Effect of Particle Size Distribution (PSD) on the Rheology of Coal Water Slurry (CWS)

Abstract

A new type of complex fluid, which was prepared using Sodium Lignosulfonate as a polymeric additive, has been investigated for its properties as a multifunctional coal water slurry system with respect to particle size distribution and rheological properties. Coal water slurry is a double-phase system consists of fine coal particles suspended in water. The properties mainly depend on the physical and chemical characteristics of coal, additives and flocculation tendency. This research article investigates the particle size distribution and rheology of the slurry formulated by adding Sodium Lignosulfonate to examine the stability parameters. The viscosity of the fluid also depends on various factors like the rank of coal used in the formulation of the slurry. Studies show that these slurries exhibit shear-thinning (pseudoplastic) behaviour. Particle size distribution and rheological properties play a major role in controlling fluid efficiency and transportation ability and pumpability. It is a well-known fact that fine solids are more comfortable to transport in pipelines in slurry form than the coarse solids. If the solids present in the slurry are too small or too large, the energy requirements for transporting it in pipelines may increase significantly. The effect of particle size distribution, and Sodium Lignosulfonate as the dispersant, on the viscosity of the slurry, have been studied in the present work. It was found that along with shear thinning characteristics, the thixotropic nature of the fluid also increased with the addition of a small amount of Sodium Lignosulfonate.