Recovering iron from organic extractant soln. - by redn., then washing with water or aq. acid

摘要

Recovery of Fe cpds. from organic solns. contg. (a) =1 alkylphosphoric acid; dialkyl- or diaryl-dithiophosphoric acid; a phosphoric ester; oxime; prim., sec., tert. or quat. amine and (b) a mineral oil diluent, comprises first reducing Fe ions to lower oxidn. state then washing them out with water or aq. soln. of inorganic or organic acid. Pref. the wash soln. contains a reducing agent to prevent FeF3 formation. The FE-contg. soln. is esp. prod. by electrolysis of a waste acid soln. from metal cleaning in the anode compartment of a divided cell. A portion of the treated acid soln. is recycled, and Fe values extracted from the anolyte with alkylphosphoric acid etc. in mineral oil. The regenerated acid is recycled, while the extract is passed to Fe recovery. In processing of metal cleaning acids, the energy demands for acid regeneration are less and pollution control costs are reduced. Separation of Fe from other more valuable metals and to recover Fe from wastes is possible.