Silver recovery from spent bleach fix solutions

Details Silver recovery from spent bleach fix solutions Silver recovery from spent bleach fix solutions

1991-08-09

1993-04-13

Bowers, Jr., Charles L.

Radiation imagery chemistry: process, composition, or product th

Regenerating image processing composition

430400, 430460, G03C 5395, G03C 544, G03C 742, G03C 744

Patent

active

052022285

ABSTRACT:
Silver sulfide is reversed in a process for regenerating a dissolved silver-containing spent bleach fixer solution. The process is particularly suited for treating the bleach fixer solution in a manner which enables recycling of the solution giving rise to considerable reduction in cost of bleach fixer solution and reduced environmental pollution. The process comprises introducing a hydrosulfide reagent into the bleach fixer solution, which contains silver, to precipitate silver sulfide while maintaining pH and thiosulfate levels in the bleach fixer to allow for reuse. The precipitate is isolated from the bleach fixer solution to remove silver thereby and hence enable recycling of the bleach fixer solution. It is preferred to adjust the pH and sulfite levels following silver removal to complete the regeneration process.

REFERENCES:
patent: 483972 (1892-10-01), Whitehead
patent: 1446405 (1923-02-01), Thomas
patent: 1545032 (1925-07-01), Born
patent: 3709660 (1973-01-01), Urban
patent: 3832453 (1974-08-01), Slovonsky et al.
patent: 4127639 (1978-11-01), Piret et al.
patent: 4755453 (1988-07-01), Kunda et al.
patent: 5055382 (1991-10-01), Long et al.
Morana, "Silver Recovery From Waste Film by Burning", Proc. Int. Prec. Met., 1981, pp. 369, 377.
Kunda et al., "Recovery of Silver from X-Ray Film", Precious Met., 1986, pp. 289-304.
Kunda, "Processing of Photographic Spent Solution by Chemical Methods", Proc. 7th Int. Precious Met. Inst. Conf. 1984, pp. 185-192.
Schreiber, "Present Status of Silver Recovery in Motion-Picture Laboratories", Journal of the SMPTE, vol. 74, Jun. 1965, pp. 505-513.
"Recovering Silver from Photographic Materials", Kodak Pub. No. J-10, 1972, Eastman Kodak, pp. 1-16.
LaPerle, "The Removal of Metals from Photographic Effluent Sodium Sulphide Precipitation", SMPTE Journal, Apr. 1976, pp. 206-216.
Branch, "Silver Recovery Methods for Photoprocessing Solutions", Journal of Imaging Technology, vol. 14, No. 6, Dec. 1988, pp. 160-166.

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