JP2000335907A - Production of silicon nitride powder with high alpha-type content - Google Patents
Production of silicon nitride powder with high alpha-type contentInfo
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- JP2000335907A JP2000335907A JP15012699A JP15012699A JP2000335907A JP 2000335907 A JP2000335907 A JP 2000335907A JP 15012699 A JP15012699 A JP 15012699A JP 15012699 A JP15012699 A JP 15012699A JP 2000335907 A JP2000335907 A JP 2000335907A
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- silicon nitride
- powder
- nitride powder
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高品質な焼結体と
なり得るα化率が９０％以上の高α型窒化ケイ素粉末を
短時間かつ簡単に効率良く製造することができる高α型
窒化ケイ素粉末の製造方法に関する。[0001] The present invention relates to a high α-type nitride which can easily and efficiently produce a high α-type silicon nitride powder having an α-rate of 90% or more which can be a high-quality sintered body. The present invention relates to a method for producing silicon powder.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】従来、
窒化ケイ素粉末の製造法の１つとして、金属ケイ素粉末
を窒素ガスあるいはアンモニアガスを含む非酸化性ガス
雰囲気で直接窒化する直接窒化法があるが、この方法
は、金属ケイ素表面の自然酸化膜が窒化反応の障壁とな
り、窒化速度（特に初期反応）が著しく低下するといっ
た問題があった。2. Description of the Related Art
One of the methods for producing silicon nitride powder is a direct nitridation method in which metal silicon powder is directly nitrided in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas. There is a problem in that it becomes a barrier to the nitridation reaction, and the nitridation rate (particularly the initial reaction) is significantly reduced.
【０００３】そこで、上記直接窒化法においては、窒化
速度を速めることを目的に窒化温度を高めたり、Ｆｅ、
Ｃａ、Ｋ、Ｎａ、Ｖ、Ｃｕ、Ｌｉといった反応促進触媒
を添加する方法が一般的に用いられている。しかし、こ
の窒化温度を高める方法は、高温安定型のβ型窒化ケイ
素粉末が生成され易く、このβ型窒化ケイ素粉末を成形
・焼結した焼結体は強度特性に劣るという欠点があっ
た。[0003] Therefore, in the direct nitriding method, the nitriding temperature is increased for the purpose of increasing the nitriding speed, or the temperature of Fe,
A method of adding a reaction promoting catalyst such as Ca, K, Na, V, Cu, and Li is generally used. However, the method of raising the nitriding temperature has a disadvantage that a high-temperature stable β-type silicon nitride powder is easily generated, and a sintered body obtained by molding and sintering the β-type silicon nitride powder has poor strength characteristics.
【０００４】また、反応促進触媒を用いる方法は、比較
的低温での窒化が可能であり、α化率が９０％以上の高
α型窒化ケイ素粉末を製造できるが、窒化ケイ素中に反
応促進触媒が金属不純物として残存し、窒化ケイ素焼結
体の特性を低下させ易く、更に、高純度化のための酸処
理工程が必要となり、工程が面倒になるといった問題点
があった。Further, the method using a reaction promoting catalyst allows nitriding at a relatively low temperature and can produce a high α-type silicon nitride powder having an α conversion of 90% or more. Remains as a metal impurity, easily deteriorating the properties of the silicon nitride sintered body, and further requires an acid treatment step for high purification, resulting in a troublesome process.
【０００５】そこで、本出願人は、反応促進触媒を添加
せず、かつ比較的低温で窒化を完了させる方策として、
原料である金属ケイ素粉末を窒化反応に供する前に、高
温及び減圧下で前処理し、得られた脱酸素原料を流動層
中で連続的に窒化反応させる方法を提案した（特開平９
−１５６９０９号公報記載）。Therefore, the present applicant has proposed a method of completing nitriding at a relatively low temperature without adding a reaction promoting catalyst.
A method has been proposed in which a metal silicon powder as a raw material is pretreated at a high temperature and reduced pressure before being subjected to a nitriding reaction, and the obtained deoxygenated raw material is continuously subjected to a nitriding reaction in a fluidized bed (Japanese Patent Application Laid-Open No. Hei 9 (1999)).
-156909).
【０００６】しかしながら、この方法を用いると、窒化
速度は著しく高まり、効率的に高α型窒化ケイ素粉末を
製造することができるが、本発明者の検討によると、市
販されている種々の金属ケイ素粉末を原料として用いる
と、反応性がまちまちになってしまうことが確認され、
窒化反応の改善が望まれた。However, when this method is used, the nitriding speed is remarkably increased, and a high α-type silicon nitride powder can be efficiently produced. When powder was used as a raw material, it was confirmed that the reactivity would be mixed,
Improvement of the nitriding reaction was desired.
