Extraction of trace metals from fly ash
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsMilton Blander, Chien M. Wai, Zoltan Nagy
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Abstract
A process for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous, the fly ash having a silicate base and containing surface deposits of the trace metals as oxides, chlorides or the like, with the process being carried out by contacting the fly ash with AlCl.sub.3 in an alkali halide melt to react the trace metals with the AlCl.sub.3 to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.
Claims7
A process for recovering one or more trace metals from a fine grained fly ash having a silicate base and a surface with deposits of the trace metals in a concentration less than about 1 wt. %, the trace metal being selected from the group consisting of Ag, Cu, Fe, Cd, Ga, Mn, Pb, Ti, Zn and mixtures thereof, comprising the steps of
- contacting the fly ash with AlCl.sub.3 in an alkali halide melt for a time sufficient for the AlCl.sub.3 and trace metals to react and form trace metal compositions soluble in the melt and a silicate based residue, and
- separating the residue from the melt.
Dependencies are inferred from the claim text.