JPH0448760B2 - - Google Patents
Info
- Publication number
- JPH0448760B2 JPH0448760B2 JP61305122A JP30512286A JPH0448760B2 JP H0448760 B2 JPH0448760 B2 JP H0448760B2 JP 61305122 A JP61305122 A JP 61305122A JP 30512286 A JP30512286 A JP 30512286A JP H0448760 B2 JPH0448760 B2 JP H0448760B2
- Authority
- JP
- Japan
- Prior art keywords
- reaction
- zone
- raw material
- silicon carbide
- cooling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000006243 chemical reaction Methods 0.000 claims description 76
- 239000002994 raw material Substances 0.000 claims description 61
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical class [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 57
- 238000001816 cooling Methods 0.000 claims description 48
- 238000010438 heat treatment Methods 0.000 claims description 43
- 239000007789 gas Substances 0.000 claims description 33
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 32
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 25
- 229910052710 silicon Inorganic materials 0.000 claims description 25
- 229910052799 carbon Inorganic materials 0.000 claims description 24
- 239000010703 silicon Substances 0.000 claims description 24
- 239000011261 inert gas Substances 0.000 claims description 21
- 239000012298 atmosphere Substances 0.000 claims description 20
- 239000007795 chemical reaction product Substances 0.000 claims description 15
- 238000003780 insertion Methods 0.000 claims description 11
- 230000037431 insertion Effects 0.000 claims description 11
- 238000010924 continuous production Methods 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 7
- 239000007809 chemical reaction catalyst Substances 0.000 claims description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 26
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 25
- 238000009835 boiling Methods 0.000 description 15
- 229910052739 hydrogen Inorganic materials 0.000 description 12
- 239000001257 hydrogen Substances 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 12
- 239000000377 silicon dioxide Substances 0.000 description 12
- 239000006229 carbon black Substances 0.000 description 10
- 229910010271 silicon carbide Inorganic materials 0.000 description 10
- 235000012239 silicon dioxide Nutrition 0.000 description 10
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 239000000843 powder Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000006227 byproduct Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 230000009257 reactivity Effects 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 238000010532 solid phase synthesis reaction Methods 0.000 description 3
- 238000001308 synthesis method Methods 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- -1 for example Substances 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/005—Growth of whiskers or needles
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、炭化ケイ素ウイスカーの連続製造装
置に関し、詳しくは、高純度であつて、且つ、直
線性にすぐれる針状炭化ケイ素ウイスカー結晶を
連続方式にて高収率にて製造するための装置に関
する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an apparatus for continuously producing silicon carbide whiskers, and more particularly, the present invention relates to an apparatus for continuously producing silicon carbide whiskers, and more specifically, a continuous method for producing acicular silicon carbide whisker crystals of high purity and excellent linearity. The present invention relates to an apparatus for manufacturing at a high yield.
従来の技術
炭化ケイ素ウイスカーは、軽量、高強度、高弾
性を有し、近年、複合材料の強化材として、種々
の用途が期待されている。BACKGROUND ART Silicon carbide whiskers are lightweight, have high strength, and high elasticity, and have recently been expected to be used in various ways as reinforcing materials for composite materials.
このような炭化ケイ素ウイスカーの製造方法
は、従来、炭素を含む原料とケイ素を含む原料の
一方又は両方を気相にて反応炉内の所定の高温の
反応域に供給する気相合成法と、炭素を含む原料
とケイ素を含む原料として共に固体を用いる固相
合成法とに大別される。気相合成法は、例えば、
特公昭50−18480号公報、特公昭52−28757号公
報、特公昭52−28759号公報等に記載されており、
また、固相合成法は、例えば、特開昭58−20799
号公報、特開昭58−45918号公報、特開昭58−
145700号公報等に記載されている。 Conventionally, methods for producing such silicon carbide whiskers include a gas phase synthesis method in which one or both of a carbon-containing raw material and a silicon-containing raw material are supplied in a gas phase to a predetermined high-temperature reaction zone in a reactor; It is broadly divided into solid-phase synthesis methods that use solids as both carbon-containing raw materials and silicon-containing raw materials. For example, the vapor phase synthesis method is
It is described in Japanese Patent Publication No. 50-18480, Japanese Patent Publication No. 52-28757, Japanese Patent Publication No. 52-28759, etc.
