EP0425825A1
Expired / Lapsed
EP
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Nitride products and method and apparatus for their production
Assignee: Phillips Petroleum Co
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Filing: 1990-10-01
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Granted: —
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Expires: 2010-10-01
Abstract
Abstract A method and apparatus are provided for producing a product comprising a nitride compound, such as for example silicon nitride. A reactor is provided which has a chamber defined therein which is divided into a combustion zone and a reaction zone. A combustible mixture is injected into the combustion zone and accordingly combusted to form hot combustion products. At least one reactant (i.e. silane) is injected at the boundary between the zones so as to be carried into the reaction zone by the combustion products and react to form raw product comprising the nitride compound. The raw product can be purified by subsequent processing to remove oxygen and convert by-products to the desired nitride compound. The product of the invention has a low level of impurties and is made up of primarily submicron, highly uniform particles. This makes the product particularly useful for fabrication of sintered ceramic parts.
Inventors
- 👤 George Francis Schuette
- 👤 Kenneth E. Inkrott
- 👤 Bruce William Gerhold
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 05:04
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/064; B; B01; B01J; B01J12/00; B01J12/02; C01B21/068; C01B21/072; C01P; C01P2002/00; C01P2002/02; C01P2002/70; C01P2002/72; C01P2002/80; C01P2002/82; C01P2002/86; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/10; C01P2006/12
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
242 words
A method comprising the steps of: providing a reactor having a chamber defined therein which has a longitudinal axis and longitudinally separated upstream and downstream ends, wherein the chamber comprises a combustion zone and a reaction zone such that the combustion zone longitudinally extends from said upstream end to a boundary between the zones and such that the reaction zone longitudinally extends from said boundary to said downstream end; establishing a flow of a combustible mixture in the combustion zone so as to generally flow in a direction toward the reaction zone, wherein the combustible mixture comprises a mixture of a fuel and an oxidant; combusting the combustible mixture in the combustion zone to produce hot combustion products; injecting at least one reactant into said chamber at said boundary such that the hot combustion products carry said at least one reactant in the reaction zone toward said downstream end, wherein temperature conditions in at least a portion of the reaction zone are at least about 1300°C, in particular wherein said temperature conditions are in the range of about 1300°C to about 1700°C, and wherein the elemental molar ratio of carbon to oxygen for the combination of the combustible mixture and said at least one reactant is at least about 0.7:1, said at least one reactant being capable of reacting in so the reaction zone to form a nitride compound; whereby a product comprising the nitride compound is produced in the reaction zone.
Claim 2
Independent Claim
242 words
A method comprising the steps of: providing a reactor having a chamber defined therein which has a longitudinal axis and longitudinally separated upstream and downstream ends, wherein the chamber comprises a combustion zone and a reaction zone such that the combustion zone longitudinally extends from said upstream end to a boundary between the zones and such that the reaction zone longitudinally extends from said boundary to said downstream end; establishing a flow of a combustible mixture in the combustion zone so as to generally flow in a direction toward the reaction zone, wherein the combustible mixture comprises a mixture of a fuel and an oxidant; combusting the combustible mixture in the combustion zone to produce hot combustion products; injecting at least one reactant into said chamber at said boundary such that the hot combustion products carry said at least one reactant in the reaction zone toward said downstream end, wherein temperature conditions in at least a portion of the reaction zone are at least about 1300°C, in particular wherein said temperature conditions are in the range of about 1300°C to about 1700°C, and wherein the elemental molar ratio of carbon to oxygen for the combination of the combustible mixture and said at least one reactant is at least about 0.7:1, said at least one reactant being capable of reacting in so the reaction zone to form a nitride compound; whereby a product comprising the nitride compound is produced in the reaction zone.
Claim 3
Dependent Claim
46 words
A method as recited in claim 1 wherein the hot combustion products as produced by said combustion step provide at least about 15% of the energy needed to maintain said temperature conditions of at least about 1300°C in at least a portion of the reaction zone.
