Abstract: Coal slurry treatment is a crucial and difficult link in coal preparation.Based on the basic properties of coal slurry, this paper studies the effects of the adsorption of anionic polyacrylamide (APAM) and shearing strength on the flocculation performance of coal slurry combined with the settlement experiment, shear experiment, adsorption experiment and X ray photoelectron spectroscopy analysis, etc.The results show that the dosage of APAM and shearing strength have great influence on the flocculation of coal slurry.The saturated adsorption amount of APAM is about 0.74 mg/g.With the increase of the APAM dosage, the adsorption efficiency of APAM reduces.When the dosage of APAM is 0.6~0.8 kg/t, the adsorption efficiency of APAM is 63%~51%.The corresponding transmission ratio is above 90% and the clarification and turbidity removal efficiency are the best.This means that the clarification effect is closely related to the adsorption efficiency.The adsorption of the APAM on the slurry makes some changes in the C and N peaks, resulting in the increase of the C—C and C=O and C—N functional groups.The high dosage can protect floc from breakage and enhance its recovery ability.The floc structure and the effect of flocculation and settling of coal slurry can be controlled by the dosage of reagent and shearing strength, thus, the solid-liquid separation efficiency of coal slurry can be improved.