Method for treatment and conversion of refuse incineration residues into environmentally acceptable and reusable material, especially for construction purposes
US5405429A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | May 12, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/91
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In the processing of mainly inorganic refuse incineration products polluted by heavy metals and/or heavy metal compounds, and/or analogues of such products, to give environmentally acceptable products by melt-thermal treatment, an iron-containing melt is used whose iron content can be adjusted by addition of iron or an iron compound. The melt is first melted above 1300.degree. C. in a reactor. The melt is then oxidized with vigorous agitation by blowing in oxygen-containing gas until all the metals and metal compounds present in the reactor have been converted to the oxide form, the melt being kept above 1450.degree. C. and preferably at about 1500.degree. C., at least at the end of the oxidation. Subsequently, the melt is reduced, preferably by means of a part fraction of the refuse incineration product and/or iron, preferably in the form of scrap, and/or hydrogen. The reduction can then be continued by means of added aluminum and/or calcium and/or ferrosilicon. If appropriate, metal melt is fractionated in a lower part of the reactor and slag melt is separately collected as a supernatant layer. Heating energy can be saved by heat exchange and recirculation of fluid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.