Jainagesh A Sekhar

US Patent:

6338785, Jan 15, 2002

Filed:

Apr 13, 1999

Appl. No.:

09/290766

Inventors:

Vittorio de Nora - Nassau, BS
Jainagesh Akkaraju Sekhar - Cincinnati OH
Jean-Jacques Duruz - Geneva, CH
James Jeng Liu - Cincinnati OH

Assignee:

Moltech Invent S.A. - Luxembourg

International Classification:

C25C 306

US Classification:

205390, 4273722

Abstract:

A method of protecting a cathode during the start-up procedure of an aluminum electrowinning cell where the cathode is optionally coated with an aluminium-wettable refractory material and when in use, aluminium is produced thereon. The start-up procedure comprises applying, before preheating the cell, one or more start-up layers in intimate contact on the aluminium-wettable refractory coating which form(s) a temporary protection against damage of chemical and/or mechanical origin to the aluminium-wettable coating; this temporary protection being eliminated before or during the initial normal cell operation. The temporary protection layers may be obtained from at least one pliable aluminium foil having a thickness of less than 0. 1 mm and/or an applied aluminium-containing metallization, optionally in combination with inter alia a boron-containing solution, a polymer, a phosphates of aluminium-containing solution, or a colloid that gels while preheating the cell, or combinations thereof.

US Patent:

6361680, Mar 26, 2002

Filed:

Oct 22, 1999

Appl. No.:

09/284523

Inventors:

Jainagesh Akkavaju Sekhar - Cincinnati OH
Vittorio de Nora - Nassau, BS

Assignee:

Moltech Invent S-A. - Luxembourg

International Classification:

C25C 308

US Classification:

205385, 2042431, 2042473, 2042901, 20429001, 20429012, 20429013, 295921

Abstract:

Method and cell component for the electrowinning of aluminum by the electrolysis of alumina dissolved in a molten fluoride electrolyte comprises a porous micropyretic reaction product of nickel, aluminum, iron, copper and at least one additive element selected from silicon, tin zinc, vanadium, indium, hafnium, tungsten, elements from the lanthanide series starting from praesodymium, and misch metal. The micropyretic reaction product contains metallic and intermetallic phases, with a composite oxide surface produced in-situ by anodic polarization of the porous micropyretic reaction product in a molten fluoride electrolyte containing dissolved alumina, or by high temperature treatment in an oxidizing gas. The composite oxide surface usually comprises an iron-rich relatively dense outer portion and an aluminate-rich relatively porous inner portion.

US Patent:

6402928, Jun 11, 2002

Filed:

Mar 31, 2000

Appl. No.:

09/446925

Inventors:

Vittorio de Nora - Nassau, BS
Jainagesh A. Sekhar - Cincinnati OH

Assignee:

Moltech Invent S.A.

International Classification:

C25C 308

US Classification:

205389, 205390, 205396, 204245, 204246, 204247, 20429001, 204293

Abstract:

A cell of advanced design for production aluminum by the electrolysis of an aluminum compound dissolve in a molten ectrolyte, has a cathode ( ) of drained configuration, and at least one non-carbon anode ( ) facing the cathode both covered by the electrolyte ( ). The upper part of the cell contains a removable thermic insulating cover ( ) placed just above the level of the electrolyte ( ). Preferably, the cathode ( ) comprises a cathode mass ( ) supported by a cathode carrier ( ) made of electrically conductive material which serves also for the uniform distribution of electric current feeders ( ) which connect the cathode carrier ( ) to the negative busbars.

US Patent:

6436250, Aug 20, 2002

Filed:

Jun 10, 1999

Appl. No.:

09/284524

Inventors:

Jainagesh Akkaraju Sekhar - Cincinnati OH
Jean-Jacques Duruz - Geneva, CH
James Jeng Liu - Cincinnati OH

Assignee:

Moltech Invent S.A. - Luxembourg

International Classification:

C25C 300

US Classification:

2042474, 252302, 427201

Abstract:

A refractory boride body or coating made of a boride of titanium, chromium, vanadium, ziconium, hafnium, niobium, tantalum, molybednum and cerium is produced from a slurry of the refractory boride or a precursor in a collidal carrier preferably composed of two more different grades of the same colloidal carrier selected from colloidal alumina, yttria, ceria, thoria, zirconia, magnesia, lithia, monoaluminum phosphate and cerium acetate. The slurry can also comprise an organic additive selected from polyvinyl alcohol; polyacrylic acid; hydroxyy propyl methyl cellulose; polythylene glycol; ethylene glycol, butyl benzyl phthalate; ammonium polymethacrylate and mixtures thereof. The retractory boride body or coated body is useful as a component of aluminum electrowinning cells.

