Tin
What it is
Tin is a bright, shiny, silver-white metal whose melting point is 231.9°C, i.e. much lower than that of lead. Its boiling point, however, is 2,270°C. The specific weight of tin is either 5.769 g/cm³ or 7.265 g/cm³, depending on the crystal structure. One characteristic feature of tin is its high degree of suppleness and ductility allowing to roll it to ultra-thin foils, and its low surface tension makes it suitable for the production of very thin surface coatings, e.g. for steel.
Where it is found
Cassiterite (or tin stone) is the most important tin mineral. There also is the less important stannite. These raw materials are primarily mined in the PR of China, Indonesia, Peru and, but to a lesser extent, in Brazil, Malaysia, Thailand and Bolivia.
What it is used for
Today more than 50 % of the total refined tin produced is used as solder. Other important fields of application are tin-plating of sheet metal and the production of chemicals. Moreover, tin is a component of various alloys.
How it is traded
Pure tin is traded worldwide mainly in a standardized form, i.e. as ingots with an average weight of about 25 kg. Its purity typically is at least 99.9 % Sn; beyond that, there are limitations, such as max 100 ppm or max 50 ppm of lead. In some cases specifications are developed according to customers’ requirements. Here in Europe the basic standard is DIN EN 610 which, however, is not really used everywhere in the international production process. Nevertheless, most producers are trying to adhere as closely to this standard as they possibly can.