Method of separating heavy metals from complex-forming substances of aminocarboxylic acid type, or salts thereof in aqueous solutions
US4664810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1985 |
| Grant date | May 12, 1987 |
| Priority date | — |
| Expiry date | May 30, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Method of separating heavy metals from complex-forming substance of aminocarboxylic acid type, or salts thereof in aqueous solutions, as well as a method of removing heavy metals from the solutions containing said complex-forming substance. A solution containing heavy metals in complex form and complex-forming substances of aminocarboxylic acid type is contacted with a ion exchanger having polyethyleneimine active groups, whereupon free non-complexed heavy metal cations are displaced out of said ion exchanger by an acid solution of 0.5-30 percent concentration, and the ion exchanger is converted back into its active form by a solution of an alkali hydroxide, carbonate, or hydrogen carbonate of 0.5-30 percent concentration. The method is applicable in the treatment of waste water from electroless copper plating processes in the electronic industry, also for the removal of heavy metals in complex form from solutions left after ore leaching in the hydrometallurgical industry, and for purifying decontamination solutions in nuclear power stations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.