Method for recovering metals from waste
US5843287A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1996 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Jan 19, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/22
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300.degree.-800.degree. C. to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000.degree.-1,550.degree. C. at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.