EFFECT OF OXIDATION ROASTING ON ILMENITE FLOTATION

In this study, the oxidation roasting was used to modify the ilmenite chemistry to improve the collector adsorption and ilmenite flotation behavior. The results indicated that the increase of the roasting temperature up to 600 degrees C increased the ilmenite flotation recovery. The maximum collector adsorption density occurred on ilmenite roasted at 600 degrees C which resulted in the increase of ilmenite flotation recovery from 73.5% to 91% at pH 6.3. This improvement was attributed to a greater conversion of Fe2+ to Fe3+ ions and significant decrease in the zeta potential of ilmenite. At the roasting temperatures of 750 degrees C and 950 degrees C, ilmenite was converted to rutile and some trivalent iron containing phases such as hematite and pseudobrookite. Under these conditions, the collector adsorption and hence ilmenite flotation improved, however the flotation recovery decreased after the roasting at 950 degrees C.