Immobilization of lead and cadmium in solid residues from the combustion of refuse using lime and phosphate
This patent describes a method of immobilizing lead and cadmium in a free flowing particulate dry solid residue which maintains its free flowing particulate nature after the immobilizing treatment. The dry solid residue comprises fly ash and mixtures of fly ash with bottom ash resulting from the incineration of municipal waste, comprising contacting the dry solid residue with at least one water soluble phosphate in an amount equivalent to about 1 to about 8% by weight of phosphoric acid based on the total residue in the presence of a free lime source selected from the group consisting of lime, hydrated lime, flue gas scrubber product, and combinations thereof, in an amount sufficient to furnish from about 1 to about 25 parts by weight calcium hydroxide per 5 parts by weight of fly ash whereby the leaching of cadmium and lead is reduced to a level no more than 1 ppm cadium and 5 ppm lead as determined in an EPA test performed on the resulting dry treated residue.
- Assignee:
- Wheelabrator Environmental Systems Inc., Hampton, NH
- Patent Number(s):
- US 4737356
- OSTI ID:
- 5005414
- Resource Relation:
- Patent File Date: Filed date 28 Nov 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
LEAD
POLLUTION CONTROL
RESIDUES
LEACHING
CADMIUM
CALCIUM HYDROXIDES
COMBUSTION
EMISSION
FLY ASH
INCINERATORS
LIMESTONE
MUNICIPAL WASTES
PARTICULATES
PHOSPHATES
PHOSPHORIC ACID
REMOVAL
SCRUBBERS
US EPA
AEROSOL WASTES
ALKALINE EARTH METAL COMPOUNDS
ASHES
CALCIUM COMPOUNDS
CARBONATE ROCKS
CHEMICAL REACTIONS
CONTROL
DISSOLUTION
ELEMENTS
EQUIPMENT
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
METALS
NATIONAL ORGANIZATIONS
OXIDATION
OXYGEN COMPOUNDS
PARTICLES
PHOSPHORUS COMPOUNDS
POLLUTION CONTROL EQUIPMENT
ROCKS
SEDIMENTARY ROCKS
SEPARATION PROCESSES
THERMOCHEMICAL PROCESSES
US ORGANIZATIONS
WASTES
320604* - Energy Conservation
Consumption
& Utilization- Municipalities & Community Systems- Municipal Waste Management- (1980-)
510200 - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)