Question

distinguish between roasting and calcination? which of the two is used for sulphide ores and why?

Answer 1

ROASTING --> it used in excess of air , it is used for sulphide ore, SO2 is produced with metal oxide like PbS+O2-----> PbO+SO2 .

CALCINATION---> it is used in limited or absence of air , it used for carbonate and bicarbonate ore, CO2 gas form with metal oxide like ZnCO3---∆----> ZnO+CO2