Lin G Gao

US Patent:

6524366, Feb 25, 2003

Filed:

Sep 22, 2000

Appl. No.:

09/668114

Inventors:

Purnesh Seegopaul - Flemington NJ
Lin Gao - Piscataway NJ

Assignee:

N.V. Union Miniere S.A. - Brussels

International Classification:

C22B 3436

US Classification:

75351, 75353, 75371, 148217, 148237, 423440

Abstract:

Tungsten carbide is formed from a tungsten material which is preferably tungsten carbide scrap. If scrap material is used, this is oxidized and acid leached to remove impurities and any binder material. This is then dissolved in a solution of sodium hydroxide and spray dried to form a precursor compound. A carbon compound such as citric acid can be added to the solution prior to spray drying to provide a carbon source for the tungsten carbide. The powder formed from the spray dried solution is calcined and carburized to form tungsten carbide.

US Patent:

6852303, Feb 8, 2005

Filed:

Sep 30, 2003

Appl. No.:

10/675078

Inventors:

Purnesh Seegopaul - Flemington NJ, US
Lin Gao - Piscataway NJ, US

Assignee:

N.V. Union Miniere S.A. et al. - Brussels

International Classification:

C01B003/16
C01B031/20

US Classification:

4234372, 423655

Abstract:

A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300 C. to maximum temperature 850 C. , a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750 C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.

US Patent:

20020172641, Nov 21, 2002

Filed:

Mar 26, 2001

Appl. No.:

09/817523

Inventors:

Purnesh Seegopaul - Flemington NJ, US
Lin Gao - Piscataway NJ, US

Assignee:

N.V. Union Miniere S.A.

International Classification:

C01B003/26

US Classification:

423/651000, 423/652000

Abstract:

A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300 C. to maximum temperature 850 C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750 C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.

US Patent:

59194286, Jul 6, 1999

Filed:

Dec 5, 1996

Appl. No.:

8/759234

Inventors:

Lin Gao - Piscataway NJ
Bernard Kear - Whitehouse Station NJ
Purnesh Seegopaul - Flemington NJ

Assignee:

Nanodyne Incorporated - New Brunswick NJ

International Classification:

C01B 3134

US Classification:

423440

Abstract:

Nanograined tungsten carbide particles are formed by a controlled, simultaneous reduction carburization reaction wherein the kinetics of the carburization and reduction reactions are controlled to permit simultaneous reduction and carburization. The kinetics are controlled by reacting a reduction carburization gas mixture, preferably hydrogen and carbon monoxide by slowly increasing the reaction temperature by controlling the rate of temperature increase. Preferably, the reaction temperature will be increased less than 25. degree. C. per minute, preferably about 1-2 degrees per minute, which prevents the formation of stable, undesirable species such as W. sub. 2 C, which in turn interferes with the reaction efficiency.

US Patent:

62076094, Mar 27, 2001

Filed:

Sep 30, 1999

Appl. No.:

9/412175

Inventors:

Lin Gao - Piscataway NJ
Purnesh Seegopaul - Flemington NJ

Assignee:

N.V. Union Miniere S.A. - Brussels

International Classification:

B01J27/22

US Classification:

502177

Abstract:

A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300. degree. C. to maximum temperature 850. degree. C. , a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750. degree. C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction.