Characterization and processing of low-grade iron ore slime from the Jilling area of India

Abstract

Detailed characterization followed by beneficiation of low-grade iron ore slime from Jilling Langalota deposit, India, was studied. The work involved separating the gangue minerals viz. quartz and kaolinite to form iron-bearing minerals, mostly hematite and goethite, as identified using XRD analysis to produce a suitable concentrate for downstream processing. The feed slime sample assayed 37.86% total Fe, 19.08% silica, and 14.4% alumina. Detailed characterization data indicated that a substantial amount of the sample was below 20 mu m in size. The finer fraction contained larger amount of gangue while the coarser fraction was richer in iron. Considering the characterization data, two flowsheets were conceptualized for the beneficiation of the slime sample with two- and four-stage processing, respectively. In the two-stage operation, the grade of the slime could be improved to 60.26% Fe, 4.45% silica, and 3.98% alumina with an overall yield of about 20%. The results from the four-stage operation showed that it is possible to upgrade the iron value to 66.97% with a yield of 14.4% while reducing the silica and alumina content down to 1.7% and 1.52%, respectively. A simple flowsheet has been suggested to improve the yield substantially for the production of sinter/pellet grade concentrate from this slime.