Abstract: The dressing plant of a low-grade porphyry copper molybdenum in Inner Mongolia adopts kerosene as collector of molybdenum minerals to make the copper molybdenum mixed flotation But the flotation indexes are not ideal，and the kerosene procurement is extremely difficult and the price is high，which seriously affected the production and the improvement of economic benefits To solve these problems in production，a new American collector is adopted to replace the original flotation reagents for mineral processing conditions research The results show that with MO+CO-47 as collector of Cu-Mo mixed flotation，Cu-Mo concentrate with Cu and Mo grade of 1970% and 0339%，and Cu and Mo recovery of 8602% and 7690% were obtained separately by the same process above Compared with the on-site result，Cu and Mo grade is increased by 145 percentage point and 0009 percentage point and the Cu and Mo recovery is increased by 706 percentage point and 1005 percentage point respectively Hence，the desired effect of cost reduction and high efficiency can be realized by adopting MO+CO-47 instead of the original collector 105+ kerosene.

Key words: Low-grade porphyry copper-molybdenum ore, Cu-Mo mixed flotation, Kerosene, MO+CO-47