Chromite is iron magnesium chromium oxide: (Fe, Mg)Cr2O4. It is an oxide mineral and majorly found in metamorphic rocks although its primary origin is ultra-mafic rocks. Ore deposits of chromite form as early magmatic differentiates. Chromite, as is indicated by its early crystallization is resistant to the altering affects of high temperatures and pressures.
PHYSICAL CHARACTERISTICS:
Color is brownish black to a deep dark black
Luster is metallic to greasy.
Transparency: Crystals are opaque.
Hardness is 5.5
Specific Gravity is 4.5 – 4.8 (average for metallic minerals)
Streak is brown.
Other characteristics: Weakly magnetic.
Industrial Uses :
The biggest use of Chromite ore is to make Ferrochromium, which is in turn used to make Steel. For the production of Ferrochromium the Chromite ore (FeCr2O4) is reduced with either Aluminium or silicon in a Aluminothermic reaction and for the production of pure chromium the iron has to be separated from the chromium in a two step roasting and leaching process. Chromite is also used as a refractory material, in the bricks and linings of blast furnaces, due to its high heat stability
