THE INFLUENCE OF SURFACE PHENOMENA ON THE DEWATERING OF FINE CLEAN-COAL

The paper presents results of experimental work carried out to study t he role of surface active agents in the dewatering of fine clean coal. The fundamental phenomena which determine their mode of action are ex amined, and the mechanism of surfactant-enhanced dewatering is investi gated in terms of the surface chemical phenomena and the physical proc esses involved in the dewatering. The performance and possible mode of action are compared between two surfactant dewatering aids. The resul ts of dewatering experiments show that the presence of the sodium dode cyl sulphate leads to a very significant reduction in the final residu al cake moisture content, A direct and strong correlation exists betwe en the point of zero charge, surface tension reduction In the coal sys tem and residual moisture reduction in the filter cake. These improvem ents are attributed to the changes in the wetting characteristics of t he coal particles in the presence of effective dewatering aids.