it, but it was impossible to see through it. Later, glassmakers called such glass “deaf.” They were obtained by adding powders of various substances to the mixture, but mainly tin dioxide or finely ground cassiterite. And at present, “blind” glasses are being prepared for various technical purposes. It is obtained with the addition of tin dioxide and a white glaze.
Perhaps even before they began to make transparent and opaque glass, glassmakers learned to make colored glass. Many centuries ago, it was noticed that impurities of certain materials color glass in different colors: cobalt - blue, chromium - yellow-green, manganese - purple.
For more than forty years, ruby stars have been burning on the towers of the Moscow Kremlin around the clock - a symbol of victory in our country.
In order for the stars to sparkle as brightly during the day as at night, the light red glass from which they are made was placed on a lining of milky white glass. And it was prepared not without the participation of tin dioxide.
Both chemists and farmers. There is a variety of products made from polyvinyl chloride, which is widely used in various industries. But for all his good qualities, he is “afraid” of the sun. To protect it from the action of light rays, organotin is used - dibutyl and dioctyl stannanes, monoalkyl stannanes, dialkyl tin laurates and dialkyl tin dimaleates are used as stabilizers.
In the 50s, chemists developed a method for synthesizing polymers from various hydrocarbons with a regular molecular structure. They are called stereoregular or isotactic. The practical value of obtaining such polymers lies in the possibility of creating materials with any desired properties. And here we cannot do without organotin catalysts. It is difficult to overestimate the importance of introducing this method in the chemical industry.
Processing of solid polyvinyl chloride to obtain transparent films, plates and plastic vessels from it is carried out at a temperature of 180°C. To prevent the polymer from spreading, thermal stabilizers are needed. And here organotin comes to the rescue - dialkyltin mercaptans and dialkyltin diisooctyl glycolates.
Tires are the most important accessory. The longer they serve, the cheaper the operation of the car. Therefore, chemists are trying to increase their permeability by creating new types of synthetic rubber, from which more durable and elastic rubber can be made.
In the fight for the durability of tires, chemists several years ago won another victory - from some organic substances obtained from the dry distillation of coal and the refining of petroleum products, they created a new type of synthetic rubber - urethane. It wears out twice as fast as natural. The catalysts that helped were tin diazurates, which serve as hardeners for silicone rubbers and epoxy resins.
The fouling of ship keels with shells and other marine and freshwater organisms brings a lot of grief and trouble to sailors and watermen. Usually, to protect the underwater parts of ships and port facilities, paint and plastic coatings are used, which are made with additives of copper and mercury compounds, less often zinc and lead. However, they have a big drawback - they cause electrochemical corrosion of metal parts. Protective coatings based on organotin polymers or copolymers with organic or organoelement monomers have proven to be much more effective.
Organotin glasses reliably protect against ultraviolet and x-rays. Organotin preparations provide many valuable services to farmers. Ever since man learned to cultivate the land, grow cereals and vegetables, he has been continuously fighting weeds. Chemists have created hundreds of new drugs - herbicides that are used to kill weeds, but do not harm crop plants. Among them are trivinylchlorostannane and some of its derivatives.
Organotin preparations are even more effective in controlling agricultural pests. Indeed, even now, with modern farming methods, losses caused by pests reach 25-30 percent. Potato crop losses from diseases and pests are even greater.
Our product “Brestan” (triphenyltin acetate) quickly destroys beet and potato pests. It is enough to spray 600 liters of its 0.01 percent solution per hectare. In addition, it is a reliable means of combating persistent fungal diseases of tropical and subtropical crops, and stimulates plant growth.
The toxic properties of many organotin compounds, known more than a hundred years ago (triethylstannanol, hexabutyldistannooxane), now help fight environmental pollution, purify industrial wastewater, and fight house fungus and other wood pests.
Copolymers of organotin acrylates with maleic anhydride, styrene, vinyl chloride, ethylene and butadiene turned out to be excellent antiseptics that completely destroy E. coli, Staphylococcus aureus, Brucella and a number of other microbes even at high infection densities. Veterinarians readily use organotin preparations to combat worms in pets.
To enhance targeted biological activity, some additives of organic substances are introduced into the preparations. For example, a solution of a mixture of benzyltriethylammonium chloride and hexabutyldistannooxane destroys Staphylococcus aureus in 5 minutes.