【０００７】本発明は、上記問題点を解決するためにな
されたもので、優れた特性を有する焼結体を与えること
ができる高α型の窒化ケイ素粉末を簡単な工程でより確
実かつ効率良く、工業的に有利に製造することができる
高α型窒化ケイ素粉末の製造方法を提供することを目的
とする。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a high-α-type silicon nitride powder capable of giving a sintered body having excellent characteristics in a simple process with more certainty and efficiency. It is an object of the present invention to provide a method for producing a high α-type silicon nitride powder which can be produced industrially advantageously.
【０００８】[0008]
【課題を解決するための手段及び発明の実施の形態】本
発明者は、上記目的を達成するため鋭意検討を行った結
果、金属ケイ素粉末を窒素ガス又はアンモニアガスを含
む非酸化性ガス雰囲気中、１２００〜１４５０℃の温度
域で窒化処理する窒化ケイ素粉末の製造方法において、
原料として金属不純物含有量を特定範囲に限定した金属
ケイ素粉末を使用することにより、α化率が９０％以上
の高α型窒化ケイ素粉末を安定的かつ効率的に製造でき
ることを知見した。Means for Solving the Problems and Embodiments of the Invention The present inventor has conducted intensive studies to achieve the above object, and as a result, has found that metallic silicon powder can be produced in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas. , A method for producing silicon nitride powder to be nitrided in a temperature range of 1200 to 1450 ° C,
It has been found that by using a metal silicon powder having a metal impurity content limited to a specific range as a raw material, a high α-type silicon nitride powder having an α conversion of 90% or more can be stably and efficiently produced.
【０００９】更に詳述すると、本出願人は、窒化速度を
高め、α化率が９０％以上の高α型窒化ケイ素粉末を効
率的に製造することを目的に窒化メカニズムを解明する
ために種々の実験、検討を行った。その結果、窒化温度
に到達しても一定時間は反応しないこと（立ち上がり時
間の遅れ）、及び窒化開始後は金属ケイ素表面に生成し
た窒化ケイ素膜の亀裂・剥離を伴って進行しているとの
知見（Ｙ．Ｉｎｏｍａｔａ，Ｙ．Ｕｅｍｕｒａ，Ｙｏｇ
ｙｏ−Ｋｙｏｋａｉ−ｓｈｉ）を得、この際、窒化を阻
害する要因が窒化ケイ素中に含まれる酸素であることを
確認するに至った。そこで、本出願人は、原料である金
属ケイ素粉末を窒化反応に供する前に高温及び減圧下で
前処理し、金属ケイ素表面に生成する自然酸化膜を窒化
反応に供する前に予め除去し、得られた脱酸素原料を金
属ケイ素粉末と窒化ケイ素粉末と窒素ガス又はアンモニ
アガスを含む非酸化性ガスとから形成された流動層中に
連続的に供給し、窒化生成物を連続的に排出する窒化ケ
イ素粉末の連続製造法を提案した（特開平９−１５６９
０９号公報）。More specifically, the present applicant has made various attempts to elucidate the nitridation mechanism in order to increase the nitriding rate and efficiently produce a high α-type silicon nitride powder having an α conversion of 90% or more. Experiments and examinations were conducted. As a result, it was found that there was no reaction for a certain period of time even after reaching the nitriding temperature (rise time delay), and that after the start of nitriding, the silicon nitride film formed on the surface of metal silicon was accompanied by cracking and peeling. Findings (Y. Inomata, Y. Uemura, Yog)
yo-Kyokai-shi) was obtained, and at this time, it was confirmed that the factor inhibiting nitriding was oxygen contained in silicon nitride. Therefore, the present applicant pre-processes the metal silicon powder as a raw material under high temperature and reduced pressure before subjecting it to the nitriding reaction, and removes a natural oxide film formed on the metal silicon surface before subjecting it to the nitriding reaction. The deoxidized raw material is continuously supplied into a fluidized bed formed of a metal silicon powder, a silicon nitride powder, and a non-oxidizing gas containing a nitrogen gas or an ammonia gas, and the nitriding product is continuously discharged. A method for continuously producing silicon powder has been proposed (Japanese Patent Laid-Open No. 9-1569).
09 publication).
【００１０】しかし、上述したようにその後の検討で、
この方法を用いても市販の金属ケイ素粉末の中で金属不
純物含有量が多いものを用いた場合は、その効果が少な
く、場合によっては逆に窒化速度が低下してしまうこと
が確認された。[0010] However, as described above, in a subsequent study,
Even when this method was used, it was confirmed that when a commercially available metal silicon powder having a high content of metal impurities was used, the effect was small, and in some cases, the nitridation rate was reduced in some cases.
