Synthesis and characterization of a thixotropic coal–water slurry for use as a liquid fuel

We reported here a novel approach to synthesize a low-viscosity and stable coal–water slurry for use in many practical applications. The slurry was prepared by mixing coal particles with a gelling solution containing water and 1 wt.% of cobalt-intercalated laponite. The coal particle sizes were less than 75 μm and the coal loading was 50% by weight. The slurry prepared this way was able to transform to a high-viscous and unflowable gel holding coal particles uniformly throughout its volume when it was stored at rest. When it was sheared, its gelling network structure was immediately broken down becoming a low-viscous flowable liquid. The transport and thixotropic properties of the prepared slurry were measured and they were described very well by the Bingham model and the thixotropic model proposed by Usui, respectively.