Claim 4
Dependent Claim
33 words
A method as recited in claim 1 wherein said elemental molar ratio is in the range of about 0.8:1 to about 1.2:1, in particular in the range of about 0.9:1 to about 1.1:1.
Claim 5
Dependent Claim
35 words
A method as recited in claim 1 wherein said fuel and oxidant are injected at a flow rate and the combustion zone is dimensioned such that there is substantially no free oxygen at said boundary.
Claim 6
Dependent Claim
52 words
A method as recited in claim 1 wherein the fuel comprises a hydrocarbon selected from the group consisting of an unsaturated hydrocarbon, a cyclic hydrocarbon, and mixtures thereof, in particular wherein said unsaturated hydrocarbon is selected from the group consisting of ethylene, propylene, butene, propadiene, butadiene, acetylene, propyne, butyne and mixtures thereof.
Claim 7
Dependent Claim
89 words
A method as recited in claim 1 wherein said at least one reactant comprises a first reactant, which includes a first component, and also a second reactant containing a second, nitrogen component, wherein said first and second reactants react to form said nitride compound which is a compound of said first component and said second, nitrogen component, in particular wherein said first reactant has a first component selected from the group consisting of silicon, boron, aluminum, tungsten, chromium, titanium and molybdenum more particularly wherein said first component is silicon.
Claim 8
Dependent Claim
68 words
A method as recited in claim 6 wherein said first reactant is selected from the group consisting of silane, a substituted silane, and mixtures thereof, in particular wherein said substituted silane is selected from the group consisting of an alkyl silane, an aryl silane, a halogenated methylsilane, a halogenated silane, a siloxane, a silazane, a silicon halide, and mixtures thereof, more particularly wherein said first reactant is silane.
Claim 9
Dependent Claim
33 words
A method as recited in claim 7 wherein said second reactant is selected from the group consisting of an amine, a hydronitride, and mixtures thereof in particular wherein said second reactant is ammonia.
Claim 10
Dependent Claim
74 words
A method as recited in claim 1 wherein said nitride compound is a compound of a first elemental component and a second, nitrogen component and wherein said at least one reactant consists essentially of a single reactant containing said first component, said method further comprises injecting into said chamber in admixture with said at least one reactant a carrier gas selected from the group consisting of helium, argon, hydrogen, carbon monoxide, and mixtures thereof.
Claim 11
Dependent Claim
71 words
A method as recited in claim 6 wherein said reactants are injected into the chamber in a direction generally perpendicular to its longitudinal axis in particular wherein said first and second reactants are substantially gaseous as injected into said chamber, and said fuel and oxidant are injected into the chamber at a location closely adjacent to the upstream end of the chamber in a direction generally parallel to the longitudinal axis.
Claim 12
Dependent Claim
107 words
A method as recited in claim 10 wherein there is provided a first nozzle which comprises a first tubular member having an outlet end which extends into the chamber, and wherein said reactants are injected into the chamber through the first tubular member and out the outlet end of the first tubular member, said method further comprising the step of flowing a generally annular stream of a gas around the first tubular member in the direction of the outlet end of the first tubular member so as to flow into the chamber and so as to generally surround said reactants as they flow from the outlet end.
Claim 13
Dependent Claim
81 words
A method as recited in claim 11 wherein there is further provided a second tubular member which generally surrounds the first tubular member so as to define therebetween a first generally annular space through which said gas flows in said generally annular stream, said second tubular member having an inner sidewall and an outer sidewall which define a second generally annular space therebetween, said method further comprising flowing a coolant fluid through the second annular space during injection of said reactants.
Claim 14
Dependent Claim
69 words
A method as recited in claim 12 wherein there is also provided a second nozzle comprising a third tubular member having an outlet end which extends into the chamber and through which fuel and oxidant are injected into the chamber, the third tubular member comprising inner and outer walls which define therebetween a third annular space, said method further comprising flowing a coolant fluid through the third annular space.
