Wolfgang A Hochleitner

US Patent:

53470745, Sep 13, 1994

Filed:

Apr 27, 1993

Appl. No.:

8/053985

Inventors:

Wolfgang A. Hochleitner - Allentown PA
Stephen P. Goff - Orefield PA

Assignee:

Air Products and Chemicals, Inc. - Allentown PA

International Classification:

C04B 1808
C04B 1806

US Classification:

588256

Abstract:

Fly ash generated from incineration of municipal solid waste (MSW) when placed in landfills can under mild acid conditions can leach lead and cadmium. A process for stabilizing heavy metals in this fly ash is presented which involves calcining the fly ash in the presence of an oxygen containing gas stream at a temperature greater than about 400. degree. C. and less than about 600. degree. C. for times from about 170 seconds up to about 5 hours fly ash which has been subjected to calcium scrubbing for acid gas removal. Such treated MSW fly ash will give leachates containing heavy metal concentrations less than the EPA regulatory limit.

US Patent:

53470737, Sep 13, 1994

Filed:

Apr 28, 1993

Appl. No.:

8/053798

Inventors:

Wolfgang A. Hochleitner - Allentown PA
Stephen P. Goff - Orefield PA

Assignee:

Air Products and Chemicals, Inc. - Allentown PA

International Classification:

B09B 300
C04B 1808

US Classification:

588256

Abstract:

Fly ash generated from incineration of municipal solid waste (MSW) when placed in landfills can under mild acid conditions 1each lead and cadmium. A process for stabilizing lead in this fly ash is presented which involves calcining a mixture of the fly ash and certain calcium-containing compounds in the presence of an oxygen containing gas stream at a temperature greater than about 475. degree. C. and less than about 600. degree. C. for times from about 30 minutes up to about 5 hours. Such treated MSW fly ash will give leachates containing lead concentrations less than the EPA regulatory limit.