Process for chemical stabilization of heavy metal bearing dusts and sludges as EAF dust
US4840671A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1988 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Jul 29, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/912
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention is directed to a process for the chemical stabilization of heavy metal bearing dusts and sludges. A preferred use for such process is the treatment of dust from an electric arc furnace (EAF). In the production of steel by the electric arc furnace process, a by-product thereof is the generation of EAF dust. Such dust, by virtue of the presence of such elements as cadmium, hexavalent chromium and lead, is classified as hazardous waste by U.S. Environmental Protection Agency (EPA). The present invention is directed to a process for the chemical stabilization of the inorganic EAF dust to render the hazardous constituents thereof virtually immobile. Such process is based on the pozzolanic reaction of materials containing anhydrous alumino-silicates which, in the presence of lime, water and chemicals, adsorb and/or physically entrap the heavy metals present in EAF dust into a calcium-alumino-silicate matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.