【００１１】そこで、本発明者は、その原因を調査すべ
く種々実験、検討を行った。その結果、原料として用い
る金属ケイ素粉末中の金属不純物含有量、特にＦｅ化合
物、その中でもγ−Ｆｅ2Ｏ3含有量が反応性に大きく寄
与することが判明し、金属ケイ素粉末を窒素ガス又はア
ンモニアガスを含む非酸化性ガス雰囲気中、１２００〜
１４５０℃の温度域で窒化処理する窒化ケイ素粉末の製
造方法において、原料として金属不純物の合計含有量が
１．３重量％以下であり、かつ金属不純物としてのＦｅ
含有量が０．３重量％以下である金属ケイ素粉末を使用
すること、より好ましくは上記方法において、原料であ
る金属ケイ素粉末を窒化反応する前に１０００〜１４０
０℃の高温、更には１０-3〜１００Ｔｏｒｒの減圧下で
脱酸素処理することにより、上記目的を達成できること
を見いだし、本発明をなすに至ったものである。Therefore, the present inventors conducted various experiments and studies to investigate the cause. As a result, it was found that the content of metal impurities in the metal silicon powder used as a raw material, in particular, the content of the Fe compound, particularly γ-Fe 2 O 3 , greatly contributed to the reactivity. In a non-oxidizing gas atmosphere containing a gas,
In a method for producing silicon nitride powder in which nitriding is performed at a temperature of 1450 ° C., the total content of metal impurities as a raw material is 1.3% by weight or less and Fe as a metal impurity is used.
It is preferable to use a metal silicon powder having a content of 0.3% by weight or less, more preferably 1000 to 140 in the above method before the nitriding reaction of the raw material silicon metal powder.
The present inventors have found that the above object can be achieved by performing a deoxygenation treatment at a high temperature of 0 ° C. and further under a reduced pressure of 10 −3 to 100 Torr, and have accomplished the present invention.
【００１２】従って、本発明は、金属ケイ素粉末を窒素
ガス又はアンモニアガスを含む非酸化性ガス雰囲気中、
１２００〜１４５０℃の温度域で窒化処理する窒化ケイ
素粉末の製造方法であって、原料として金属不純物の合
計含有量が１．３重量％以下であり、かつ金属不純物と
してのＦｅ含有量が０．３重量％以下である金属ケイ素
粉末を使用することを特徴とする高α型窒化ケイ素粉末
の製造方法を提供する。Accordingly, the present invention provides a method for producing a metal silicon powder in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas.
A method for producing silicon nitride powder in which nitriding is performed in a temperature range of 1200 to 1450 ° C., wherein the total content of metal impurities as a raw material is 1.3% by weight or less, and the Fe content as metal impurities is 0.3% by weight. Provided is a method for producing a high α-type silicon nitride powder, which comprises using metal silicon powder of 3% by weight or less.
【００１３】以下、本発明につき更に詳述すると、本発
明の高α型窒化ケイ素粉末の製造方法は、金属ケイ素粉
末を窒素ガス又はアンモニアガスを含む非酸化性ガス雰
囲気中、１２００〜１４５０℃の温度域で窒化処理する
窒化ケイ素粉末の製造方法であって、原料として金属不
純物の合計含有量が１．３重量％以下であり、かつ金属
不純物としてのＦｅ含有量が０．３重量％以下である金
属ケイ素粉末を使用する。Hereinafter, the present invention will be described in more detail. The method for producing a high α-type silicon nitride powder according to the present invention comprises the steps of: placing a metal silicon powder in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas at 1200 to 1450 ° C. A method for producing silicon nitride powder in which nitriding is performed in a temperature range, wherein the total content of metal impurities as a raw material is 1.3 wt% or less, and the Fe content as a metal impurity is 0.3 wt% or less. A metal silicon powder is used.
【００１４】ここで、原料の金属ケイ素粉末において、
金属不純物としては、例えばＦｅ，Ａｌ，Ｃａ，Ｋ，Ｎ
ａ，Ｖ，Ｃｕ，Ｌｉやこれらの化合物などである。本発
明においては、原料の窒化ケイ素粉末中の上記金属不純
物の合計含有量が１．３重量％以下であり、かつＦｅ含
有量が０．３重量％以下であることが必要である。金属
不純物の合計含有量が１．３重量％を超えると脱酸素処
理により金属ケイ素と珪化物をつくり、反応性が低下し
てしまう。また、金属不純物としてのＦｅ含有量が０．
３重量％を超えると反応性が著しく低下する。Here, in the raw material silicon metal powder,
Examples of metal impurities include Fe, Al, Ca, K, and N.
a, V, Cu, Li and their compounds. In the present invention, the total content of the metal impurities in the raw material silicon nitride powder must be 1.3% by weight or less, and the Fe content must be 0.3% by weight or less. If the total content of metal impurities exceeds 1.3% by weight, silicon oxide and silicide are produced by the deoxidation treatment, and the reactivity decreases. Further, the content of Fe as a metal impurity is not more than 0.1.
