chromium processing, preparation of the ore for use in various products.
Chromium is a brilliant, hard, refractory metal that melts at 1,857 C (3,375 F) and boils at 2,672 C (4,842 F). In the pure state, it is resistant to ordinary corrosion, resulting in its application as an electroplated protective coating for other metals. It dissolves in nonoxidizing mineral acids but not in aqua regia or nitric acid, which passivate the metal.
Because chromium and chromium-rich alloys are brittle at room temperature, they have limited application. By far the largest consumption is as an alloying addition to iron. In amounts varying from 10 to 26 percent, chromium imparts corrosion resistance to steel; it is also used to improve hardenability, wear-resistance, and high-temperature strength.
As the mineral chromite, chromium is employed extensively as a refractory material. Other chromium chemicals are used as pigments and tanning agents.
Mining and concentrating
Chromite deposits are mined by both underground and surface techniques. Much of the ore is rich enough to be used directly: for production of ferrochromium, a rich, lumpy ore containing more than 46 percent Cr2O3 and having a chromium-iron ratio greater than 2:1 is preferred, but ores with a lower ratio and as little as 40 percent Cr2O3 are also used. (Ores high in alumina are preferred for processing into refractory brick.) As finely divided ores, which do not smelt efficiently, come under greater exploitation, a number of processes are employed to agglomerate them for more satisfactory use in furnaces. Fines can be blended with fluxes and coke (the principal source of carbon) and then preheated or prereduced before being charged into an electric smelting furnace.
Chromium Processing Equipment
Cone crusher for Chromium ore processing: Cone crusher is the chrome ore crushing machine used in chrome processing plant. hydraulic cone crusher gets to world advanced level, which is designed and made through absorbing world advanced crushing technology. It is widely used in metallurgical, aggregate, building material industries. It is suitable for crushing varies of hard and above mid hard ores and rocks.
