Magnesium hydroxide is the third magnesium chemical after magnesia and light-burned magnesium oxide in magnesium chemicals. Slurry magnesium hydroxide is an environmentally friendly water treatment agent, widely used as an acid neutralizer, precipitating heavy metal ions, and removing sulfur dioxide. It is one of the products favored and respected by developed countries in the process of promoting sustainable development strategies, protecting the environment, and beneficial ecological development. It is called a green and safe neutralizer, an environmentally friendly flame retardant, and a third alkali. Therefore, the use of cheap raw materials and processes to prepare stable and highly active slurry magnesium hydroxide has become an important research topic with good development prospects.
my country’s coastal seawater resources are rich, and my country is one of the countries in the world that produces more sea salt. The national raw salt production capacity is nearly 30 million tons, and the by-product brine is about 20 million cubic meters. Brine is a renewable resource with high utilization value. The optimal conditions for producing magnesium hydroxide with brine as raw material and ammonia as precipitant and the influence of various dispersants on the slurry properties are investigated experimentally. The dispersant ratio required for slurry stability is investigated, and on this basis, a stable magnesium hydroxide slurry is prepared. Through the research of this experiment, we can make up for the gap in the high stability technology of slurry magnesium hydroxide products in my country and solve the problems in the production process of slurry magnesium hydroxide.
Slurry magnesium hydroxide was prepared with brine as raw material and ammonia water as precipitant. The optimal process conditions for preparing magnesium hydroxide by brine ammonia precipitation were determined through experiments. The effects of the type and amount of dispersant on the performance of slurry magnesium hydroxide were studied, and the synthesis conditions and optimal ratio of epoxy succinic acid for preparing slurry magnesium hydroxide were determined through experiments. The optimal dispersant ratio of slurry magnesium hydroxide is: 0.3% sodium metasilicate, 2.4% alkylphenol polyoxyethylene ether solution, and 0.7% polyepoxy succinic acid. The product prepared under this condition does not delaminate after three weeks and has good fluidity.