Research On Flotation Process Of High-silicon High-calcium Magnesia

Magnesite is one of the dominant mineral resources in China. The magnesite reserves, production and export volume of China rank the first in the world. Since China’s reform and opening up, unreasonable exploitation of magnesite resources leads to high quality magnesite resources becoming fewer and fewer, resulting purification by flotation of low-grade magnesite has attracted more and more attention. The scholars at home and abroad have done a lot of works in the field of low-grade magnesite flotation, but have done little about flotation process of high-silicon high-calcium low-grade magnesia.In the paper, taking magnesite, dolomite as the research minerals, the surface properties of minerals and magnesium in the surface properties of the solution and the flotation of minerals in different modifiers was studied, and identified the chemical characteristics of mineral crystals, the surface characteristics and the relationship between floatability relevant laws.According to the dissolution balance of mineral, the dissolved components in the solution of magnesite, dolomite were calculated, and the solution composition and mineral composition of the surface electrical properties could be determined with different pH values, and predicted magnesite, dolomite PZC were 7.0,6.5. The natural floatability of magnesite and dolomite were good in sodium oleate and lauryl amine flotation system and the natural floatability of magnesite and dolomite under sodium oleate system was superior to lauryl amine system.Taking one typical high-silicon high-calcium low-grade magnesia from Dandong Liaoning province as raw material, this paper carried out throughout technical process studyincluding double reverse flotation process, reverse-positive flotation and single positive flotation. Under the study of double reverse flotation process and single positive flotation process, kinds of flotation regulator were studied. In the study of reverse-positive flotation, basing on technological mineralogy results and combining with previous achievements,a novel flotation system for recovering magnesite concentrate from low-grade magnesite ore was developed. The results of flotation experiments showed that a magnesite concentrate containing 46.94 percent MgO0.30 percent SiO20.76 percent CaO could be produced and 76.02 percent of the magnesite could be recovered through the process.This research give some innovations standpoints, which is using one single positive flotation and the research gives some relative advices double reverse flotation process purify high-silicon high-calcium low-grade magnesia, providing new directions for low-grade magnesite flotation research.