RHEOLOGICAL PROPERTIES OF 3-PHASE COAL-WA TER MIXTURE (CWM)

Three-phase coal water mixture (CWM) in which small gas bubbles were d ispersed with surfactants was developed to reduce the apparent viscosi ty 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 rheologica l behavior becomes increasingly pseudoplastic, and the apparent viscos ity decreases with the increase in the gas holdup. Little temperature dependency of flow curves for the three-phase CWM was observed. Signif icant reductions in apparent viscosity were achieved for the three-pha se CWM. The apparent viscosity of the three-phase CWM was one fifth as large as that of CWM at 275 It and one third at 288 K. It was found t hat three-phase CWM makes it possible to transport highly loaded coal slurry with reduced viscosity even at low temperature.