Extraction of Tin from Cassiterite

What is Cassiterite?

Cassiterite is the primary ore of tin, with the chemical formula $\text{SnO}_2$. It is a heavy, metallic, and brown-to-black mineral.

Steps in the Extraction of Tin

The extraction of tin from cassiterite involves several steps:

• Mining: Cassiterite is mined from alluvial deposits or underground mines.
• Concentration: The ore is concentrated by gravity separation methods, such as jigging or shaking tables, to remove impurities.
• Roasting: The concentrated ore is roasted in the presence of air to remove sulfur and arsenic impurities, forming tin oxide $\text{SnO}_2$.
• Reduction: The tin oxide is then reduced to tin metal by heating it with carbon in a furnace. The reaction is as follows:

$$\text{SnO}_2 + 2\text{C} \rightarrow \text{Sn} + 2\text{CO}$$

• Refining: The crude tin obtained is refined by liquation or electrolytic refining to obtain pure tin.

Uses of Tin

• Used in the production of tinplate for food packaging.
• Alloyed with copper to produce bronze.
• Used in soldering materials.
• Protective coatings for other metals to prevent corrosion.