The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Dec. 18, 1990

Filed:

Apr. 04, 1989
Applicant:
Inventors:

Haruhiko Iwano, Minami-ashigara, JP;

Fumio Nakagawa, Minami-ashigara, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25B / ; C25B / ; C02F / ; C25C / ;
U.S. Cl.
CPC ...
204 92 ; 204149 ; 204D / ; 204109 ;
Abstract

There is disclosed a method for recovering silver from photographic processing solution by electrolysis, in which method the cathode potential is set at a potential range wherein a precipitate of silver sulfide is formed in the electrolytic cell. According to the method, intensive silver recovering leading to low concentration of residual silver in the solution is achieved. Structure of electrolytic apparatus enabling easy separation of silver sulfide precipitates is also disclosed. Application of lead peroxide to the material of anode improves the life of the anode. Further advantages of the method are remarkable decreases in COD and iron contents of waste solution.


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