US 4,559,216 AGranted

Method for purification of sulfuric acid solution

AssigneeUnitika Ltd.

InventorsTadao Nagai, Yoshiaki Echigo

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Abstract

A method for purification of a sulfuric acid solution such as, for example, a copper electrolyte which entrains at least one metal ion species selected from the group consisting of antimony ions, bismuth ions, and iron ions and having a sulfuric acid concentration of at least 50 g/liter is disclosed. The method comprises exposing the sulfuric acid solution to a chelating resin possessing aminomethylenephosphonic acid group as a chelate forming group thereby effecting adsorptive separation of the aforementioned at least one metal ion species from the solution. By the method described above, the antimony ions, bismuth ions, and/or iron ions contained as impurities in the copper electrolyte can be easily and efficiently separated out of the system without entailing any ecological problem.

Claims15

Dependent claims

A method for purification of a sulfuric acid solution entraining a metal ion species selected from the group consisting of antimony ions, bismuth ions, or at least two metal ion species selected from the group consisting of antimony ions, bismuth ions and iron ions, and containing at least 50 g of sulfuric acid per liter, comprising:

exposing the sulfuric acid solution to a chelating resin possessing a group having methylene-phosphonic acid group substituted for a hydrogen atom or a primary or secondary alkylamino group incorporated as a chelate forming group into a resin matrix to effect adsorption on the chelating resin;
and
allowing the chelating resin to separate the metal ion species adsorbed on the chelating resin from the sulfuric acid solution, wherein the metal ion species separated by adsorption on the chelating resin is a metal ion species selected from the group consisting of antimony ions, bismuth ions or at least two metal ion species selected from the group consisting of antimony ions, bismuth ions and iron ions.

Dependencies are inferred from the claim text.