There are about 50 kinds of ferrochromium found in nature, which belong to oxides, chromates and silicates. There are also a few hydroxides, iodates, nitrides and sulfides. Among them, chromium nitride and chromium sulfide minerals are only found in meteorite.
Ferrochromium chromium minerals with industrial value belong to chromium spinel minerals, and their chemical formula is (Mg, Fe2+) (Cr, Al, Fe3+) 2O4 or (Mg, Fe2+) O (Cr, Al, Fe3+) 2O3, its Cr2O3 content is 18% ~ 62%.
