Recovery of Iron Values from Waste Iron Ore Slime

Abstract

Iron ore slime is a waste material generated after beneficiation of iron ores. Due to limited iron ore resources and fast depleting of high grade iron ore, iron ore producers are emphasizing on recovery of iron values from iron ore slime. Different beneficiation techniques such as Hydrocyclone, Wet High Intensity Magnetic Separator (WHIMS), Dispersionflocculation, and Flotation are some options to recover the lost iron value from the waste. In the present work an attempt has been made, to beneficiate iron ore slime using Hydrocyclone, WHIMS and dispersion-flocculation. Iron ore slime (-150 μm) was obtained after scrubbing and wet screening of a low grade iron ore assayed 42.7% Fe with 12.5% Al2O3 and 13.68% SiO2. Size analysis revealed that 90% of the iron ore slime was having size less than 72 μm. The isoelectric point of the iron ore slime was found to be at pH 4.21.The optimum condition was applied for Hydrocyclone to obtain maximum recovery i.e., 89.2%. The cyclone underflow was enriched to 54.8% Fe with 45% recovery using WHIMS at current intensity of 2 Amp. Dispersion-flocculation could upgrade up to 47% Fe only. The nonmagnetic fraction of WHIMS was upgraded from 37 to ~39% Fe using dispersion-flocculation under the optimized condition