Question
Answer the following question:
What is the difference between calcination and roasting?
What is the difference between calcination and roasting?
| Calcination | Roasting |
| 1. The ore is heated in the absence of air. | 1. The ore is heated in excess of air. |
| 2. Moisture and organic impurities are removed and the ore becomes porous and more reactive. | 2. Volatile impurities are removed as oxides $(SO_2, P_2O_5, As_2O_3)$ and the ore becomes porous and more reactive. |
| 3. Carbonate and hydrated ores are calcined and $CO_2 $or water vapour is given off. $ZnCo _3 \longrightarrow ZnO + CO _2$ | 3. Sulphide ores are roasted, so $SO_2$ is given off.$2 ZnS +3 O _2 \xrightarrow{800^{\circ}-900^{\circ} C } 2 ZnO +2 SO _2$ |
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.