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Sergey Venezky
STORIES ON METALS

TIN:

HARD, BUT SOFT...

The death of the expedition. - "Tin plague". - Joke of the Russian winter. - Missing buttons. - Blame witches. - Atoms are povorotny. - "Vaccine" against "the plague". - "Tin cry". - There are no competitors. - The secret of the Saxons. - Banks in the bathhouse. - The fate of the tin soldier. - Hephaestus equips Achilles. - "Little Mary ..." - High temperature? - Hard or soft? - Money of the Aztecs. - Julius Caesar can confirm. - The king was wrong. - Ore in the "packaging". - Significant exhibit. - On the eternal settlement. - The search for the Holy Nose? - The standard of the London stock exchange. - The glass ribbon. - Trap for the sun. - Fail "banking operations".

In 1910, English polar Explorer captain Robert Scott sent an expedition whose purpose was to reach the South pole, where at that time was not yet stepped on. Many difficult months progressed brave travelers on a snowy deserts of the Antarctic continent, leaving in its path a small stock of food and kerosene stocks on the way back. In early 1912, the expedition finally reached the South pole, but to my great disappointment Scott found a note: it turned out that a month before it was visited by Norwegian Explorer Roald Amundsen. But the main trouble was waiting for Scott on the way back. The first warehouse was not kerosene: tin, in which he was kept, stood empty. Tired, shivering and hungry people could not get warm, they had nothing to cook. With difficulty they reached the next warehouse, but even there they were met by empty cans: all kerosene leaked. Unable to resist the polar cold and terrible storms that erupted at that time in Antarctica, Robert Scott and his friends soon died.

What was the cause of the mysterious disappearance of kerosene? Why carefully thought-out expedition ended so tragically? What happened to captain Scott?

The reason was simple. Tin cans of kerosene were sealed tin. Must be the travelers did not know that the cold tin "sick": shiny white metal first turns to dull gray, and then crumbles into a powder. This phenomenon, called "tin plague", and played a fatal role in the fate of the expedition.

Tin plagueBut the susceptibility of tin "disease" in the cold was known long before the events described. In the middle ages the owners of tin ware noticed that it is covered with frost "plagues", which gradually grow, and eventually ware turns into powder. And cost "prostudilsya" tin plate to touch the "healthy", as she soon began to be covered with gray spots and scattered.

At the end of the last century from Holland to Russia was sent a train loaded with bars of tin. When in Moscow cars opened, they found grey no suitable powder - Russian winter played with recipients tin cruel joke.

Approximately in the same years in Siberia went well-equipped expedition. It seemed that everything was provided to the Siberian frosts did not prevent its successful work. But one mistake travelers still made: they took the tin dishes, which soon failed. Had to cut the spoon and bowl of wood. Only then the expedition was able to continue on his way.

In the beginning of XX century in St. Petersburg at the warehouse of military equipment has been scandalous story: during audit to the horror of the quartermaster was found that tin buttons for soldiers ' uniforms disappeared, and the boxes in which they were stored, filled with grey powder. Although the warehouse was bitter cold, mountain-the quartermaster was hot. Why: it is, of course, suspected of theft, and it is nothing but hard labor, not promises. Saved the poor conclusion, the chemical laboratory, where the auditors have sent the contents of the boxes: "you Sent for analysis substance, undoubtedly, tin. Obviously, in this case occurred a phenomenon known in chemistry under the name "tin plague".

What processes underlie these transformations tin? In the middle ages ignorant churchmen believed that "tin plague" is called hex witches, and so many innocent women were burned at "cleansing" the stake. With the development of science absurdity of such claims was evident, but to find the true cause of "tin plague" scientists for a long time could not.

Only after to help metalloved came x-ray analysis, which allowed to look inside metals and to determine their crystal structure, was able to fully rehabilitate "witches" and give a truly scientific explanation for this mysterious phenomenon. It was found that the tin (as well as other metals) can have various crystal forms. At room and higher temperature, the most stable modification (variation) is a white tin - viscous, plastic metal. At temperatures below 13°C the crystal lattice of the tin is rebuilt so that the atoms are located in the space of less tightly. Generated new modification grey tin - already loses the properties of the metal and becomes a semiconductor. The internal stresses that occur in places of contact of different crystal lattices, lead to the fact that the material cracks and crumbles into powder. One modification goes into the other rather than below the ambient temperature. At -33°C, the rate of this transformation reaches its maximum. This is why extreme cold so quickly and ruthlessly dealt with pewter products.

