Rheological Properites of Three-phase Coal Water Mixture (CWM)

Abstract

Three-phase coal water mixture (CWM) in which small gas bubbles were dispersed with surfactants was developed to reduce the apparent viscosity of highly loaded CWM. The gas holdup in the three-phase CWM was 0.3-0.4. The rheological behavior of the three-phase CWM has been studied in a coaxial rotating cylinder rheometer at 275-323 K. The rheological behavior becomes increasingly pseudoplastic, and the apparent viscosity decreases with the increase in the gas holdup. Little temperature dependency of flow curves for the three-phase CWM was observed. Significant reductions in apparent viscosity were achieved for the three-phase CWM. The apparent viscosity of the three-phase CWM was one fifth as large as that of CWM at 275 K and one third at 288 K. It was found that three-phase CWM makes it possible to transport highly loaded coal slurry with reduced viscosity even at low temperature.