Experimental Study of High-concentration Coal-water-slurry Rheological Properties and Stability

Coal-water-slurry is a kind of non-Newtonian fluid,composed of liquid-and-solid two-phase substance.Being subjected to many influencing factors,its rheological properties and stability are very complicated,and play a decisive role in pipeline transmission and combustion performance.With the help of a coal-water-slurry viscosity meter,a rheological measurement has been made of the slurry,which has a mass concentration of over 60%.The influence of temperature,concentration and additives on the rheological properties of the slurry has also been studied.The visual viscosity of the slurry will decrease with an increase of temperature and increase with an increase of the slurry concentration.An introduction of additives will greatly improve the rheological properties of the slurry.Through a study of stability of the slurry,the authors have concluded that its stability will decrease with an increase of its concentration,and is related to coal ranks.A proper amount of additives can improve its stability and the latter will decrease with an increase of temperature.As judged from the comprehensive cost-effective viewpoint of the slurry transmission,its transmission temperature at between 20 and 40 ℃ has been regarded as appropriate.