Question

The slag obtained during the extraction of copper from copper pyrites is composed of________.
(A) $C{{u}_{2}}S$
(B) $CuSi{{O}_{3}}$
(C) $FeSi{{O}_{3}}$
(D) $Si{{O}_{2}}$

Answer 1

Hint: When a metal is separated from its ore, the product left behind is called slag. It is actually the impurities. This process is smelting. It occurs as a molten liquid. After cooling, the slag solidifies. Slag contains a high amount of iron. This is the reason why slag gets stuck to the magnet. There are two types of flux: Acidic flux and basic flux. The acidic flux combines with basic impurity, and the basic flux combines with acidic impurity to form slag.

Complete Step by Step Answer:
$CuFe{{S}_{2}}$ is the chemical formula for copper pyrites. Since it contains sulphide ore, extraction is done by the process of roasting. In the metallurgical process of roasting, ore is heated below its melting point in the presence of excess air and converted into its oxide.

$CuFe{{S}_{2}}$ Is first converted into $C{{u}_{2}}S$,$FeS$and$S{{O}_{2}}$.$C{{u}_{2}}S$ is heated to convert into $C{{u}_{2}}O$ and $S{{O}_{2}}$. Also, $FeS$ is then heated to convert it into $FeO$ and $S{{O}_{2}}$. $C{{u}_{2}}S$ and $C{{u}_{2}}O$ then combines to form pure $Cu$ and $S{{O}_{2}}$. Finally, the impurity $FeO$ combines with flux $Si{{O}_{2}}$ to get iron silicate ($FeSi{{O}_{3}}$) as slag.
$Fe+SiO_2\rightarrow FeSiO_3$. The slag produced when copper is extracted from copper pyrites is made of $FeSi{{O}_{3}}$.
Correct Option: (C) $FeSi{{O}_{3}}$.

Note: The slag formed is a mixture of metal oxide and silicon dioxide. $C{{u}_{2}}S$ is a sulphide compound. $Si{{O}_{2}}$ is silicon dioxide. $CuSi{{O}_{3}}$ is formed by the combination of$CuO$ and$Si{{O}_{2}}$.