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US 4,678,647 AGranted
Process for the recovery of gallium and germanium from coal fly ash
AssigneeEnron Corp.
InventorsBohdan Lisowyj, David C. Hitchcock, Henry Epstein
Life of this patent
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Abstract
A method is disclosed for recovering gallium and/or germanium from fly ash which comprises pelletizing the fly ash, treating the pellets in the presence of an oxidizing gas at a temperature of from about 900.degree. C. to just below the fusion temperature of the pellets, treating the pellets in the presence of a reducing gas at the same temperature range, and recovering gallium and/or germanium suboxides from the gas.
Claims11
A method of recovering gallium and germanium from fly ash which comprises:
- (a) pelletizing the fly ash, then
- (b) heating the pellets in an oxidizing atmosphere at a temperature of from about 900.degree. C. to just below the fusion temperature of the pellets, the temperature being high enough to remove trace elements volatile in an oxidizing atmosphere, then
- (c) treating the pellets in a reducing atmosphere at a temperature of from about 900.degree. C. to just below the fushion temperature of the pellets to reduce the gallium and germanium oxides to suboxides and cause them to sublime, and then
- recovering the gallium and germanium suboxides from the gas.
1 more element
Dependencies are inferred from the claim text.