In addition, the solid phase synthesis method is, for example, JP-A No. 58-20799
No. 45918, JP 58-45918, JP 58-
It is described in Publication No. 145700, etc.
上記のような従来の気相合成法は、一般に、針
状結晶を得るには有利であるが、反面、気相原料
の利用率が著しく低い、気相原料が反応炉内で分
解し、反応炉がこれら分解物によつて汚染され
る、更に、生成した炭化ケイ素ウイスカー中にこ
れら分解物が混入する等の問題を有しているの
で、炭化ケイ素ウイスカーの大量生産には不適当
である。 The conventional gas phase synthesis method described above is generally advantageous in obtaining needle-shaped crystals, but on the other hand, the utilization rate of the gas phase raw material is extremely low, and the gas phase raw material decomposes in the reactor, causing the reaction to occur. This method is unsuitable for mass production of silicon carbide whiskers because the furnace is contaminated with these decomposed products and furthermore, these decomposed products are mixed into the produced silicon carbide whiskers.
一方、従来の固相合成法によれば、ケイ素を含
む原料粉末と炭素を含む原料粉末とを混合し、こ
れを加熱して、主として、これら粉末間の固相反
応にて直接に炭化ケイ素を生成させるので、粉末
乃至屈曲状の炭化ケイ素を多く生成し、直線性に
すぐれる炭化ケイ素ウイスカーを得ることが困難
である。更に、得られた炭化ケイ素ウイスカーか
ら上記のような粉状乃至屈曲状の炭化ケイ素を分
離除去することも容易ではない。 On the other hand, according to the conventional solid-phase synthesis method, silicon carbide is directly synthesized by mixing raw material powder containing silicon and raw material powder containing carbon, heating the mixture, and directly producing silicon carbide mainly through a solid-phase reaction between these powders. As a result, a large amount of powdery or curved silicon carbide is produced, making it difficult to obtain silicon carbide whiskers with excellent linearity. Furthermore, it is not easy to separate and remove the powdered or bent silicon carbide as described above from the obtained silicon carbide whiskers.
そこで、本発明者は、炭素含有原料として炭素
粉末を用い、ケイ素含有原料として二酸化ケイ素
を含有する所定形状の成形体を用いる方法を既に
提案している。この方法によれば、成形体の反応
残分としてのケイ素は、生成する炭化ケイ素ウイ
スカーに混入することがなく、従つて、生成する
炭化ケイ素ウイスカーには、その生成時に副生す
るケイ素及び／又は二酸化ケイ素が微量に混入す
るにすぎない。また、反応残分としての炭素は、
反応終了後に反応生成物を大気中で燃焼させるこ
とによつて容易に除去することができるので、高
純度の炭化ケイ素ウイスカーを得ることができ
る。 Therefore, the present inventor has already proposed a method using carbon powder as the carbon-containing raw material and a molded body of a predetermined shape containing silicon dioxide as the silicon-containing raw material. According to this method, silicon as a reaction residue of the compact does not mix with the silicon carbide whiskers produced, and therefore, the silicon carbide whiskers produced contain silicon and/or by-products during the production. Only a trace amount of silicon dioxide is mixed in. In addition, carbon as a reaction residue is
After the reaction is completed, the reaction product can be easily removed by burning it in the atmosphere, so that highly pure silicon carbide whiskers can be obtained.
しかし、本発明者は、上記した方法によつて炭
化ケイ素ウイスカーを連続製造する場合に、炉材
や反応原料を充填した反応容器からナトリウム、
カリウム、マグネシウム、カルシウム、イオウ、
鉄、ケイ素等の元素を含む低沸点成分の蒸気が反
応炉内に発生し、反応炉の排ガス管系を閉塞し
て、長期間にわたる炭化ケイ素ウイスカーの連続
製造を妨げることがあることを見出した。 However, the present inventor discovered that when silicon carbide whiskers are continuously produced by the method described above, sodium and
potassium, magnesium, calcium, sulfur,
It was discovered that steam of low-boiling components containing elements such as iron and silicon is generated in the reactor, which can clog the reactor's exhaust gas pipe system and prevent continuous production of silicon carbide whiskers over a long period of time. .
