When polymeric ferric sulfate(PFS) and organic cationic polymer flocculants(OCPF) are used together to treat the circulating water with suspended solids in iron mineral processing,as the synergistic effect of them the treatment efficiency of circulating water is much better than that when only equivalent PFS or OCPF is used added.As PFS which is made of acidic waste water from steel rolling is used as the purifying agent,not only the water purification effect can be improved but also the treatment cost can be cut down.When a mixture of 75mg/L and 2mg/L OCPF is added,the flocculation effect will reach a best level.The regression equation of the concentration and turbidity of suspended solids in flooding water during mineral processing is y=0.00094x2+0.351x+1.732.A great deal of time can be saved for determining suspended solids in the circulating water by measuring the turbidity.