tin ore - 04

This silvery, malleable poor metal is not easily oxidized in air and is used to coat other metals to prevent corrosion. The first alloy used in large scale since 3000 BC was bronze, an alloy of tin and copper. After 600 BC pure metallic tin was produced. Pewter, which is an alloy of 85% to 90% tin with the remainder commonly consisting of copper, antimony and lead, was used for flatware from the Bronze Age until the 20th century. In modern times tin is used in many alloys, most notably tin/lead soft solders, typically containing 60% or more of tin. Another large application for tin is corrosion-resistant tin plating of steel. Because of its low toxicity, tin-plated metal is also used for food packaging, giving the name to tin cans,
Characteristics

Tin is a malleable, ductile, and highly crystalline silvery-white metal. When a bar of tin is bent, a crackling sound known as the tin cry can be heard due to the twinning of the crystals.[2]
β-tin(the metallic form), which exists at room temperature and hotter, is malleable; while the α-tin(nonmetallic form), formed when tin is cooled below 13.2 °C, is brittle. It has a diamond cubic crystal structure, similar to diamond, silicon or germanium. α-tin has no metallic properties at all. It is a dull-gray powdery material with no common uses, other than a few specialized semiconductor applications.[2] These two allotropes, α-tin and β-tin, are more commonly known as gray tin and white tin, respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C and pressures above several GPa.[3] Although the α-β transformation temperature is nominally 13.2 °C, impurities (e.g. Al, Zn, etc.) lower the transition temperature well below 0 °C, and upon addition of Sb or Bi the transformation may not occur at all, increasing the durability of the tin.[4]
Chemical properties
Tin resists corrosion from distilled, sea and soft tap water, but can be attacked by strong acids, alkalis, and acid salts. Tin can be highly polished and is used as a protective coat for other metals in order to prevent corrosion or other chemical action. Tin acts as a catalyst when oxygen is in solution and helps accelerate chemical attack.[2]

Creation
Tin is created via the long S-process in low-medium mass stars (.6 -> 10 solar masses). This takes thousands of years to do. It requires an Indium atom to capture a neutron and then undergo Beta decay.
Compounds and Chemistry
Tin forms the dioxide SnO2 (cassiterite) when it is heated in the presence of air. SnO2 is amphoteric and forms stannate (SnO32−) salts with bases and tin(IV) salts with acids. There are also stannates with the structure [Sn(OH)6]2−, like K2[Sn(OH)6], although the free stannic acid H2[Sn(OH)6] is unknown.
Occurrence
Tin is the 49th most abundant element in the Earth's crust, representing 2 ppm compared with 75 ppm for zinc, 50 ppm for copper, and 14 ppm for lead.[26]
Tin does not occur naturally by itself, and must be extracted from a base compound, usually cassiterite (SnO2). Cassiterite is the only commercially important source of tin, although small quantities of tin are recovered from complex sulfides such as stannite, cylindrite, franckeite, canfieldite, and teallite. Minerals with tin are almost always in association with granite rock, which, when they contain the mineral, have a 1% tin oxide content.[27]
Because of the higher specific gravity of tin dioxide, about 80% of mined tin is from secondary deposits found downstream from the primary lodes. Tin is often recovered from granules washed downstream in the past and deposited in valleys or under sea. The most economical ways of mining tin are through dredging, hydraulic methods or open cast mining. Most of the world's tin is produced from placer deposits, which may contain as little as 0.015% tin.
Production
Tin is produced by reducing the ore with coal in a reverberatory furnace.
Mining and smelting
In 2006, total worldwide tin mine production was 321,000 tons, and smelter production was 340,000 tons. From its production level of 186,300 tons in 1991, around where it had hovered for the previous decades, production of tin increased 89% to 351,800 tons in 2005. Most of the increase came from China and Indonesia, with the largest spike in 2004–2005, when it increased 23%. While in the 1970s Malaysia was the largest producer, with around a third of world production, it has steadily fallen, and now remains a major smelter and market center. In 2007, the People's Republic of China was the largest producer of tin, where the tin deposits are concentrated in the southeast Yunnan tin belt,[33] with 43% of the world's share, followed by Indonesia, with an almost equal share, and Peru at a distant third, reports the USGS.[32]
The table below shows the countries with the largest mine production and the largest smelter output.[note 2]
Mine and smelter production (tons), 2006[34]

Country
Mine production
Smelter production

China
114,300 129,400
Indonesia
117,500 80,933
Peru
38,470 40,495
Bolivia
17,669 13,500
Thailand
225 27,540
Malaysia
2,398 23,000
Belgium
0 8,000
Russia
5,000 5,500
Congo-Kinshasa ('08)
15,000 0
After the discovery of tin in what is now Bisie, North Kivu in the Democratic Republic of Congo in 2002, illegal production has increased there to around 15,000 tons.[35] This is largely fueling the ongoing and recent conflicts there, as well as affecting international markets.
Applications


In 2006, about half of tin produced was used in solder. The rest was divided between tin plating, tin chemicals, brass and bronze, and other uses. See graph at right.[38]
Metal or alloy
Tin is used by itself, or in combination with other elements for a wide variety of useful alloys. Tin is most commonly alloyed with copper. Pewter is 85–99% tin;[39] Babbitt metal has a high percentage of tin as well.[40][41] Bronze is mostly copper (12% tin), while addition of phosphorus gives phosphor bronze. Bell metal is also a copper-tin alloy, containing 22% tin.
Tin bonds readily to iron, and is used for coating lead or zinc and steel to prevent corrosion. Tin-plated steel containers are widely used for food preservation, and this forms a large part of the market for metallic tin. A tinplate canister for preserving food was first manufactured in London in 1812. Speakers of British English call them "tins"; Americans call them "cans" or "tin cans". One thus-derived use of the slang term "tinnie" or "tinny" means "can of beer". The tin whistle is so called because it was first mass-produced in tin-plated steel.
Window glass is most often made via floating molten glass on top of molten tin (creating float glass) in order to make a flat surface (this is called the "Pilkington process").[42]
Most metal pipes in a pipe organ are made of varying amounts of a tin/lead alloy, with 50%/50% being the most common. The amount of tin in the pipe defines the pipe's tone, since tin is the most tonally resonant of all metals. When a tin/lead alloy cools, the lead cools slightly faster and makes a mottled or spotted effect. This metal alloy is referred to as spotted metal.[43][44]