そこで、本発明者は、かかる問題を解決するた
めに鋭意研究した結果、反応炉内に非酸化性ガス
雰囲気下で反応原料を均一に加熱する加熱帯と共
に、その下流側にこの加熱帯よりも大きい断面積
を有する冷却帯を設けて、加熱反応によつて生じ
た反応生成物と炉内雰囲気を強制冷却し、上記加
熱反応時に副生した低沸点成分の蒸気を析出させ
て、これを補集することによつて、長期にわたる
安定な連続運転が可能となることを見出して、本
発明に至つたものである。 Therefore, as a result of intensive research to solve this problem, the inventors of the present invention found that a heating zone for uniformly heating the reaction raw materials in a non-oxidizing gas atmosphere is installed in the reactor, and a heating zone is placed downstream of the heating zone. A cooling zone with a large cross-sectional area is provided to forcibly cool the reaction products produced by the heating reaction and the atmosphere in the furnace, and the vapor of low-boiling components produced as a by-product during the heating reaction is precipitated to compensate for this. The present invention was developed based on the discovery that stable continuous operation over a long period of time can be achieved by collecting the following materials.
本発明による炭化ケイ素ウイスカーの連続製造
装置は、ケイ素含有原料、炭素含有原料及び反応
触媒からなる反応原料を管状の反応炉内において
非酸化性ガス雰囲気下に所定の反応温度に加熱し
て、炭化ケイ素ウイスカーを生成させる装置にお
いて、上記反応炉内に上記反応原料を挿入するた
めの挿入帯、反応原料を予熱するための予熱帯、
反応原料を所定の反応温度に加熱するための加熱
帯、冷却用不活性ガスの導入管及び排出管を備
え、上記加熱帯よりも大きい断面積を有し、反応
生成物と雰囲気ガスとを上記冷却用不活性ガスに
て強制冷却するため冷却帯及び強制冷却された反
応生成物を取出すための取出帯が順次に形成され
ていると共に、前記挿入帯と予熱帯との間と前記
冷却帯と取出帯との間とにそれぞれ炉断面を横切
るように中扉が開閉可能に設けられていることを
特徴とする。 The continuous production apparatus for silicon carbide whiskers according to the present invention heats a reaction raw material consisting of a silicon-containing raw material, a carbon-containing raw material, and a reaction catalyst to a predetermined reaction temperature in a non-oxidizing gas atmosphere in a tubular reactor, and carbonizes it. In the apparatus for generating silicon whiskers, an insertion zone for inserting the reaction raw material into the reaction furnace, a preheating zone for preheating the reaction raw material,
It is equipped with a heating zone for heating the reaction raw materials to a predetermined reaction temperature, an inlet pipe for cooling inert gas, and an exhaust pipe, and has a cross-sectional area larger than the above-mentioned heating zone. A cooling zone for forced cooling with a cooling inert gas and a take-out zone for taking out the forcedly cooled reaction product are sequentially formed, and a space between the insertion zone and the preheating zone and between the cooling zone and It is characterized in that a middle door is provided between the take-out zone and the furnace so as to be openable and closable so as to cross the cross section of the furnace.
先ず、本発明における炭化ケイ素ウイスカーの
製造について説明する。 First, the production of silicon carbide whiskers in the present invention will be explained.
本発明による炭化ケイ素ウイスカーの製造にお
いては、ケイ素含有原料としては、後述するよう
に、二酸化ケイ素を含む成形体を用いることが好
ましいが、しかし、粉末状のケイ素含有原料を用
いることもできる。 In the production of silicon carbide whiskers according to the present invention, as the silicon-containing raw material, it is preferable to use a molded body containing silicon dioxide, as described below, but a powdered silicon-containing raw material can also be used.
