Hebei Messi Biology Co., Ltd. stated that adding magnesium carbonate to lithium batteries can improve the conductivity of the battery, extend the service life of the battery, slow down the self-discharge of the battery, improve the storage performance, and improve the utilization rate of the battery active substances. However, the performance of battery materials is closely related to the purity and fineness of the magnesium carbonate therein, especially the content of magnetic substances such as iron, chromium, and nickel in the magnesium carbonate.
At present, the main method for preparing magnesium carbonate is the “dolomite carbonization method”. The calcination process during the production of the dolomite carbonization method requires the ore to be calcined to 900-1000℃, which consumes a large amount of coal or natural gas, and the energy consumption is very large, which is not conducive to saving production costs. Moreover, the gas generated by calcination brings out a large amount of dust, which not only has a bad production environment, but also cannot guarantee the working environment, affecting the health of employees. At the same time, it is difficult to produce high-purity ultrafine magnesium carbonate powder by the dolomite carbonization method, so it is difficult to improve the performance of battery materials.
A method for preparing high-purity ultrafine magnesium carbonate for battery materials belongs to the technical field of magnesium carbonate preparation. The present invention firstly performs a first impurity removal on the ferromagnetic material in the raw material, so as to remove the ferromagnetic impurities with larger particles in the raw material; then performs a second impurity removal in the reaction process of the suspension, so as to remove the ferromagnetic impurities to the maximum extent in the suspended state of the suspension; finally, performs a third impurity removal after pulverization, so as to remove the only small amount of ferromagnetic impurities remaining in the powder; through the three impurity removal means, the content of the magnetic material in the magnesium carbonate product can be effectively controlled to meet the requirements for preparing the battery; and through the suspension reaction, the original calcination process is replaced, so that the energy consumption in the whole preparation process is greatly reduced, which is conducive to saving the production cost.