Microporous membrane process for making concentrated silica sols
US3969266A · kind A · utility
16Cited by
4References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 2, 1973 |
| Grant date | Jul 13, 1976 |
| Priority date | — |
| Expiry date | Jul 2, 1993 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B33/143
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Aqueous silica sols having a pH from 8 to 11 containing 1 to 40% by weight of colloidal silica and soluble salts can be purified and concentrated by filtering the soluble salt from the sol using a microporous membrane filter while maintaining the salt concentration within a range determined by the concentration of silica in the sol. In one embodiment, colloidal silica particles are grown to a larger size by starting with a sol of nuclei, and adding sodium silicate solution and acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.