本発明において用いるケイ素含有原料として
は、例えば、ケイ素、ケイ石粉、粉状シリカゲ
ル、各種の非晶質シリカ、沈降性シリカ、粘土等
を挙げることができるが、好ましくは、二酸化ケ
イ素を含有し、特に、良好な収率にて炭化ケイ素
ウイスカーを製造し得るように、二酸化ケイ素を
30重量％以上含有することが好ましい。 Examples of the silicon-containing raw material used in the present invention include silicon, silica powder, powdered silica gel, various amorphous silicas, precipitated silica, clay, etc., but preferably contain silicon dioxide, In particular, silicon dioxide is used to produce silicon carbide whiskers with good yield.
The content is preferably 30% by weight or more.
本発明において、かかるケイ素含有原料からな
る成形体とは、この原料を適宜の手段、例えば、
押出成形、プレス成形、造粒等の手段にて成形
し、焼成して、板、棒、管、筒、球、線状及びこ
れらの組み合わせとしての形状を与えた立体的な
固体をいう。 In the present invention, a molded body made of such a silicon-containing raw material is defined as a molded body made of such a silicon-containing raw material, which is formed by processing this raw material by appropriate means, for example,
A three-dimensional solid that is formed by extrusion molding, press molding, granulation, etc. and fired to give it a shape such as a plate, rod, tube, tube, sphere, line, or a combination thereof.
一般に、固体状のケイ素含有原料と炭素含有原
料とを加熱反応させて、炭化ケイ素ウイスカーを
製造する場合は、これら原料を反応容器内に充填
し、加熱手段を備えた反応炉、例えば、トレープ
ツシヤー式電気炉内に挿入して、所定の温度に加
熱するが、本発明においては、上記ケイ素含有原
料からなる成形体は、例えば、管状や箱型の容器
等のように、炭素粉末を充填するための反応容器
を兼ねることができる。 Generally, when producing silicon carbide whiskers by heat-reacting a solid silicon-containing raw material and a carbon-containing raw material, these raw materials are filled into a reaction vessel, and a reaction furnace equipped with a heating means, such as a Tröpscher type, is used. The molded body made of the silicon-containing raw material is inserted into an electric furnace and heated to a predetermined temperature. In the present invention, the molded body made of the silicon-containing raw material is used for filling carbon powder, such as a tubular or box-shaped container. It can also serve as a reaction vessel.
このように、固体状のケイ素含有原料をその成
形体として用いるとき、この成形体からケイ素化
合物が選択的に気化し、炭素と反応して、炭化ケ
イ素ウイスカーを生成するので、固体ケイ素含有
原料として、ケイ素又は酸化ケイ素含有量の低い
ものを使用しても、不純物が数％以下の高純度の
炭化ケイ素ウイスカーを得ることができる。しか
も、生成する炭化ケイ素ウイスカーは、成形体か
ら分離することが非常に容易である。 In this way, when a solid silicon-containing raw material is used as a molded body, the silicon compound from this molded body selectively vaporizes and reacts with carbon to produce silicon carbide whiskers. Even if a material with a low content of silicon or silicon oxide is used, a highly pure silicon carbide whisker containing impurities of several percent or less can be obtained. Furthermore, the silicon carbide whiskers produced are very easy to separate from the compact.
炭素含有原料としては、粉末状炭素を用いるこ
とが好ましく、カーボンブラツクや粉末不活性炭
等を用いることができるが、これら炭素粉末は、
微粉であつて、嵩高いほど反応性が高いので、特
にカーボンブラツクが好ましい。しかも、後述す
るように、所定の性質を有するカーボンブラツク
を用いることが好ましい。即ち、本発明において
は、カーボンブラツクとして、BET比表面積100
m2／ｇ以上、平均粒子径35nm以下、及び嵩密度
0.06〜0.2ｇ／cm3であるカーボンブラツクを用い
ることが特に好ましい。 As the carbon-containing raw material, it is preferable to use powdered carbon, and carbon black, powdered inert carbon, etc. can be used.
