Preparation of high-concentration coal-water slurry based on the bearing model method of spherical particles

Abstract

ABSTRACT Coal-water slurry (CWS), a mixture of pulverized coal, water, and additives, is a clean liquid coal-based fuel for gasification. Superhydrophobic surface modification using a secondary particle-second liquid system is an effective CWS preparation method. In this study, the effect of the sphericity of the secondary particles on the rheological properties of CWS samples was investigated. Spherical secondary particles were found to roll in the film layer of the second liquid, resulting in a lower apparent viscosity of the CWS. The bearing model refers to the spherical secondary particle on the surface of the coal particle, similar to the balls in a bearing, which can transform sliding friction into rolling friction. The bearing model can effectively reduce frictional resistance. By modifying the coal particles with the suspension of secondary particles in the second liquid, a 73% CWS sample with good fluidity was prepared. The apparent viscosity of the 73% CWS prepared without any modification of the coal particles was 13,329.2 mPa·s, and the flow grade was C. The apparent viscosity of the 73% CWS prepared using coal particles modified with the spherical glass bead suspension was 2102.8 mPa·s, and its flow grade was A.