Question

Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.

Answer 1

Metals in the middle of the reactivity series such as iron, zinc, lead, copper, etc., are moderately reactive metals and are usually present as sulphides or carbonates. A metal is obtained from its ore by the processes of reduction or by electrolysis. In the reduction process, it is the oxide ore that is reduced.

To reduce a carbonate ore, metal in the middle of the reactivity series follow certain steps. Let us consider a metal from the middle of reactitvity series, zinc.

Zinc ore is concentrated and roasted in air to produce zinc oxide. Zinc oxide and carbon(IV) oxide, CO2, are formed when ZnCO 3 is roasted in air.

ZnCO₃ (s) → ZnO(s) + CO₂ (g)

The zinc oxide produced from the ores is then heated with carbon to reduce it into metallic zinc.

Carbon forms carbon(II) oxide, CO, and zinc metal Zn(s).

ZnO(s) + C(s) → Zn(s) +CO(g)