Application scope and role of aluminum hydroxide

Aluminum hydroxide is white powder, insoluble in water, soluble in acid or alkali, is a typical amphoteric hydroxide, aluminum hydroxide, melting point 300 ℃, insoluble in water and alcohol, soluble in inorganic acids and alkali solutions. According to the use is divided into industrial grade and pharmaceutical grade two kinds.

Aluminum hydroxide has a wide range of uses, specific applications and roles are as follows:

1, chemical raw materials: because aluminum hydroxide can be produced on a large scale, sufficient raw materials, high purity products, and easily soluble in acids and alkalis. Therefore, aluminum hydroxide is an important raw material for the preparation of aluminum salts, such as barium aluminate, aluminum sulfate and so on.

2、Flame retardant: According to Beit Chemical, aluminum hydroxide powder is usually regarded as an ideal flame retardant filler for plastics, unsaturated polyester, rubber and other organic polymers because of its function of filling, flame retardant, smoke elimination and non-toxic and harmless. The flame retardant mechanism of aluminum hydroxide: when the temperature exceeds 200℃, aluminum hydroxide begins to absorb heat and decompose and release three crystalline water, and its decomposition rate is the largest at about 250℃. That is: this reaction is a strong heat-absorbing reaction, thus inhibiting the polymer temperature rise, reducing its decomposition rate, and only produce water vapor, will not generate toxic and harmful gases.

3, ceramics: aluminum hydroxide after high-temperature roasting to get alumina, and alumina has high thermo-chemical stability, thermal strength, creep resistance, dielectric properties and low coefficient of thermal expansion, is an important material for the synthesis of ceramics. In the process of ceramic synthesis, aluminum hydroxide activation and control of the crystallization process, so as to achieve the control of the phase formation of composite materials.

4, sewage treatment: Aluminum hydroxide in water to Al (OH) 4 - based, can be toxic heavy metals in the sewage through the co-precipitation method of precipitation down and then filtered to achieve the effect of water purification. Aluminum hydroxide has a high surface area, which can adsorb the colloids, suspended solids, dyes and organic matter in the sewage on the surface.

5, medicine: aluminum hydroxide can neutralize stomach acid, and non-toxic and harmless, is the traditional treatment of stomach problems. And aluminum hydroxide as an adjuvant can improve the immunogenicity of vaccines, the mechanism of its role in the antigen adsorbed on the surface of aluminum hydroxide, so that its slow release, to achieve the role of prolonging the efficacy of the drug.

6, catalyst carrier: as aluminum hydroxide in the preparation process, through the control of the reactant temperature, concentration and pH and other conditions to prepare a different specific surface area, pore volume, pore structure and crystal structure of the target product, can be effectively used as a catalyst carrier for the hydrogenation of unsaturated carbonyl compounds, the preparation of fullerenes and so on.

7、Paper industry: Aluminum hydroxide has high whiteness, ultra-fine particle size, complete crystalline form, and strong compatibility with whitening agents. As an additive of coating and resin, it can effectively improve the whiteness, opacity, smoothness and inking of coated paper.