Magnesium oxide is highly refractory insulation properties, slightly soluble in water and organic solvents, can be dissolved in acid or salt solution, formula MgO, molecular weight 40.31. Magnesium oxide as a white light loose amorphous powder. Odorless, non-toxic. Light volume occupied by about three times the mass of about heavy magnesium oxide. Exposed in the air easily absorb moisture and carbon dioxide, insoluble in water and alcohol, soluble in dilute acid to form the corresponding magnesium salt solution. Used in metallurgy, smelting, advanced brick, refractory materials and moisturizing materials manufacturing, is also widely used in rubber, rubber sheet, rubber, pharmaceutical industry, food industry, plastic plate accelerator, glass, steel and silicon steel plasticizer surface coating of paint, the production of paper fillers and reinforcing agents, ball polishing agents, leather treatment, insulating material, oil, dyes, ceramics, desiccants, resins, rubber products used as a flame retardant fillers and reinforcing agents , ferrite, adhesives, chemical industry as a catalyst and the manufacture of other magnesium compound, enamel, ceramic, glass and other materials.