Scientists have developed many methods for synthesizing a variety of organotin drugs. The starting raw materials are either pure metal tin or its alloys, but most often tin tetrachloride and various organic (and often organoelement) compounds. The reaction occurs in the presence of a catalyst.
Organotin is still a “baby”. She has a great future ahead of her. This is guaranteed by her wonderful qualities.
Both the motorist and the printer. A car, machine tool, or engine has a shaft. When it rotates, strong friction occurs, which causes rapid rubbing of parts. How to reduce the harmful effects of friction, how to eliminate it? You can use lubricant. Under ideal operating conditions, the shaft and bearing shells should not come into contact with each other and therefore they will not wear out. Under normal operating conditions of bearings, this cannot be achieved. To reduce the coefficient of friction, antifriction alloys are used, which must be hard and at the same time sufficiently soft and plastic so that in the case of different configurations of the shaft and liner, the liner can “break in” to it.
In search of a suitable composition for the manufacture of bearing alloys, metallurgists turned their attention to lead and tin as the softest metals.
The first antifriction alloy, proposed in 1839 by engineer I. Babbitt, contained 83 percent tin, 11 percent antimony and 6 percent copper. Subsequently, similar antifriction alloys with slightly changed content of constituent parts began to be called babbitt (named after the inventor) and became widespread. Currently, in addition to standard babbitts, alloys with increased ductility are produced in our country and abroad.
In the soft plastic mass of the alloy, hard metal crystals are evenly distributed, which resist abrasion well and, if necessary, are pressed into the liner.
Tin is an expensive and scarce metal, so now they are increasingly trying to replace bearings with Babbitt liners with roller and ball bearings.
Printers and printers began to use tin alloys several hundred years earlier.
He decided to make a typeface for printing by casting letters in a metal mold. It was made of lead, the bottom of it was a copper block with an in-depth letter pattern embossed on it. At first, Gutenberg cast letters from tin with a small addition of lead. Later, he selected the best alloy with a significant admixture of antimony (over 20 percent), called hart (from the German word “hart” - hard). It turned out to be much stronger than an alloy of lead and tin, and fully justified its name.
The typographic alloy, composed by Gutenberg with minor changes in the content of its constituent parts, is still used today, but tin still occupies a dominant place in it.
Benefactor of humanity. In those years when Gutenberg cast printed letters from tin, pewter utensils were widely used in Austria, Belgium, and England. The production of tin spoons and cups, bowls and jugs, plates and dishes began in the 12th century, when rich deposits of tin ore were discovered in the Ore Mountains in Bohemia. For better pouring of liquid metal, tin was alloyed with lead (10: 1).
Later, kitchen and tableware began to be made from a tin alloy with a higher lead content (up to 15 percent), as well as the addition of antimony and sometimes small amounts of copper and zinc. One of these alloys was called "British metal".
Tin utensils were made in molds made of brass or iron, less often from plaster. Lids, handles, and individual parts were connected by soldering. Dishes with artistic ornaments, flat and relief images of plants and animals were especially highly valued. In central Europe, tin products made by German craftsmen were famous. There was no city in Germany where at least one crockery master did not work. There were 159 tin workers in Nuremberg alone. Each new product was branded with the mark of the master or the city. Large tin jugs, made as a symbol of the workshop, were considered the pride of urban artisans.
Over the centuries, traditions of artistic decoration and forms characteristic of a particular city and area have been preserved.
Along with deep-rooted folk motifs, the artistic decoration of goblets, bowls, candlesticks, and jugs was also influenced by classical art.
In recent years, less and less tin is being obtained from recycled materials due to a decrease in its content, which is caused by the wider use of the electrolytic tinning method, which allows reducing tin consumption per unit of production.
The first plant that began to smelt tin in the Union of Soviet Socialist Republics (CCCP) from indigenous ores was built in 1934 in Podolsk near Moscow. He worked for seven years on tin-rich ores (the concentrate supplied to the plant for processing contained from 40 to 70 percent tin). First, impurities of arsenic and sulfur were removed from the concentrate by roasting. Fluxes were added to the cinder and melted in reverberatory furnaces. The resulting crude tin was refined in boilers with special additives that bind impurities into refractory compounds. This smelting process left slag with a high tin content. They were refined, and slag containing no more than one percent of tin went into the dump. The plant also produced secondary tin from various scrap and waste containing metal.
