Patent · US Expired

Apparatus for recovery of silver from spent, waste, acidic processing fluids

US4854552A · kind A · utility

13Cited by
8References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 1, 1987
Grant dateAug 8, 1989
Priority date
Expiry dateDec 1, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P10/20
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Apparatus for recovery of silver from spent, waste acidic silver halide photographic processing fluid, e.g., fixer solution, comprising passing the fluid through finely divided iron e.g., steel wool, contained in a vessel in the presence of a metal salt of copper or cadmium, e.g., copper(II)sulfate, copper chloride dihydrate, cadmium sulfate, etc. The ratio of iron to metal salt is 25 to 1 to 4 to 1.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.