Question

How can Zinc metal be extracted from Zinc oxide ore? Suggest a chemical reaction and explain the key concept involved in the process.

Answer 1

Metallurgy: The process of extraction of metals from their ore.

Since Zinc lies in the middle of the reactivity series, is moderately reactive. It is usually present in sulfides or carbonates.

Roasting: the process of heating sulfide ore at high temperatures in the excess of air.

Calcination: the process of heating carbonate ores, at an optimum temperature in the absence of air.

1. Zinc blend is roasted at ${800}^{°}\mathrm{C}$, to obtain Zinc oxide. $\underset{(Zincblend)}{\underbrace{2ZnS\left(s\right)}}+3O_2\left(g\right)\stackrel{{800}^{\circ }C}{\to }\underset{(Zincoxide)}{\underbrace{2ZnO\left(s\right)}}+2S{O}_2\left(s\right)$
2. Calamine is calcinated to obtain Zinc oxide.

$\underset{Calamine}{\underbrace{ZnC{O}_3\left(s\right)}}\stackrel{∆}{\to }ZnO\left(s\right)+C{O}_2\left(s\right)$

3. Now zinc oxide and coke are heated in a retort to get Zinc.

$ZnO\left(s\right)+C\left(s\right)\stackrel{{1400}^{\circ }C}{\to }Zn\left(s\right)+CO\left(g\right)$

Hence this is how we could obtain Zinc from Zinc oxide ore.