Cobalt(II) oxide

UsesCobalt(II) oxide is used as a pigment for ceramics and paints; for drying paints, varnishes and oils; for coloring glass; as a catalyst; and for preparation of other cobalt salts. The commercial product is a mixture of cobalt oxides.

DescriptionThis is obtained as an olive-green powder by heating the metal in air or steam or by thermal decomposition of the hydroxide, carbonate or nitrate. It has the sodium chloride lattice and is antiferromagnetic below 292°K. When heated in oxygen above 400° the black oxide Co3O4 is obtained. This oxide is isomorphous with magnetite Fe3O4, and has tetrahedrally surrounded cobalt(II) ions and octahedrally surrounded cobalt(III) ions. Both these oxides are readily reduced to the metal by heating in hydrogen or with carbon. The reactions of CoO with silica, alumina and zinc oxide are used to form pigments in the ceramic industry.

UsesIn pigments for ceramics; glass coloring and decolorization; oxidation catalyst for drying oils, fast-drying paints and varnishes; preparation of cobalt-metal catalysts, Co powder for binder in sintered tungsten carbide; in semiconductors.

UsesCobalt oxide, typically 3.4-4.5%, Molybdenum oxide typically 11.5-14.5% on alumina is used in the preparation of biofuel production by using algae.