Views:8 Author:Site Editor Publish Time: 2019-12-16 Origin:Site
There is a difference between heavy and light magnesium oxide. The apparent density of light magnesium oxide is equal to or less than 0.5g/ml, while that of heavy magnesium oxide is about three times that of light magnesium oxide. The light is white amorphous powder, the heavy is white or beige powder, but the relative density of the two is 3.58, which is odorless and non-toxic; it can be dissolved in acid absorbing and ammonium salt solution, but almost insoluble in water overseas ethanol; the melting point is 2800 ℃, which has excellent thermal insulation and fire resistance. If it is kept in humid air for a long time, magnesium oxide will absorb the water and carbon dioxide in the air, generate acid magnesium carbonate and deteriorate. At the same time, light magnesium oxide and heavy magnesium oxide are easier to absorb water and carbon dioxide.
Heavy magnesium oxide is mainly used to make thermal insulation materials and refractories. Light magnesium oxide can be used as reinforcement and filler of plastics and rubber. It can also be used as inorganic accelerant and curing activator in rubber industry. It can be used as an acid inhibitor in the pharmaceutical industry, as a catalyst in the chemical industry, or as a raw material for other magnesium compounds. At the same time, it is also the raw material of dye, grease, enamel, ceramics, glass and other industries.
In NBR, MgO acts as the reinforcing agent of heat-resistant rubber. For example, the heat resistance of NBR with 100 parts of MgO is 177 ℃. Adding appropriate amount of MgO to chloroprene rubber can improve the hardness, constant elongation stress and tensile strength of vulcanizate, and also neutralize a small amount of hydrogen chloride produced by rubber during vulcanization or product under sunlight, but the heat resistance will be poor.
matters needing attention:
Magnesium oxide should be packed and sealed in polyethylene bags with protective bags; moisture proof measures should be taken, and the storage period should be less than 6-12 months.