COMMERCIAL EXTRACTION TECHNOLOGY AND PROCESS WASTE DISPOSAL IN THE MANUFACTURE OF CHROMIUM CHEMICALS FROM ORE

Abstract

Chromite refers to the mineral (Mg, Fe) (Al, Cr, Fe)2O4in which the chromicoxide content varies typically between 15 and 65%; iron exists in both di andtrivalent states; minor compounds of significance are silicates and oxides of vana-dium. Not all chromites are true spinels; some are a mixture of spinel and corundumoxides (Cr2O3,Fe2O3). The challenge for the chromium chemicals industry hasalways been to find the most effective way of using available raw materials toconvert the chromium contained in this relatively unreactive mineral into a rangeof products of the purity required by user industries. Commercial production isvia sodium chromate or more typically via the dichromate to give the range ofhexavalent or trivalent chromium compounds.