Abstract: The grinding fineness of the comprehensive utilization production line of Bayan Obo oxidized ore resources reaches −0.025 mm75%. The comprehensive recovery of polymetallic ore in the stage leads to a large amount of flotation reagent residues in the beneficiation wastewater. In order to improve the water quality of the wastewater，in view of the high content of suspended solids in the beneficiation wastewater，the dosing method of polyferric sulfate 0.175 mg/L-polyacrylamide 0.054 mg/L was adopted. After each step of stirring for 10 s，the content of suspended solids in the water was reduced from 90 000 mg/L to below 200 mg/L，and the water quality was improved，which promoted the smooth operation of the whole process. After clarification，the water quality can reduce the iron flotation collector by 22.7%，the fluorite flotation collector by 13.26%，the inhibitor by 27.14%，the dosage of sodium silicate and sulfuric acid by 115.81%， while maintaining the stability of the index.

Key words: PFS, PAM, suspended solids content, iron reverse flotation, rare earth, fluorite, flotation