STUDY ON FLOTATION OF SILLIMANITE USING PLANT-BASED COLLECTOR

The coastal lines of India are rich in placer deposits of valuable heavy minerals such as ilmenite, garnet, rutile, zircon and sillimanite. The conducting and magnetic minerals are separated first, leaving behind the non-conducting and non-magnetic sillimanite along with quartz in the processing of heavies in beach sand. Sillimanite, an important mineral for refractory application is mainly recovered by flotation technique from its associated major gangue mineral, quartz by imparting selective surface hydrophobicity on sillimanite using a suitable collector. A placer sample after the removal of heavies from eastern coast of India was studied for beneficiation using froth flotation technique. Detailed characterization studies of the feed sample and the types of collectors used for this study have been carried out using XRD and FTIR analyses. Sillimanite feed sample assaying 55.4% sillimanite along with 33.9% quartz, 1.7% magnetics, 1.4% rutile, 2.4% zircon, 5.6% kynite was subjected to beneficiation using flotation technique for enriching the sillimanite content using oleic acid and a plant-based reagent SFA as collector. The effect of variation of input parameters such as pH, depressant and collectors were evaluated and flotation process optimization was carried out. Based on the results, it was found that flotation performance of the natural source based collector has better selectivity and improved recovery as compared to that of oleic acid as collector. Weight recovery of 67.8% with 85.1% sillimanite was obtained using the plant-based collector while a weight recovery of 55.5% with 84.9% sillimanite was obtained using oleic acid. The improved sillimanite recovery by using the plant-based collector than that of the conventional oleic acid would be more economical in industrial scale sillimanite recovery in beach sand processing industries