Preperation Of Highly Active Magnesium Oxide By The Carbonization Of Magnesite

Active magnesium oxide is an important inorganic micro-nano-grade material, which is widely used in many fields. The study is involved in the preparation process of highly active magnesium oxide with carbonization method, which the raw material is light-burned magnesia. The main preparation processes of magnesium oxide are as follows:digestion, purify, carbonization, pyrolysis, calcination, and finally got the optimal process conditions, improved the efficiency of the entire experimental process, and obtained the active magnesium oxide. During the experiment, in order to improve the efficiency of the carbonization process section, we used the higee technology to achieve process intensification, we used a new type of carbonation equipment called Rotor-Stator Reactor （RSR）, which can be used to increase the gas-liquid contact area, improve the efficiency of gas-liquid mass transfer, strengthening the reaction mixture.The study included experimental efficiency and product activity, and finally got the best conditions:in the digestive process, the slurry concentration was 60 g·L^-1, digestion temperature was 90 ℃,the digestion time was 60 min;In the impurity removal process, we used MgCl·6H2O to remove CaO, the slurry was removed by filtration and washed with calcium impurities;In carbonization process, carbonization temperature is 25℃, each feed 1000mL, carbide slurry concentration was 0.3 mol·L^-1, Rotor-Stator Reactor speed was 2800 r·min^-1, CO2 gas velocity was 0.1 m3·h^-1, the amount of liquid circulation was 900 ml·min^-1, carbonation rate could up to 73% within 12 min; In pyrolysis process, we mainly studied the pyrolysis temperature and pyrolysis time and other factors, ultimately determine the pyrolysis temperature was 95 ℃, the pyrolysis time was 20 min, at this time the efficient pyrolysis was highest and precursor basic magnesium carbonate crystals had small size; In calcination process, we mainly studied the influence of calcination temperature and calcination time on the activity of the product, and ultimately determined the calcination temperature was 600 ℃, calcination time was 2 h.For the active magnesium oxide obtained under optimum conditions, we characterized by determining the purity and activity of the product, magnesium oxide content of up to 98.3%, calcium oxide content of 0.03%, was a high purity product, its activity magnesia iodine adsorption was 189 mgI2·g^-1, consistent with high activity indicators.