我国菱镁矿资源丰富,从1965年开始,一些单位对菱镁矿进行了浮选和热选的试验研究。近几年来,海城镁矿、武汉钢铁学院和鞍山钢铁学院等分别对海城镁矿和大石桥镁矿开展了工作。根据要求,大石桥镁矿一级菱镁矿粉矿石经浮选后,必须达到下列指标:MgO≥47％,CaO<0.6％,SiO_2<0.3％,烧成的镁砂中MgO≥98％。为此,1978～1979年我们先后在鞍山钢铁学院和马鞍山矿山研究院分别进行了小型 Magnesite rich in resources in our country, from 1965 onwards, some units on the magnesite flotation and heat-election pilot study. In recent years, Haicheng Magnesium Mine, Wuhan Iron and Steel Institute and Anshan Iron and Steel Institute, respectively, Haicheng magnesium and Dashiqiao magnesium mine carried out work. According to the requirements, after the fiststone of Dashiqiao Magnesium Mine primary flotation, the following indicators must be met: MgO≥47%, CaO <0.6%, SiO_2 <0.3%, MgO≥98% in the calcined magnesia. To this end, 1978 ~ 1979, we successively in Anshan Iron and Steel Institute and Maanshan Institute of Mining conducted a small