Question

Define calcination and roasting. Give one example of each?

Answer 1

Calcination:

• The calcination process occurs in the absence of oxygen.
• It is the process in which the ore is heated to a high temperature below its melting point in the absence of oxygen
• Moisture is removed from the ore during the calcination process.
• Carbonate ores are calcified by this method like ZnCO₃

Roasting:

• The roasting process occurs in the presence of oxygen.
• The process in which the ores are heated below their melting point in the presence of oxygen.
• The impurities are oxidized to their volatile oxides while the moisture is removed from the ore.
• Sulfide ores are roasted by this method like ZnS.