- Tin exists as stanum(IV) oxide, SnO2 in the mineral casiterite, that is tin. Tin contains a lot of foreign matter such as sand, soil, sulphur, carbon and oil.
- Firstly the tin ore is made concentrated by the method of floatation. In this process, the ore is crushed and shaken in oily water. The foreign matter such as sand and soil drown while the tin ore sticks to the oil and floats on the surface of the water.
- The tin ore is then collected and roasted to take away foreign matter such as carbon, sulphur and oil.
- Lastly, the tin ore is mixed with carbon in the form of charcoal and is heated in a blast furnace at a high temperature.
- Stanum(IV) oxide in the ore is reduced to tin by the reducing agent carbon and carbon monoxide.
SnO2 (s) + 2C(s) → Sn (s) + 2CO (g)
SnO2 (s) + C(s) → Sn (s) + CO2 (g)
SnO2 (s) + 2CO(s) → Sn (s) + 2CO2 (g)
- The melted tin that is formed collects at the base of the furnace and then is channeled out into a mould to form tin ingot.