Beneficiation of low grade chromite for preparation of charge-chrome

Abstract

Low grade chromite samples from rejected dumps and over-burdens were taken for beneficiation study to produce a material suitable for charge-chrome preparation. The chromite samples with about 25% Cr2O3 in average, are ferr-uginous, but non-magnetic and contain 30-40% Fe2O2 SiO2 content is significantly low. low. Limonite, followed by laterite, is the main gangue material. In general, the fraction between 0.5 mm and 0.045 mm size is richer in Cr203 than the both +0.5 mm and —0.045 mm fraction. A process involving (i) crushing to —1 mm size, (ii) desl-iming and rejection of the slime, (iii) sieving at 0.2 mm and (iv) tabling of the — 0.2 mm fraction, has been found to be successful to produce a material with Cr203 content around 44%, raising the Cr203lFe203 ratio from 0.6 to above 2.2. The process is a low cost oriented one and the beneficiated Product satisfies the requirements for chrom-ite used for preparation of charge-chrome.