Magnesium hydroxide, chemical formula Mg(OH)2, formula 58.32. White amorphous powder. The name is caustic soda, light burned magnesia, etc., the suspension of magnesium hydroxide in water is called magnesium hydroxide emulsion, referred to as magnesium milk, the English name is Magnesium hydroxide. Magnesium hydroxide is a colorless hexagonal column crystal or white powder, hardly soluble in water and alcohol, soluble in dilute acid and ammonium salt solution, and the aqueous solution is weakly alkaline. The solubility in water is small, but the water-soluble fraction is completely ionized. The concentration of the saturated aqueous solution was 1.9 mg/liter (18 ° C). Heating to 350 ° C loses water to form magnesium oxide. Natural mineral brucite of magnesium hydroxide. Can be used in sugar and magnesium oxide. Because magnesium hydroxide is abundant in nature and its chemical properties are similar to aluminum, users have begun to use magnesium hydroxide instead of aluminum chloride for fragrance products. Used as an analytical reagent and also used in the pharmaceutical industry.
Chemical properties: Magnesium hydroxide is a medium-strong base (magnesium hydroxide has a low solubility, the solution is very alkaline, sometimes treated as a weak base), heated to 623K (350 ° C), ie dehydration decomposition: Mg(OH) 2 →MgO+ H2O, soluble in acid or ammonium salt solution. As with magnesium oxide, it absorbs carbon dioxide in the air and gradually forms a basic carbonate having a composition of 5MgO·4CO2·xH2O. Decomposes to magnesium oxide and water at temperatures above 350 ° C, but only at temperatures above 1800 ° C can be completely dehydrated.
Application Field
1. Magnesium hydroxide is an excellent flame retardant for plastics and rubber products. As a flue gas desulfurizer in environmental protection, it can replace caustic soda and lime as a neutralizing agent for acid-containing wastewater. Also used as an oil additive to protect against corrosion and desulfurization. In addition, it can also be used in the electronics industry, medicine, sugar refining, as insulation materials and in the manufacture of other magnesium salt products.
2. Magnesium hydroxide has excellent buffering performance, reactivity, adsorption power and thermal decomposition properties, and can be used as chemical materials and intermediates, as well as a green environmentally friendly flame retardant and additive for rubber, plastic and fiber. And in polymer materials such as resins. Magnesium hydroxide is mainly used as a flame retardant, an acidic wastewater treatment agent, a heavy metal removal agent, a flue gas desulfurizer, etc. in the field of environmental protection.
3. This product can be used as a flame retardant or flame retardant filler to be added to polyethylene, polypropylene, polystyrene and ABS resin. It has good flame retardant and smoke eliminating effect, and the dosage is 40~20 parts. However, it is necessary to treat the surface of the particles with an anionic surfactant, and an anionic surfactant such as an alkali metal salt of a higher fatty acid or an alkyl sulfate or a sulfonated succinate may be used in an amount of about 3%. The product is also used in the manufacture of magnesium salts, the refining of sugar, the pharmaceutical industry, and household chemicals.
4. Magnesium hydroxide is a new type of filled flame retardant. It releases the bound water when it is decomposed by heat and absorbs a large amount of latent heat to reduce the surface temperature of the synthetic material it fills in the flame, which inhibits polymer decomposition and The effect of cooling the combustible gas produced. The magnesium oxide formed by decomposition is also a good refractory material, and can also help improve the fire resistance of the synthetic material, and the water vapor released by it can also be used as a smoke suppressant. Magnesium hydroxide is recognized as an excellent flame retardant with three functions of flame retardant, smoke suppression and filling in the rubber and plastics industry. Widely used in rubber, chemicals, building materials, plastics and electronics, unsaturated polyester and paints, coatings and other polymer materials. Especially for mine air duct coating cloth, PVC whole core conveyor belt, flame retardant aluminum composite panel, flame retardant tarpaulin, PVC wire and cable material, mining cable sheath, cable accessory flame retardant, smoke and antistatic It can replace aluminum hydroxide and has excellent flame retardant effect. Magnesium hydroxide has better smoke suppression effect than similar inorganic flame retardants. Magnesium hydroxide has no harmful emissions during production, use and disposal, and it also neutralizes the acidic and corrosive gases generated during combustion. When used alone, the dosage is generally 40% to 60%. It has good compatibility with the base resin. It is an excellent flame retardant for thermoplastic resins and rubber products. It is often used as an additive flame retardant or flame retardant filler in adhesives. The reference dosage is 40~200 parts. Industrially used in the manufacture of magnesium salts, active magnesium oxide, pharmaceuticals, fine ceramics, thermal insulation materials, sugar refining, flue gas desulfurizers, oil anti-corrosion additives, acid-containing wastewater neutralizers, color TV tube conical glass coatings, etc.
5. This product is also used in the manufacture of magnesium salts, the refining of sugar, the pharmaceutical industry, and daily chemicals. At the same time, the water vapor it emits can also be used as a smoke suppressant. Magnesium hydroxide is an excellent flame retardant with three functions of flame retardant, smoke suppression and filling in the rubber and plastics industry.
6. The milky suspension of magnesium hydroxide is medically used as an antacid and a laxative.
