Eltech Systems Corporation

Zane A Wade

Gerald R Pohto

Edward M Halko

Kenneth L Hardee

Carl W Brown, Jr

Michael S Moats

Robert L Wilhelm

Kevin B Garland

H Kirk Fowler

Various systems and methods for protecting electrowinning anodes having electrocatalytically active coatings in a bank of electrolytic cells from being damaged by reverse currents. In the first embodiment, one or more auxiliary power sources are provided that, when triggered by one or more predetermined conditions being met, keep the bank of electrolytic cells in an electrical state that is relatively harmless to the anodes having electrocatalytically active coatings. In a second embodiment, the invention is directed to a method of maintaining the polarization of anodes in an electrowinning cell positive of the cathodes (i.e. in a potential region where the anode coating is not susceptible to significant damage). In a final embodiment, the invention is directed to various methods for the installation of replacement anodes and maintenance of electrowinning cells.

Anodic protection systems and methods

An existing, usually used radial lead anode in an electroplating cell is machined to a specific radius. This provides a curved, machined surface for the lead anode to serve as a support structure. A thin gauge, dimensionally stable sheet anode of a multitude of side-by-side strip anodes is formed, with each strip anode being typically formed to a larger radius then the radius of the support structure. The sheet anode strips may be precurved into a series of chords. The strip anodes are flexed into place onto the surface of the lead support structure. Fastening these strips and the support structure together can be accomplished by a series of fastening means attached to the back of each strip anode, which means can project into or through holes in the lead support structure. Electrical connection can be provided, such as through the fastening means, with the lead support structure serving as a current distributor member. The lead support structure, which may be slightly soluble in cell electrolyte, is protected by the sheet anode. Moreover, the sheet anode is readily removable, such as for renovation of an active anode coating.

Anode electroplating cell and method

Electrodes such as mesh electrodes can be in configurations where they are separated from electrode back pans by standoffs. The mesh electrodes are very adherently secured to the standoffs. When the electrodes are in need of repair, removal and refurbishing can be a problem. There is now disclosed a method of electrode repair which in large part retains original structure by first removing the mesh electrode and then at least substantially the top of the standoff. A replacement standoff assembly is placed against the retained portion of the original standoff and secured thereto. Refurbished or new electrode mesh can be adhered to the resulting replacement standoff. This may include welding of mesh electrode strands utilizing weld nuggets which are substantially the size of the strands. The refurbishing technique can maintain original separation distances between the back pan and the electrode. The structure provided can be in an 'as new' condition without need for repair at an off site location from where the electrode will be used.

Repair of mesh electrode spaced from electrode pan

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Montville, OH, United States of America

Zane A Wade