Classification and Categories of silica gel

Silica gel can be classified in different ways. For example, according to the classification of preparation method, use and nature.

According to the preparation method, silica gel can be divided into silica gel, silica sol, aerogel and fine silica gel products after secondary processing. According to the state, there are liquid, powder, block, spherical and powder shaped silica gel and various corresponding specifications. According to the purpose, it has industrial use, preparation and separation, chromatography analysis, packaging, etc.

Silica gel can be classified according to its properties in terms of chemical composition, purity and physical structure of pore size. The characteristics of silica gel and the differences between them largely depend on the characteristics of pore structure. Therefore, it is important to classify according to pore structure.

Silica gel is classified according to pore structure:

1. Fine porous silica gel (or standard density silica gel)

The average pore diameter of fine porous silica gel is 20-30 μ m, and the specific surface area is generally more than 600m2 / g. Silica gel in this category and its main specifications include:

Porous spherical silica gel - 1-2mm 2-5mm 3-4mm 1-3mm 4-8mm

Porous block silica gel - 1.5-4MM above 6mm, 2.8-7mm, 0.25-2mm

Water resistant silica gel with fine pores - 2-12mm (spherical)

Blue glue indicator - 1-2mm 1-3mm 2-5mm 3-4mm

Color changing silica gel - 2-5mm, etc

2. Coarse porous silica gel (medium density silica gel)

The average pore diameter of coarse porous silica gel is generally 80-125 μ m, and the specific surface area is 300-400m2/g, which varies due to different varieties and specifications. The main varieties and specifications of macroporous silica gel are as follows:

Coarse porous spherical silica gel - 1-2mm 2-5mm 3-4mm 1-3mm 4-8mm

Macroporous microsphere silica gel - 20-50 mesh 40-120 mesh 20-40 mesh 100-200 mesh

Coarse pore water-resistant silica gel - 2-12mm

Silica gel for column chromatography - 60-80 mesh 80-120 mesh 200-250 mesh 80-100 mesh 100-200 mesh 200-300 mesh

Silica gel for liquid chromatography-3 μ, five μ, seven μ, ten μ

Activated silica gel - 0.3-0.6mm

Coarse porous block silica gel - 1.5-4MM above 6mm, 2.8-7mm, 0.25-2mm

3. Macroporous silica gel (low density silica gel)

The average pore size of low-density macroporous silica gel is generally 120-300 μ m, the specific surface area is about 100-200 m2/g, and the pore volume is about 1.4-2.0ml/g. Silica, such as silica (as a reinforcing agent) and silica used for other dispersion and filling, are low-density macroporous silica.