Abstract: Due to serious alteration of gangue mineral in a low-grade pyritic gold in Xinjiang province，and the high content of gangue slime has strong impacts on the flotability of gold-carrier mineral. This problem could be properly solved by adopting methods as strengthening the dispersion of the slime and inhibition on gangue，and reinforcing the activation and collection on gold-carrier mineral. By using sodium carbonate and soluble glass as the combined modifier，copper sulfate as activator，isoamyl-xanthate and dithiophosphate BA as the combined collector，the RB-3 as frother，a closed-circuit flotation flowsheet consisting of two roughings，two concentratings and three scavengings has been performed. The original grades of gold and silver are 1.49 g/t and 6.11 g/t separately for the run-of-mine ore，the grade and recovery of gold in the concentrate of closed-circuit test have attained 20.07 g/t and 67.49%，while the grade and recovery of silver have reached 42.45 g/t and 34.81%.

Key words: Gold ore, Pyrite, Gangue slime, Flotation