The process of preparing magnesium hydroxide by chemical liquid phase method is to use the reaction of soluble magnesium salt solution and alkali solution to form magnesium hydroxide precipitate. This method has the advantages of simple equipment, easily available raw materials, convenient operation, and high product purity. It is currently the main method for producing magnesium hydroxide in industry.
The flow chart of the process for preparing magnesium hydroxide by chemical liquid phase method is as follows:
- Raw materials
The main raw materials for the process of preparing magnesium hydroxide by chemical liquid phase method are soluble magnesium salt solution and alkali solution. Soluble magnesium salt solutions include magnesium chloride, magnesium sulfate, magnesium nitrate, etc., among which magnesium chloride is used in the largest amount. Alkaline solutions include sodium hydroxide, potassium hydroxide, milk of lime, etc., among which sodium hydroxide is used in the largest amount.
- Reaction
Add the soluble magnesium salt solution and the alkali solution into the reaction kettle in a certain proportion, and react under certain temperature and conditions to generate magnesium hydroxide precipitation. The reaction equation is as follows:
MgCl2 + 2NaOH = Mg(OH)2↓ + 2NaCl
- Solid-liquid separation
The reacted slurry is subjected to solid-liquid separation to obtain magnesium hydroxide precipitate and mother liquor. The magnesium hydroxide precipitate is washed and dried to obtain the finished magnesium hydroxide product.
- Mother liquor treatment
The mother liquor can be concentrated, crystallized and other processes to recover raw materials such as magnesium chloride or magnesium sulfate.
- Process characteristics
The process of preparing magnesium hydroxide by chemical liquid phase method has the following characteristics:
① The equipment is simple and easy to operate.
② Raw materials are easily available and cheap.
③ The product has high purity and stable quality.
④ The particle size and morphology of magnesium hydroxide products can be controlled as needed.
Application
Magnesium hydroxide has various functions such as flame retardancy, filling, adsorption, and neutralization, and is widely used in plastics, rubber, papermaking, coatings, medicine, environmental protection and other fields.
Development trends
In recent years, with the continuous expansion of magnesium hydroxide application fields, the requirements for its performance and quality have become higher and higher. Research on the process of preparing magnesium hydroxide by chemical liquid phase method mainly focuses on the following aspects:
Develop new precipitants to improve the purity and particle size uniformity of magnesium hydroxide products.
Research the modification technology of magnesium hydroxide products to improve its performance and application scope.
Develop a green and environmentally friendly magnesium hydroxide preparation process to reduce production costs and environmental pollution.