High purity fine metal powders and methods to produce such powders

• US 20030126948A1
• Filed: 12/10/2002
• Published: 07/10/2003
• Est. Priority Date: 02/15/2000
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: NanoProducts Corporation (Nouryon BV)
• Inventors: Pfaffenbach, Karl, Yadav, Tapesh, Dirstine, Roger
• Granted Patent: US 6,786,950 B2
• Time in Patent Office: Days
• US Class Current: 75/346
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0886 Gas-solid
• CPC Class Codes: B01J 2219/0894 Processes carried out in the presence of a plasma
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/12 starting from gaseous material
• CPC Class Codes: B22F 9/14 using electric discharge
• CPC Class Codes: B22F 9/30 with decomposition of metal compounds, e.g. by pyrolysis
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/14 Methods for preparing oxides or hydroxides in general particular individual oxides or hydroxides, see the relevant groups of subclasses C01B - C01G or C25B, according to the element combined with the oxygen or hydroxy group
• CPC Class Codes: C01B 13/20 by oxidation of elements in the gaseous state; by oxidation or hydrolysis of compounds in the gaseous state
• CPC Class Codes: C01B 21/06 Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boronazides C01B21/08
• CPC Class Codes: C01B 21/0828 Carbonitrides or oxycarbonitrides of metals, boron or silicon
• CPC Class Codes: C01B 32/956 Silicon carbide
• CPC Class Codes: C01B 32/977 Preparation from organic compounds containing silicon
• CPC Class Codes: C01F 17/218 Yttrium oxides or hydroxides
• CPC Class Codes: C01F 17/235 Cerium oxides or hydroxides
• CPC Class Codes: C01F 5/06 by thermal decomposition of magnesium compounds calcining magnesite or dolomite C04B2/10
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 19/00 Compounds of tin
• CPC Class Codes: C01G 25/00 : Compounds of zirconium
• CPC Class Codes: C01G 49/04 : Ferrous oxide [FeO]
• CPC Class Codes: C01G 49/06 : Ferric oxide [Fe2O3]
• CPC Class Codes: C01G 49/08 : Ferroso-ferric oxide [Fe3O4]
• CPC Class Codes: C01G 53/04 : Oxides; Hydroxides
• CPC Class Codes: C01P 2002/34 : perovskite-type (ABO3)
• CPC Class Codes: C01P 2002/52 : containing elements as dopants
• CPC Class Codes: C01P 2004/54 : Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2004/61 : Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 : Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 : Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 : Surface area
• CPC Class Codes: C01P 2006/80 : Compositional purity
• CPC Class Codes: C04B 2235/3205 : Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
• CPC Class Codes: C04B 2235/3206 : Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 : Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3215 : Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3224 : Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 : Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 : Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3236 : Alkaline earth titanates
• CPC Class Codes: C04B 2235/3249 : containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT)
• CPC Class Codes: C04B 2235/3272 : Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• CPC Class Codes: C04B 2235/3282 : Cuprates
• CPC Class Codes: C04B 2235/3286 : Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3293 : Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3427 : Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/3804 : Borides
• CPC Class Codes: C04B 2235/3817 : Carbides
• CPC Class Codes: C04B 2235/3826 : Silicon carbides
• CPC Class Codes: C04B 2235/3852 : Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3895 : Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/449 : Organic acids, e.g. EDTA, citrate, acetate, oxalate
• CPC Class Codes: C04B 2235/5409 : expressed by specific surface values
• CPC Class Codes: C04B 2235/5445 : submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/5454 : nanometer sized, i.e. below 100 nm
• CPC Class Codes: C04B 2235/72 : Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/721 : Carbon content
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions

Abstract

A method of producing metal and alloy fine powders having purity in excess of 99.9%, preferably 99.999%, more preferably 99.99999%. Fine powders produced are of size preferably less than 10 micron, more preferably less than 1 micron, and most preferably less than 100 nanometers. Methods for producing such powders in high volume, low-cost, and reproducible quality are also outlined. The fine powders are useful in various applications such as biomedical, sensor, electronic, electrical, photonic, thermal, piezo, magnetic, catalytic and electrochemical products.

Claims

1. A process for producing fine metal powder comprising:

providing a feed composition wherein the feed composition comprises a fluid precursor;

processing the precursor at a temperature greater than 2000°

C. in a gas comprising oxygen; and

transforming the precursor to fine metal powder.

2. The process of claim 1, where the temperature is greater than 3000°

C.

3. The process of claim 1, wherein the fine metal powder comprises a submicron powder.

4. The process of claim 1, wherein the fine metal powder comprises a nanoscale powder.

5. The process of claim 1, wherein the purity of the fine metal powder is greater than 99.9% on metal basis.

6. The process of claim 1, wherein the purity of the fine metal powder is greater than 99.99% on metal basis.

7. The process of claim 1, wherein the fine metal powder comprises a multimetal composition.

8. The process of claim 1, wherein the fine metal powder comprises nickel.

9. The process of claim 1, wherein the fine metal powder comprises a metal from the group consisting of:

aluminum, silicon, titanium, and zirconium.

10. The process of claim 1, wherein the fine metal powder comprises a metal from the group consisting of:

iron and copper.

11. A process for producing fine metal powder comprising:

providing a feed precursor;

processing the feed precursor at a temperature greater than 2000°

C. in a plasma reactor in a gas comprising oxygen; and

transforming the feed precursor to fine metal powder.

12. The process of claim 11, where the temperature is greater than 3000°

C.

13. The process of claim 11, wherein the fine metal powder comprises a submicron powder.

14. The process of claim 11, wherein the fine metal powder comprises a nanoscale powder.

15. The process of claim 11, wherein the purity of the fine metal powder is greater than 99.9% on metal basis.

16. The process of claim 11, wherein the purity of the fine metal powder is greater than 99.99% on metal basis.