Claim 15
Dependent Claim
39 words
A method as recited in claim 13 further comprising the steps of: passing the powder formed in the reaction zone from such zone and through a heat exchanger wherein the powder is cooled; and collecting the thus cooled powder.
Claim 16
Dependent Claim
87 words
A method as recited in claim 14 further comprising the steps of: adding carbon to the thus collected powder; heating the thus collected powder with added carbon in the presence of a nitrogen-containing gas within the temperature range of about 1300°C to about 1900°C for a time of at least about 15 minutes; and then heating the thus collected powder with the added carbon in an oxygen-containing atmosphere within the temperature range of about 600°C to about 900°C for a time of at least about 15 minutes.
Claim 17
Dependent Claim
77 words
A method as recited in claim 15 wherein the thus collected powder is heated with the added carbon in the nitrogen-containing gas at a temperature of about 1400°C to about 1700°C for a time of about 1 hour to about 2 hours and the thus collected powder is heated with the added carbon in the oxygen-containing atmosphere at a temperature of about 600°C to about 700°C for a time of about 30 minutes to about 2 hours.
Claim 18
Dependent Claim
224 words
A product composition produced according to one the preceding claims which comprises silicon nitride and which is characterized by the following weight percentages: silicon in amount of about 40 weight percent to about 75 weight percent; nitrogen in the amount of about 10 weight percent to about 40 weight percent; carbon in the amount of about 1 weight percent to about 10 weight percent; and oxygen in the amount of about 1 weight percent to about 30 percent, in particular wherein said silicon is present in the amount of about 50 weight percent to about 70 weight percent, nitrogen is present in the amount of about 15 weight percent to about 35 weight percent, carbon is present in the amount of about 1 weight percent to about 6 weight percent, and oxygen is present in the amount of about 1 weight percent to about 20 weight percent, more particularly wherein said silicon is present in the amount of about 55 weight percent to about 65 weight percenc nitrogen is present in the amount of about 25 weight percent to about 35 weight percent, carbon is present in the amount of about 1 weight percent to about 3 weight percent, and oxygen is present in the amount of 1 weight percent to about 15 weight percent, even more particularly wherein said composition further comprises hydrogen.
Claim 19
Dependent Claim
26 words
A product composition as recited in claim 17 wherein said composition comprises particles having a diameter in the range of about 0.01 to about 0.5 micron.
Claim 20
Dependent Claim
37 words
A product composition as recited in claim 17 which comprises less than about 500 ppm elemental impurities, wherein such elemental impurities include aluminum and those elements of higher atomic numbers, except silicon, up to and including uranium.
Claim 21
Dependent Claim
123 words
A product composition as recited in claim 17 comprising oxygen in the amount of about 5 to about 15 weight percent and which is sinterable to a ceramic part having a density of at least about 2.7 g/cc by a process comprising: pressing said composition to produce a pressed ceramic part: heating said pressed ceramic part to a temperature of about 1500°C to about 1900°C so as to produce the sintered part having said density of at least about 2.7 g/cc; wherein no steps are performed prior to said heating step for removal of oxygen from said composition or pressed ceramic part produced therefrom, in particular wherein said composition is sinterable without applying compaction force to said ceramic part during said heating step.
Claim 22
Dependent Claim
126 words
A composition comprising silicon nitride and about 5 to about 15 weight percent oxygen which is sinterable to a sintered ceramic part having a density of at least about 2.7g/cc by a process comprising: pressing said composition to produce a pressed ceramic part; heating said pressed ceramic part to a temperature of about 1500°C to about 1900°C so as to produce the sintered part having said density of at least about 2.7g/cc; wherein no steps are performed prior to said heating step for removal of oxygen from said composition or pressed ceramic part produced therefrom, in particular wherein it is sinterable to a sintered ceramic part having a density of at least about 2.7g/cc without applying compaction force to said ceramic part during said heating step.
