Improving Silver Recovery in Small Installations I. Expendable Electrodes

Abstract

To make the operation of the small-scale electrolytic desilvering of fixers more convenient, an attempt is made to design a system involving expendable electrodes. The factors controlling the relevant aspects of the electrolysis are discussed. Corrosion limited the choice of materials for expendable cathodes and excluded thin films of metals that were not excluded on price. Carbon-fibre was the material finally chosen and was formed into expendable cathodes as a sandwich between layers of netting material A practical, expendable cathode is described comprising a combustible plastic holder carrying a cylindrical carbon-fibre cathode through which the used fixer is pumped. It is used at 10 A. Silver does not plate onto this cathode but deposits in granular form Asa result the electrode is highly resistant to sulphiding.