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