Abstract: The Al2O3 and SiO2 contents of a lowgrade bauxite from Wenshan,Yunnan are 44.35% and 10.52%,Fe and TiO2 contents are 13.36% and 4.64%,respectively,which belongs to high iron and titanium,low aluminum and silicon bauxite.The recoverable aluminum minerals mainly exist in diaspore phase.The iron minerals mainly include hematite and goethite.The titanium minerals mainly exist in anatase phase,and the gangue mineral mainly is kaolinite.The flotation separation research of aluminum and silicon were carried out for the ore,focusing on influence of the kind and dosage of collectors,the grinding fineness,dosage of adjusting agent,kind and dosage of inhibitors on the flotation effects,and finally determine the agent system with modified fatty acids KYB as collector,sodium silicate + GY3 as combination inhibitor,sodium carbonate as adjusting agent.Under the condition of grinding fineness of -0.074 mm accounting for 90%,the technical indexes of Al2O3 contents of 53.34%,Al—Si ratio of 9.79 and Al2O3 recovery rate of 81.62% were obtained by closedcircuit test of "one roughing,two cleaning and one scavenging".The research results could provide technical support and reference for the development of the bauxite resources.

Key words: low-grade bauxite,high iron and titanium contents,separation of aluminum and silicon,modified fatty acid,combination inhibitor