Dissolution Kinetics Of Da Shiqiao’s Magnesite In Acetic Solutions

For45%(C material) and47%(A material), low-grade magnesite from Da Shiqiao, It is difficult to obtain fine quality high-grade magnesite, which used in the production of fused magnesia, only by flotation and other physical mineral separations. There is no breakthrough to settle the flotation of low-grade magnesite, nor, look for a good way that economic efficiency and friendly to the environment. This article studies that using acetic acid to dissolve calcium and silicate impurities aims to improve the quality of magnesite. It will solve the problem of the flotation of low-grade magnesite.In the first, do a theoretical analysis and discussion to the feasibility of the subject. Calculate for dissolution process by using dissolution kinetics. Analysis on the reactivity of acetic acid dissolve magnesite and calcium. The results of expermental are E(Mg)A=28.92kJ·mol-1,E(Ca)A=1.370kJ-mol"1; E(Mg)c=8.701kJ·mol-1,E(Ca)c=4.288kJ·mol-1.It shows that calcium impurities response with acetic acid more easily. So, using acetic acid to separate calcium from magnesite is feasible. Secondly, in the application of purify magnesite by using acetic acid, dressing respectively for C and A material. Through studying the pH value, temperature and reaction time of solution, determine the best conditions of impurity:For C material, the best conditions are, concentration is2.6mol/L, the amount of eluent is0.5to1times of magnesite, temperature is20-30degree, without placing too long, impurity removal rate is35.69%; For A material, the best conditions are, concentration is2.6mol/L, the amount of eluent is0.5to1times of magnesite, temperature is20-30degree, without placing too long, impurity removal rate is27.41%.The results show that, using acetic acid to purify magnesite fast, effective, mild, friendly to environmental and low cost, has a higher economic efficiency. This study plays an extremely important significance for the scientific and rational use of magnesite and promoting the magnesite mining and processing industry in China turn from production efficiency to quality efficiency. It will improve the comprehensive utilization and utilization levels of magnesite resources and achieve the sustainable development of magnesite mining and processing industry.