If it exceeds 3% by weight, the reactivity is significantly reduced.
【００１５】更に、上記原料の窒化ケイ素粉末は、金属
不純物としてのＦｅ化合物の中のγ−Ｆｅ2Ｏ3含有量が
０．３重量％以下、好ましくは０．１重量％以下、更に
好ましくは０．０５重量％以下であることが好ましい。
金属不純物中のＦｅは、珪化物をつくるのに加えてα−
Ｆｅ2Ｏ3がγ−Ｆｅ2Ｏ3に変態し、著しく反応性を低下
させてしまうおそれがあるもので、γ−Ｆｅ2Ｏ3含有量
が０．３重量％を超えると反応性が著しく低下してしま
うおそれがある。Further, the silicon nitride powder as the raw material has a γ-Fe 2 O 3 content in the Fe compound as a metal impurity of 0.3% by weight or less, preferably 0.1% by weight or less, more preferably 0.1% by weight or less. It is preferably at most 0.05% by weight.
Fe in the metal impurities not only forms silicide but also α-
Fe 2 O 3 is transformed into γ-Fe 2 O 3, in which there is a possibility that reduce significantly reactive, γ-Fe 2 O 3 content is significantly reactive with more than 0.3 wt% There is a possibility that it will decrease.
【００１６】また、原料の金属ケイ素粉末は、平均粒子
径が１００μｍ以下、特に４４μｍ以下、とりわけ１０
μｍ以下であることが好ましく、平均粒子径が１００μ
ｍを超えると短時間で反応を行うことができない場合が
ある。このような条件を満たす金属ケイ素粉末は、市販
の金属ケイ素粉末から選択することで入手可能である
が、特に半導体グレードの金属ケイ素粉末あるいは金属
ケイ素団塊を微粉砕した後、酸処理したものが好まし
い。なお、Ａｌ合金用金属ケイ素あるいは金属ケイ素団
塊を微粉砕しただけの金属ケイ素は、粉砕機からの金属
不純物（特にＦｅ）の混入があり、上記条件を満たす金
属ケイ素粉末となり難い。The raw material metal silicon powder has an average particle diameter of 100 μm or less, particularly 44 μm or less, especially 10 μm or less.
μm or less, the average particle diameter is 100μ
If it exceeds m, the reaction may not be able to be performed in a short time. Metal silicon powder that satisfies such conditions can be obtained by selecting from commercially available metal silicon powders, and in particular, those obtained by finely pulverizing semiconductor-grade metal silicon powder or metal silicon nodules and then acid-treating them are preferable. . Metal silicon for Al alloy or metal silicon obtained by merely pulverizing metal silicon nodules is hard to become metal silicon powder that satisfies the above conditions due to the mixing of metal impurities (especially Fe) from the pulverizer.
【００１７】更に本発明では、このような金属ケイ素粉
末を１００μｍ〜１０ｍｍ、好ましくは３００μｍ〜１
ｍｍに造粒・成形したものがより好適に用いられる。な
お、造粒・成形方法は通常の方法を採用することがで
き、例えば金属ケイ素粉末にポリビニルアルコール等の
結合剤を添加、造粒し、この造粒物を１０００〜１４０
０℃程度の温度でケイ素粉末同士がくっつくが溶融しな
いように短時間焼結したものを使用することができる。Further, in the present invention, such a metal silicon powder is used in an amount of 100 μm to 10 mm, preferably 300 μm to 1 μm.
What was granulated and molded to mm is more preferably used. In addition, a normal method can be adopted as a granulation / molding method. For example, a binder such as polyvinyl alcohol is added to metal silicon powder, and granulation is performed.
At a temperature of about 0 ° C., a silicon powder that has been sintered for a short time so that the silicon powders adhere to each other but do not melt can be used.
【００１８】また、本発明においては、金属ケイ素粉末
の反応性を高めるために原料としての金属ケイ素粉末を
窒化反応に供する前に１０００〜１４００℃の温度範囲
で脱酸素処理することが好ましい。この場合、上記原料
の金属ケイ素粉末をそのまま脱酸素処理してもよいが、
窒化炉として後述の竪型移動層反応炉、流動層反応炉、
回転炉といった原料自体に流動性を持たせる必要がある
ものを用いる場合には、前述のように金属ケイ素粉末を
１００μｍ〜１０ｍｍ、好ましくは３００μｍ〜１ｍｍ
に造粒・成形したものを脱酸素処理することが好適であ
る。In the present invention, in order to increase the reactivity of the metal silicon powder, it is preferable to subject the metal silicon powder as a raw material to a deoxygenation treatment at a temperature in the range of 1000 to 1400 ° C. before subjecting it to the nitriding reaction. In this case, the metal silicon powder as the raw material may be subjected to a deoxygenation treatment as it is,
As a nitriding furnace, a vertical moving bed reactor, a fluidized bed reactor described below,
When a material such as a rotary furnace that needs to have fluidity in the raw material itself is used, as described above, the metal silicon powder is 100 μm to 10 mm, preferably 300 μm to 1 mm.
