Abstract: The minerals are closely associated in a molybdenum ore from Inner Mongolia and the target mineral dissemination particle size distribution is uneven.In light of these features,based on staged grinding,preferential flotation flowsheet and suitable process conditions,closed circuit test obtained the molybdenum concentrates with molybdenum grade 48.500 % and molybdenum recovery 83.14 %.The index is good and the impurity content in the concentrate all meets the requirements of molybdenum concentrate quality standards.