Difference between Roasting and calcination
Difference between Roasting and calcination are in tabular form below –
Roasting |
Calcination |
1) The procedure of heating the ore in the existence of air to a high temperature so as not to melt it is called as roasting. | 1) It is procedure of heating the ore to a high temperature in the nonexistence of air, or where air does not play a part in in the reactions. |
2) Usually sulphide ores are roasted. | 2) Usually carbonate ores containing water are calcinated |
3) It requires excess amount of air or oxygen. | 3) Done at limited air or oxygen. |
4) Roasting process released toxic gaseous. | 4) Calcination releases toxic and volatile compounds |
5) So2 is produced along with metal oxides. | 5) CO2 is produced along with metal oxide. |
6) Sulphide ore are converted into oxides | 6) Carbonate ores are converted into oxides |
7) The impurities of p, as and S are removed as their oxides which being volatile, escape as gaseous. | 7) The presence of Organic matter in the ore, gets excluded and the ore become porous. |
8) It is done in reverbratory furnace but the holes of the furnace are kept open to allow the entry of the air into the furnace. | 8) It also done in revebratory furnace, the holes of the finance are kept closed. |
9) Oxygen is consumed the reaction | Oxygen is not consumed in the reaction |
10) It is applied to sulphide ores. | It is applied to hydrated oxides, hydroxide and carbonates. |
11) Examples of roasting-
ZnCo3 →ZnO(s)+ Co2(g) |
Example of calcination:
2Pbs + 3O2 → 2Cu2O + 2SO2
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