Method for removal of nickel and iron from alkali metal hydroxide streams without requiring the use of sodium borohydride
US6123826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1999 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Oct 14, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25B1/46
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention relates to a method to control of the presence of nickel and/or iron in a caustic solution using at least two magnets to remove about one third of the nickel and/or iron present in a caustic solution. The method involves passing cell liquor through a first magnet at a flow rate of about 600-900 gallons per minutes removing a significant amount of nickel and/or iron from the cell liquor forming first fluid, then evaporating a significant amount of water out of that first fluid and raising the temperature of that first fluid to above 330 F., then cooling the more concentrated caustic solution to a temperature of between about 75 and 100 F. forming a cooled solution, passing the cooled solution through a second magnet and removing additional nickel and/or iron forming a second cooled solution, filtering that second cooled solution forming a filtered solution, passing the filtered solution through an optional third magnet to remove remaining nickel and/or iron forming a substantially metal free caustic solution .
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.