Process for reprocessing slag and/or ash from the thermal treatment of refuse
US6036484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1998 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Oct 9, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23G2209/30
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
In a process for reprocessing slag and/or ash from the thermal treatment of refuse, the refuse (1) is pyrolyzed, gasified or partially combusted in a first process step, heavy-metal-containing slag and/or ash (8) having a comparatively high carbon content being formed. Said slag and/or ash (8) is then heated in a rotary kiln (6) to a temperature below the melting temperature of the slag and/or ash (8) in a second process step, the slag and/or ash (8), prior to its discharge from the rotary kiln (6), dwelling sufficiently long in the rotary kiln (6), that the heavy metals present therein are converted into their metallic form by reduction at the carbon endogenous to the slag and the readily volatile heavy metals are transferred to the gas phase and are discharged from the rotary kiln (6) together with the flue gas (9), and finally a slag (15) depleted in heavy metals being discharged from the rotary kiln (6).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.