The phase transition temperature of magnesium chloride hexahydrate (bischofite) is about 117 ℃, and the phase transition enthalpy is 160 kJ/kg. It has the advantages of high heat storage density, non-flammability, relatively low price and high thermal conductivity, so it is an important phase change material in the field of medium temperature energy storage.
The research progress of the thermophysical properties of magnesium chloride hexahydrate, such as phase change temperature, phase change enthalpy, specific heat capacity, thermal conductivity, density, etc., revealed that magnesium chloride hexahydrate has inherent shortcomings of supercooling characteristics, phase separation, and corrosion as a phase change material, and analyzed the methods of adding suitable nucleating agent and thickening agent to improve its performance.
At the same time, the application of magnesium chloride hexahydrate as a single or mixed phase change material in the field of energy storage is reviewed. The phase change gets larger after the enthalpyagnesium chloride hexahydrate is mixed with other salts (eutectic), which has good application prospects.
Magnesium chloride hexahydrate is a colorless monoclinic crystal. Industrial products are often yellowish brown, containing about 40-50% magnesium chloride, and also contain impurities such as magnesium sulfate and chloride, and have a bitter and astringent taste.
1. In the metallurgical industry, magnesium chloride hexahydrate is used as a refractory material and a binder for furnace walls. It is a material for producing No. 2 flux and smelting magnesium metal.
2. Magnesium chloride hexahydrate is a raw material for producing various magnesium salts in the chemical industry.
3. Magnesium chloride hexahydrate is a protein coagulant in the food industry and produces soy products.
4. Magnesium chloride hexahydrate is used in the construction industry to produce magnesium cement and used as an antifreeze during construction in winter.
5. Magnesium chloride hexahydrate can produce cotton defoliants in agriculture. In addition, it can also be used as coal mine fireproofing agent and highway dustproofing agent.