Industrial magnesium chloride is widely used, it is an important product of salt chemical industry, is the preparation of a variety of magnesium and magnesium compounds of the basic raw materials. Use it as raw material, can produce metal magnesium, No. 2 flux, magnesium carbonate, magnesium hydroxide, magnesium oxide, hydrochloric acid and other metallurgical and chemical products. In the construction industry, the use of magnesium chloride aqueous solution and magnesium oxide powder mixture, solidification can produce high strength magnesium oxide cement (3MgO · MgCl · 6 ~ 10H2O), used to process the production of building components, particleboard and so on. Magnesium oxide as a cement quick-setting early strength agent for the production of large cement pipes, poles, building base, commonly used in winter construction. Lime slurry powder wall, add a small amount of magnesium chloride as cement, the wall can not afford to dry powder. The use of magnesium chloride solution of ice salt eutectic temperature of -33.6 ℃ this feature, the refrigeration industry commonly used as a cold carrier. Spraying the magnesium chloride solution onto the surface of the coal has a good effect on the prevention of spontaneous combustion of low sulfur bituminous coal and lignite coal mining face.