Claim 23
Dependent Claim
126 words
A composition comprising silicon nitride and about 5 to about 15 weight percent oxygen which is sinterable to a sintered ceramic part having a density of at least about 2.7g/cc by a process comprising: pressing said composition to produce a pressed ceramic part; heating said pressed ceramic part to a temperature of about 1500°C to about 1900°C so as to produce the sintered part having said density of at least about 2.7g/cc; wherein no steps are performed prior to said heating step for removal of oxygen from said composition or pressed ceramic part produced therefrom, in particular wherein it is sinterable to a sintered ceramic part having a density of at least about 2.7g/cc without applying compaction force to said ceramic part during said heating step.
Claim 24
Independent Claim
220 words
An apparatus comprising: a reactor having a chamber defined therein, said chamber having an upstream end and a downstream end; so a first nozzle which has an outlet end which communicates with said chamber at a position intermediate to said upstream and downstream end. said first nozzle comprising first and second tubular members having respective interior and exterior surfaces, and wherein said first tubular member is generally coaxially positioned within said second tubular member such that a first generally annular space is defined between the interior surface of said second tubular member and the exterior surface of said first tubular member; means for passing at least one reactant through said first tubular member so as to exit said first tubular member at said outlet end and into said chamber, wherein said at least one reactant is capable of reacting in said chamber to form a nitride product; means for passing a gas through said first generally annular space so as to exit said first nozzle and generally surround said at least one reactant flowing from said outlet end; a second nozzle having an outlet end which communicates with said chamber at a position closely adjacent to said upstream end; and means for passing a combustible mixture through said second nozzle so as to exit its outlet end into said chamber.
Claim 25
Independent Claim
220 words
An apparatus comprising: a reactor having a chamber defined therein, said chamber having an upstream end and a downstream end; so a first nozzle which has an outlet end which communicates with said chamber at a position intermediate to said upstream and downstream end. said first nozzle comprising first and second tubular members having respective interior and exterior surfaces, and wherein said first tubular member is generally coaxially positioned within said second tubular member such that a first generally annular space is defined between the interior surface of said second tubular member and the exterior surface of said first tubular member; means for passing at least one reactant through said first tubular member so as to exit said first tubular member at said outlet end and into said chamber, wherein said at least one reactant is capable of reacting in said chamber to form a nitride product; means for passing a gas through said first generally annular space so as to exit said first nozzle and generally surround said at least one reactant flowing from said outlet end; a second nozzle having an outlet end which communicates with said chamber at a position closely adjacent to said upstream end; and means for passing a combustible mixture through said second nozzle so as to exit its outlet end into said chamber.
Claim 26
Dependent Claim
43 words
An apparatus as recited in claim 22 wherein said second tubular member comprises an inner sidewall and an outer sidewall which define a second generally annular space therebetween, said apparatus further comprising a means for passing coolant fluid through said second annular space.
Claim 27
Dependent Claim
47 words
An apparatus as recited in claim 23 wherein said second nozzle comprises a third tubular member having an inner sidewall and an outer sidewall which define a third annular space therebetween, said apparatus further comprising a means for passing a coolant fluid through said third annular space.
Claim 28
Dependent Claim
68 words
An apparatus as recited in claim 24 wherein said chamber has a longitudinal axis and wherein said first nozzle is situated so as to inject said at least one reactant into said chamber in a direction generally perpendicular to said longitudinal axis, and wherein said second nozzle is situated so as to inject the combustible mixture into said chamber in a direction generally parallel to said longitudinal axis.
Claim 29
Dependent Claim
26 words
An apparatus as recited in claim 25 further comprising a collecting means in communication with said downstream end of said chamber for collecting said nitride product.
Claim 30
Dependent Claim
40 words
An apparatus as recited in claim 26 further comprising a conduit means having an end in communication with said downstream end of said chamber and extending to said collecting means, in particular wherein said conduit means comprises a quartz conduit.
References Cited (Backward Citations)
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