Due to the rapid growth of tin ore mining and concentrate production in the pre-war years, construction of a second tin plant in Novosibirsk began in 1940. Its launch was scheduled for 1943. The treacherous attack of the Nazis on our country changed these plans. In the fall of 1941, the Podolsk plant was evacuated to Novosibirsk. Workers and engineers delivered equipment from the dismantled Podolsk plant, as well as concentrate and crude tin. Two months later, the plant began to produce tin-lead alloys.
At first, the enterprise encountered many difficulties, in particular, all work on loading and unloading raw materials and materials, their transportation, and preparing the charge was carried out manually. Nevertheless, the plant fulfilled its production plans and supplied its customers with tin-lead alloy without interruption.
Initially, the Novosibirsk plant used the technology of tin smelting and alloy production adopted at the Podolsk tin plant. The first melt was produced from the first reverberatory furnace on February 23, 1942. Six months later, several more reverberatory furnaces came into operation. Later, the plant began developing more modern tin smelting technology. The new scheme provided for the enrichment of the poorest tin concentrates of complex composition. The finished concentrates were melted in an electric furnace.
The development of new technological production was completed only in the post-war years. In 1947, a scheme for finishing concentrates was introduced, which is still used today with some changes, and at the end of 1948 the electric smelting process was introduced.
Since 1953, the plant began to produce tin and babbitts with a high tin content. This was made possible thanks to improvements in the refining process, which made it possible to remove all impurities from the crude tin.
Many other technical improvements have been introduced at the plant: zone smelting method, electric smelting of sludge concentrates, vacuum refining of tin.
All these improvements allow the processing of poorer concentrates and make it possible to obtain tin of high purity. However, the plant team does not rest on the successes achieved. In the coming years, an even more advanced tin production scheme will be introduced, which will ensure even more complete extraction of tin and other metals from the concentrate. It involves chemical enrichment processes, direct-flow leaching, and reduction at low temperatures.
Along with the Novosibirsk Tin Plant, tin-lead alloys are produced by the Ryazan Non-Ferrous Metals Production and Processing Plant, which also processes secondary raw materials. The plant's product range also includes zinc sulfate and various intermediate products. One of the plant's achievements is the successful processing of slags with low tin content.
Metallurgical plants have achieved ever-increasing high technical and economic production indicators, in particular a higher percentage of metal recovery. Thanks to close creative collaboration with research and design institutes, during the tenth five-year plan it was possible to increase tin extraction by 1.1 percent. Foreigners are willing to buy some of the developments of our scientists and engineers, which are successfully used in factories.
However, until now, some of the valuable components of the concentrate go into the tailings during finishing and accumulate in dumps. Carrying out the decisions of the XXVI Congress of the CPSU, tin production schemes are being developed and implemented that will make it possible to widely use the plant’s internal reserves, taking into account the deterioration in the quality of the processed ore (the presence of sulfides, tourmaline, arsenic and other harmful impurities).
The Central Scientific Research Institute of the Tin Industry (TsNIIolovo) has developed an effective and cost-effective technology for the production of rough concentrates with centralized finishing, which will make it possible to fully utilize all waste. To process sulfide polymetals obtained through centralized finishing, you can use the cyclone-electrothermal method or processing in a vacuum fluidized bed using various options for chloride sublimation. Centralized finishing between the beneficiation and metallurgical processes will allow, firstly, to extract at least half of the tin from rough concentrates, and secondly, to almost halve the amount of tin-poor products that go to metallurgical processing.
The introduction of a beneficiation and metallurgical complex will make it possible to practically use any ores for processing, regardless of their quality. And this, in turn, will contribute to the expansion of the raw material base of the tin mining and processing industries.
Tin products
The planet, named after the thunder god Jupiter, was correlated by medieval alchemists with tin. It is difficult to imagine this soft and pliable metal as a symbol of a formidable and vengeful god. What were the alchemists guided by when establishing this connection?
The scientifically accepted Latin name for tin “stannum” is derived from the Sanskrit root “sta”, meaning “resistant”, “solid”.
