Effects of Composite Reagents on the Flocculation and Settling Performance of Slime Water

Objective To explore the flocculation and sedimentation laws of several flocculants and coagulants under different dosage conditions and optimize the chemical system for treating coal slime water. Method In this article, the effects of flocculants only and the composite reagents on the settling performance of slime water in the Liangzhuang coal washing plant were studied. The particle number and the average chord length of slime floc were measured at the different reagent conditions by focused beam reflectance meter (FBRM). Result Adding flocculants only had no obvious effect on the settlement of slime water whereas the composite reagents made of flocculant and coagulant promoted the settlement of coal slime water effectively. The best results were obtained when 200 g/t flocculant with 20 million molecular weight was combined with 1 000 g/t CaCl₂ coagulant. Conclusion The average chord length results showed that the number of flocs obtained with the composite reagent was obviously higher than that observed with flocculant only, indicating that the composite reagent had a better agglomeration effect.