Electrokinetics involves the movement of charged particles or water molecul
es in an applied dc field. Applications in particle-fluid systems include t
he dewatering of soils, the densification of mill tailings and the treatmen
t of coal wastes. In this paper, a novel application of this technique is d
iscussed, wherein an electric field is applied to a coal-water slurry flowi
ng through a pipe, resulting in lower pressure losses in the system. A uniq
ue experimental setup was designed and built to study the effect of an elec
tric field (dc) on the wall shear stress for the flow of coal-water slurry
through the pipe. The effect of solids concentration, current strength and
pH on drag reduction across the system was quantified.