X-ray analysis has helped to unravel the mystery of tin plague

But tin is widely used for soldering electronic (especially semiconductor) devices, for tinned coatingand wires and various parts with which it comes in the Arctic and in Antarctica and other cold places on our planet. So, all these devices that use tin, easily damaged? Of course, no. Scientists have learned how to make tin immunisation, providing metal immunity against "tin plague". Suitable for this purpose, a "vaccine" is used, for example, bismuth. Bismuth atoms, supplying additional electrons into the lattice of tin, stabilize his condition, which eliminates the possibility of "disease".

Pure tin has an interesting property: when bending rods or plates of metal heard a slight crackle - "tin cry". This characteristic sign occurs due to the mutual friction of tin crystals during their displacement and deformation. Alloys of tin with other metals in such situations, as they say, keep your mouth shut.

Almost half of all mined in the world tin is spent today on the production of tinplate, used mainly for the manufacture of cans. Here is shown to be a valuable metal quality: its chemical stability against oxygen, water, organic acids and, however, full consciousness of its salts for the human body. Tin copes with this role and knows practically no competitors. It is called "metal cans". Thanks thinnest tin layer covering the tin, people have the opportunity for a long time to store millions of tons of meat, fish, fruit, vegetables, dairy products.

Above for deposition of the tin coating was applied hot, the way in which purified and fat-free sheet iron was immersed in molten tin. If I had to poledit one side of the sheet, it was cleaned, heated and greased tin. Now this method has already been put into the archive, and replace it occurred tinning in electroplating baths.

The history of technology known example of industrial espionage, associated with production of tinplate. In the second half of the XVII century England, and had iron, and tin, however, was forced to buy a white sheet, because the English genestelle did not know the secret of its manufacture. By the time the metallurgists of the Saxon Duchy for more than a hundred years able to tin thin iron sheets and their production was, in many countries. To solve the mystery of German artists were commissioned in 1665 a certain Andrew Yarranton. A few years later he described the goal of his "creative travel" published "treatise on Ways to strengthen England at sea and on land": "I was given enough money to cover the expense of traveling there, where do sheets of tinplate. From there I had to bring the art of its manufacture". A visit to Saxony was successful, and soon the English Industrialists could already boast of a great white sheet of its own production.

But fast forward again for three centuries to come, and mentally imagine a mountain of hundreds of billions of cans issued annually during our time in all countries of the world. Next to this constructed fantasy canning hill giant Everest, should be, would be no more than a modest hill. Sooner or later an empty tin can gets to the landfill, however, the tin (and each Bank about half a gram) not going to be here forever buried: people care about how to extract the valuable metal and re-use it for their needs.

Collected cans sent to the special unit, where under the action of alkalis and electric current iron is forced to shoot tin shirt. This kind of "baths" out refined tin and bright tin ingots, they are ready again to turn in cans.

A characteristic feature of the tin - its fluidity. Remember in the fairy tale of Hans Christian Andersen instantly melted in the fire of the steadfast tin soldier, when an evil person he was in the stove?

Due to the relatively low melting point of this metal has earned the reputation of being the main component of solders and fusible alloys. It is interesting to note that the tin alloy (16%) bismuth (52%) and lead (32%) may melt even in boiling water: melting point of this alloy is only 95°C, while its components melt at much higher temperatures: tin at 232°C, bismuth - at 271 °C, and the lead - in 327°C. Even more readily liquefy alloys in which tin is additive to Gaul and India: known, for example, alloy, melting already at 3°C. the Alloys of this type are used in electrical engineering as fuses.

Hephaestus forged for Achilles sword with a picture of the tinGood casting properties, ductility, beautiful silvery-white opened the tin door of decorative and applied arts. In Ancient Greece and Ancient Egypt it was performed decoration, soldered to other metals. Homer says in the Iliad, as the ancient Greek God of fire and blacksmiths Hephaestus, forged for the hero Achilles shield, inflicted on him a picture of the tin. At a later time, about the thirteenth century, in Europe appeared pewter dishes, bowls, cups, Church utensils and other items with relief images.

Tin is one of the few materials used for the manufacture of organ pipes: it is believed that this metal gives the sound power and purity. Audio is connected and another line from the biography tin: in 1877, the famous American inventor Thomas

Alva Edison with his phonograph for the first time recorded on tin foil, covered with a layer of wax, and then repeated the words included in the history recording: "little Mary had a little lamb".

Long tin is an important component of various bronzes, typographical alloys, Babbitt (this name was invented in 1839 by the American Babbitt bearing alloys, capable of strongly resist abrasion).

