Magnesite is a kind of magnesium carbonate mineral, which is the main source of magnesium. China's Magnesite reserves are highly concentrated, and there are many large and medium-sized deposits, and the quality of the ore is excellent, which has strong competitiveness in the international market. At present, China is actively carrying out the exploration, mining and beneficiation of magnesite. In this paper, we will briefly understand the magnesite beneficiation process. Magnesite is a kind of carbonate mineral with chemical composition of MgCO3 and its crystal belongs to trigonal system. Iron and manganese are often substituted for magnesium, but the iron content of natural magnesite is generally not high. In view of the different impurities, the magnesite beneficiation process is also different. Therefore, in the process of magnesite beneficiation, the following methods are generally adopted:
1. For the high-grade ore with less Ca and Fe, the flotation of siliceous minerals is carried out with cationic collector, and the tailings are the concentrate of magnesite, i.e. reverse flotation.
2. For low-grade ores, silicon minerals are removed by reverse flotation and calcium and iron minerals are removed by positive flotation. When evaluating the flotation effect of magnesite, the main oxides in raw ore are MgO, Cao and SiO2, so the recovery index of these oxides in flotation products is used to directly evaluate the flotation effect. If the higher the recovery rate of MgO, the lower the recovery rate of Cao and SiO2, the better the quality of concentrate, otherwise the worse. When evaluating the effect of reverse flotation, the higher the recovery of SiO2 and the lower the recovery of MgO, the better the effect of reverse flotation. The concentrate selected by magnesite beneficiation process can be used as raw material for smelting magnesium, basic refractory, crushed material for furnace bed, and main raw material for magnesia cement.