Silica is a general term for white powdered X-ray amorphous silicic acid and silicate products. It mainly refers to precipitated silica, fumed silica and ultrafine silica gel, as well as powdered synthetic silicic acid. Aluminum and calcium silicate. Silica is a porous substance whose composition can be represented by SiO2?nH2O, wherein nH2O is in the form of a surface hydroxyl group. Soluble in caustic and hydrofluoric acid, insoluble in water, solvents and acids (except hydrofluoric acid). High temperature resistance, non-combustible, odorless, odorless, and has good electrical insulation.

Properties

1, Physical properties

Appearance: white powder or granular or irregular agglomerates.

True density: about 2.0 g/ml. False density: about 0.2 g/ml (common product).

High temperature resistance, no burning; good electrical insulation.

2. Chemical properties:

Can react with caustic soda SiO2nH2O+2NaOH=Na2SiO3+(n+1)H2O

Can react with hydrofluoric acid SiO2nH2O+4HF=SiF4+(n+2)H2O

3. Main Chemical Index

SiO2 content (dry product) ≥90%

Sieve residue (4.5цm) ≤ 0.5%

Heating loss: 4.0-8.0%

Burning reduction: (dry) ≤7.0%

PH value: 5.0-8.0

Total copper content: ≤30mg/kg

Total manganese content: ≤50mg/kg

Total iron content: ≤1000mg/kg

DBP absorption value: 2.00-3.50cm/g

Specific surface area: different applications have different ranges, generally 145-165m/g (HT2) 165-185m/g (HT1)

200-300m/g (HT3)

3, Main physical properties (with rubber products)

Tensile strength ≥17.0Mpa 500% tensile strength ≥6.3Mpa

Break elongation ≥675%

Production Method