Slurryability of direct coal liquefaction residue-water slurry

In this work, the slurryability of direct coal liquefaction residue (DCLR) was systematically studied, and the effects of particle size distribution (PSD), stirring time, dosage and types of dispersant on the quality of direct coal liquefaction residue-water slurries (DCLRWS) was investigated. The results show that the dispersancy of naphthalenesulfonate formaldehyde (NSF) is much better than that of sodium lignosulfonate (SL), while the rheology of DCLRWS dispersed by NSF is poorer, which is mainly related to chemical characteristics of SL and NSF and interaction between dispersant with particles. Based on the experiments, the optimum conditions for preparing DCLRWS are determined, as follows: particle size distribution of Alfred model (d_{280~154 μm}, 14%, d_{154~74 μm}, 16%, d_{<74 μm}, 70%), stirring strength, 3 000 r/min; stirring time, 20 min; the dosage of NSF, 1.0%. Under the optimal experimental condition, the maximum concentration of DCLRWS is up to 73.5% and 71.0% by using the NSF and SL as dispersant, respectively.