Development and application of brucite

Brucite is widely used in fire protection coating, paper making, Magnesium Oxide, magnesium chloride, environmental protection and other fields.



(1) fire retardant coatings



The water content of brucite is very high, about 31%. The differential thermal analysis of brucite shows that the thermal decomposition and dehydration temperature is between 420~520 degrees C, and the temperature is close to the burning temperature of general articles, so it can be used as a fire-retardant coating and a flame retardant. Japanese scholars have developed a kind of coating, which is made of cement, brucite and some other materials in a proper proportion of the mixture. The coating has the characteristics of light weight, good decoration, strong weathering resistance, good fire resistance and no spalling after fire. It can be used for surface coating of ship and advanced residence.



It is reported that at present, the consumption of flame retardants in the world is close to a million tons, of which about half of the inorganic substances, so the magnesium hydroxide has a great development space, the annual growth rate of the flame retardant of magnesium hydroxide in the United States is 15%, and the magnesium hydroxide has always maintained a high demand.



(2) paper industry



Brucite has the characteristics of high whiteness, good flaking, strong adhesion and no water absorption. The former Soviet Union used it as a papermaking filler together with calcite, making papermaking changed from acid to alkali and reducing the pollution of water. In the paper industry, brucite can replace lime in the process of producing magnesium based sulfite pulp, which can be used to recycle waste water and greatly reduce the pollution of waste water to the environment. Because brucite does not absorb water in air, it can also be used as a packing for moistureproof wrapping paper.



(3) preparation of Magnesium Oxide



Magnesium oxide can be prepared by calcining brucite directly because of its high content of magnesium oxide in brucite. The process is simple, the cost is low and it is easy to control. The refractory grade Magnesium Oxide has been made from water magnesium Shi Ke. Brucite as a refractory material has made great progress in foreign countries. Magnesium and dolomite are calcined into magnesium and calcium oxide at high temperature, then grinded, and then mixed with organic adhesives to suppress the molding. After two calcination, the refractory brick products are prepared. The high grade magnesia can be made by using brucite. Brucite as a refractory has been greatly developed abroad. Japan needs to import about 40-50,000 tons of brucite every year to meet the needs of industrial development.



Domestic scholars have compared the advantages and disadvantages of magnesium smelting with water magnesite, magnesite and serpentine, and discussed the feasibility and advantages and disadvantages of using the skin River method and semi continuous silicon heat method, and pointed out that magnesium hydrmaking with brucite has the advantages of reducing cost, saving energy, reducing environmental pollution and so on. It was also reported that some samples were produced from Liaodong brucite and made products.



(4) preparation of magnesium chloride



Anhydrous magnesium chloride is the main raw material for the electrolytic preparation of magnesium metal. At present, magnesium chloride is mainly prepared by chlorination of magnesite particles, and in order to supplement the lost chlorine gas and be prepared by the method of carnallite dehydration. There are abundant brucite resources in China. Brucite can be prepared by using brucite with the advantages of high magnesium content, less decomposition and heat absorption, and easy treatment of tail gas.



When magnesium chloride is used to prepare magnesium chloride, A is not easily broken when it is heated. It has better strength, faster chlorination and obvious advantages than magnesite. It is an ideal raw material for preparation of magnesium chloride.



(5) application in the field of environmental protection



Because of the composition characteristics of brucite, it can be used as neutralizing agent for acidic waste water. It is not only superior to traditional alkali substances (such as calcium hydroxide, sodium hydroxide, etc.) in many aspects, but also can greatly reduce the cost in the treatment and discharge of the product. In recent years, brucite has a great demand in treating acid rain contaminated soil, regulating soil pH value and neutralizing acid wastewater. Brucite can also be used as a flue gas desulphurizer. Brucite added to boiler fuel can reduce the harm of high mercury and sulfur fuels to boiler and reduce the emission of sulfur dioxide and other harmful gases. The deep processing of brucite into a kind of non-sedimentation and non-condensation active magnesium hydroxide can be widely used in the field of flue gas desulfurization.



(6) application in other fields



In addition to the above use, the brucite can be used to produce very dense, high thermal conductivity and electrical insulation, which is more than 2~3 times longer than the smelting of magnesite. If brucite and dolomite are calcined, the products can be used in the steel manufacturing industry to remove impurities such as P, S, and the slag; brucite and carbon. The products of calcination of calcium and calcium mixed at 800~1150 degrees can be used to treat beet sugar juice in the sugar industry as a decolorant.