Introduction to physical and chemical properties of silica

Introduction of physicochemical properties of white carbon black by white carbon black manufacturers

      Melting point: 1610 °C (lit.)

      Boiling point: >100 °C (lit.)

      Density: 2.6 g/mL at 25 °C (lit.)

      Refractive index: n20/D 1.544 (lit.)

      Storage conditions: 2-8 ° C

      Form tablets (~0.5 g each)

      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 indicators

SiO2 content (dry product) ≥90%

Sieve residue (4.5цm) ≤ 0.5%

Heating loss: 4.0-8.0%

Burning loss: (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, the main physical properties (with rubber products)

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

Break elongation ≥675%