Enhancing the flowability of limestone water suspension for economical transportation by variation in particle size distribution

Abstract

Hydrotransport is increasingly a popular technology due to its low specific energy consumption and nonpolluting nature. The current work presents a thorough characterization of a limestone sample to explore the influence of blending medium and coarse particles with fine particulate slurry on the rheology, slurryability, and stability of a limestone water suspension. Various bench-scale studies are performed to identify the physicochemical, morphological, and flow features of limestone samples. Eight separate bi-modal slurry samples are prepared using limestone materials with three unique particle size ranges (53, 53–75, and 75–106 µm). The rheological properties of the slurry are tested at shear rates ranging from 50 to 500 1/s, and regression analysis is used to determine the nature of the slurry. The solid concentration of the suspension sample ranges between 10 and 70% with a flow velocity range of 0.25–1.5 m/s through a 100 mm diameter pipeline. Finally, essential criteria such as apparent viscosity, settling properties, pressure drop, and specific energy consumption are used to determine the optimal particle size distribution. The ideal proportion of medium particles (53–75 µm) mixing in the fine particulate slurry suspension is 40%, while the fraction of coarse particles (75–106 µm) is 30% (by weight).