Purification of phosphoric acid by means of organic solvents
US4196180A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1978 |
| Grant date | Apr 1, 1980 |
| Priority date | — |
| Expiry date | Feb 27, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/462
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Contaminated phosphoric acid, particularly wet-processed phosphoric acid, is purified by extracting it from its aqueous solution by means of an organic solvent, which is immiscible or partially miscible with water and in which phosphoric acid is soluble, separating the phosphoric acid being dissolved in the organic solvent from extraction residue, and recovering the phosphoric acid from the organic solution. The aqueous phosphoric acid is more particularly mixed in a reaction zone, in a ratio by volume within the range 1:0.3 to 1:30, with a solvent having a boiling point higher than that of water or higher than that of the resulting water solvent-azeotrope, the phosphoric acid/solvent-mixture is heated to temperatures between the boiling point of water or of the said azeotrope and that of the solvent until distillation of substantially all uncombined water originally present in the mixture, and residue and resulting anhydrous phosphoric acid solution in the organic solvent are separated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.