The method of magnesium hydroxide is an ammonia method, a caustic soda method, etc., and an ammonia method is mainly used. Due to the high ammonia nitrogen content in the ammonia production wastewater discharge, the environmental pollution is large, and at the same time, due to the volatile and irritating smell of ammonia, the labor environment of workers is poor, and the expansion of this method is limited; the production cost of the caustic soda method is relatively high. Therefore, a new process for preparing magnesium hydroxide is studied using low-cost lime and brine as raw materials.
At present, the resources of the brine - especially the rich magnesium - have not been utilized, resulting in a large loss of resources; in addition, the bitter brine produced in the production of sea salt also contains a large amount of magnesium. This has resulted in a large amount of magnesium waste liquid being discharged into salt lakes or sea salt every year, which wastes resources and pollutes the environment. China's bitter brine water ranks first in the world, but it has not been obtained from red powder and effective development and utilization. The use of magnesium resources in brines is an important issue in the comprehensive utilization of bitter brine chemical resources. Among them, the preparation of magnesium hydroxide by using brine as an raw material is an effective way.
Magnesium hydroxide is a weak base. Compared with strong alkaline materials such as lime, caustic soda and soda ash, it has the advantages of large cushioning capacity, high activity, strong adsorption capacity, no corrosiveness, safety and reliability, non-toxic and harmless. . Magnesium hydroxide has strong adsorption capacity and high activity. It has good fluidity, easy to transport, store, use and adjust. It is widely used in environmental protection in foreign countries. It can be used as a neutralizing agent for industrial acid-containing wastewater, industrial and mining enterprises and Remover of heavy metals in mine effluents, smoke desulfurizer, land acid rain treatment and pH adjuster. Magnesium hydroxide is an inorganic additive-type non-toxic flame retardant after special treatment, which has multiple properties such as flame retardant, anti-dropping and filling. The research, development and production of magnesium hydroxide is very active, and its application fields are constantly expanding, with broad market prospects.