Process for treating aqueous chemical waste sludges and compositions produced thereby
USRE29783E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Feb 8, 1977 |
| Grant date | Sep 26, 1978 |
| Priority date | — |
| Expiry date | Feb 8, 1997 |
Classification
- Technology area (CPC —)General
Abstract
Waste sludges containing small amounts of certain types of reactive materials are treated by adding to such sludges materials capable of producing aluminum ions, lime and/or sulfate bearing compounds to produce a composition having a sufficient concentration of sulfate ions, aluminum ions and equivalents thereof, and calcium ions and equivalents thereof. Fly ash is preferred source of aluminum ions for this purpose. Over a period of time such compositions harden by the formation of calcium sulfo-aluminate hydrates. Hardening of the sludge facilitates its disposition and may permit the reclamation of the land now occupied by large settling ponds for such sludge. Still further, the solidification of such settling ponds may provide permanent land fill which permits immediate use of the land without the necessity for removal of the sludge. Aggregate materials may also be incorporated in the solidified waste.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.