Hebei Messi Biology Co., Ltd. stated that my country’s magnesite resources rank first in the world and have resource advantages that are unmatched by other countries in the world. However, a large amount of high-quality resources are used to produce low value-added products, resulting in waste of resources and low economic benefits. Magnesium oxide is a magnesium chemical with commercial value. It has a wide range of applications and has attracted widespread attention from scholars in recent years.
In view of the current situation of magnesite resources in my country, the market potential of magnesium oxide, and the main problems existing in magnesium oxide production. Magnesite is used as raw material, and a magnesium salt solution is obtained through processes such as roasting, ammonium leaching of magnesium, and impurity removal. High-purity magnesium hydroxide is prepared by direct precipitation using ammonia water as a precipitant, and finally high-purity magnesium oxide is obtained by roasting.
In the experiment, the influence of various experimental conditions on the preparation of high-purity magnesium oxide was investigated. It was determined that the optimal roasting conditions for magnesite are: roasting temperature of 800°C and roasting time of 2 hours. The optimal experimental conditions for leaching light-burned magnesium oxide are: the dosage of 2.8mol/L ammonium chloride solution is 150mL (the reaction molar ratio of magnesium oxide and ammonium chloride is 1:3.5), the reaction time is 4h, and the reaction temperature is 80℃, stirring speed is 15r/min. The optimal experimental conditions for the ammonia precipitation experiment are: reaction time is 45min, reaction temperature is 60°C, ammonia concentration is 5mol/L, and sedimentation time is 60min.
The magnesium hydroxide powder obtained under optimal experimental conditions was subjected to TG-DTA analysis, and the magnesium hydroxide was roasted at high temperature to obtain the final product. After chemical composition analysis, XRD analysis and particle size analysis, it was concluded that the content of MgO in the product is: 99.82%, with high purity, concentrated particle size and good dispersion.