Eltech Systems Corporation

Dravo Lime Company

Edward M Halko

Kenneth L Hardee

Lynne M Ernes

Marilyn J Niksa

Andy W Getsy

Richard J Coin

Zane A Wade

Gerald R Pohto

Carl W Brown, Jr

Robert L Wilhelm

Kevin B Garland

Michael S Moats

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 electrode, electrochemical cell, and electrochemical processes are disclosed. The electrode is a porous, multi-layered electrode which can have an element in flexible, strip form wound around a central, usually flat plate core, which core may serve as a current distributor. In any form, each layer can be represented by a very thin, highly flexible metal mesh. This can be a fine, as opposed to a coarse, mesh which has extremely thin strands and small voids. The electrode will have an active coating. For utilizing this electrode, the cell in one form will be a monopolar cell providing upward, parallel electrolyte flow through the porous, multi-layered electrode. A representative cell can have such electrode at least substantially filling an electrode chamber. The cells can be contained in a cell box that will provide the desired flow-through relationship for the electrolyte to the electrode. In cell operation, electrochemical processes which can be carried out include metal ion oxidation or reduction, oxidation of organic substituents, nitrate reduction as well as salt splitting.

Electrode, electrochemical cell and electrochemical processes

Electrochemical process

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

Growing community of inventors

Mentor, OH, United States of America

Edward M Halko