Flotation Kinetics of Sillimanite and Garnet

Abstract

Sillimanite is being produced from the heavy mineral beach sands at Orissa Sands Complex, Orissa, India (M/s. Indian Rare Earths Limited) by flotation using oleic acid as collector. It was found that garnet inevitably contaminates sillimanite mineral concentrate. A study was made on the flotation kinetics of different natural grain sizes of sillimanite and garnet for better understanding and control of the flotation process to separate these two minerals more efficiently. Kinetic data on different grain sizes of sillimanite indicate that it follows the non-integral-order rate equation and the rate constant was 0.0704 min-1 and similar studies on garnet indicate that its flotation process can be assimilated in the first order rate equation and the corresponding rate constant was found to be 0.0347 min-1. The study shows that the rate constants for each of the sizes considered for both sillimanite and garnet were found to be different under the same experimental conditions and that sillimanite floats much faster at all the natural grain sizes, twice as fast as garnet.