Stability, Rheology and Flow of Coal-Water Mixtures: Final Report.

摘要

This report presents the results of studies on the characterization and rheology of coal-water mixtures (CWM) made up of five different coals. The report covers the period from 9/1/84 to 2/29/88. Results presented include: coal analyses, particle characterization; suspension characterization; measurements of the yield stress of CWM as a function of particle size distribution, solids concentration and suspension pH and their correlation; measurements of the shear stress/shear rate/concentration dependence of CWM for different particle size distributions and their correlation; measurement and correlation of the heat capacities and thermal conductivities of CWM; and studies on sedimentation and sediment property characterization for CWM. The shear stress/shear rate data cover the shear rate range between 10/sup /minus/1/ (l/sec) and 10 sup 5 (l/sec), and were taken mainly using a capillary tube viscometer. A significant characteristic of most of the capillary shear stress/shear rate measurements was the existence of marked wall slip effects, which required correction. Slurry yield stresses were measured directly using the vane geometry and were correlated with concentration using the maximum packing volume fraction as a parameter. The heat capacities of the coal powders and of the coal-water mixtures were found to follow a simple additive group contribution model. The thermal conductivity data on CWM were used to a correlation for effective mixture conductivity based on volume fraction of solids and on ratio of solids to liquid conductivities. In addition, these data were used to develop a procedure for estimating the solid thermal conductivity of the granular coal. 33 refs., 19 figs., 25 tabs. (ERA citation 14:000021)