Method for treating incinerator ash
US5041398A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1989 |
| Grant date | Aug 20, 1991 |
| Priority date | — |
| Expiry date | Feb 22, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S106/01
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for treatment of incinerator ash typically including heavy metals and both water soluble and insoluble fractions. The insoluble fraction is first removed from the fly ash. The soluble fraction is treated to precipitate heavy metal compounds. Preferably, the heavy metal precipitates are incorporated in a vitrifiable batch. In a separate vitrifiable batch, the insoluble fly ash portions may also be incorporated. Most preferably, bottom ash from the incinerator is also incorporated in a glass batch. The bottom ash glass batch may also incorporate the insoluble fraction from the fly ash. Precipitation of the heavy metal constituents in the soluble portion of the fly ash is preferably accomplished by raising the pH of the solution, most preferably above 10 by addition of alkali metal or alkaline earth metal hydroxides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.