Study on Flotation of Sillimanite Using Plant-Based Collector

Abstract

The coastal lines of India are rich in placer deposits of valuable heavy minerals such as ilmenite, garnet, rutile, zircon, and sillimanite. 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, and 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 collectors. The plant-based collector, i.e., Sillimanite Flotation Agent (SFA), is a natural extract. The effect of variation of input parameters such as pH, depressant dosage, and collector dosage were evaluated, and flotation process optimization was carried out. Concentrate weight recovery of 67.8% with 85.1% sillimanite was obtained using the plant-based collector SFA, while a weight recovery of 58.5% with 79.9% sillimanite was obtained using oleic acid from feed of 55.4% sillimanite. The recovery of the sillimanite was found to be maximum at depressant (sodium silicate) dosage of 0.5 kg/t and collector (SFA) dosage of 1.5 kg/t at pH 8.0. Based on the results, it was found that flotation performance of the natural plant-based collector SFA has better selectivity as compared to that of oleic acid.