Given below are the steps for extraction of copper from its ore. Write the reaction involved.

a. Roasting of copper (I) Sulphide


b. Reducing of copper (I) oxide with copper (I) sulphide


c. Electrolytic refining

a. Roasting:


Roasting is the process by which sulphide ores are concentrated. The sulphides ores are converted into oxides by heating strongly in the presence of excess air. This process is known as roasting. The reaction is given below:


2ZnS + 3O2 + Heat 2ZnO + 2SO2


b. Calcination:


The carbonates ores are changed into oxides by heating strongly in the presence of excess air. This process is known as calcination. The reaction is given below:


ZnCO3 + Heat ZnO + 2CO2


c. Electrolytic refining:


Many metals such as copper, zinc, silver, gold, copper are refined electrolytically. For example:


At cathode: Cu2+ + 2e- Cu


At anode: Cu Cu2+ + 2e-


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