It is preferable to deoxidize the granulated and molded product.
【００１９】脱酸素処理の雰囲気は、Ｈ2ガスを含む不
活性ガス雰囲気下で行うことができるが、脱酸素処理を
効率的に行うには減圧下で処理することが好ましい。こ
の場合、真空度は１０-3〜１００Ｔｏｒｒ、特に１０-2
〜５０Ｔｏｒｒの範囲が好ましく、真空度が１００Ｔｏ
ｒｒより高いと処理に時間を要し、生産性が低下する場
合があり、１０-3Ｔｏｒｒより低いと金属ケイ素が蒸発
・減量し、収率が低下してしまうおそれがある。The deoxidizing treatment can be carried out in an atmosphere of an inert gas containing H 2 gas, but it is preferable to carry out the treatment under reduced pressure in order to carry out the deoxidizing treatment efficiently. In this case, the degree of vacuum is 10 −3 to 100 Torr, especially 10 −2.
~ 50 Torr is preferable, and the degree of vacuum is 100
If it is higher than rr, processing takes time and the productivity may be reduced. If it is lower than 10 -3 Torr, metal silicon may evaporate and lose its weight, and the yield may be reduced.
【００２０】脱酸素処理温度は１０００〜１４００℃、
特に１２００〜１３５０℃の範囲が好ましい。処理温度
が１０００℃より低いと処理効果が得られない場合があ
り、逆に処理温度が１４００℃を超えると金属ケイ素が
溶融し、反応性を阻害するおそれがある。The deoxidizing temperature is 1000-1400 ° C.
Particularly, the range of 1200 to 1350 ° C is preferable. If the processing temperature is lower than 1000 ° C., the processing effect may not be obtained. On the other hand, if the processing temperature is higher than 1400 ° C., metal silicon may be melted and the reactivity may be impaired.
【００２１】本発明では、上記特定の金属ケイ素粉末を
窒素ガス又はアンモニアガスを含む非酸化性ガス雰囲気
中、窒化処理する。この場合、窒化処理条件としては、
１２００〜１４５０℃の温度域で行う。窒化処理温度が
１２００℃未満では金属ケイ素粉末粒子の表面に窒化物
が形成され難く、一方１４５０℃を超えると金属ケイ素
が溶融し、反応性が阻害される場合がある。また、この
窒化処理に使用する非酸化性ガスは、窒素ガス又はアン
モニアガスの含有量が１０〜１００容量％、特に６０〜
９０容量％とすることができ、必要に応じてこの非酸化
性ガスは水素ガスやヘリウム、アルゴン等の不活性ガス
を含むことができる。In the present invention, the specific metal silicon powder is nitrided in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas. In this case, the nitriding conditions are as follows:
It is performed in a temperature range of 1200 to 1450 ° C. If the nitriding temperature is lower than 1200 ° C., it is difficult to form a nitride on the surface of the metal silicon powder particles. On the other hand, if it exceeds 1450 ° C., the metal silicon is melted and the reactivity may be hindered. The non-oxidizing gas used for this nitriding treatment has a nitrogen gas or ammonia gas content of 10 to 100% by volume, particularly 60 to 100% by volume.
The non-oxidizing gas can include an inert gas such as hydrogen gas, helium, or argon, if necessary.
【００２２】また、窒化反応に用いる窒化炉は特に限定
はなく、例えばバッチ炉、トンネル炉、竪型移動層反応
炉、流動層反応炉、回転炉等をその目的によって使用す
ることができるが、特に連続流動層反応炉を用いると、
従来は流動層内が完全混合系であり、ショートパスによ
る反応性低下が問題となったが、本発明ではこのような
問題がなく、特に連続流動層反応炉の使用が効果的であ
る。The nitriding furnace used for the nitriding reaction is not particularly limited. For example, a batch furnace, a tunnel furnace, a vertical moving bed reactor, a fluidized bed reactor, a rotary furnace and the like can be used depending on the purpose. Especially when using a continuous fluidized bed reactor,
Conventionally, the inside of a fluidized bed is a completely mixed system, and the reactivity is reduced by a short path. However, the present invention does not have such a problem, and the use of a continuous fluidized bed reactor is particularly effective.
【００２３】本発明において連続流動層反応炉を用いる
場合は、例えば金属ケイ素粉末を窒化ケイ素粉末と窒素
ガス又はアンモニアガスを含む非酸化性ガスとから形成
された流動層中に連続的に供給し、窒化生成物を連続的
に排出する連続製造方法を好適に採用することができ
る。When a continuous fluidized bed reactor is used in the present invention, for example, metal silicon powder is continuously supplied into a fluidized bed formed of silicon nitride powder and a non-oxidizing gas containing nitrogen gas or ammonia gas. In addition, a continuous production method of continuously discharging the nitrided product can be suitably adopted.
