Study on Flotation of Sillimanite Using Plant-Based Collector

Abstract

In India, the heavy mineral beach sand carry minerals like ilmenite, garnet, rutile, monazite, sillimanite, and zircon. The west coast of Kerala, the east coast from Tamil Nadu to Odisha contains heavy mineral (ilmenite) rich beach sand deposits. These ilmenite samples of Indian origin has 50-60% ofTiO2 and is most suited for beneficia­tion by different processes. Also minerals such as monazite, sillimanite, and zircon are present in inland red Teri sands, apart from heavy mineral beach sands and has high potential for beneficiation. 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. The placer minerals of 348 Million tons (Mt) ilmenite, 107 Mt garnet, 21 Mt zircon, 18 Mt monazite, and 130 Mt Sillimanite are present in Indian resources. About 35% of world resources are contributed from India. The heavy mineral sands are basically sedimentary deposits of dense minerals which pile up with sand, silt, and in association with clay along the coastal line, leading to economic concentrations of these heavy minerals [1-5]. 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. Sillimanite is a non-conducting and non-magnetic mineral and hence flotation technique was of valuable minerals from its accompanying gangue minerals. Flotation process have been effectively used for fines and size of the sillimanite mineral present in the heavy mineral beach sand is most appropriate to be processed by flotation. In any separation process based on flotation, the flotation reagents added in order to modify/enhance the surface hydrophobic nature of the minerals intended to be separated and hence the appropriate selection of reagent plays a vital role in the efficiency of the flota­tion technique. Apart from the reagent selection, the dosage of the reagents added in the flotation circuits needs to be optimized for the required grade and recovery. Flotation studies on sillimanite by flotation column on Odisha sands were carried out using oleic acid as collector [6-14]. Recovery of sillimanite by flotation tree analysis method and conventional flotation technique from the non-magnetic product of red sediments were also studied. Also, some investigation on flotation of sillimanite at acidic pH were reported. In this work, one such Indian beach placer sample has been attempted for bene­ficiation using flotation method. In preliminary flotation studies, pH and depressant dosage were varied to establish the optimized process criteria. lypes of collectors used for flotation studies are oleic acid and plant-based collector SFA. Flotation of sillimanite sample was optimized by studying various process parameters. Silli­manite feed sample, collectors, and concentrate obtained from optimized set have been characterized using X-ray diffraction (XRD) and Fourier-transform infrared (FfIR) spectroscopy.