IPC Subgroup
C01B 33/158 Purification; Drying; Dehydrating
Introduced: January 1980
Last revised: January 2006
Full Title
Silicon; Compounds thereof > Silicon oxides; Hydrates thereof > Silica; Hydrates thereof, e.g. lepidoic silicic acid > Colloidal silica, e.g. dispersions, gels, sols > After-treatment of gels > Purification; Drying; Dehydrating
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- INORGANIC CHEMISTRY
- Subclass:
- NON-METALLIC ELEMENTS; COMPOUNDS THEREOF