US4080431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of refractory hard metal powder product
Assignee: PPG Industries Inc
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Filing: 1976-12-20
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Granted: 1978-03-21
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Expires: 1996-12-20
Abstract
Abstract Finely divided borides, carbides, and nitrides of metals of Groups III-VI of the Periodic Table, formed by reacting vaporous metal halide and a boron, carbon, or nitrogen source reactant at high temperatures, e.g., 1500° C., are separated from gaseous reactor effluent stream at temperatures between about 200° C. and 1500° C. with the use of a porous sintered filter. By separating the finely divided product from the effluent stream before the stream cools to below about 200° C., adsorption of impurities, e.g., unreacted metal halide or metal subhalides, on the product is reduced. The use of a filter, e.g., a porous sintered filter, avoids the size classification of product which may result when cyclones and a bag filter are used to collect product.
Inventors
- 👤 Robert L. Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:30
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/0084; B01D46/0091; B01D46/0093; B01D46/24; B01D46/2403; B01D46/66; B01D46/70; B01D46/71; B01D50/00; B01D50/60; C; C01; C01B; C01B21/00; C01B21/06; C01B21/064; C01B32/00; C01B32/90; C01B35/00; C01B35/02; C01B35/04; B01J; B01J2219/00; B01J2219/08; B01J2219/0894; C01P; C01P2004/00; C01P2004/50; C01P2004/60; C01P2004/61; C01P2004/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
192 words
In the process of producing refractory metal boride, carbide, or nitride powder of a metal selected from Groups III-VI of the Periodic Table of the Elements by vapor phase reaction of (a) a vaporous halide of the selected metal and (b) a vaporous source of boron, carbon, or nitrogen respectively, wherein reactants (a) and (b) are reacted in a reactor to form finely divided refractory metal powder and the resulting metal powder is recovered, the improvement which comprises: withdrawing from the reactor refractory metal powder entrained in the reactor effluent gas stream and forwarding directly said effluent gas into a filtration zone, the temperature of said refractory powder and effluent gas being at least 200° C., separating substantially all of the entrained finely divided refractory metal powder from the effluent gas stream in said filtration zone by passing the effluent gas stream through an inert porous metal filter, removing powder collected on the filter from the filter and forwarding the powder so removed to a receiver which is purged with inert gas and maintained at least at 200° C., and cooling the powder to less than 200° C. under an inert atmosphere.
Claim 2
Dependent Claim
192 words
In the process of producing refractory metal boride, carbide, or nitride powder of a metal selected from Groups III-VI of the Periodic Table of the Elements by vapor phase reaction of (a) a vaporous halide of the selected metal and (b) a vaporous source of boron, carbon, or nitrogen respectively, wherein reactants (a) and (b) are reacted in a reactor to form finely divided refractory metal powder and the resulting metal powder is recovered, the improvement which comprises: withdrawing from the reactor refractory metal powder entrained in the reactor effluent gas stream and forwarding directly said effluent gas into a filtration zone, the temperature of said refractory powder and effluent gas being at least 200° C., separating substantially all of the entrained finely divided refractory metal powder from the effluent gas stream in said filtration zone by passing the effluent gas stream through an inert porous metal filter, removing powder collected on the filter from the filter and forwarding the powder so removed to a receiver which is purged with inert gas and maintained at least at 200° C., and cooling the powder to less than 200° C. under an inert atmosphere.
Claim 3
Dependent Claim
17 words
The process of claim 1, wherein the ultimate particles of the refractory powder are submicron in size.
Claim 4
Dependent Claim
17 words
The process of claim 2, wherein the refractory powder is the diboride of titanium, zirconium, or hafnium.
Claim 5
Dependent Claim
26 words
The process of claim 3, wherein the refractory powder is titanium diboride, the metal halide is titanium tetrachloride, and the source of boron is boron trichloride.
Claim 6
Dependent Claim
15 words
The process of claim 1, wherein the temperature is between 200° C. and 600° C.
Claim 7
Dependent Claim
16 words
The process of claim 5, wherein the temperature is between about 260° C. and 370° C.
Claim 8
Dependent Claim
28 words
The process of claim 5 wherein the refractory powder is a boride, carbide or nitride of a metal of Groups IV-V of the Periodic Table of the Elements.
Claim 9
Dependent Claim
27 words
The process of claim 5 wherein the refractory powder is a boride or carbide of a metal selected from the group titanium, zirconium, hafnium, silicon, and tungsten.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |