Novel process and flotation chemistry for valuable metal recovery from municipal solid waste incineration (mswi) ash
AssigneePhinix, LLC
InventorsSubodh Das, Wencai Zhang
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Abstract
The present disclosure concerns processes and the combinations thereof for the enrichment and/or isolation of valuable metals from municipal solid waste incineration (MSWI) ash. Included are processes of size separation, froth floatation, magnetic separation, specific gravity separation, chemical separation, as well as the removal of lime. BY utilizing two or more, circuits of treatment are also provided that allow for fractionation of enriched valuable metals(s) from which purification thereof can be readily achieved.
Claims19
A method to concentrate one or metals from a municipal solid waste incineration (MSWI) ash comprising at least one step selected from:
- a. reducing the MSWI ash in size by crushing and sizing particles thereof from about 100 to about 400 mesh;
- b. adding the MSWI ash in a froth floatation solution to separate the MSWI ash in a froth floating fraction and a tailings fraction, wherein the froth floatation solution comprises a sulfide and a cationic collector;
- c. contact of the MSWI ash with a magnetic field to provide a magnetic fraction of the ash and a non-magnetic fraction of the ash;
- d. adding the MSWI ash to a float/sink solution with a specific gravity of 2.4-3.0 to provide a float fraction and a sink fraction;
- e. placing the MSWI ash in an aqueous solution and treating with a gas comprised of carbon dioxide to generate calcite-coated lime;
- f. treating the ash with a leaching solution to provide a leachate;
- or
- g. preparing a chemically separated fraction of the ash by solvent extraction, ion-exchange, selective precipitation, or passage through a membrane.
Dependencies are inferred from the claim text.