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1. (WO1991005882) SILVER RECOVERY FROM SPENT PHOTOGRAPHIC SOLUTIONS
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/005882 International Application No.: PCT/CA1990/000347
Publication Date: 02.05.1991 International Filing Date: 10.10.1990
Chapter 2 Demand Filed: 29.04.1991
IPC:
G03C 5/395 (2006.01)
G PHYSICS
03
PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
C
PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR OR STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
5
Photographic processes or agents therefor; Regeneration of such processing agents
26
Processes using silver-salt-containing photosensitive materials or agents therefor
395
Regeneration of photographic processing agents other than developers; Replenishers therefor
Applicants:
THE GOVERNORS OF THE UNIVERSITY OF ALBERTA [CA/CA]; 1-3 University Hall Edmonton, Alberta T6G 2J9, CA
Inventors:
KUNDA, Wasyl; CA
ETSELL, Thomas, H.; CA
Agent:
ERRATT, Judy, A.; Gowling, Strathy & Henderson 160 Elgin Street Ottawa, Ontario K1P 1C3, CA
Priority Data:
2,000,52712.10.1989CA
Title (EN) SILVER RECOVERY FROM SPENT PHOTOGRAPHIC SOLUTIONS
(FR) RECUPERATION DE L'ARGENT CONTENU DANS DES SOLUTIONS PHOTOGRAPHIQUES EPUISEES
Abstract:
(EN) A process is disclosed for recovering silver sulfide from a spent photographic fixer solution, which contains silver. The process is particularly suited for treating the fixer solution in a manner which enables recycling of the solution giving rise to considerable reduction in cost of fixer solution and reduced environmental pollution. The process comprises introducing a hydrosulfide reagent into the fixer solution, which contains silver, to precipitate silver sulfide while maintaining pH and thiosulfate levels in the fixer to allow for reuse. The precipitate is isolated from the fixer solution to remove silver thereby and hence enable recycling of the fixer solution.
(FR) Le procédé décrit sert à récupérer le sulfure d'argent contenu dans une solution de fixage photographique épuisée, qui contient de l'argent. Ce procédé convient particulièrement pour traiter la solution de fixage en vue de la recycler, ce qui permet de réduire considérablement les coûts en solutions de fixage et la pollution de l'environnement. Le procédé consiste à introduire un réactif d'hydrosulfure dans la solution de fixage, qui contient l'argent, afin de précipiter le sulfure d'argent, tout en maintenant les niveaux de pH et de thiosulfate de la solution de fixage, pour permettre sa réutilisation. Le précipité est isolé de la solution de fixage, pour en extraire l'argent, ce qui permet le recyclage de la solution de fixage.
Designated States: AT, AU, BB, BG, BR, CH, DE, DK, ES, FI, GB, GR, HU, JP, KP, KR, LK, LU, MC, MG, MW, NL, NO, RO, SD, SE, SU
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
African Intellectual Property Organization (BF, BJ, CF, CG, CM, GA, ML, MR, SN, TD, TG)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
FI921617NO19921424IL95847EP0565518US5162106JPH05506269
DE000069017052PT95565AU1990065010