Importance

Loading Importance Indicators...

Abstract

A metal recovery apparatus in which metal-laden fluid is cycled through an electrolytic cell at a relatively low flow rate, but fluid within the cell is forced to swirl at a relatively high speed to improve electroplating of metal on an electrode. Two fluid circuits are used to achieve the high speed within the cell: a fluid supply circuit runs fluid through the apparatus at a relatively low flow rate (about 2 to about 4 gallons per minute); a fluid circulation circuit boosts the speed of the fluid within the cell and forces it to swirl by discharging fluid drawn from the cell back into the cell at a relatively high flow rate (about 20 to about 40 gallons per minute). The apparatus includes inner and outer electrodes defining an annular space in which the fluid circulates. The outer electrode is preferably removable from the apparatus and is preferably the cathode. A seam in the cathode allows the cathode to be opened for removal of metal plated on the cathode. Current efficiency within the circulating fluid is optimized by using a cathode-to-anode surface area ratio of between about 1.8:1 and about 2.4:1, further enhancing recovery of metal from the fluid. The apparatus is particularly suited for the recovery of silver from photographic chemicals, especially bleach-fix solutions.

Loading the Abstract Image...

First Claim