关键词: 低品位菱镁矿, 立式辊磨机, 反浮选, 正浮选

Abstract: There is 45.23% MgO，3.36% SiO₂ and 0.98% CaO in magnesite from Kuandian of Liaoning Province，main gangue minerals are quartz，talcum，dolomite andcalcite.In order to develop and utilize the ore，vertical roller mill grinding-flotation process tests were carried out.The results indicated that，at the feeding fineness of -12 mm，using vertical roller mill at the rotate speed of 24.5 r/min，single roller presser of 2 100 kN，ground products with grinding fineness of 81.6% passing 0.074 mm，using dodecylamine acetate as collector，2# oil as frother，via one roughing-two cleaning reverse flotation process to desilicication，concentrate of reverse flotation using sodium carbonate as pH regulator，sodium silicate and sodium hexametaphosphate as depressor，sodium oleate as collector，via one roughing one cleaning direct flotation process to concentration magnesite，magnesite concentrate was obtained with MgO content of 47.24%，SiO₂ content of 0.27%，CaO content of 0.29% and the recovery of MgO is 65.14%.Good beneficiation test results had been obtained，which can provide technique basis for the utilization of the ore.

Key words: Low grade megnesite, Vertical roller mill, Reverse flotation, Direct flotation