physical properties
Appearance: White powder or granular or irregularly shaped blocks.
True density: about 2.0g/mL
False density: about 0.2g/mL
High temperature resistance, non combustible, and good electrical insulation.
Chemical properties
Can react with caustic soda: SiO2 · nH2O+2NaOH=Na2SiO3+(n+1) H2O
Can react with hydrofluoric acid: SiO2 · nH2O+4HF=SiF4+(n+2) H2O
Main chemical indicators
SiO2 content (dry) ≥ 90%
Sieve residue (45 μ m) ≤ 0.5%
Heating reduction: 4.0-8.0%
Burning loss: (dry product) ≤ 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 145-165m2/g (HT2) 165-185m2/g (HT1)
200-300m/g（HT3）
Main physical properties (in combination with rubber products)
Tensile strength ≥ 17.0Mpa
Tensile strength ≥ 6.3Mpa
Tensile length ≥ 675%
