Chem que 6.

Solution:
Pyrometallurgy is the process of extraction and purification involving the application of heat.

2AgCl + Na₂​O + SiO₂​ $\stackrel{}{\to }$ Ag_2​O+2NaCl+SiO₂​
Ag_2​O $\stackrel{}{\to }$2Ag+ 1/2 O₂​
Option (3)