Selective flotation of phosphates from dolomite using cationic collectors. Part II. Effect of particle size, abrasion and pH

Abstract

Flotation behavior of apatite and dolomite, both of crystalline and sedimentary varieties, was studied using an octadecylamine-kerosene mixture. In a single mineral flotation, dolomite floated better than apatite. When dolomite was mixed with apatite and conditioned at high-percent solids, apatite floated preferentially to dolomite. Pulp density in conditioning played a role in inducing the selectivity of separation. Crystalline and sedimentary minerals behaved alike, but the crystalline minerals had much lower surface areas and consumed less collector than the sedimentary minerals. Both minerals approached respective equilibrium pH values upon addition of acid or alkali. Their flotation behaviors were relatively insensitive to the pulp pH. Electrophoretic mobility measurements suggest that the electrostatic model of adsorption of aminium ion in these minerals may not fully account for the foregoing flotation behavior.