What are the preparation methods of magnesium hydroxide?
Magnesium Hydroxide is a medium-strong base. Generally, the hydroxide that dissolves in water and ionizes into metal cations and hydroxyl complexes and a part of hydroxide is called a medium-strong base. The so-called strong base and weak base are relatively speaking, - bases can be completely ionized when dissolved in water, and belong to strong bases. The base corresponding to the active metal is generally a strong base.
What are the preparation methods of magnesium hydroxide：
1. Seawater and calcium hydroxide solution
It is obtained through the reaction of lime milk, so that magnesium hydroxide precipitate can be obtained.
2. Preparation of brine-lime method
Prepare milk of lime with pre-purified brine and lime after slag removal, precipitate in the tank, react, and add a certain amount of flocculant to the slurry, after mixing, enter the settling tank for separation, and then After filtration, washing and drying, after crushing, it can be made into magnesium hydroxide.
3. Preparation of brine-ammonia
It is to use purification treatment to remove impurities such as sulfate, carbon dioxide and boron, use its brine as the basic raw material, and use ammonia as a precipitant to precipitate in the reactor and then react. Before this reaction, a certain amount of Seed crystals, after stirring. The ratio of brine and ammonia water is generally in the form of 1:0.9, but the temperature needs to be controlled at about 40°C. After the reaction, a flocculant is added, and the precipitate can be washed and dried after filtration, and then it can be made into a magnesium hydroxide product. This method has high recovery rate and short washing cycle, which is an advanced production technology.
4. Lingkite-hydrochloric acid-ammonia water method
Magnesium hydroxide and carbon dioxide can be prepared by burning magnesite ore and anthracite or coke in a shaft kiln. Magnesium hydroxide can also be prepared by reacting with a certain concentration of hydrochloric acid after the bitter soil powder is slurried.
