How is granulated zinc obtained? Write its an important application.

Granulated zinc is obtained by the distillation of zinc oxide (or zinc vapour) in a retort. The process involves the following steps:

1. Roasting of zinc blende (ZnS): Zinc blende (ZnS) is roasted in the presence of air to form zinc oxide (ZnO) and sulfur dioxide (SO₂): $$2\mathrm{ZnS}+3\mathrm{O}{}_2\to 2\mathrm{ZnO}+2\mathrm{SO}{}_2$$

2. Reduction of zinc oxide: Zinc oxide is then reduced to metallic zinc using carbon (coke) at high temperatures (~1200°C): $$\mathrm{ZnO}+\mathrm{C}\to \mathrm{Zn}+\mathrm{CO}$$

3. Distillation: The zinc vapour is collected and cooled rapidly to form granulated zinc (small, granular particles).

Important application: Granulated zinc is primarily used in the galvanization of iron to prevent rusting. It is also used in the production of dry cells (batteries) and as a reducing agent in chemical reactions.