Abstract: A poor molybdenum-bismuth-sulphur mixed concentrate with low grade and coarse particles，of which -0.074 mm account for 64%.Molybdenum and bismuth is mainly intergrowth in the ore.In order to obtain qualified molybdenum concentrate and bismuth concentrate，flotation separation test were carried out.Results indicated that，samples reground to 85% passing 0.074 mm，via one roughing-one cleaning-two scavenging molybdenum and bismuth bulk flotation，one roughing-two cleaning-two scavenging bismuth depression and molybdenum flotation process，finally，obtained molybdenum concentrate with molybdenum grade of 53.13% and recovery of 88.95%，respectively，and 1.46% bismuth，bismuth concentrate with bismuth grade of 23.68% and recovery of 80.06%，and 3.87% molybdenum，sulphur concentrate with sulphur grade of 31.16% and recovery of 71.98%，0.32% molybdenum and 1.11% bismuth.

Key words: Mixed concentrate of molybdenum-bismuth-sulphur, Flotation, Intergrowth, Molybdenite, Bismuthinite