The Study On Preparation Of The Pure Basic Magnesium Carbonate And Magnesia By Bischofite

The study is mainly to make full use of the salt lakes resources in Qinghai province. After the preparation of potassium salt, the mother liquor is of high concentration in magnesium chloride. Using bischofite as raw materials, Na₂CO₃ as precipitant, basic magnesium carbonate was prepared by liquid deposition method through studying, the suitable process parameters were obtained. And using basic magnesium carbonate by synthesizing as raw materials, the condition of calcining magnesium oxide was studied in this paper. A method for exploiting and utilizing magnesium source of salt lakes in the area of Qinghai was supplying. The main research contents are as follows:(1) This paper utilizes the lagging phenomenon of carbonate precipitates, optimum react temperature was obtained. And using single factor experiment, the factors of mix speed , washing way, washing water consumption and drying temperature ,etc. were studied, then the influence rule was discovered.(2) Through orthogonal experiment, the factors of raw materials ratio, the concentration of Mg²⁺, pyrogenation time, quiescence time, and drying time etc on purity of basic magnesium carbonate were obtained, and the influence of the content of magnesium oxide in the product was studied. Through investigating the structure of the products, confirm that the product is monocline crystal of basic magnesium carbonate 3MgCO₃·Mg(OH)₂·3H₂O.(3) Using self-made basic magnesium carbonate as raw materials, prepare magnesium oxidize products. And condition of calcining magnesium oxide was studied. And the calcium was got rid of by rehydration method in this paper.