EFFECT OF PARTICLE-SIZE DISTRIBUTION ON RHEOLOGY OF LIGNITE-WATER SLURRY

The particle size distribution of the solids forming a slurry has a pr edominant role because of its direct effect on the slurry's rheology. The process of comminution, which is the most important factor affecti ng the cost of the slurry preparation, is directly affected by the par ticle size distribution. Control or particle size and size distributio n is generally considered to be the means for reducing slurry viscosit y in the field of coal-slurry research. it is believed that by control ling particle size distribution and particle loading coupled with the use of additive chemicals, a coal-water slurry can be economically pro duced that is compatible with the physical characteristics needed for storage, handling, and burner nozzle atomization. In this study the ef fect of particle size distribution on the rheology of lignite-water sl urries was investigated, and the optimum particle size distribution wa s obtained for the lignite particle size less than 125 mu m. The relat ion between the apparent viscosity of the slurry at the shear rare of 100 s(-1) and the particle size distribution was demonstrated. Sedimen tation behavior of the slurries prepared was also investigated.