Carbon black is particularly preferred because it is a fine powder and the more bulky it is, the higher the reactivity is. Moreover, as will be described later, it is preferable to use carbon black having predetermined properties. That is, in the present invention, carbon black has a BET specific surface area of 100
m 2 /g or more, average particle diameter 35 nm or less, and bulk density
Particular preference is given to using carbon black having an amount of 0.06 to 0.2 g/cm 3 .
本発明によれば、二酸化ケイ素含有原料と炭素
粉末とを非酸化性ガス雰囲気下において、所定温
度に加熱して、炭化ケイ素ウイスカーを得る。 According to the present invention, silicon dioxide-containing raw materials and carbon powder are heated to a predetermined temperature in a non-oxidizing gas atmosphere to obtain silicon carbide whiskers.
かかる本発明においては、炭化ケイ素ウイスカ
ーは、非酸化性ガスとして水素ガスを用いる場合
を例として説明すれば、主として、次のような反
応によつて生成するものとみられる。但し、本発
明は、反応機構によつて何ら制限されるものでは
ない。 In the present invention, silicon carbide whiskers are mainly produced by the following reaction, taking as an example the case where hydrogen gas is used as the non-oxidizing gas. However, the present invention is not limited in any way by the reaction mechanism.
Ｃ（ｓ）＋2H2（ｇ）→CH4（ｇ） (1)
SiO2（ｓ）＋CH4（ｇ）→SiO（ｇ）＋CO（ｇ）＋2H2
（ｇ） (2)
SiO（ｇ）＋2C（ｓ）→SiC（ｓ）＋CO（ｇ） (3)
即ち、先ず、水素ガスと炭素粉末とが反応(1)に
よつてメタンガスを生成し、これが二酸化ケイ素
含有成形体の表面において、反応(2)によつて一酸
化ケイ素ガスが生成する。次いで、この一酸化ケ
イ素ガスと炭素との反応(3)によつて、炭化ケイ素
が生成する。従つて、総括反応式は、
SiO2（ｓ）＋3C（ｓ）→SiC（ｓ）＋2CO（ｇ） (4)
で表わされることとなる。C (s) + 2H 2 (g) → CH 4 (g) (1) SiO 2 (s) + CH 4 (g) → SiO (g) + CO (g) + 2H 2
(g) (2) SiO (g) + 2C (s) → SiC (s) + CO (g) (3) That is, first, hydrogen gas and carbon powder generate methane gas through the reaction (1), and this Silicon monoxide gas is generated by reaction (2) on the surface of the silicon dioxide-containing molded body. Next, silicon carbide is produced by reaction (3) between this silicon monoxide gas and carbon. Therefore, the overall reaction formula is expressed as: SiO 2 (s) + 3C (s) → SiC (s) + 2CO (g) (4).
本発明においては、通常、二酸化ケイ素含有成
形体と炭素粉末は適宜の反応容器内に充填され、
反応炉内で水素雰囲気下に加熱される。例えば、
反応容器内に板状の二酸化ケイ素含有成形体が間
隔をおいて平行に立てられ、その空隙に炭素粉末
が充填される。反応容器は、例えば、アルミナ製
でもよく、また、高純度炭素製であつてもよい。 In the present invention, the silicon dioxide-containing molded body and carbon powder are usually filled into an appropriate reaction container,
It is heated in a reactor under a hydrogen atmosphere. for example,
Plate-shaped silicon dioxide-containing molded bodies are placed in parallel at intervals in a reaction vessel, and the gaps are filled with carbon powder. The reaction vessel may be made of, for example, alumina or high-purity carbon.
前記反応式(4)においては、水素は炭化ケイ素の
生成に関与していないなが、水素は、炭素のメタ
ンガス化反応(1)に不可欠であるので、炭素は、水
素ガスと高い反応性を有することが要求される。
他方、反応(2)は、炭素を充填した空間全体にわた
つてほぼ一様に進行し、その結果、炭化ケイ素ウ
イスカーは、この空間全体にわたつて生成し、他
方、この空間以外では殆ど生成しない。従つて、
反応温度、雰囲気ガス、触媒等の反応条件と共
に、成形体から生じる一酸化ケイ素を炭素を充填
した反応空間中に所定濃度に保持することが重要
であり、このために、炭素が適度の空隙をもつ凝
集構造を有することが必要である。 In the reaction formula (4) above, hydrogen is not involved in the production of silicon carbide, but since hydrogen is essential for the methane gasification reaction (1) of carbon, carbon has high reactivity with hydrogen gas. required to have one.