In the technique is widely used and many chemical compounds of tin. They serve as a stain in the dyeing of cotton and silk, give the porcelain and glass Reds, act as Golden paint, if necessary, create a dense smoke screen. Organic compounds of this element make the fabric water-repellent, prevents rotting wood destroying insect pests. But, perhaps, of all compounds of tin best known in the technique acquired his stunned, which becomes superconducting at relatively high temperatures: if the majority of metals, alloys, compounds lose all resistance to electric current only near absolute zero, stunned niobium freely flows the current already at 18 (or -255°C).

Start Dating man with tin is lost in the mists of time. At first tin was used only in Union with brass: an alloy of these metals, called bronze, was known long before the Christian era. Bronze tools were considerably harder and stronger than copper. Apparently, this explains the Latin name for tin "stannum" - from the Sanskrit word "hundred" is a solid, stable. The tin in its pure form is a soft metal, it is not true to its name. The time has legitimized this historical paradox, and metallurgists can easily handle malleable tin, unaware that we are dealing with "hard" material.

Bronze items were found during the excavation of burials made almost six years ago. Pliny, speaking of mirrors, argued that the "best known to our forefathers were made in Brondizio from a mixture of copper and tin".

To establish the exact period when human society began to use tin in its pure form, is quite difficult. In one of the Egyptian tombs belonging to the era of the XVIII dynasty (mid-first Millennium BC), found the ring and a bottle of tin, which are considered to be the earliest tin products. In the writings of Greek historian Herodotus (fifth century B.C.) we find mention of tin coatings that protect the iron from rust.

In one of the oldest fortresses of Peruvian Incas, scientists have discovered pure tin, designed, apparently, to make bronze: the inhabitants of this castle was known as an excellent metallurgists and skilled masters for the production of bronze objects. Should be, the Incas did not use tin in its pure form, as in the fortress could not find a single pewter ware.

Spanish Conquistador Hernan Cortes in the early sixteenth century conquered Mexico, wrote: "a Few small pieces of tin were found among the natives of the province of Taxco in the form of very thin coins; continuing my search, I found that in this province, as well as in many others, it was used as money..."

In the mid 20-ies in England was conducted excavations at the ancient castle, which was built in the III century B.C., Archaeologists found the melting pit, and they slag containing tin. This meant that there are more than two thousand years ago was developed tin industry. By the way, and Julius Caesar in his book "the Comment about the Gallic war" refers to the production of tin in some areas of Britain.

In 1971, he held the posthumous rehabilitation 94 English chasers coins, which were condemned... 847 years ago. In 1124 king Henry I was accused of working his mint fraud: someone told him that when minting silver coins in metal add too much tin. The Royal court was swift and harsh sentence - off criminals right hand - the court executioners immediately put in execution. And now, after eight and a half centuries one of the Oxford scientists who ill-fated coins careful analysis using x-rays, came to the firm conclusion: "Coins contain very little tin. The king was wrong."

Since immemorial been the main source of tin served as the mineral cassiterite, or tin-stone. Long BC the Phoenicians had outfitted their ships to distant Cassiterides - the so-called rich tin ore small Islands in the North Atlantic, near the British Isles. In more recent times, the centre of world production of tin moved to the Malay archipelago. This metal is closely connected with the whole history of Malaysia, land which has long been famous for its tin resources. The modern capital of the state of Kuala Lumpur (which means "the mouth of the muddy river") is a relatively young beautiful city that emerged in the second half of the last century on the spot where the Chinese miners found a large Deposit of tin ore. Everyone who has visited Kuala Lumpur, take away a souvenir from the tin vase, ashtray, candle holder, made by skillful hands of Malaysian artists.

But sometimes countries export and different "gifts", as evidenced by an incident at the border of Malaysia and Singapore. These countries are linked by a Causeway, passing through the Strait of Johor. Laid on the dam road is always filled with cars. One of these days to the checkpoint on the Malaysian side drove the rig loaded with huge concrete pillars. Pillars as the pillars, but something seemed suspicious customs officers, and they decided to "sound out" the goods: told the driver to pull to the side with the help of a crane removed one of the pillars of the car and a heavy sledgehammer broke it into pieces. And what? Professional instincts had been correct customs employees: each disc was a metal container with tin concentrate is a desirable raw material for owners loveplaying plant in Singapore. Just concrete "packaging" was 127 tons of rich concentrate. Another time in a huge truck, which is called here "the land of the tanker, instead of palm oil, as argued by the driver, was eight and a half tons of the same smuggling concentrate.

