An approach for recovery of iron values from slimes

In India iron ores processing industries play a vital role in Indian economy. During washing and processing of iron ores, slimes less than 0.15 mm are generated and discarded into the tailing pond. These slimes need processing as they cannot be used directly in blast furnaces. In the present investigation, typical iron ore slime sample containing 59.22% Fe, 4.76% SiO2 and 4.57% Al2O3 was taken. The desliming operation was carried out by using 2” Mozley hydrocyclone. The process variables used to attain the optimum condition of desliming include spigot opening, feed pressure and diameter of vortex finder maintaining the pulp density at 10% solid. The deslimed sample was treated by different techniques including enhanced gravity separator to achieve iron concentrate with 65% Fe so that it can be used for steel making through pelletization. The yield of the flotation concentrate is about 54% with 65% Fe. To improve the yield, the over flow from 2” hydrocyclone and the rejects from flotation were processed to recover the iron values. The final concentrate is 74% yield with 64.8% Fe, 1.7% SiO2 and 1.8% Al2O3.