Study of rheological parameters due to coal particle size change in pipeline transported coal slurry

This article proposes using abrasion equilibrium equations for refining coarse-grained coal slurry hydrodynamic conveying, combining experimental data and theoretical analysis. It presents a particle refinement solution model and a viscosity prediction formula for mixed coarse and fine coal samples. Experimental data indicate that prolonged conveying time decreases coarse particle content and increases fine particles (< 0.074 mm), with a tendency for slurry viscosity to rise, though the rate of increase slows. Comparing predicted and measured particle refinement values showed a maximum deviation of 10% for 30 and 50-minute conveying times. Using the Herschel-Bulkley fluid model for viscosity prediction post-grading, verified with experimental data, the minimum viscosity value is observed at a 58% slurry concentration with varying coarse and fine coal ratios. The deviation between predicted and measured viscosity values is 5.23%, providing a formula for the viscosity reduction effect of blending.