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Metal Production

Alloys

Pure metals themselves are often not satisfactory for many practical applications. For example, pure gold is too soft for most uses and is combined with other metals to form harder, more resistant mixtures. Mixtures that contain two or more metals are known as alloys. Perhaps the best known and most widely used of all alloys is steel.

The term steel refers to a number of different substances that contain iron as their major component along with one or more other elements. Stainless steel, as an example, contains about 18% chromium, 10% nickel, and small amounts of manganese, carbon, phosphorus, sulfur, and silicon, along with iron. When niobium is added to a steel alloy, the final product has unusually great strength. The addition of cobalt produces a form of steel that withstands the high temperatures of jet engines and gas turbines, and silicon steels are used in making electrical equipment.

In the final stages of metal production, the finished product is formed into some shape that can be used in other industries to make final products. Thus, steel can be purchased in the form of flat sheets, rings, wire rope and thread, slabs, cylinders, and other shapes.

See also Metallurgy.


Resources

Books

Braungart, Michael and William McDonough. Cradle to Cradle: Remaking the Way We Make Things. New York: North Point Press, 2002.

Engh, T. Abel. Principles of Metal Refining. New York: Oxford University Press, 1992.

Klein, C. The Manual of Mineral Science. 22nd ed. New York: John Wiley & Sons, Inc., 2002.

Metals & Minerals. 2 vols. New York: Gordon Press, 1992.

Patterson, James W., and Roberto Passino, eds. Metals Speciation, Separation and Recovery. Vol. 2. Boca Raton, FL: Lewis Publications, 1990.


David E. Newton

KEY TERMS

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Alloy

—A mixture of two or more metals with properties distinct from the metals of which it is made.

Bayer process

—A process in which sodium hydroxide is added to a mixture of naturally occurring oxides so that aluminum oxide is dissolved out of the mixture.

Hall process

—A process for the production of aluminum metal by passing an electric current through a mixture of aluminum oxide dissolved in cryolite (sodium aluminum fluoride).

Noble metal

—A metal that does not readily react with other elements and that, therefore, normally occurs in nature in a free, or uncombined, state.

Ore

—A compound of a metal from which the metal can be extracted at an economically feasible cost.

Reduction

—The process by which an atom's oxidation state is decreased, by its gaining one or more electrons.

Additional topics

Science EncyclopediaScience & Philosophy: Mathematics to Methanal trimerMetal Production - Mining, Purification, Reduction, Alloys