Chemistry - Metallurgy Question with Solution | TestHub

The ore Calamine contain ${\mathrm{ZnCO}}_3$. The Calamine on heating produces $\mathrm{ZnO}$.${\mathrm{ZnCO}}_3\stackrel{∆}{\to }\mathrm{ZnO}+{\mathrm{CO}}_2$

Cyanide process, also called Macarthur-forrest Process, method of extracting silver from impure ores by dissolving them in a dilute solution of sodium cyanide in the presence of oxygen. The complex formed in the above process reduced to silver metal by the treatment with zinc.

$$\begin{gathered} {\mathrm{O}}_2+{\mathrm{H}}_2\mathrm{O}+\mathrm{Ag}+\mathrm{NaCN}\stackrel{}{\to }\mathrm{Na}\left[\mathrm{Ag}{\left(\mathrm{CN}\right)}_2\right]+\mathrm{NaOH} \\ \mathrm{Na}\left[\mathrm{Ag}{\left(\mathrm{CN}\right)}_2\right]\stackrel{\mathrm{Zn}}{\to }{\mathrm{Na}}_2\left[\mathrm{Zn}{\left(\mathrm{CN}\right)}_4\right]+\mathrm{Ag} \end{gathered}$$

${\mathrm{SiO}}_2$​ (Silica) is a flux material. It removes impurities as slag. Here, slag consists of Iron in Sulphide ore of $\mathrm{Cu}$, here impurity is $\mathrm{FeO}$.

$\mathrm{FeO}+{\mathrm{SiO}}_2\stackrel{}{\to }{\mathrm{FeSiO}}_3$

Malachite green is ${\mathrm{CuCO}}_3.\mathrm{Cu}{\left(\mathrm{OH}\right)}_2$ and cuprite is ${\mathrm{Cu}}_2\mathrm{O}$. The ore malachite green on heating gives cupric oxide but not cuprous oxide.

${\mathrm{CuCO}}_3.\mathrm{Cu}{\left(\mathrm{OH}\right)}_2\stackrel{∆}{\to }2\mathrm{CuO}+{\mathrm{CO}}_2+{\mathrm{H}}_2\mathrm{O}$