The Nature and Function of Magnesia

The main component of magnesia is carbonate magnetite. Dolomite’s main component is the crystals of MgCO3 CaCO3, accounting for 3.65-3.9 in artificial marble.The melting point is 2800  and the relative molecular weight is 40.3, according to the different production processes and purposes, it can be divided into following categories:1. Calcined magnesia is parted according to operating temperature points: the magnesite raw materials obtained after calcination of magnesium oxide is calcined magnesia. With coke as raw material in 1400-1800  firing heavy burned magnesium as magnesium oxide, also known as dead-burned magnesium, coal or gas as fuel in 700-1000  firing of magnesia is calcined magnesite, and said the caustic beauty; also use low-grade magnesite mixed with anthracite firing was the low level of magnesium oxide, also known as magnesia powder. The chemical composition of magnesite MgCO3, relative molecular weight of 84.31, the main component of MgCO3, minor components of CaO, SiO2, Fe2O3, Al2O3, MgO content of generally 35% -47%, mainly used for refractory dead-burned magnesia materials used in the manufacture of calcium magnesium carbon brick, magnesia chrome brick, insulation and heating electrical components filler, can be used for building materials, feed area2.Fused Magnesia is usually made of natural high-quality magnesite stone, water, magnesium ore, light-burned magnesia, dead burned magnesia and sea water magnesia and other raw material, through the three-phase electric arc furnace, the temperature controlled at 2800  above, according to the purity, crystal shape, and use can be divided; magnesium oxide single crystal, polycrystalline, high purity fused magnesia, electric appliance use and industrial use fused magnesia refractories, ceramics and other industrial use of magnesium3.Industrial magnesia is also knew as light magnesia. The one made by Mgcl.6H2o or sea brine system for raw materials is known as light magnesia. Magnesia using dolomite carbonization method can also be classified in this kind of the product. Light magnesium oxide is odorless. Odorless, nontoxic white amorphous powder, mainly for the manufacture of ceramics. Enamel. Refractories, polishing agent in adhesives, paint manufacturing as filler in synthetic rubber (chloroprene rubber. Fluorine rubber) the agent and catalyst for the promotion, in medicine as an antacid and laxative for the treatment of gastric hyperacidity and duodenal ulcer disease, in food processing when used as a bleaching agent of refined sugar, ice cream powder PH regulation agents.4. The role of heavy magnesia in industry is that magnesium oxide in the magnetic material used to replace light color TV deflection coils and other ferrite magnetic materials, steel ball polishing agent for polishing industry, electrical industry, the raw material for phenolic resin, dye industry against amino phenol production accessories, in ceramic glass, feed, industrial catalysts, the environmental protection industry also has applications. A light burning magnesium powder as raw materials, water-election, hydrolysis, solid-liquid separation dried, calcined and crushed obtained5.The active magnesia. In general, the high activity of magnesium oxide are ultrafine powder, Nickel oxide and refers to the size of the particles in the 10-1000nm, due to very small particle size of ultrafine particles, often in the magnetic, electric, acoustic, thermal and sensitivity, etc. performance of conventional materials do not have a special nature, as a new material is widely used, with citric acid activity value, indicating the activity of 12-25, the smaller the higher the activity, with the absorption of iodine that activity of 80-120 (mgI/100gMgO), specific surface area in between 5-20, depending on the specific volume in 6-8.5ml / g between the specific surface area due to its large, have high chemical activity and physical adsorption capacity , has a good sintering without sintering additives used to achieve low-temperature sintering, the preparation of high functional fine inorganic materials. Electronic components, printing ink, an important raw material harmful gas adsorbent can be made of high density low-temperature sintering ceramics and multi-crystalline magnesium oxide film, is expected to develop a high temperature, high corrosion under harsh conditions such as advanced materials with high activity and high dispersion, or even made into fibrous magnesium oxide, it is easy to compound with the polymer or other materials. Also, such ultra-fine magnesium oxide can be used as paint filler paper and cosmetics.6.Magnesia is mainly used for manufacturing-oriented silicon steel sheet, the main purpose is to manufacture silicon steel core and the transformer core motor, magnesium oxide is mainly used in the manufacture of high-temperature annealing process, annealing process in order to make the iron metal atoms into There are rules-oriented arrangement, while the silicon surface to form a good insulating film, the role of magnesium oxide is first made as a silicon release agent in the high-temperature annealing, while it has and vitreous silica to form magnesium silicate insulation coating the role of It can remove silicon in high-temperature reaction of sulfur and phosphorus and other impurities in the role.7.Medicinal magnesia is mainly used for the pharmaceutical industry, and the acid used in the manufacture of drugs, and in the role of a strong and lasting gastric acid, does not produce carbon dioxide, generated during and after magnesium chloride, can cause mild diarrhea.8. Reagent-grade magnesia is mainly used for chemical analysis reagent, but also for adhesives, soft magnetic materials and high-tech fields.9. High-purity magnesia refers to more than 99% of the content. The bulk density is greater than 3.4g/cm3 sintered magnesia, magnesia production methods are high-purity magnesium compounds as raw materials. Has good high-temperature high-purity magnesia bending strength, slag resistance and corrosion resistance, can improve the life of steel-making furnace lining, it is widely used in steel-making furnace refractory lining. Also be used for ceramic materials, used in medical devices and defense industry.10. Electrical grade magnesia has special requirements in the application of the electric including chemical properties, particle shape, particle size distribution and crystal shape. Because magnesium is directly related to the electrical heating tube temperature and service life, so according to heating tube manufacturing process to select a different level of electrical performance, and magnesium oxide.Source:http://www.mhcocm.com