Integrated process for purification of low grade talc ores

Abstract

This study examines the development of an integrated process for separation and purification of low grade talc ores. This procedure involves leaching with HCl to dissolve gangue minerals and to purify a low purity talc ore containing up to 40% gangue minerals. Also, all cations from gangue minerals are recovered as hydroxides via selective precipitation. The effects of acid concentration, talc/acid solution ratio, time, and reaction temperature on talc purification were studied and the optimal conditions were determined. Laboratory-scale tests revealed that the resulting talc is free of gangue minerals, consisting of small particles with nanometric thicknesses. Reactants are fully consumed during dissolution and byproducts like ammonium chloride could be recirculated and reused. Resulting hydroxides can be used as a coagulation aid for water treatment.