Hebei Messi Biology Co., Ltd. stated that it takes circular economy as a guide, fully recycles and utilizes various components in raw materials without discharging waste, waste gas and waste residue into the environment. The raw materials are MgCl2, NH3 and NH4HCO3, and active magnesium oxide is produced as the main product; NH4Cl is a by-product; calcination produces CO2, part of which is recycled for carbonization and recycled to save raw material ammonium bicarbonate, and part of which is absorbed, compressed and cooled to recover dry ice, which is used in the pharmaceutical and food industries to solve the greenhouse effect gas CO2 utilization and effectively protect the environment. The mother liquor is recycled and not discharged, ensuring that all substances can be effectively utilized, which fully meets the requirements of circular economy.
The price of marine energy is high, and dolomite and brucite are low, so magnesium is mainly produced from non-ore magnesium salt products. However, it is difficult to achieve the purity of the product with magnesium ore as the raw material, especially the development and application of salt lake brine and magnesite in the Northwest Development has made great progress, and the number of enterprises producing magnesium salt with magnesium chloride as the raw material is increasing, and its process routes are diverse, and the technology is often overcome.
The magnesium hydroxide produced by Hebei Messi Biology Co., Ltd. using the brine-ammonia method has larger crystal particles and is easy to filter. The water content of the filter cake is ≤18%, and the purity of magnesium hydroxide is ≥99.0%. It provides technical guarantee for the preparation of high-purity magnesium salt using magnesium chloride as raw material. Enterprises use ammonia, ammonia water, ammonium bicarbonate, etc. as precipitants. Some of them adopt the recovery of by-products-ammonium chloride; some use lime to evaporate ammonia to recycle ammonia. The process is relatively mature, but the environmental protection issues of the ammonia method should be given enough attention and sufficient environmental protection investment should be given to ensure that environmental protection standards are met.
Hebei Messi Biology Co., Ltd. stated that the process route of using lime or dolomite as a precipitant to produce light magnesium carbonate and active magnesium oxide by carbonization should attract the attention of peers, and will have greater advantages in reducing costs and protecting the environment.