【００２４】ここで、連続流動層反応装置としては、図
１に示すものを使用することができる。即ち、図中１は
反応器で、この反応器１内の下部にはガス分散板２が配
設されており、このガス分散板２上方に流動層３が形成
され、またこの流動層３形成域を取り囲むように反応器
１の外側に加熱装置４が配設されたものである。更に、
上記反応器１の下端部にはガス供給口５が形成され、こ
のガス供給口５にガス供給管６の一端が連結されている
と共に、このガス供給管６の他端にガスブレンダー７が
連結されて、例えばガスブレンダー７に供給された窒素
ガスと水素ガスとがこのガスブレンダー７で混合された
後、この混合ガスがガス供給管６内を通ってガス供給口
５より反応器１内の下部の反応ガス供給室８に導入さ
れ、次いでガス分散板２の通気孔より流動層３形成域に
導入されることにより、予め該域に投入された窒化ケイ
素粉末と共に流動層３が形成されるものである。そし
て、この流動層３の下部には原料供給管９の下端が反応
器１の上壁を気密に貫通して挿入され、この原料供給管
９の上端はホッパー１０に接続されたスクリューフィー
ダー１１に連結されていると共に、窒化ケイ素排出管１
２の上端が反応器１の底壁を気密に貫通し、上記流動層
３の上端部位置まで挿入され、この排出管１２の下端は
窒化ケイ素回収器１３に連結されて、ホッパー１０内を
予め高温、減圧処理された金属ケイ素原料がスクリュー
フィーダー１１から原料供給管９を通って流動層３の下
部に供給され、流動層３上端から窒化ケイ素排出管１２
を通って回収器１３に回収されるものである。なお、反
応器１内の圧力は圧力計１４により管理される。Here, the continuous fluidized bed reactor shown in FIG. 1 can be used. That is, in the figure, reference numeral 1 denotes a reactor, in which a gas dispersion plate 2 is provided in a lower portion of the reactor 1, a fluidized bed 3 is formed above the gas dispersion plate 2, and a fluidized bed 3 is formed. A heating device 4 is provided outside the reactor 1 so as to surround the region. Furthermore,
A gas supply port 5 is formed at the lower end of the reactor 1. One end of a gas supply pipe 6 is connected to the gas supply port 5, and a gas blender 7 is connected to the other end of the gas supply pipe 6. Then, for example, after the nitrogen gas and the hydrogen gas supplied to the gas blender 7 are mixed in the gas blender 7, the mixed gas passes through the gas supply pipe 6 and passes through the gas supply port 5 to the inside of the reactor 1. The fluidized bed 3 is formed together with the silicon nitride powder previously introduced into the fluidized bed 3 formation region by being introduced into the lower reaction gas supply chamber 8 and then into the region for forming the fluidized bed 3 through the ventilation holes of the gas dispersion plate 2. Things. The lower end of the raw material supply pipe 9 is inserted into the lower part of the fluidized bed 3 through the upper wall of the reactor 1 in an airtight manner, and the upper end of the raw material supply pipe 9 is inserted into a screw feeder 11 connected to a hopper 10. Connected and silicon nitride discharge pipe 1
The upper end of 2 is airtightly penetrated through the bottom wall of the reactor 1 and is inserted up to the upper end of the fluidized bed 3. The lower end of the discharge pipe 12 is connected to the silicon nitride recovery unit 13, and the inside of the hopper 10 is A high-temperature, reduced-pressure metallic silicon raw material is supplied from the screw feeder 11 to the lower part of the fluidized bed 3 through the raw material supply pipe 9, and the silicon nitride discharge pipe 12 is supplied from the upper end of the fluidized bed 3.
And is collected by the collection device 13 through the passage. In addition, the pressure in the reactor 1 is managed by the pressure gauge 14.
【００２５】[0025]
【実施例】以下、実施例及び比較例を示して本発明を具
体的に説明するが、本発明は下記実施例に限定されるも
のではない。EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.
【００２６】〔実施例１〜３、比較例１，２〕表１に示
す原料物性を有する市販の５種類の金属ケイ素粉末５０
０ｇをそれぞれ窒化ケイ素製トレイに仕込んだ後、内容
積１ｍ3のバッチ炉内に静置し、０．５Ｔｏｒｒの減圧
下、１２５０℃で１時間脱酸素処理を行った。得られた
脱酸素処理品の物性は、表２に示す通りであった。Examples 1-3, Comparative Examples 1 and 2 Five types of commercially available metallic silicon powders 50 having the raw material properties shown in Table 1
After each of 0 g was charged in a silicon nitride tray, it was allowed to stand in a batch furnace having an internal volume of 1 m 3 and subjected to a deoxidation treatment at 1250 ° C. for 1 hour under a reduced pressure of 0.5 Torr. Physical properties of the obtained deoxygenated product were as shown in Table 2.
