Zero discharge process for preparing potassium tripolyphosphate
US4935213A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1989 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Jul 31, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/41
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed is a method of making potassium tripolyphosphate by loading an ion exchange resin with either potassium or hydrogen ions and passing an aqueous solution of sodium tripolyphosphate through the resin so that the sodium ions of the sodium tripolyphosphate are exchanged with the ions loaded onto the resin, forming either potassium tripolyphosphate or tripolyphosphoric acid, respectively. The tripolyphosphoric acid is reacted with potassium hydroxide to form potassium tripolyphosphate. When the ion exchange resin becomes exhausted it is regenerated using a potassium-containing ionic solution, forming a sodium ion containing stream. The sodium ion containing stream is reacted with a phosphoric acid to form a stream of sodium phosphates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.