Chrome

(Cr) Atomic Number 24

Chrome is the twenty first most abundant element in the Earth’s crust, its name is derived from the Greek word Chroma to mean colour due to the many colourful compounds made from it. Chrome does not occur free in nature, rather as the mineral Chromite. Chromite ore was first discovered in the Ural mountains of Russia in 1778 and chrome metal was subsequently isolated by Nicholas Louis Vauquelin in Paris, France in 1797. Initially it was incorrectly identified as being a lead compound due to its metallic red appearance. South Africa has 90% of the world’s economic chrome reserves and produces over 50% of the world's Chromite. Other producers are Kazakhstan and India with increasing amounts being produced in Turkey.

Properties of Ferro Chrome

Over 80% of the world’s ferro chrome is utilised in the production of stainless steel, which is defined as a steel alloy with a minimum of 10% chrome by content, the average chrome content being 18%. Stainless steel depends on chrome for its appearance and its corrosion resisting properties. High Carbon Ferro Chrome is most commonly used in specialist applications such as engineering steels. Lower carbon ferro chromes are produced in smaller quantities for more specialised applications. A full list of the ferro chrome grades supplied by Westbrook Resources Ltd including Nitrided Ferro Chrome can be found in the adjacent tables.

Production of Ferro Chrome

The two main products of chromite refining are Ferro Chrome and Chrome Metal. For the production of Ferro Chrome the chromite ore is reduced, usually by coal and coke in a high temperature reaction to form the iron-chrome alloy. For production of pure chrome the iron has to be separated from the chrome in a two step roasting and leaching process. Over 80% of the world’s ferro chrome is utilised in the production of stainless steel, which is defined as a steel alloy with a minimum of 10% chrome by content, the average chrome content being 18%. Stainless steel depends on chrome for its appearance and its corrosion resisting properties.