It has not yet been possible to establish exactly the time when tin in its pure form began to be used for the manufacture of products. Only fragmentary information is known, which is occasionally supplemented by archaeological excavations. In one or another center of ancient civilizations there are isolated finds of almost pure tin. Thus, in one of the ancient Egyptian burial grounds dating back to the 1st millennium BC. e., a tin vial and ring were found.
Since ancient times, tin has been smelted from the so-called tin stone - cassiterite, which received its name from a group of islands in the North Atlantic 3.5 Tin products
The ancient Phoenicians, who were not only skilled metallurgists, but also remarkable navigators, going to the Cassirids for tin stone, took on board the ship an anchor made of a hollow cedar log, filled with stones for weight. Upon arrival at the site, the ship's holds were loaded with tin ore. In order not to bring back ordinary cobblestones, the anchor blocks were filled with tin ore instead. Thus, only the payload remained on the ship.
Although tin was known to man already in the 4th millennium BC. e. This metal was inaccessible and expensive, since products made from it are rarely found among Roman and Greek antiquities. There are mentions of tin in the Bible, the Fourth Book of Moses.
Nowadays, tin is used mainly as a safe, non-toxic, corrosion-resistant coating in its pure form or in alloys with other metals. The main industrial uses of tin are in tinplate (tinned iron) for the manufacture of food containers.
The technique of creating “frosty patterns” was basically very simple. The tin-coated metal was heated and then sharply cooled by spraying with cold water, or even dipping into water. This operation changed the crystal structure of tin. To develop it, to make it visible, a layer of tin was moistened with hydrochloric acid. The crystalline pattern revealed shimmered on the metal, like a mosaic made of sparkling pieces of ice. Under a thin layer of colored varnish, the iridescent “frosty patterns” looked even more expressive. But no matter how simple the technology for creating “frosty patterns” was, only the masters knew the technological subtleties that made it possible to reveal the beauty of the metal as deeply as possible. For many years, Panteleimon Antonovich Sosnovsky, who died in 1972 at the age of 99, remained the keeper of these “secrets” and the soul of the craft. He was the last master of the ancient art craft.
Tin has a disease called “tin plague.” The metal “gets cold” in the cold already at -13°C and begins to gradually deteriorate. At a temperature of -33°C, the disease progresses with incredible speed - tin products turn into gray powder.
At the end of the last century, this phenomenon failed the members of the expedition working in Siberia. In the severe frost, the pewter utensils suddenly became ill. In a short time it was so destroyed that it could no longer be used in cooking. Perhaps the expedition would have had to interrupt the work it had begun, if not for the bowls and spoons that they managed to carve out of wood. Having repeatedly encountered the “tin plague,” people finally came to the conclusion that tin can only be used where it is not exposed to frost.
3.19 Tin content 95
As already mentioned, tin is directly related to the birth of melodic sounds in a wide variety of bells, since it is part of the copper alloys used for casting them. But it turns out that it is capable of singing completely independently: pure tin has no less outstanding musical abilities. Listening to the solemn sounds of organ music, few listeners realize that enchanting sounds are born in most cases in tin pipes. They give the sound special purity and strength.
Since ancient times, man has used not only tin and its alloys, but also its various chemical compounds. Golden-yellow crystals of tin disulfide are used by craftsmen to imitate gold leaf when gilding plaster and wooden reliefs.
Glass and plastic are treated with an aqueous solution of tin dichloride before applying a thin layer of any metal to their surface. Tin dichloride is also included in fluxes used in metal welding.
Tin oxide is used in the production of ruby glass and glazes.
Tin dioxide is a white pigment used to color enamels and opaque glazes. In nature, this is a tin stone called cassiterite, which serves as a raw material for tin smelting. It is produced artificially by calcining tin in air.
Among the many other “useful deeds” of tin compounds are: Protecting wood from rotting, killing insect pests and much more.
I would also like to note that many foundries, having lost mass orders, switched to the production of tin miniatures: at the beginning of the 19th century, not only in Nuremberg and Augsburg, but also in Berlin, Potsdam, Leipzig, Freiburg, Meissen, Dresden and other German cities, "factory of tin figures".
After the advent of the German Empire, the market was flooded with figures of soldiers and commanders of the Prussian army from all eras.
Today, dozens of companies around the world make plastic soldiers, but tin miniatures have gradually become high art and an object of desire for collectors - they are now almost never produced en masse.
As an example, samples of tin products:
for the provision of artistic metal forging services.
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