Process for removal of mercury from hydroxyl-ammonium nitrate solutions
US5294417A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1992 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | Apr 6, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2101/20
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A process for the removal of mercury from industrial waste streams is disclosed wherein the waste stream is a nitrate based solution that has been decomposed by the addition of hypochlorite. The method involves adding a reducing agent to reduce the hypochlorite and/or adjusting the pH by the use of a strong acid to less than about 2.0, converting any residual chlorine to a soluble unreactive salt, adding a soluble precipitating agent, such as sodium sulfide, to the solution in a ratio to the mercury present of greater than 1:1 to about 2:1 to precipitate out the mercury as a mercury compound. The solution is then filtered to remove the precipitated mercury compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.