Abstract

Selenium, the 30th most abundant element, lies between sulfur and tellurium in Group 16 (IVA) of the Periodic Table. There are no ores mined for selenium value. Rather, selenium is recovered throughout the world as a by-product in the refining of sulfide-bearing copper minerals. Those processes are discussed.

The chemical and physical properties of selenium are often similar to those of sulfur but are sufficiently different to account for specialized industrial applications. Both inorganic and organic compounds are known. Principal markets for selenium include those as decolorizing agents in glass, photoreceptors for xerography, stable high temperature pigments, free machining additives for steel and brass, and as a nutritional additive to animal and human diets. Selenium deficiency occurs in some parts of the world and diseases relating to this deficiency have been discovered.