What is the name of the process that converts sulphide ores into oxides by heating strongly in the presence of excess air ?

Roasting is the metallurgical process where concentrated sulphide ores are converted into metal oxides by heating them strongly below their melting point in the presence of excess air [1]. This process is a solid-gas thermal reaction that facilitates the removal of volatile impurities like sulphur, which is released as sulphur dioxide gas. For example, zinc sulphide (ZnS) reacts with oxygen to form zinc oxide (ZnO) and sulphur dioxide. In contrast, calcination involves heating ores (typically carbonates or hydroxides) in the absence or limited supply of air to remove moisture and volatile matter. Smelting is a broader reduction process often involving a furnace to extract the base metal, while incineration refers to the combustion of waste materials [1]. Therefore, roasting is the specific term for the oxidation of sulphide ores in excess air.

Sources

1. [1] https://sathee.iitk.ac.in/ncert-books/udaan/udaan-che-12/chem-12-unit-06-general-principles--processes-of-isolation-of-elements/