Thermodynamics of Polymeric Flocculant adsorption on Hematite and other Mineral Surfaces

Abstract

Organic macromolecules are widely used as flocculant in waste water treatment and in mineral beneficiation. Their selection for beneficiation requires adsorption of these molecules through chemical interaction and hydrogen bon-ding. The factors which affect their adsorption are dis-cussed in this paper. Thermodynamic measurements of the adsorption of starch on hematite surface has shown their specificity in adsor-ption. Role of chemical complexes formed at the mineral surface has been highlighted. Computation of N-I from the adsorption isotherms at different temperatures using Clausis-Clayperon equation, in this case, is not valid because the starch molecules get adsorbed on the surface by specific (chemical) means.