Eltech Systems Corporation

Diamond Shamrock Corporation

Ew Metals LLC

Jeries I Bishara

Jean M Hinden

James R Brannan

Anthony R Sacco

Roland J Horvath

Gerald R Pohto

Kenneth L Hardee

Lynne M Ernes

Henri B Beer

Andy W Getsy

Carl W Brown, Jr

Thomas J Schue

Thomas R Turk

Barry L Martin

Anthony J Vaccaro

Mary R Suchanski

Eric J Rudd

Mark R Honard

Joseph K Walker, Jr

Paul E Cook

Frans A Van Den Keybus

William A Kovatch

Disclosed is a method of recovering metal from waste plating stream and using the recovered metal comprising: providing a waste metal plating stream containing metal ions in an aqueous solution; passing the waste metal plating stream containing the metal ions into an electrochemical cell assembly having an inlet for the waste metal plating stream, a plurality of alternating anodes and cathodes porous to the waste metal solution and an exit from the cell; passing the waste metal plating stream through pores of the cathode; passing an electrical current through the anodes and cathodes, thereby depositing a portion of the metal ions onto the cathodes and reducing the amount of the metal ion in the solution from that in the introduced waste metal plating stream; recovering the deposited metal from the cathode; and using the recovered deposited metal as a source of soluble metallic anode to be deposited on to a substrate in a subsequent metal plating process.

Method of recovering metal ions recyclable as soluble anode from waste plating solutions

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

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.

Methods, and various apparatus therefor, are disclosed for the electrolytic treatment of an acidic solution. Generally the method comprises: (a) providing an electrolytic cell, the cell comprising: (i) an anode chamber and an anode therein; (ii) a cathode chamber and a cathode therein; and (iii) a diaphragm. Usually the diaphragm is of a non-isotropic fibrous mat comprising 5-70 weight percent organic halocarbon polymer fiber in adherent combination with about 30-95 weight percent of finely divided inorganic particulate impacted into said fiber during fiber formation, the diaphragm having a weight per unit of surface area of about 3-12 kilograms per square meter. The method can continue by (b) introducing the acidic solution into the cell; (c) impressing a current on the anode and the cathode causing the migration of ions through the diaphragm; and (d) recovering a product of the electrolytic treatment from the anode chamber, or the cathode chamber, or from both chambers. In one method, the acidic solution is a cell bath circulated to the anode chamber, while rinse solution downstream of the cell bath is circulated to the cathode chamber. The method, and apparatus therefor, are particularly applicable to the recovery of hexavalent chromium from a dilute chromium electroplating rinse solution.

Apparatus for electrolytic treatment of an electrolytic solution

Electrolytic treatment of an electrolytic solution

Compressed diaphragm and electrolytic cell

A method, and apparatus therefor, for the electrolytic treatment of an acidic solution which comprises: (a) providing an electrolytic cell, the cell comprising: (i) an anode chamber and an anode therein; (ii) a cathode chamber and a cathode therein; (iii) a diaphragm of a non-isotropic fibrous mat comprising 5-70 weight percent organic halocarbon polymer fiber in adherent combination with about 30-95 weight percent of finely divided inorganic particulate impacted into said fiber during fiber formation, the diaphragm having a weight per unit of surface area of about 3-12 kilograms per square meter; (b) introducing the acidic solution into the cell; (c) applying a DC voltage between the anode and the cathode causing the migration of ions through the diaphragm; and (d) recovering a product of the electrolytic treatment from the anode chamber, or the cathode chamber, or from both chambers. The method, and apparatus therefor, are particularly applicable to the recovery of hexavalent chromium from a dilute chromium electroplating rinse solution.

Electrolytic cell apparatus

A highly magnetic isotropic iron oxide powder with a uniform particle size distribution and particle size in the range from 0.005 to 0.2 micrometer consists of a mixed iron oxide exhibiting gamma (Fe.sub.2 O.sub.3) and ferrite (Fe.sub.3 O.sub.4) structure, having the empirical formula Fe.sub.72-x O.sub.96, where x has a value between 2 to 7, an aspect ratio of at most 2:1 and a temperature coefficient of coercivity of less than -0.7% per degree Celcius. The mixed oxide is optionally a cobalt-modified mixed iron oxide containing 2-6% by weight of cobalt and is obtained by heating ultrafine, ferrite particles in a controlled, oxidizing atmosphere at a temperature of 240.degree. C. to 320.degree. C. for a period of one to three hours.

Highly magnetic iron oxide powder

A porous high surface area composite electroconductive catalytic material, particularly as electrocatalyst for electrolysis electrodes, comprises a porous pre-formed matrix which is a catalytic mixed crystal material of at least one platinum group metal oxide and at least one valve metal oxide throughout which a subsequently-added additional catalyst preferably consisting of at least one platinum group metal and/or oxide is dispersed by chemideposition in an oxidizing or reducing atmosphere preferably followed by an annealing post heat treatment. The porous matrix may be ruthenium-titanium oxide and the additional catalyst advantageously comprises at least two oxides of ruthenium, rhodium, palladium and iridium, other combinations being possible.

Composite catalytic material particularly for electrolysis electrodes

An electrode having a lead base and a catalyst is manufactured by (a) compressing titanium sponge particles so as to consolidate them to a coherent porous layer, (b) applying the catalyst to the titanium sponge particles, and (c) fixing the layer of consolidated sponge particles to the lead base. The catalyst is formed on the titanium sponge particles before or after their consolidation to a coherent layer. This layer may be produced and fixed to the base in a single compressing and fixing step combining (a) and (c). Oxygen is anodically evolved at a reduced, stable potential by means of this electrode, so that it can be usefully applied as an anode in processes for electrowinning metals from acid electrolytes.

Manufacture of electrodes with lead base

Disclosed is an electrode for use in electrochemical processes wherein a metal substrate made of a valve metal mesh such as titanium carries a semiconductive intermediate coating consisting of tin and antimony oxides laid down upon the valve metal mesh in a series of layers and an electrocatalytically active top coating of an oxide of manganese, applied in a series of layers or by electroplating and subsequently baked in an oxidizing atmosphere at a temperature in the range of 380.degree. to 420.degree. C.

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Mentor, OH, United States of America

Jeries I Bishara