中文摘要：

针对辽宁某低品位菱镁矿，采用反一正浮选工艺进行了硅钙杂质脱除研究。其中，反浮选作业采用阳离子捕收剂BK428，主要脱除含硅脉石；正浮选作业采用阴离子捕收剂BK420，强化含钙脉石脱除。试验结果表明，采用上述工艺流程与药剂制度可以使MgO品位为43．52％，Si02含量3．74％和CaO含量2．69％的原矿，获得MgO品位为47．02％的精矿，菱镁矿精矿中Si02和CaO含量分别降低到0．29％和0．93％，Mg0回收率为71．64％。达到了选矿除杂的目的。为综合利用菱镁矿资源打下基础。

英文摘要：

In this paper, the research of removing impurities by flotation for the low grade magesite with high contents of silicate and calcite in Liaoning province is introduced. In the flotation process, reverse flotation by novel anionic collector BK428 is adopted to remove silicate, and direct flotation by cat- ionic collector BK420 is used to remove calcite. By this ＂reverse -direct flotation＂ process, from the low grade magnesite with MgO content of 43.52%, the grade and recovery of obtained concentrate （calculated by MgO） are 47.02% and 71.64%, at the same time, SiO2 and CaO content are decreased from 3.74% and 2.63% to 0.29 and 0.93 respectively, which achieves the goal of mineral processing and removing impurities and lays a foundation for comprehensive utilization magnesite.