| Magnesite is a kind of carbonate minerals that has commercial value, which is also one of superiority mining resources of china, and the yield and export volume of magnesite’s produce of china is the champion in the world. The produce of magnesite is usually used for metallurgy, building materials, chemical industry, light industry, faming and graziers and the refining of magnesium due to its fire resistance, agglutinating value and the other excellent physicochemical properties.The main application of magnesite ore is used for refractory, but the iron in it will break the fire resistance property of its product, so there is a rigorous criterion of magnesite’s impurities if it will be used for fireproofing. Although the magnesite ore has the property of high MgO content and less impurity in china, there are few mineral reserves of high MgO content due to the years of exploitation. With the lower content of MgO of magnesite ore, the physicochemical properties, mechanism of magnesite’s manufacture and application, optimization of magnesite’s processing technology and conditions, guarantee recovery and MgO content of the concentrate should be conducted to reduce the waste of resources, provide technical support and guarantee for the development and utilization of magnesite ore resource and keep the advantage of original industry and economy. Consequently, there is great significance of the investigation on deironing and purification of magnesite ore.Desilicate must be conducted during the deironing process for the reason of silica is an important harmful impurity in magnesite ore and the quality standards of the concentrate. The flotation is the most widely used and effective method which is used for desilicate in magnesite ore’s beneficiation, the sodium hexametaphosphate, sodium silicate, lauryl amine and sodium oleate are the most widely used floating reagents, and the people’s passion for improving the flotation process of magnesite beneficiation never faded. There are applications of using magnetic method on deironing to the high iron contained magnesite ore in abroad, but there are few applications of using magnetic method on deironing to the low iron content magnesite ore that produced in Liaoning area, China. In view of the concentrate quality is the mineral processing industry insist purpose, the flotation and magnetic separation method have been investigated on the deironing and purification process of magnesiteThe origin source of silica and iron in magnesite ore have been analysed by the process mineralogy research of magnesite ore, the content of the iron is 0.27%(Fe2O3) in the form of somorphism have been confirmed, which indicate the direction for magnesite’s flotation separation and magnetic separation process.A new mixed amines collector named Wely with the properties of high selectivity and effective have been invented. The theoretical foundation of magnesite’s concentrate recovery can be increased substantially when Wely is used for collector comparing with lauryl amine is used for collector have been achieved, and the flotation reagent system of magnesite ore’s reverse flotation have been carried out when Wely is used for collector, and the flotation concentrate of MgO content is 47.,20%, SiO2 content is 0.11%, Fe2O3 content is 0.45% and the recovery of MgO is 87.70% have been achieved while the raw ore of MgO content is 46.37%, SiO2 content is 0.76%, Fe2O3 content is 0.61% at the conditions of the product’s size fraction is 77.00%-0.075mm, pH value is 5.50, dosage of sodium hexametaphosphate is 150.00g/t, dosage of Wely is 120.00g/t.The effects of different types of high-intensity magnetic separators on deironing have been conducted according to the type of removable iron impurities in magnesite ore, and the CRIMM DCJB70-200 laboratory electromagnetic splint high-intensity magnetic separator is the most suitable type of high-intensity magnetic separator. The best operating conditions and the best separating medium have been confirmed according to the magnetic separation tests, of which background magnetic field intensity is 641.00kA/m, pulp density is 23.00% and rod spacing of steel bars is 1.50mm. The content of Fe2O3 dropped from 0.41% of raw ore to 0.34% of magnetic concentrate of magnesite.According to the results of flotation separation tests and magnetic separation tests of magnesite ore, the co-separation flow path composed of flotation and magnetic separation tests have been conducted, and three flow paths which are flotation-low intensity magnetic separation-high intensity magnetic separation flow path, low intensity magnetic separation-flotation-high intensity magnetic separation flow path and low intensity magnetic separation-high intensity magnetic separation-flotation have been presented and their beneficiation effect on magnesite ore have been assessed, the beneficiation results of three flow paths have been achieved, which are the content of MgO are 47.06,47.09% and 47.15%, the content of SiO2 are 0.07%, 0.12% and 0.09%, the content of Fe2O3 are 0.33%,0.34% and 0.32%, and the recoveries of three concentrates are 82.60%,81.33% and 77.58%. The results listed above show that there is little difference of the separation indexes achieved through three flow paths, and the purpose of deironing and purification of magnesite ore can be realized through all three flow paths.The existence form and the mode of action of active principle in the system of reverse flotation of magnesite ore have been analysed from micro-perspective, and the existence form and the trending of Fe in the magnetic separation process of magnesite ore have been studied from macro-perspective. |
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