The influence of surface phenomena on the dewatering of fine clean coal

Abstract

The paper presents results of experimental work carried out to study the role of surface active agents in the dewatering of fine clean coal. The fundamental phenomena which determine their mode of action are examined, and the mechanism of surfactant-enhanced dewatering is investigated in terms of the surface chemical phenomena and the physical processes involved in the dewatering. The performance and possible mode of action are compared between two surfactant dewatering aids. The results of dewatering experiments show that the presence of the sodium dodecyl sulphate leads to a very significant reduction in the final residual cake moisture content, A direct and strong correlation exists between the point of zero charge, surface tension reduction In the coal system and residual moisture reduction in the filter cake. These improvements are attributed to the changes in the wetting characteristics of the coal particles in the presence of effective dewatering aids.