Question

Which process is used in smelting during metallurgy of copper?
A.Self reduction of copper
B.${\text{C}}{{\text{u}}_2}{\text{S}}$ is converted into ${\text{C}}{{\text{u}}_2}{\text{O}}$
C.${\text{FeS}}$ convert into ${\text{FeO}}$
D.Reduction of ${\text{Fe}}$

Answer 1

During smelting, in metallurgy of copper, instead of reduction of iron, the iron oxidises and forms iron oxide with silicon. Copper ore remains in sulphide form but the silica slag gets removed.

Complete step by step solution:
The commonly used ore in the extraction of copper is known as chalcopyrite whose molecular formula is ${\text{CuFe}}{{\text{S}}_2}$ . The percentage of copper is less in sulphide ore, so we cannot extract the copper directly. Hence, the froth flotation process is used for the extraction of copper by doing concentration of ores.
Smelting is the process to extract the main metal from the concentrated with the help of either heat or chemical agents. In copper smelting concentrated ore is heated strongly with silicon dioxide calcium carbonate and air in a furnace. First of all the copper ore is reduced to copper sulphide basically iron from the chalcopyrite ore and iron silicate slag is formed, the reaction occurs as follow:
$2{\text{CuFe}}{{\text{S}}_2} + 2{\text{Si}}{{\text{O}}_2} + 4{{\text{O}}_2} \to {\text{C}}{{\text{u}}_2}{\text{S}} + 2{\text{FeSi}}{{\text{O}}_3} + 3{\text{S}}{{\text{O}}_2}$
According to the above reaction we can see that iron sulphide is basically converting into iron oxide.

Hence, the correct option is C.

Note:
First of all, concentration of ore occurs. Ore is crushed into very fine powder and then mixed in water. A suspension solution is formed. Then collectors and frog stabilizers are added. Collectors are fine oils and fatty acids which ensure the non wettability of metal and froth stabilizers are added which makes the formation of froth. The copper formed by the above process is matte copper, it is called so due to its texture and appearance.