Abstract: Flocculant settlement tests are performed by adding different amounts of flocculation agents, alum, sodium dodecylbenzenesulfonate and polyacrylamide into varied slurry concentrations, 68 %, 70 % and 72 %, respectively, to determine the transport solubility of filling material, type and adding flocculant amount. The results are compared and analyzed by taking the supernatant liquid drop height and economic cost into account. The settlement regression models for the three kinds of flocculant addition amounts are determined by working out the economic efficiency of flocculation and sedimentation parameters. The results show that the best flocculant is alum with additive amount of 29 g/t and the total tailings concentration is 70 %.