PROCESS FOR RECOVERING ALUMINUM AND OTHER METALS FROM FLY ASH

摘要

ABSTRACT OF THE INVENTIONA process for recovering aluminum from fly ash con-taining iron, silicon and titanium which comprises: (a)chlorinating the fly ash in an oxidizing atmosphere toselectively chlorinate and vaporize iron chloride from theremaining chlorides, (b) chlorinating the residue fromstep (a) in a reducing atmosphere of carbon monoxide, inthe presence of added silicon chloride to suppress thechlorination of silicon, and vaporizing the chlorides ofaluminum, silicon, titanium, and the residual iron, (c)separating and recovering the vaporized chlorides byselective condensation, and treating the residue of step(b) with sulfuric acid to convert calcium chloride togypsum, and to regenerate a chloridizing and binder solutionfor pelletizing fly ash feed.