METHOD OF AND APPARATUS FOR RECOVERING SILVER FROM SPENT PHOTOGRAPHIC FILM FIXING AGENT

摘要

l. A method and device for the recovery of silver from photographic film fusers, especially colour ones, based on the electroreduction of silver ions, wherein the initial phase of the electrolysis process is conducted so that the current gradually increases in phase one of the process by a constant value, from the minimum (Imin) to the maximum value (Imax), then, in phase two of the process the maximum (Imax) and minimum (Imin) current value is maintained alternately, with the cycle of the alternating change in current value in phase two being repeated many times, concurrently conducting a measurement of the inter-electrode voltage value, and phase two ending when the end-voltage (Uend) value is no longer stable, to which value the initial-current value (Uinit) determined at the start of phase two increases, and then, in phase three, the electrolysis current gradually drops from the maximum (Imax) to the minimum (Imin) value, preferably in a time equal to the duration of phase one.