Hebei Messi Biology Co., Ltd. stated that anhydrous magnesium carbonate, as an important inorganic chemical product, can be used as a raw material for the preparation of high-purity magnesia and magnesium salt series products, and can also be used as an additive and modifier for rubber, medicine, insulation materials, food and various chemical products. It has a very broad application prospect. At present, most of the magnesium carbonate products on the market are hydrated magnesium carbonate and basic magnesium carbonate. Anhydrous magnesium carbonate exists in the form of natural magnesite and has a low purity. Therefore, the preparation and research of anhydrous magnesium carbonate has attracted more and more attention. In recent years, the preparation of anhydrous magnesium carbonate has become a hot topic in research.
①Use soluble magnesium salt as raw material, soluble carbonate as precipitant, and ethylenediamine, tetrahydrofuran, dimethylformamide, methanol, ethanol, isopropanol, acetone, butanone, methyl pyrrolidone, ethyl acetate, butyl acetate, ethylene glycol diethyl ether, diethylene glycol butyl ether or propylene glycol methyl ether as solvent to prepare anhydrous magnesium carbonate.
② Using light-burned powder or magnesium hydroxide as raw materials, after carbonization reaction and removal of iron ions and heavy metal impurities, the generated magnesium bicarbonate is decomposed to generate trihydrated magnesium carbonate and carbon dioxide, and after precipitation and filtration, it is mixed with ammonium bicarbonate solution for hydrothermal reaction to obtain a single phase of high-purity ultrafine anhydrous magnesium carbonate loose powder.
In view of this, it is necessary to find a method for preparing high-purity ultrafine anhydrous magnesium carbonate that is easy to operate:
The present invention provides a method for preparing anhydrous magnesium carbonate, using a soluble magnesium salt as a magnesium source and a soluble carbonate as a precipitant, without adding other solvents and other additives. The carbonate is dissolved in a soluble magnesium salt solution by direct mixing, a polytetrafluoroethylene-lined crystallization kettle is used as a reactor, and a blast drying oven is used as a heating device, so that the reactants are co-precipitated to generate a magnesium carbonate product, and anhydrous magnesium carbonate powder can be obtained by filtering, washing, and drying. The method produces high-purity ultrafine anhydrous magnesium carbonate powder. No additives are needed during the preparation process. The product has high purity and a simple process route. The powder is suitable for use in inorganic flame retardant materials, engineering plastics, medicines, foods and other fields.