Patent ID: 8480785
Filing Date: 2013-07-09
Classification: C22B,Y02P

Abstract:
1. A method for recovering indium from an etching waste solution containing at least indium and ferric chloride, comprising immersing a precipitation-inducing metal which includes zinc and is made into the form of a solid such that any part coming into view three-dimensionally has a longitudinal length of 2.5 to 10 mm in the etching waste solution and allowed to stand, thereby allowing indium contained in the etching waste solution to precipitate on the surface of the precipitation-inducing metal based on a difference in ionization tendency between zinc and indium, detaching the indium precipitated on the precipitation-inducing metal to recover the indium, immersing the precipitation-inducing metal with indium precipitated on the surface thereof in hydrochloric acid to dissolve indium in the hydrochloric acid, supplying the hydrochloric acid solution with indium dissolved therein and the precipitation-inducing metal to a fluidizing apparatus which fluidizes the precipitation-inducing metal in the hydrochloric acid solution with indium dissolved therein and thereby fluidizing the precipitation-inducing metal in the hydrochloric acid solution in the fluidizing apparatus, precipitating indium again on the surface of the precipitation-inducing metal based on a difference in ionization tendency between zinc and indium, and detaching the indium precipitated on the precipitation-inducing metal to recover the indium.