Hebei Messi Biology Co., Ltd. stated that China is a country with many salt lakes. Starting from the southern end of the Greater Khingan Mountains in the northeast, and along the northern end of the Yinshan Mountains, the eastern end of the Qilian Mountains, and the Gangdise Mountains, there are about 1,000 salt lakes. Qinghai, Xinjiang, Inner Mongolia and Tibet are the four provinces and regions with the highest concentration of salt lakes in China. Qinghai Province has unique advantages in salt lake resources, and there are many advantages in using liquid magnesium resources such as seawater and brine to produce high-purity and ultra-high-purity magnesium products. Seawater and brine contain relatively few impurities, so the process of removing impurities from using them as raw materials is simpler than removing impurities from magnesium ore, and the cost of impurity removal can also be greatly reduced. The methods for preparing basic magnesium carbonate mainly include brine soda ash method, brine ammonium carbonate method, brine carbonization method, etc.
Brine-soda ash method: The raw material is old brine (a saturated solution of magnesium chloride, the sodium chloride content should not be too high). Add water to dilute the old brine to about 20Be’. After the soda ash is dissolved and clarified in warm water, add water to dilute to about 20Be’, and preheat them to about 55℃. Put the old brine into the reactor, slowly add the soda ash solution under stirring conditions, and perform a metered reaction or react until there is a slight amount of magnesium ions remaining in the solution. Stop adding the soda ash solution and continue stirring the slurry for 5 minutes. The reaction temperature is maintained at 55°C. , after the reaction is completed, the reacted mixture is pyrolyzed at 90~100°C for a certain period of time and precipitated, followed by two vacuum filtrations, washing, crushing, drying, crushing, and winnowing to obtain basic magnesium carbonate product.
Brine-ammonium carbonate method: After impurities are removed from the brine from the salt field, it is put into a reaction pot, and carbonized ammonia is added quantitatively. Brine: carbonized ammonia = 1:0.4~0.5. Stir continuously. The resulting precipitate is aged and centrifuged. , washing and drying to obtain basic magnesium carbonate products.