Abstract: In order to quicken the slurry settling rate,a sedimentation test is made at the plant with the use of different types of polyacrylamides as flocculants and 2019 and 2011 as coagulants. The test made is directed toward the study of the sedimentation characteristics of the slurry as well as the optimum combination,dosage and proportioning of different agents. Test result indicates that the slurry water of the plant is high in content of high-ash coal fines and mud,making it rather hard to undergo natural sedimentation and when anionic polyacrylamide with a molecular weight of 8 million is used alone at a dosage of 8 g/cm³,a much better slurry settling effect can be expected.