Question

Consider the following statements. Roasting is carried out to:
(i) convert sulphide to oxide and sulphate.
(ii) to remove impurities of $CuS$ and $FeS$ present in the ore of tin stone $\left(Sn{O}_2\right)$ as $CuS{O}_4$ and $FeS{O}_4$.
(iii) melt the ore.
(iv) remove arsenic and sulphur impurities.
Of these statements:

• A. (i), (ii) and (iii) are correct
• B. (ii), (iii) and (iv) are correct.
• C. (i), (ii), and (iv) are correct.
• D. (i), (ii), (iii), (iv) are correct.

Answer 1

Answer: (C)

(i), (ii), and (iv) are correct.

Roasting:- It is the process in which concentrated ore is heated to high temperatures in presence of excess of air. It is used for conversion of concentrated ore into its oxide.

This process is mainly used for sulphide ores to get the corresponding oxides, as the extraction of metal is easier from oxides.

Impurities like $As$ and $S$ are removed be roasting.

Also, in extraction of tin, it is used to remove impurities of $CuS$ and $FeS$ present in the ore of tin stone $\left(Sn{O}_2\right)$ as $CuS{O}_4$ and $FeS{O}_4$.

Roasting is the process in which the ore is heated below its melting point in presence of air to oxidise the impurities.

Hence, option $C$ is correct.