Inorganic silica gel is a highly active adsorption material, which is usually prepared by reacting sodium silicate and sulfuric acid and undergoing a series of post-treatment processes such as aging and acid foaming. Silica gel is an amorphous substance, and its chemical formula is mSiO2. nH2O. It is insoluble in water and any solvents, non-toxic, tasteless, chemically stable, and does not react with any substances except strong alkalis and hydrofluoric acid. Various types of silica gel form different microporous structures due to their different manufacturing methods. The chemical composition and physical structure of silica gel determine that has many characteristics which other similar materials are difficult to replace: high adsorption performance, good thermal stability, stable chemical properties, high mechanical strength, etc., household use as a desiccant, humidity Conditioner, deodorant, etc.; industrially used as oil hydrocarbon decolorizer, catalyst carrier, pressure swing adsorbent, etc.; separation and purification agent for fine chemical industry, beer stabilizer, paint thickener, toothpaste friction agent, matting agent, etc.
According to the size of its pore size, silica gel is divided into microporous silica gel, coarse pore silica gel, type B silica gel, and fine pore silica gel. Due to the difference in pore structure, their adsorption properties have their own characteristics. Coarse-pored silica gel has a higher adsorption capacity when the relative humidity is high, while fine-pored silica gel has a higher adsorption capacity than coarse-pored silica gel when the relative humidity is low. Type B silica gel has a pore structure between coarse and fine. Between the pores, the amount of adsorption is also between the coarse and fine pores.
Inorganic silica gel can also be divided into beer silica gel, pressure swing adsorption silica gel, medical silica gel, color-changing silica gel, silica gel desiccant, silica gel opening agent, and toothpaste silica gel according to its use.
Fine-pored silica gel is a colorless or slightly yellow transparent glass body. Its basic quality parameters are as follows: average pore distance 2.0-3.0nm, specific surface area 650-800㎡/g, pore volume 0.35-0.4ml/g, specific heat 0.92KJ /kg.℃, the thermal conductivity is 0.63KJ/m. hr.℃.
Uses: suitable for drying, moisture-proof and rust-proof. It can prevent instruments, meters, weapons and ammunition, electrical equipment, medicines, food, textiles, and other various packaging items from being damp, and can also be used as a catalyst carrier and dehydration refining of organic compounds. Because it has the characteristics of high bulk density and obvious moisture absorption effect under low humidity, it can be used as an air purifier to control air humidity. It is also widely used in sea transportation because the goods are often damp and deteriorated due to high humidity during transportation. The product can effectively dehumidify and prevent moisture, so that the quality of the goods can be guaranteed. Fine-pored silica gel is also commonly used for dehumidification between two parallel sealed window panels, which can maintain the transparency of the two layers of glass.
l Type B silica gel
Properties: Type B silica gel is milky white transparent or translucent spherical or massive particles. The pore structure of Type B gel is between coarse-pored silica gel and fine-pored silica gel. Basic quality parameters: pore volume is 0.60-0.85ml/g, average pore size is 4.5-7.0nm, specific surface area is 450-650m2/g.
Uses: Mainly used as air humidity regulator, catalyst and carrier, pet litter, and as a raw material for fine chemical products such as chromatography silica gel.
l Coarse pore silica gel
Coarse-pored silica gel, also called C-type silica gel, is a kind of silica gel. It is a highly active adsorption material and is an amorphous substance. Its chemical formula is mSiO2·nH2O. It is insoluble in water and any solvents, non-toxic, tasteless, chemically stable, and does not react with any substances except strong alkalis and hydrofluoric acid. The chemical composition and physical structure of coarse-pored silica gel determine that it has many other similar materials that are difficult to replace: high adsorption performance, good thermal stability, stable chemical properties, and high mechanical strength.
The appearance of coarse-pored silica gel is white, and there are three types of products: lump, spherical and micro-spherical. Coarse-pored spherical silica gel is mainly used for gas purifiers, desiccants and insulating oil deacidifies, etc.; coarse-pored block silica gel is mainly used for catalyst carriers, desiccants, gas, and liquid purifiers, etc.