Question

difference between Calcination and Roasting​

Answer 1

Answer:

Roasting vs Calcination

Roasting-One is heated in the presence of excess of oxygen or air.

Calcination- one is heated in the absence or limited supply of oxygen or air.

Roasting- This method is employed for sulphide ores.

Calcination- This method is employed for carbonate ores.

Roasting- Sulphur dioxide is produced along with metal oxide.

Calcination- Carbon dioxide is produced along with metal oxide.

Roasting - Example: For the ores ZnS (sphalerite) and Cu2S (chalcocite), balanced equations for the roasting are:

2ZnS+3O2-->2 Zno+ 2SO2

2 Cu2S + 3O2 → 2 Cu2O + 2 SO2

Calcination- Example: ZnCO3--> ZnO+ C02

Answer 2

CALCINATION IS THE PROCESS OF HEATING CONCENTRATED ORE IN THE ABSENCE OF AIR AT A TEMPERATURE BELOW ITS MELTING POINT.CARBONATES AND HYDROXIDES OF METALS DECOMPOSE TO FORM OXIDES.

ROASTING IS THE PROCESS OF HEATING CONCENTRATED ORE IN A CURRENT OF AIR AT A TEMPERATURE BELOW ITS MELTING POINT.WHEN THE CONCENTRATED ORE IS SUBJECTED TO ROASTING ,THE MOISTURE PRESENT IN IT IS REMOVED AS VAPOUR.