Analysis of the factors affecting the free settling of slurry at Jining No.2 Mine Coal Preparation Plant

The trouble with Jining No.2 Mine Coal Preparation Plant is that it treats an unstable raw coal feed which varies both in rate and property and the thickener overflow is high in density. An analysis is made in the paper of the property of the thickeners feed slurry through X-ray diffraction and screen analysis. Meanwhile,test is made to determine the factors affecting the natural settling of slurry and the extent of the influence exerted by each of the factors in the absence of any coagulant aid. Test result indicates that: it is very hard for the slurry to undergo natural settling,hence,making it possible to meet expected result in this manner; slurry density,water hardness and content of fine clay are the key factors affecting the free settling of slurry; and the settling rate influencing factors are sequentially slurry density ＞ content of fine clay ＞ water hardness ＞ pH value in terms of their degree of influence while those affecting the turbidity of supernatural are water hardness ＞ slurry density ＞ pH value in order of importance.