【００２７】次いで、この脱酸素処理品を同様のバッチ
炉内でＮ2＝２ｍ3／Ｈｒ、Ｈ2＝０．５ｍ3／Ｈｒを流入
しながら１００℃／Ｈｒの速度で昇温させ、１３５０℃
で２時間反応させた。得られた窒化生成物の物性は、表
２に示す通りであった。Next, the deoxygenated product was heated at a rate of 100 ° C./Hr while flowing N 2 = 2 m 3 / Hr and H 2 = 0.5 m 3 / Hr in the same batch furnace to increase the temperature to 1350. ° C
For 2 hours. Physical properties of the obtained nitrided product were as shown in Table 2.
【００２８】[0028]
【表１】 備考：＊ Ｓｉ団塊を粉砕、酸処理 ＊＊Ｓｉ団塊を粉砕のみ[Table 1] Remarks: * Pulverized Si nodules, acid treatment ** Only pulverized Si nodules
【００２９】[0029]
【表２】 [Table 2]
【００３０】〔実施例４、比較例３〕表３に示すように
市販の上記（１）、（２）の金属ケイ素粉末それぞれに
ポリビニルアルコール水溶液を固形物換算で１重量％添
加・混練し、造粒機で平均粒子径０．５ｍｍに造粒・成
形した。この造粒品を１５０℃で１時間乾燥し、水分を
除去した後、内容積１ｍ3のバッチ炉内に静置し、０．
５Ｔｏｒｒの減圧下１２５０℃で１時間脱酸素処理を行
った。得られた脱酸素品の物性を表３に示す。Example 4, Comparative Example 3 As shown in Table 3, 1% by weight of a polyvinyl alcohol aqueous solution was added and kneaded to each of the commercially available metal silicon powders (1) and (2) in terms of solids. It was granulated and formed into an average particle diameter of 0.5 mm by a granulator. After drying the granulated product at 150 ° C. for 1 hour to remove water, the granulated product was allowed to stand still in a batch furnace having an internal volume of 1 m 3 .
The deoxidation treatment was performed at 1250 ° C. for 1 hour under a reduced pressure of 5 Torr. Table 3 shows the physical properties of the obtained deoxygenated product.
【００３１】次に、この造粒・脱酸素処理品を図１に示
す連続流動層反応装置にて窒化生成物を製造した。Next, the granulated and deoxygenated product was nitrided by a continuous fluidized bed reactor shown in FIG.
【００３２】図１において、流動層３は、予め内径２５
０ｍの反応器１内に窒化ケイ素粉末２７ｋｇを仕込み、
ガス供給口５より窒素ガス４．５ｍ3／Ｈｒ、水素ガス
１．２ｍ3／Ｈｒの混合ガスを導入し、形成した。その
後、加熱装置４を加熱し、温度を１３００℃に昇温・保
持した。次に、スクリューフィーダー１１を作動し、上
記、造粒・脱酸素原料を４ｋｇ／Ｈｒの割合で連続的に
供給した。流動層３内で窒化された窒化生成物は窒化ケ
イ素排出管１２から排ガスに同伴されて排出され、回収
器１３により回収される。得られた窒化生成物の物性を
表３に併記する。In FIG. 1, the fluidized bed 3 has an inner diameter of 25 in advance.
27 kg of silicon nitride powder were charged into a 0 m reactor 1,
Nitrogen from the gas supply port 5 Gas 4.5 m 3 / Hr, a mixed gas of hydrogen gas 1.2 m 3 / Hr was introduced, was formed. Thereafter, the heating device 4 was heated to raise and maintain the temperature at 1300 ° C. Next, the screw feeder 11 was operated to continuously supply the above-mentioned granulated / deoxygenated material at a rate of 4 kg / Hr. The nitridation product nitrided in the fluidized bed 3 is discharged from the silicon nitride discharge pipe 12 together with the exhaust gas, and is recovered by the recovery unit 13. Table 3 also shows the physical properties of the obtained nitrided product.
【００３３】[0033]
【表３】 [Table 3]
【００３４】[0034]
【発明の効果】本発明の高α型窒化ケイ素粉末の製造方
法は、反応促進触媒を添加しなくても、比較的低温での
反応が可能となり、優れた特性を有する焼結体を与える
ことができる高α型窒化ケイ素粉末を簡単な工程で安定
的に効率良く製造することができ、工業的規模の生産に
おいても十分に適用し得るものである。According to the method for producing a high α-type silicon nitride powder of the present invention, a reaction can be carried out at a relatively low temperature without adding a reaction accelerating catalyst, and a sintered body having excellent characteristics can be obtained. Thus, a high α-type silicon nitride powder that can be produced can be stably and efficiently produced by a simple process, and can be sufficiently applied to production on an industrial scale.
