The methods chiefly used for the extraction of lead and tin from their ores are respectively _________________.

The methods chiefly used for the extraction of lead and tin from their ores are respectively self reduction and carbon reduction. Self reduction for lead is as follows.
$2PbS+3O_2\to 2PbO+2S{O}_2\uparrow$
$PbS+2O_2\to PbS{O}_4$
$2PbO+PbS\to 3Pb+S{O}_2\uparrow$
$PbS{O}_4+PbS\to 2Pb+2S{O}_2\uparrow$
Carbon reduction for tin is as follows.
$Sn{O}_2+2C\to Sn+2CO\uparrow$