Study On The Preparation Of Active Magnesium Oxide By Low-grade Magnesite

Due to unreasonable exploitation and utilization,high quality magnesite resources have been reduced,which can not meet the needs of industrial production now.Therefore,the study on purification of low-grade magnesite is gradually increased.And the factors of the rate of magnesium hydrochloric acid leaching were analyzed and the kinetic equation was established.The final product and the activity of the product were studied by calcination after evaporation.The analysis of raw materials of low-grade magnesite shows that the research of calcinated at different temperatures magnesite: raw material calcined at different temperatures respectively from room temperature to 10?/min up to 550?,600?,650?,700 ?,750 ?,respectively,thermal insulation 60 min,40min,30 min,15min,5min,magnesite decomposition in full;The kinetics of thermal analysis was obtained,and the activation energy was 76.989 k J/mol,and the prefactor was 2.36x105.The decomposition mechanism is: (?)The results of leaching test of low-grade magnesite are known to show that magnesium leaching rate is the best under the conditions of mixing + ultrasonic.Stirring,under the external force of magnesite 30 min at 650? temperature heat preservation,in hydrochloric acid content was 14.8%,the liquid-solid ratio was 3.48ml: 1g,stirring speed of 600r/min optimum leaching test at room temperature was under the condition of leaching 10 min,and eventually magnesium leaching rate can reach 89.87%.Evaporation crystallization was carried out on the filtrate after calcining the preparation of active magnesium oxide,which shows that when the evaporation crystallization temperature is 85?,and the crystallization product calcination temperature is 460? and calcination is 3.5h,the activity of magnesia is best.