Question

giving examples differentiate between roasting and calcination?.

Answer 1

Calcination- Changing of carbonate ores into oxides
Ex.- ZnCo3--->Zno+Co2

Roasting- Changing of sulphide ores into oxides 
Ex.- ZnS+O2------>ZnO+SO2

Calcination happens in the presence of heat but absence of air whereas roasting happens in the presence of heat and excessive air
(NOTE:--equations are not balanced)

Answer 2

heating in the presence of oxygen is known as roasting 
example - 2FeS + 3O2 → 2Fe + 2SO2

heating in absence on oxygen is known as calcination
example - CaCO3 → Cao + CO2.


     hope this helps u......