Use of magnesium oxide

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Submitted by admin on Wed, 11/21/2018 - 07:54

Magnesium oxide is commonly known as bitter soil, also known as magnesium oxide. Magnesium oxide is a basic oxide and has the property of a basic oxide. It is a gelling material. White powder (light yellow is magnesium nitride), odorless, tasteless, non-toxic, is a typical alkaline earth metal oxide, chemical formula MgO. A white powder having a melting point of 2852 ° C, a boiling point of 3600 ° C and a relative density of 3.58 (25 ° C). Soluble in acid and ammonium salt solution, insoluble in alcohol. Solubility in water is 0.00062 g/100 mL (0 °C), 0.0086 g/100 mL (30 °C). Exposure to the air, easy to absorb water and carbon dioxide and gradually become basic magnesium carbonate, lighter products are faster than heavy products, combined with water to form magnesium hydroxide under certain conditions, slightly alkaline reaction, pH of saturated aqueous solution It is 10.3. Soluble in acid and ammonium salts are insoluble in water, and the solution is alkaline. Do not dissolve in ethanol. Strong refraction in the visible and near-ultraviolet range.

 Magnesite (MgCO3), white clouds (MgCO3·CaCO3) and seawater are the main raw materials for the production of magnesium oxide. Thermal decomposition of magnesite or dolomite gives magnesia. The seawater is treated with slaked lime to obtain magnesium hydroxide precipitate, and the magnesium hydroxide is burned to obtain magnesium oxide. The magnesium chloride halide block obtained by comprehensive utilization of seawater or the brine after bromine extraction may be used as a raw material, and sodium hydroxide or sodium carbonate may be added to form magnesium hydroxide or basic magnesium carbonate precipitate, and then calcined to obtain magnesium oxide. 

Magnesium oxide China's annual output is about 12 million tons.

Magnesium oxide is a measure of sulfur and pyrite in coal and sulfur and arsenic in steel. Used as a standard for white pigments. Light magnesium oxide is mainly used as a raw material for the preparation of ceramics, enamels, refractory crucibles and refractory bricks. Also used as a binder for polishing agents, coatings, and paper, accelerators and activators for neoprene and fluororubbers. After mixing with a solution such as magnesium chloride, it can be made into a magnesium oxide water balance. 3. It is used as an antacid and laxative in medicine for gastric acid and duodenal ulcer disease. Used as a catalyst in the chemical industry and as a raw material for the manufacture of magnesium salts. Also used in the manufacture of glass, dyed enamel, phenolic plastics, etc. Used in the heavy magnesia rice milling industry for firing and semi-rollers. The construction industry is used to manufacture artificial chemical flooring artificial marble heat-insulating panels. The plastics industry is used as a filler. Can also be used to produce other magnesium salts.

One of the main uses of magnesium oxide is as a flame retardant, a traditional flame retardant material, a flame retardant mixture of halogen-containing polymers or halogen-containing flame retardants. However, in the event of a fire, a large amount of smoke and toxic corrosive gases are generated due to thermal decomposition and combustion, which hinders fire fighting and personnel evacuation and corrosion of instruments and equipment. In particular, it has been found that more than 80% of fatal accidents in fires are caused by heavy smoke and toxic gases produced by materials. Therefore, in addition to flame retardant efficiency, low smoke and low toxicity are also essential indicators of flame retardants. The development of China's flame retardant industry is extremely unbalanced, and the proportion of chlorine-based flame retardants is relatively heavy. It is the first of all flame retardants, and chlorinated paraffin has a monopoly position. However, the chlorine-based flame retardant releases toxic gases when it acts, which is far from the non-toxic and high efficiency pursued by modern life. Therefore, in order to comply with the development trend of low smoke, low toxicity and pollution-free flame retardant in the world, the development, production and application of magnesium oxide flame retardant are imperative.