Question

Extraction of metal from the ore cassiterite involves:
(A)Carbon reduction of an oxide ore
(B)Self-reduction of a sulphide ore
(C)Removal of copper impurity
(D)Removal of iron impurity

Answer 1

Cassiterite is an oxide ore of the metal tin (Sn). Oxide ores extraction involves removal of oxygen by addition of reducing agents.

Complete step by step solution:
The natural mineral ore of the metal tin (Sn) is cassiterite; it is an oxide ore of tin with the formula ${\text{Sn}}{{\text{O}}_{\text{2}}}$. To remove the oxygen and to get a pure metal in the extraction process, the ore is heated to high temperatures of about ${\text{250}}{{\text{0}}^{\text{o}}}{\text{F}}$. This process of heating an ore in the absence of oxygen is known as smelting. It is done by adding coal/coke (Carbon) and limestone in the reverberatory furnace. The coke is a good reducing agent thus the ore gets reduced first. Tin is also found in another ore stannite and its formula is ${\text{C}}{{\text{u}}_2}{\text{SnFe}}{{\text{S}}_4}$. But in cassiterite along with tin, usually iron gets associated with the ore as impurity. Thus, the extraction of metal from the ore cassiterite involves carbon reduction of an oxide ore, removal of iron impurity.

Two options are correct for this question. So, the answer for the above question is multi correct type and the correct options are (A) and (D).

Note: Cassiterite is also known as tinstone. In the process of smelting tin oxide is chemically reduced by carbon (coke) to from tin (Sn) and carbon dioxide${\text{C}}{{\text{O}}_{\text{2}}}$.