STRUCTURIZATION OF SALINE CLAY DISPERSIONS FLOCCULATED BY POLYACRYLAMIDE

Abstract

Under the laboratory conditions, processes of flocculation, phase separation and structurization of saline clay dispersion have been simulated and investigated. Effect of polymer (polyacrylamide) introduced at flocculation stage on properties of final products was studied. It has been found that at polymer concentrations of 0.01–0.2 mg/g, solid phase density and dewatering capability of flocs increase 1.4–1.6 times. Strength yield stress and optimal granules size have a maximum at polyacrylamide concentration of 0.2 mg/g of the disperse phase. Introduction of polyacrylamide into saline clay dispersion during structurization step reduces yield stress, density and plasticity 1.4–1.7 times, compared to adding the polymer at flocculation stage. This could be explained by adsorption of polymer macromolecules on the clay particles during flocculation step, to form bridges, whereas during structure formation step polymer binds larger clay aggregates and the strength of such contacts is weaker.
Results of the study allow to estimate a concentration range of polymeric flocculant which provides optimal parameters of the studied processes and properties of the final products. The results are used in the complex recycling technology of clay-containing wastes of potash production.