RHEOLOGY OF VERY CONCENTRATED COAL SUSPENSIONS

Abstract

Non-Newtonian viscosity curves of coal slurries were measured over a 3-5 decade shear rate range with a Weissenberg Rheogoniometer, for coal volume fractions up to 0.6 and particle sizes under 62 fim. Suspending media were Aroclor 1254 (a chlorinated biphenyl), glycerin, and glycerin with surfactant; these have densities very close to that of coal, so no settling occurred. Viscosity magnitudes generally exceeded predictions of correlations and theory established for spherical particles; explanations are sought in terms of particle aggregation, shape irregularity, and surface effects.