Eltech Systems Corporation

Dravo Lime Company

Lynne M Ernes

Kenneth L Hardee

Richard C Carlson

Richard J Coin

Andy W Getsy

Marilyn J Niksa

Carl W Brown, Jr

Barry L Martin

David E Thomas

Gerald R Pohto

Jeries I Bishara

Thomas J Schue

Thomas R Turk

Edward M Halko

Albert R Prasnikar

Catherine M Lezan

Jean M Hinden

Thomas A Mitchell

Eric J Rudd

Mark L Arnold

Rudolf C Matousek

Zoilo J Colon

Gary F Wyman

Patrick E Visel

Joseph J Chance

There is disclosed a method for cooper electrowinning and a modified lead electrode for use in such method. The modified electrode is suitable for use as an oxygen anode in low current density, oxygen-evolving applications.

Copper electrowinning

The present invention pertains to electrolytic diaphragm cells, particularly for the electrolysis of brine to produce chlorine and caustic. The innovation resides generally in the discovery that electrolytic cell operation can be desirably enhanced by compressing the diaphragm between anode and cathode. This compression of the diaphragm reduces the diaphragm thickness from an original thickness, e.g., from an original thickness of a diaphragm freshly deposited on a cathode. The reduced thickness of the diaphragm provides for cell operation that is less than zero gap operation. By maintaining the diaphragm under compression and in a reduced thickness, the cell operates with a narrower interelectrode gap and consequently at a desirably reduced cell voltage.

Diaphragm cell

There is disclosed a method for copper electrowinning and a modified lead electrode for use in such method. The modified electrode is suitable for use as an oxygen anode in low current density, oxygen-evolving applications.

A compound electrode incorporating a lead substrate utilizes the lead as a support structure. This support structure provides a surface that engages a valve metal expanded metal mesh. The mesh member has a front and back surface with the back surface facing the lead support structure. At least the front surface of the mesh member is an active surface. Securing of the mesh member to the lead support structure in electrical connection permits the lead support structure to serve as a current distributor for the mesh member. The mesh member may engage the surface of the lead support structure by pressing or rolling the mesh onto the lead. Other engagement means can include the use of fasteners, or welding and the like. The resulting structure can be particularly useful as an electrode assembly for use in an electrolytic cell that serves for the electrowinning of a metal.

Lead electrode

An electrode is disclosed having a coating on part of the electrode, e.g., a front face, comprising the oxides of tin, antimony, at least one platinum group metal and at least one valve metal. Another part of the electrode, such as a back face, has a coating comprising the oxides of at least one valve metal and at least one platinum group metal. The electrode can be generally plate-shaped and most desirably has at least one chamfered corner. The electrode is particularly useful in a cell wherein brine electrolyte is electrolyzed to prepare a disinfectant solution containing hypochlorite. The disinfectant solution can be especially serviceable, such as in maritime application, for treating water, e.g., freshwater as represented by desalinated water.

Electrode and electrolytic cell containing same

A compound electrode incorporating a lead substrate utilizes the lead as a support structure. This support structure provides a surface that engages a mesh member, e.g., a valve metal expanded metal mesh. The mesh member has a front and back surface with the back surface facing the lead support structure. At least the front surface of the mesh member is an active surface. Securing of the mesh member to the lead support structure in electrical connection permits the lead support structure to serve as a current distributor for the mesh member. The mesh member may engage the surface of the lead support structure as by pressing or rolling the mesh onto the lead. Other engagement means can include the use of fasteners, or welding and the like. The resulting structure can be particularly useful as an electrode assembly for use in an electrolytic cell that serves for the electrowinning of a metal.

A method of preparing electrodes is now described, which electrodes have enhanced adhesion of subsequently applied coatings combined with excellent coating service life. In the method, a substrate metal, such as a valve metal as represented by titanium, is provided with a highly desirable rough surface characteristic for subsequent coating application. This can be achieved by various operations including etching to ensure a roughened surface morphology. In subsequent operations, a barrier layer is provided on the surface of enhanced morphology. This may be achieved by operations including heating, as well as including thermal decomposition of a layer precursor. Subsequent coatings provide enhanced lifetime even in the most rugged commercial environments.

Electrodes of improved service life

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 and electrochemical cell

Electrode, electrochemical cell and electrochemical processes

Electrode for electrochemical cell

Electrochemical process

A method of preparing electrodes is now described, which electrodes have enhanced adhesion of subsequently applied coatings combined with excellent coating service life. In the method a substrate metal, such as a valve metal as represented by titanium, is provided with a highly desirable rough surface characteristic for subsequent coating application. This can be achieved by various operations including etching and melt spray application of metal or ceramic oxide to ensure a roughened surface morphology. In subsequent operations: a barrier layer is provided on the surface of enhanced morphology. This may be achieved by operations including heating, as well as including thermal decomposition of a layer precursor. Subsequent coatings provide enhanced lifetime even in the most rugged commercial environments.

Method of preparing electrodes of improved service life

A metal surface is now described having enhanced adhesion of subsequently applied coatings. The substrate metal of the article, such as a valve metal as represented by titanium, is provided with a highly desirable surface characteristic for subsequent coating application. This can be initiated by selection of a metal of desirable metallurgy and heat history, including prior heat treatment to provide surface grain boundaries which may be most readily etched. In subsequent etching operation, the surface is made to exhibit well defined, three dimensional grains with deep grain boundaries. Subsequently applied coatings, by penetrating into the etched intergranular valleys, are desirably locked onto the metal substrate surface and provide enhanced lifetime even in rugged commercial environments.

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Willoughby, OH, United States of America

Lynne M Ernes