Significant reserves of tin ore there and in the Soviet Union in the far East, Transbaikalia, Kazakhstan. In the Museum complex "Dulyovo" in Ussuriysk is stored rare largest cluster of tin stone: it weighs almost poolcenter.

A few years ago in our country was created portable portable device - gamma-resonance lovostatin. To determine the content of tin in the ore to hundredths of a percent, geologist, armed in such a device, it only takes a few minutes. The value of the device lies in the fact that it only responds to cassiterite and does not pay attention to another mineral containing tin, stannite, which as a tin raw material is much less interested in the industry.

A major discovery was made by the Soviet scientists have established that a specific indicator of the presence of tin in a particular geological area can serve as fluorine. Numerous tests and experiments made it possible to reproduce a picture of mineralization that occurred many millions of years ago. In those days the tin, as it turned out, was in the form of complex compounds, which certainly was attended by fluorine. Gradually tin and its compounds to precipitate, forming deposits, and his former companion fluorine remained near deposits of tin ore to perpetual exile. This discovery identifies potential areas of occurrence of tin and even predict its reserves.

Tin seek not only on land but also underwaterGeologists are looking for cassiterite not only on land but also underwater. The search has been unsuccessful: placer tin stone was found at the bottom of the sea of Japan in one of the bays. Rich in them, and coastal waters of the seas of the Arctic ocean - Vankina lip, the sea area of Cape Svyatoy and other areas. Great help marine professionals have divers. Even the geologists to her casual outfit added scuba gear, without which the shelf Holy Nose will not pokoviriaeshsia.

Produced cassiterite enters the steel industry, where it turns into the tin. In the first months of the great Patriotic war from Moscow to Novosibirsk was evacuated alofokemusic, which gave the first fusion in early 1942. Then the plant produced only black 85 %tin, but this metal at that difficult time was very necessary for the country. Now Siberian tin of high purity (from the first letters of these words formed brand of metal - VHF)designed for the semiconductor industry, listed on the London stock exchange as a benchmark, not surpassed in quality by any company in the world. Metal brand VHF-000 contains 99,9995% tin, and the metal VHF-0000 cleaner: it only 0,0001 % of impurities.

The scarcity of tin makes scientists and engineers are constantly seeking out his substitutes. At the same time, this metal finds new applications. The American company Ford motor company built a plant on which applied a curious method of manufacturing a continuous wide strip for window glass. Liquid glass from the furnace enters the huge length of several tens of meters, a bath here and spread on a layer of molten tin. Since the metal melt has a perfectly smooth surface, glass, cooling down and solidify it, too, becomes completely smooth. This glass does not require grinding and polishing, which significantly reduces production costs.

Original glass, which serves as a trap for the sun, created by Soviet scientists. It looks just like normal, but differs from it by the fact that covered with a thin film of tin oxide. This invisible film allows unobstructed sunlight, but does not allow heat rays cross the border in the opposite direction. This glass is a godsend for growers: heated by the sun during the day the greenhouse at night will remain almost the same temperature, while through ordinary glass heat joules one after the other by the morning easily slipped out would. In the new greenhouse plants feel comfortable, even if the street is ten degrees below zero cold. Glass with tin coating will be useful for a variety of solar heaters and other devices, where the energy of the fluorescent light is converted into heat.

Biography tin will be incomplete if you do not talk about one almost detective story with a happy ending, in which the metal has played not the last role.

...The second world war came to an end. Realizing that the future promises nothing pleasant, the rulers of the independent Slovak state, fabricated by Hitler in 1939, on the territory of Czechoslovakia, has conceived something to store for a rainy day. The easiest way, as it seemed, was to run hands in the Golden Fund created by the labour of the Slovak people. However, a group of patriots, who are responsible banking posts, decided not to allow this. The gold was secretly transferred to a Swiss Bank and locked there until the end of the war in favor of the Czechoslovak Republic. Something had managed to bring the guerrillas. But part of the gold still remained in the vaults Bratislava Bank.

One of the leaders of the puppet government secretly informed the German Ambassador in Bratislava on the values stored in armoured basements, and asked to select soldiers for carrying out banking operations for the confiscation of gold. However had to take a third companion, and the General SS troops, but in the success of the robbery could not doubt.

The SS surrounded the building of the Bank and the officer, threatening employees of the executions were ordered to return values. After a few minutes crates of gold came from the safes in the SS trucks. Dealers gleefully rubbed his hands together, not knowing that the boxes are stored bullion "gold", prudently made by the Director of the Mint... tin. And employees of the Bank have once again checked the locks on the caches, which was kept real gold and steel with impatience to wait for the liberation of their country from the Nazi troops.

 

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