Selective flocculation separations involving hematite

Selective flocculation was investigated as a possible method of recovering values from mineral slimes which are too finely devided to be treated by conventional mineral processing methods. It has proved possible to selectively flocculate either hematite or a silicate from a stably dispersed mixture by varying the anionic character of the high molecular weight, partially hydrolyzed, polyacrylamide employed. Different separation methods have been developed for hard and soft water media. Electrokinetic and infrared techniques have been employed in the elucidation of the mechanism whereby selectivity has been attained in the different cases.