Process for removing dissolved silica from extracted phosphoric acid
US4169881A · kind A · utility
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9Claims
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Key dates
| Filing date | Nov 14, 1977 |
| Grant date | Oct 2, 1979 |
| Priority date | — |
| Expiry date | Nov 14, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/462
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of purifying extracted phosphoric acid containing substantially no metallic impurities which comprises: PA1 (a) adjusting the phosphoric acid concentration to from 20 to 65 wt.% as P.sub.2 O.sub.5, PA1 (b) adjusting the Si/F atomic ratio in said extracted phosphoric acid to less than 0.2; and PA1 (c) contacting said extracted phosphoric acid with silica gel at a temperature of 20.degree.-100.degree. C. to remove the dissolved silica from said extracted phosphoric acid; and PA1 (d) recovering extracted phosphoric acid having a reduced silica content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.