US Patent:

6455107, Sep 24, 2002

Filed:

Apr 30, 1996

Appl. No.:

08/640115

Inventors:

Jainagesh A. Sekhar - Cincinnati OH
Vittorio de Nora - Nassau, BS

Assignee:

Moltech Invent S.A.

International Classification:

B05D 136

US Classification:

4274192, 427113, 4271261, 4274197, 501 31, 501 53, 501102, 501133

Abstract:

A body of carbonaceous or other material for use in corrosive environments such as oxidising media or gaseous or liquid corrosive agents at elevated temperatures, in particular in molten salts such as cryolite, is coated with a protective surface coating which improves the resistance of the body to oxidation or corrosion and which may also enhance the bodies electrical conductivity and/or its electrochemical activity. The protective coating is applied in one or more layers from a colloidal slurry containing reactant or non-reactant substances, or a mixture of reactant and non-reactant substances, in particular mixtures containing silicon carbide and molybdenum silicide or silicon carbide and silicon nitride, which when the body is heated to a sufficient elevated temperature reaction sinter as a result of micropyretic reaction and/or sinter without reaction to form the protective coating.

US Patent:

6607657, Aug 19, 2003

Filed:

Jul 25, 2001

Appl. No.:

09/915212

Inventors:

Vittorio de Nora - Nassau, BS
Jainagesh A. Sekhar - Cincinnati OH

Assignee:

Moltech Invent S.A.

International Classification:

C25C 308

US Classification:

205381, 205384, 205380, 2042431, 2042473, 204280

Abstract:

Carbon-containing components of cells for the production of aluminium by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte are protected from attack by liquid and/or gaseous components of the electrolyte in the form of elements, ions or compounds, by a refractory boride coating applied from a slurry composed of pre-formed particulate refractory boride in a colloidal carrier which is dried and heated to consolidate the coating.

US Patent:

6656340, Dec 2, 2003

Filed:

Jun 4, 2002

Appl. No.:

10/163013

Inventors:

Vittorio de Nora - Nassau, BS
Jainagesh A. Sekhar - Cincinnati OH

Assignee:

Moltech Invent S.A. - Luxembourg

International Classification:

C25C 306

US Classification:

205389, 205372, 205379, 205380, 205385, 205387, 205391, 205392

Abstract:

A cell of advanced design for the production of aluminium by the electrolysis of an aluminium compound dissolved in a molten electrolyte, has a cathode ( ) of drained configuration, and at least one non-carbon anode ( ) facing the cathode both covered by the electrolyte ( ). The upper part of the cell contains a removable thermic insulating cover ( ) placed just above the level of the electrolyte ( ). Preferably, the cathode ( ) comprises a cathode mass ( ) supported by a cathode carrier ( ) made of electrically conductive material which serves also for the uniform distribution of electric current to the cathode mass ( ) from current feeders ( ) which connect the cathode carrier ( ) to the negative busbars.

US Patent:

6783655, Aug 31, 2004

Filed:

Jun 27, 2002

Appl. No.:

10/183269

Inventors:

Jainagesh Akkaraju Sekhar - Cincinnati OH
Jean-Jacques Duruz - Geneva, CH
James Jenq Liu - Cincinnati OH

Assignee:

Moltech Invent S.A.

International Classification:

C25C 306

US Classification:

205372, 205230, 205381, 205383

Abstract:

A refractory boride body or coating made of a boride of titanium, chromium, vanadium, ziconium, hafnium, niobium, tantalum, molybednum and cerium is produced from a slurry of the refractory boride or a precursor in a collidal carrier preferably composed of two more different grades of the same colloidal carrier selected from colloidal alumina, yttria, ceria, thoria, zirconia, magnesia, lithia, monoaluminum phosphate and cerium acetate. The slurry can also comprise an organic additive selected from polyvinyl alcohol; polyacrylic acid; hydroxyy propyl methyl cellulose; polythylene glycol; ethylene glycol, butyl benzyl phthalate; ammonium polymethacrylate and mixtures thereof. The retractory boride body or coated body is useful as a component of aluminum electrowinning cells.

Address:

2310 Easthill Ave, Cincinnati, OH 45208

VIN:

WDBRF92H77F883761

Make:

MERCEDES-BENZ

Model:

C-CLASS

Year:

2007