Abstract: The trouble with Buertai Coal Washery is that the slurry water has a high content of degraded fine slimes and this presents much difficulties for its treatment. A study is made in the paper of the effect of slurry settlement in the case of using a single flocculant or compound agents. Test result shows that: for the treatment of the slurry produced by coarse and small coal cleaning systems,a best settlement result can be achieved with the use of a single agent TDX1215,however,for further reducing the turbidity of circulating water,much more agent needs to be used; and in this case,the combined use of flocculant TDX1215 and coagulant TDN2109 at dosages of 8 g/t and 48 g/t respectively proves to be most effective.Industrial test shows that the combined use of the 2 agents for treating the slurry water from coarse and small coal washing systems can reduce the turbidity of thicker overflow to a level below 100 NTU. As compared with the regime of reagents previously applied,the consumptions of flocculants and coagulant can be reduced respectively by 23%~55% and 23%~26%.