General Smelting Processes

Pyrometallurgical technologies: use of heat to separate desired metals from unwanted materials by exploiting differences in oxidation potential, melting point, vapour pressure, density, and/or miscibility when melted.

Hydrometallurgical technologies: use of differences in solubility and/or electrochemical properties while in aqueous acid solution to separate desired metals from unwanted materials.

Vapo-metallurgical technologies: apply to the Inco Carbonyl Process. To refine impure nickel, alloys are treated with carbon monoxide gas to form nickel carbonyl gas, which is later separated into nickel metal powder and carbon monoxide gas.