Question

Explain the following terms used in metallurgy. Roasting

Answer 1

1. Metallurgy

Metallurgy is the field of science and technology that deals with the commercial production of metals from their ores and further modifying the required metals. It follows the series of metallurgical steps.

2. Roasting

Roasting is the process of heating ores in the presence of an excess of air or oxygen to produce their respective metal oxides. An example of roasting is:

Zinc blende (ZnS), on heating with an excess of air, gives Zinc oxide (ZnO) and Sulphur dioxide $\left({\mathrm{SO}}_2\right)$.

$$\begin{gathered} 2\mathrm{ZnS}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{heat}}{\to }2\mathrm{ZnO}\left(\mathrm{s}\right)+2{\mathrm{SO}}_2\left(\mathrm{s}\right) \\ \left(\mathrm{Zinc}\mathrm{sulphide}\right)\left(\mathrm{Oxygen}\right)\left(\mathrm{Zinc}\mathrm{oxide}\right)\left(\mathrm{Sulphur}\mathrm{dioxide}\right) \end{gathered}$$