The process described in the question is known as roasting. Roasting is a metallurgical process in which a sulphide ore, such as copper, lead or zinc sulphide, is heated strongly in the presence of excess air. This process aims to convert the sulphide ores into oxides by oxidizing the sulphur in the ores.

Option 1: Calcination is a similar process to roasting, but it involves the heating of carbonate ores instead of sulphide ores. Calcination is the process of converting carbonate ores, such as limestone or dolomite, into oxides by heating them strongly in the absence of air.

Option 2: Roasting is the correct answer as explained above.

Option 3: Smelting is a different process altogether. Smelting involves the extraction of a metal from its ore by heating it with a reducing agent, such as carbon, to remove the impurities and obtain the desired metal in its pure form.

Option 4: Incineration is the process of burning wastes to reduce their volume and eliminate any harmful substances. It is not related to the conversion of sulphide ores into oxides.

Overall, the correct answer is 2 - Roasting.