Abstract: The main molybdenum mineral in a low-grade molybdenum ore in Shaanxi is molybdenite，and molybdenite was disseminated in gangues in micro-fine particle.Molybdenum concentrate with Mo grade of about 50% and Mo recovery of about 80% was obtained by adopting the process of one-stage grinding-one roughing，one cleaning，two scavenging，and two-stage grinding-nine cleanings and two scavenging-middles back to the flow-sheet in turn,on site. In order to further improve the separation indexes，the technical conditions tests on beneficiation of this ore were studied.The results showed molybdenum concentrate with Mo grade of 54.23% and Mo recovery of 89.70% was gained by the process of one-stage grinding-one roughing，one cleaning，two scavenging，and two-stage grinding-five cleanings，two scavenging of the concentrate，three-stage grinding-tree cleaning-middles back to the flow-sheet in turn.Thus，the final concentrate index has been significantly improved.

Key words: Molybdenum, Regrinding of the concentrate, Concentration