Study On The Preparation Of High-grade MgO By Using Magnesite From Da Shiqiao

In our country, there are abundant magnesium resources. And it ranks first in the world. But, a large number of high-quality resources were used to produce low value-added products, leading to the waste of resources, and low economic efficiency. MgO is a commercially valuable chemical, and it is applied in many fields. So, in recent years, it is attentioned widely by scholars.Aiming at the existing state of magnesite resource, market potentiality and main problems existing in preparation of MgO, in this article, magnesite from Da Shiqiao is chosen as raw material. In the first, calcine magnesium. In the second, magnesium sulfate solution is gotten after extraction of magnesium under ammonia leaching and separation of impurities. And then with the precipitant ammonia, magnesium hydroxide is synthesized by direct precipitation method. In the last, calcine to obtain products.In the experiment, studying on the effects of condition to the preparation of MgO. The best conditions to calcine magnesium are:calcine temperature is800degree,2hours. The best conditions to the leaching of light burning powder are:2.8mol/L ammonium chloride150mL(MgO and ammonium chloride reaction molar ratio is1:3.5), four hours,80degree,15r/min. The best conditions of precipitation ammonia are:45minutes,60degree,5mol/L,60minutes for precipitation. Do TG-DTA for Mg(OH)2which get under the best conditions. Calcinate them to get products, then analysis their components, and do XRD, granularity analysis. Conclud that the Content of MgO is99.82%, the characteristics of products are high purity, particle size concentration, and good dispersion.