GB1500748A - Method and apparatus for electrolytic recovery of silver from photographic fixing baths - Google Patents

Abstract

1500748 Electrolytic recovery of silver GALAFIT SNC DI ARRIGONI & C 23 Oct 1975 [12 Dec 1974] 43542/75 Heading C7B Silver is electrolytically recovered from a photographic fixing bath by simultaneously supplying voltage from a variable voltage generator to an electrolytic silver recovery cell 6 and an auxiliary electrolytic test cell 14, both cells containing the liquid of the bath, increasing the voltage to a value at which silver deposited on the cathode 18 of the test cell is sulphurized, terminating the voltage supply to the test cell, and continuing electrolytic recovery of silver in the cell 6 with the voltage initially at the value. The test cell may be a glass vessel 14, in which are immersed steel electrodes 16, 18, disposed on one side of a cabinet (10), Fig. 1 (not shown), on the front face of which are arranged a 3-section and 3-position switch 30, scale (24) and control knob (26) for regulating the setting of a device 3 of a voltage changer 15 connected to electrical supply leads 34 mounted inside the cabinet with a transformer 4, rectifier diode 7 and geared motor 13 for automatically operating the changer 15 via a drive shaft; a button 28 may be provided for (un)coupling the motor shaft to the regulating device 3. The recovery cell 6 may comprise two parallel steel plate cathodes 56, 58 between which is disposed at least one parallel graphite plate anode 60, and a stirring belt (52), Fig. 3 (not shown) with projections (54), moving around rollers (48, 50) driven by electric motor 40 between the cathode and the or each anode.