Process for recovering mineral values from fly ash
A process is disclosed for recovering mineral values from fly ash in commercial quantities comprising forming an alkaline aqueous fly ash blend, filtering the alkaline aqueous fly ash blend and recovering a solids blend therefrom, leaching the solids blend with hydrochloric or hydrofluoric acid to form dissolved chloride or fluoride salts of iron, aluminum and other metals, electrolyzing the dissolved chloride or fluoride salt solution to plate out at least iron, and , optionally, one or more other metals, recovering silicon dioxide as a precipitate from the leaching solution, and recovering the leaching solution free of silicon dioxide. Neutralizing the leaching solution in a certain pH range permits precipitation and recovery of aluminum hydroxide as a solid. The hydroxide may then be converted to alum or alumina by conventional methods.
- Assignee:
- TIC; EDB-79-037137; ERA-04-023690
- Patent Number(s):
- US 4130627
- OSTI ID:
- 6520232
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
320305* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Industrial Waste Management
42 ENGINEERING
420900 -- Engineering-- Waste Processing Plants & Equipment-- (-1989)
AEROSOL WASTES
CHEMICAL REACTIONS
DESIGN
ELECTROLYSIS
ELEMENTS
FLY ASH
LYSIS
MANAGEMENT
MATERIALS RECOVERY
METALS
PROCESSING
RECOVERY
RECYCLING
WASTE MANAGEMENT
WASTE PROCESSING
WASTES