Preparation process of anhydrous magnesium carbonate

Anhydrous magnesium carbonate, as an important inorganic chemical product, can not only be used as a raw material for preparing high-purity magnesium sand and magnesium salt series products, but also as an additive and modifier for rubber, medicine, insulation materials, food, and various chemical products.

          Anhydrous magnesium carbonate, as an important inorganic chemical product, can not only be used as a raw material for preparing high-purity magnesium sand and magnesium salt series products, but also as an additive and modifier for rubber, medicine, insulation materials, food, and various chemical products. Its application prospects are very broad. Currently, 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 low purity. Therefore, the preparation of anhydrous magnesium carbonate is receiving more and more attention from people. In recent years, the preparation of anhydrous magnesium carbonate has become a hot research topic.
           ① Anhydrous magnesium carbonate was prepared using soluble magnesium salts as raw materials, soluble carbonate as precipitant, and ethylenediamine, tetrahydrofuran, dimethylformamide, methanol, ethanol, isopropanol, butanone, methylpyrrolidone, ethyl acetate, butyl acetate, diethylene glycol butyl ether or propylene glycol methyl ether as solvents.
            ② Using light burned powder or magnesium hydroxide as raw materials, after carbonization reaction to remove iron ions and heavy metal impurities, the generated magnesium bicarbonate decomposes to form trihydrate magnesium carbonate and carbon dioxide. After precipitation filtration, it is mixed with ammonium bicarbonate solution for hydrothermal reaction to obtain single-phase high-purity ultrafine anhydrous magnesium carbonate loose powder.
In view of this, it is necessary to find a simple and convenient method for preparing high-purity ultrafine anhydrous magnesium carbonate:
               The present invention provides a method for preparing anhydrous magnesium carbonate using soluble magnesium salts as magnesium sources and soluble carbonates as precipitants, without the need for the addition of other solvents and additives. Carbonate is dissolved in a soluble magnesium salt solution by direct mixing. A crystallization reactor lined with polytetrafluoroethylene is used as the reactor, and a blast drying oven is used as the heating device to cause co precipitation of reactants and generate magnesium carbonate products. After filtration, washing, and drying, anhydrous magnesium carbonate can be obtained. This method produces high-purity ultrafine anhydrous magnesium carbonate without the need for additives during the preparation process. This product has high purity, a simple process route, and is suitable for fields such as inorganic flame retardant materials, engineering plastics, medicine and food.