Chromium is the most abundant of the Group VIA family of metallic elements, comprising chromium, molybdenum and tungsten. At a concentration of nearly 400 parts per million in the earth's crust as various minerals, it is the 13th most common element.

Geology and Mineralogy
Chromium ore, or chromite, occurs exclusively in ultramafic igneous rocks.The chromium occurs as a chromium spinel, a complex mineral containing magnesium, iron, aluminium and chromium in varying proportions depending upon the deposit.
The chromium spinel is a heavy mineral and concentrates to form ore deposits by gravity separation as the molten magma cools.
Commercial chromite deposits occur mainly in two forms; stratiform deposits in layers in basin-like intrusions, and podiform or lenticular deposits.

Mining
Mining of chromite deposits is carried out both by open-pit and by underground mining. The most intensive mining is now in the Bushveld Igneous Complex in South Africa.
According to the United States Geological Survey, world resources of chromite exceed 11 billion tonnes, sufficient to meet world demand for many centuries.
South Africa and Zimbabwe hold about 90% of the world's chromite reserves and resources.
World production of chromite in 2008 was 24 million tonnes, with South Africa being the largest producer of both chromite and ferrochromium, followed by Kazakhstan and India. Other important countries with chromite deposits include Brazil, Finland, Russia, Turkey and Zimbabwe.

Ore Processing
Most of the world's production of chromite (95%) is converted into various ferrochromium alloys for use in the stainless steel and other alloy industries. The chromite is generally smelted in submerged arc furnaces, together with carbonaceous reductants and fluxes, although other technologies such as Direct Current (DC) arc furnace smelting are also in use. Agglomeration of the ore fines, especially those produced from South Africa's friable chromites, is an important aspect of processing prior to smelting. Pelletising of the fines is currently the preferred route. A wide range of possible technologies for smelting chromite to ferrochromium has been investigated. Stainless steel is produced from the ferrochromium alloys by melting the alloys in electric arc furnaces together with varying amounts of carbon steel and stainless steel scrap, and then adding nickel and other minor elements as required for the grade of stainless steel being produced.

Uses and Applications
Chromium is an extremely versatile element and finds a wide variety of uses in applications in the steel and alloy, chemical and refractory industries.
Of the world's total production of chromite, approximately 95% is smelted into ferrochromium alloys. These are for subsequent use in the stainless steel, steel and other alloy industries. Chromium metal, composed of nearly 100% chromium, is produced by the aluminothermic or electrolytic process. It is mainly used for specialty alloys. 2% of the world's production of chromite was used in 2008 for chromium chemicals.The primary product from the chromite is sodium chromate. From this, a variety of other chemical products are made and used, for example, for tanning leather, as coloured pigments in paints, plastics and ceramics, and metal finishing such as chromium plating. Production of chromite for refractory use and foundry sands is about 3% of world production of chromite. Refractory chromite is used in sectors of ferrous and non-ferrous metallurgy, in cement kilns and in the glass industry.