Abstract: Sulfur and Fluorine content is very high in a copper molybdenum flotation separation waste water of a copper ore in Yunnan，direct reuse seriously affect copper molybdenum mixed flotation index.Test of chemical precipitation-flocculation settlement method is used to deal with waste water，precipitating agent dosage，influence of stirring reaction time on desulfurization and fluorine removal of wastewater，types，dosage，pH value of flocculant on wastewater flocculation effect，and reuse of wastewater before and after processing condition were compared.Research shows that initial wastewater pH = 12.5，sulfur precipitant copperas dosage is 83.33 g/L，fluorine precipitant lime dosage is 40 g/L，stirring reaction time for 60 min，sulfur removal rate was 93.37%，fluorine removal rate is 98.52%；New type flocculant M5250 dosage of 50 mg/L，turbidity of clarify water is 8.1 FTU.Copper molybdenum separation waste water after processing parts used in grinding and copper molybdenum mixed floating operation，can obviously improve copper molybdenum mixed floating effect.Therefore，chemical precipitation-flocculation sedimentation process in dealing with sulfur and fluorine on copper and molybdenum separation wastewater has characteristics of simple，rapid，efficient，economic and environmental benefit is remarkable.

Key words: Chemical precipitation-flocculation process, Copper-molybdenum separation, High sulfide and high fluoride