1.
Main source of lead is galena. It is converted to Pb by:

(X) PbS+O2→PbO+SO2\text{PbS} + \text{O}_2 \rightarrow \text{PbO} + \text{SO}_2; PbO+C→Pb+CO2\text{PbO} + \text{C} \rightarrow \text{Pb} + \text{CO}_2

(Y) PbS+O2→PbO+PbS\text{PbS} + \text{O}_2 \rightarrow \text{PbO} + \text{PbS}; heating →Pb+SO2\rightarrow \text{Pb} + \text{SO}_2

(Z) PbS+O2→PbO+SO2\text{PbS} + \text{O}_2 \rightarrow \text{PbO} + \text{SO}_2; PbO+CO→Pb+CO2\text{PbO} + \text{CO} \rightarrow \text{Pb} + \text{CO}_2

Self-reduction process is:
d- and f-Block Elements - Medium - Question