Method for fixing fluorine and phosphorus in waste water containing fluorophosphoric acid-derived compound to remove them
US6666973B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2002 |
| Grant date | Dec 23, 2003 |
| Priority date | — |
| Expiry date | Feb 12, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2303/18
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method is provided for fixing and eliminating fluorine and phosphorus in waste water wherein the waste water includes a fluorophosphate compound in which hydrochloric acid is added to the waste water including the fluorophosphate compound. The waste water to which hydrochloric acid has been added is heated in order to decompose the fluorophosphate compound into hydrogen fluoride and phosphoric acid, while hydrogen chloride gas located within a treating vessel in which the waste water is contained is introduced into a condenser provided outside of the treating vessel, and then a calcium salt is added to the waste water after decomposition in order to fix and eliminate fluorine and phosphorus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.