AN IMPROVED DEWATERING PROCESS FOR ULTRAFINE IRON ORE SLIME OF SIZE LESS THAN 10 MICRON TO ACHIEVE A MOISTURE CONTENT IN ULTRAFINE IRON ORE SLIME CAKES, TO 20 (BY WEIGHT)

摘要

The invention relates to an improved dewatering process for ultrafine iron ore slime of size less than 10 micron to achieve a moisture content in ultrafine iron ore slime cakes, to 20% (by weight), the process comprising the steps of conducting a thickening process where optimized dose of cationic coagulant followed by anionic clocculant is added and mixed to form a slurry (5 wt% of solid) inside a hi-rate thickener and allowing the slurry to settle for a specific time for producing a thick slurry in the underflow and a clear water in overflow; subjecting the underflow from the hi-rate thickener to a filtration unit for producing a cake containing 80% moisture content; conditioning the slurry in an agitator for 10 minutes before transferring the conditioned slurry to said hi rate thickener; operating the hi-rate thickner under optimum operating parameters consisting of coagulant dosing at the rate of 200 gm/ton, flocculant dosing at the rate of 30 gm/ton and a lime dosing maintaining 7.0 pH value of the slurry, settling the slurry initially @ 24.66 m/hr; setting the slurry further for a period of 10 minutes for determining the moisture content of thickened slurry; subjecting the thickened slurry if the moisture content of the slurry by wt% is about 41:7 to a filtaration unit for achieving 20% moisture content of the final product.