On the other hand, reaction (2) proceeds almost uniformly throughout the carbon-filled space, and as a result, silicon carbide whiskers are produced throughout this space, while hardly any silicon carbide whiskers are produced outside this space. . Therefore,
In addition to reaction conditions such as reaction temperature, atmospheric gas, and catalyst, it is important to maintain the silicon monoxide produced from the compact at a predetermined concentration in the carbon-filled reaction space. It is necessary to have a cohesive structure with
以上のように、上記の反応においては、水素ガ
スが炭化ケイ素ウイスカーの生成に重要な寄与を
なし、本発明によれば、反応域における雰囲気の
水素ガスを常に70％以上とすることによつて、炭
化ケイ素ウイスカーの収率を著しく高めると共
に、その針状性を著しく高めることができる。反
応域における雰囲気を常に70％以上の水素ガスを
含むようにするには、具体的には、例えば、反応
炉中に大量の水素を流通させ、上記したように、
副生する一酸化炭素の生成に伴う水素濃度の低減
を防止する。水素ガス濃度が70％よりも少ないと
きは、炭化ケイ素ウイスカーの収量が著しく低減
するのみならず、その長さも短く、また、粉状や
屈曲状等の異形の炭化ケイ素ウイスカーの生成量
が増大する。 As described above, in the above reaction, hydrogen gas makes an important contribution to the production of silicon carbide whiskers, and according to the present invention, hydrogen gas in the atmosphere in the reaction zone is always kept at 70% or more. , it is possible to significantly increase the yield of silicon carbide whiskers and to significantly increase their acicularity. In order to make the atmosphere in the reaction zone always contain 70% or more hydrogen gas, for example, a large amount of hydrogen is passed through the reactor, and as described above,
Prevents a reduction in hydrogen concentration due to the production of carbon monoxide as a by-product. When the hydrogen gas concentration is less than 70%, not only the yield of silicon carbide whiskers is significantly reduced, but also the length is short, and the amount of silicon carbide whiskers produced in irregular shapes such as powder and curved shapes increases. .
本発明によれば、反応炉の少なくとも加熱帯の
雰囲気が水素濃度70％以上の雰囲気に保持され
る。 According to the present invention, the atmosphere in at least the heating zone of the reactor is maintained at an atmosphere with a hydrogen concentration of 70% or more.
カーボンブラツクのBET比表面積、粒子径及
び嵩密度の三つの物性は、相互に完全に独立した
物性ではなく、相互に関連を有しつつ、水素ガス
との反応性及び凝集構造を規定する。しかし、こ
れらのうち、BET比表面積は、カーボンブラツ
クと水素ガスとの接触量をあらわす量であり、主
として、気体との反応の指標となる。一方、平均
粒子径及び嵩密度は、カーボンブラツクの主とし
て凝集構造の指標となる。ここに、本発明の方法
によれば、好ましくは、BET比表面積100m2／ｇ
以上、平均粒子径35nm以下、及び嵩密度0.06〜
0.2ｇ／cm3であるカーボンブラツクを用いるとき、
かかるカーボンブラツクが水素ガスとの高い反応
性をもち、前記した条件を満たすために、粉状、
粒状、屈曲状等の異形の副生なしに、針状性の高
い炭化ケイ素ウイスカーを生成することができる
のであろう。 The three physical properties of carbon black, BET specific surface area, particle size, and bulk density, are not completely independent physical properties, but are interrelated and define the reactivity with hydrogen gas and the agglomerated structure. However, among these, the BET specific surface area is an amount that represents the amount of contact between carbon black and hydrogen gas, and is mainly used as an index of reaction with gas. On the other hand, the average particle diameter and bulk density are mainly indicators of the agglomerated structure of carbon black. Here, according to the method of the present invention, preferably a BET specific surface area of 100 m 2 /g
or more, average particle diameter of 35 nm or less, and bulk density of 0.06 or more
When using carbon black which is 0.2g/ cm3 ,
Such carbon black has high reactivity with hydrogen gas, and in order to satisfy the above conditions, it is available in powder form,
It would be possible to produce highly acicular silicon carbide whiskers without producing irregularly shaped by-products such as granular or bent shapes.
