Through the analysis of size composition, ash and other properties of Qidong coal mine, three kinds of coagulants and flocculants are used to do the settlement test. The concentration of coal slime water, the types and effect of flocculant and coagulant on the settling are also studying. The research shows that when the concentration of coal slime water is 50g/L, 75g/L and 100g/L, the best flocculant is APAM whose dosage is respectively 4g/m3, 8g/m3 and 12g/m3, and the optimal coagulant is poly-aluminum whose dosage is respectively 150g/m3, 700g/m3 and 1100g/m3. In addition, the coal slime water flocculation will get a better result if the flocculant is added later than the coagulant.
