Beneficiation of low grade Garnet sample from Nellore, Andhra

A low grade garnet sample from Nellore, Andhra, was received from M/S. Inden Biselers, Madras, with a view to upgrading it for abrasive purposes. As received, the sample contained 75% garnet. Almandite was the principal garnet mineral. Quartz and muscovite were the predominant gangue minerals. Tabling of -20 mesh sample after hydraulic classification followed by magnetic separation of table middling products, yielded a combined concentrate containing 92.5% garnet and 0.68% free gangue with an overall garnet recovery of 89%. Heating the concentrate to 700°C and 800°C for varying lengths of time improved the capillarity of the product considerably. The heat treated as well as unheated concentrates after sizing, have been sent to M/s. Inden Biselers, for finding out their suitability for abrasive manufacture, by service trials with the paper and cloth abrasives made with these concentrates.