The term smelting refers to the bulk production of the major metal bearing liquid phase as one of the process steps during the pyrometallurgical production of Metals
Smelting of nonferous sulphide ore concentrates to liquid metals is now predominately performed by either of two methods.
Flash smelting is a process in which fine powder of the sulfide together with an air/oxygen mixture are injected into the top of a large shaft. The subsequent combustion of a proportion of the sulfur content results in autogeneous production of a liquid matte phase containing the major part of the metal, and a liquid oxide (slag) phase bearing the impurity oxide content of the concentrate. The liquid matte and slag are collected at the bottom of the shaft.
Bath smelting is a process in which fine powder sulfide is fed directly into a liquid matte bath, which is agitated by injection of air/oxygen.
In smelting iron and steel and zinc and lead, the oxide bearing the metal is reduced to metal with carbon (in the form of coke) in a shaft furnace (known as a blast furnace). The carbon also acts as a fuel and its combustion leads to the production of Carbon Monoxide and Carbon Dioxide. This provides both the reducing atmosphere and the heat required for the production of a liquid metallic phase and a liquid oxide (slag) phase bearing the oxide impurities of the concentrate.
In aluminum smelting the reduction of aluminum oxide is performed electrochemically by the Electrolysis of Al2O3 dissolved in a liquid fluoride flux.
Davenport, W. and Partlepo, G. (1987) Flash Smelting, Pergamon Press.
Peachey, J. and Davenport, W. (1978) The Iron Making Blast Furnace, Pergamon Press.
George, D. B., Sohn, H. Y., and Zunkel, A., Eds. (1983) Advances in Sulfide Smelting, TMS-AIME, Warrendale, PA, USA.
Gojtheim, K. (1979) Aluminium Electrolysis, Springer Verlag.