Typical General Properties
• Apperance – Fluffy white powder
• Crystal structure of SiO2 – Amorphous


Hydrophilic Grades

SiO2 min. wt%99,999,999,999,999,9
Fe2O3 max. wt%0,0030,0030,0030,0030,003
Al2O3 max. wt%0,050,050,050,050,05
TiO2 max. wt%0,030,030,030,020,02
pH value3,6-4,53,6-4,53,6-4,53,6-4,53,6-4,5
Loss on drying
max. wt% (2hrs at 105°C)
Ignition loss max.
wt% (2hrs at 1000°C)
Bulk density, g/dm340-6040-6040-6040-6040-60
compacted density, g/dm3120-140120-140120-140110-140 -
BET surface area, m2/g 120±20150±20200±25300±30380±40
Sieve residue max.
wt% (acc. to Mocker 4,5μm)
max. 0,06max. 0,06max. 0,04max. 0,04max. 0,05


Hydrophobic Grades

SiO2 min. wt%99,0-99,399,0-99,5
Fe2O3 max. wt%0,010,01
Al2O3 max. wt%0,050,05
TiO2 max. wt%0,030,03
pH value≥ 3,9≥ 3,9
Loss on drying
max. wt% (2hrs at 105°C)
< 0,5< 0,5
Ignition loss max.
wt% (2hrs at 1000°C)
≤ 2≤ 2
Bulk density, g/dm340-5040-50
compacted density, g/dm351-10051-100
BET surface area, m2/g 120±20 *170±25 *
Hydrophobicity % **> 99,0> 99,0

* is not normalized, but actually maintained
** at boiling in the water for 30 min.