【図１】本発明の実施例で使用した連続流動層反応装置
の概略図である。FIG. 1 is a schematic view of a continuous fluidized bed reactor used in Examples of the present invention.
１ 反応器 ２ ガス分散室 ３ 流動層 ４ 加熱装置 ５ ガス供給口 ６ ガス供給管 ７ ガスブレンダー ８ 反応ガス供給室 ９ 原料供給管 １０ ホッパー １１ スクリューフィーダー １２ 窒化ケイ素排出管 １３ 回収器 １４ 圧力計 Reference Signs List 1 reactor 2 gas dispersion chamber 3 fluidized bed 4 heating device 5 gas supply port 6 gas supply pipe 7 gas blender 8 reaction gas supply chamber 9 raw material supply pipe 10 hopper 11 screw feeder 12 silicon nitride discharge pipe 13 recovery device 14 pressure gauge
Claims (7)
アガスを含む非酸化性ガス雰囲気中、１２００〜１４５
０℃の温度域で窒化処理する窒化ケイ素粉末の製造方法
であって、原料として金属不純物の合計含有量が１．３
重量％以下であり、かつ金属不純物としてのＦｅ含有量
が０．３重量％以下である金属ケイ素粉末を使用するこ
とを特徴とする高α型窒化ケイ素粉末の製造方法。1. A metal silicon powder is placed in a non-oxidizing gas atmosphere containing nitrogen gas or ammonia gas in an atmosphere of 1200 to 145.
A method for producing silicon nitride powder in which nitriding is performed at a temperature of 0 ° C., wherein the total content of metal impurities as a raw material is 1.3.
A method for producing a high α-type silicon nitride powder, characterized by using a metal silicon powder having a content of Fe of 0.3% by weight or less and not more than 0.3% by weight.
が１００μｍ以下である請求項１記載の高α型窒化ケイ
素粉末の製造方法。2. The method for producing a high α-type silicon nitride powder according to claim 1, wherein the metal silicon powder as a raw material has an average particle diameter of 100 μm or less.
2Ｏ3含有量が０．３重量％以下である請求項１又は２記
載の高α型窒化ケイ素粉末の製造方法。3. γ-Fe in a metal silicon powder as a raw material
3. The method according to claim 1, wherein the content of 2 O 3 is 0.3% by weight or less.
子径１００μｍ〜１０ｍｍに造粒する請求項１〜３のい
ずれか１項に記載の高α型窒化ケイ素粉末の製造方法。4. The method for producing a high α-type silicon nitride powder according to claim 1, wherein the raw material silicon metal powder is granulated in advance to an average particle diameter of 100 μm to 10 mm.
る前に１０００〜１４００℃の高温下で脱酸素処理する
請求項１〜４のいずれか１項に記載の高α型窒化ケイ素
粉末の製造方法。5. The method for producing a high α-type silicon nitride powder according to claim 1, wherein a deoxidation treatment is performed at a high temperature of 1000 to 1400 ° C. before nitriding the metal silicon powder as a raw material. Method.
減圧下で行う請求項５記載の高α型窒化ケイ素粉末の製
造方法。6. The method for producing a high α-type silicon nitride powder according to claim 5, wherein the deoxidizing treatment is performed under a reduced pressure of 10 −3 to 100 Torr.
項１〜６のいずれか１項に記載の高α型窒化ケイ素粉末
の製造方法。7. The method for producing a high α-type silicon nitride powder according to claim 1, wherein the nitriding treatment is performed in a continuous fluidized bed reactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15012699A JP2000335907A (en) | 1999-05-28 | 1999-05-28 | Production of silicon nitride powder with high alpha-type content |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15012699A JP2000335907A (en) | 1999-05-28 | 1999-05-28 | Production of silicon nitride powder with high alpha-type content |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000335907A true JP2000335907A (en) | 2000-12-05 |
Family
ID=15490061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115432676A (en) * | 2021-06-04 | 2022-12-06 | 中国科学院过程工程研究所 | System and method for preparing high-quality silicon nitride powder by using multistage fluidized bed |
-
1999
- 1999-05-28 JP JP15012699A patent/JP2000335907A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115432676A (en) * | 2021-06-04 | 2022-12-06 | 中国科学院过程工程研究所 | System and method for preparing high-quality silicon nitride powder by using multistage fluidized bed |
| CN115432676B (en) * | 2021-06-04 | 2024-03-26 | 中国科学院过程工程研究所 | System and method for preparing high-quality silicon nitride powder by multistage fluidized bed |
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