本発明による炭化ケイ素ウイスカーの製造にお
いては、好ましくは反応触媒が用いられる。反応
触媒としては、鉄、ニツケル、コバルト又はこれ
らの化合物、例えば、酸化物、硝酸塩、炭酸塩、
硫酸塩等が用いられる。これら化合物は、粉末、
水溶液その他適宜の形態で炭素含有原料粉末に加
え、混在せしめられる。これら触媒は、直線状で
高純度の炭化ケイ素ウイスカーの生成速度を早め
ると共に、その結果として、併発的に生じる望ま
しくない反応を抑制する作用がある。 In the production of silicon carbide whiskers according to the invention, preferably a reaction catalyst is used. As a reaction catalyst, iron, nickel, cobalt or compounds thereof, such as oxides, nitrates, carbonates,
Sulfates and the like are used. These compounds can be powdered,
It is added to and mixed with the carbon-containing raw material powder in an aqueous solution or other appropriate form. These catalysts have the effect of accelerating the production of linear, high-purity silicon carbide whiskers and, as a result, suppressing undesirable reactions that occur concurrently.
本発明において、二酸化ケイ素含有成形体と固
体炭素原料とを水素を含む雰囲気下で加熱する温
度は、1300℃以上が好適であり、特に、1400℃以
上が好ましい。1300℃よりも低い温度では、炭化
ケイ素ウイスカーの生成が極めて遅く、実用上好
ましくないからである。一方、余りに高温である
ときは、反応条件が過激にすぎて、ウイスカー径
が肥大化し、また、ウイスカーに分岐や折れ曲が
り等の乱れが発生するようになる。従つて、反応
温度は、通常、1700℃以下がよい。また、加熱時
間は、特に制限されるものではないが、通常、
0.5〜30時間が適当である。反応時間が余りに短
いときは、未反応原料が多量に残留し、一方、余
りに長時間反応させても、炭化ケイ素ウイスカー
の収量の増加が僅かであるので、生産性及び熱エ
ネルギー費用の観点からみて、何ら利点がないか
らである。 In the present invention, the temperature at which the silicon dioxide-containing molded body and the solid carbon raw material are heated in an atmosphere containing hydrogen is preferably 1300°C or higher, particularly preferably 1400°C or higher. This is because at temperatures lower than 1300°C, silicon carbide whiskers are extremely slow to form, which is not practical. On the other hand, if the temperature is too high, the reaction conditions are too extreme, the diameter of the whiskers increases, and the whiskers become disordered, such as branching or bending. Therefore, the reaction temperature is usually 1700°C or lower. In addition, the heating time is not particularly limited, but usually
0.5 to 30 hours is appropriate. If the reaction time is too short, a large amount of unreacted raw materials will remain; on the other hand, if the reaction time is too long, the yield of silicon carbide whiskers will increase only slightly, so it is difficult from the viewpoint of productivity and thermal energy cost. , because there is no advantage.
上記のように、本発明による炭化ケイ素ウイス
カーの製造においては、反応原料を高温に加熱す
るので、前述したように、この加熱反応時に炉材
や反応原料を充填した反応容器からナトリウム、
カリウム、マグネシウム、カルシウム、イオウ、
鉄、ケイ素等の元素を含む低沸点成分の蒸気が発
生し、反応炉の排ガス管系を閉塞することを防止
するために、上記反応原料の加熱の後、反応生成
物と雰囲気とを強制冷却して、上記低沸点成分の
蒸気を強制的に冷却し、これを炉壁に析出付着さ
せて、補集する。 As mentioned above, in the production of silicon carbide whiskers according to the present invention, the reaction raw materials are heated to a high temperature.
potassium, magnesium, calcium, sulfur,
In order to prevent the generation of steam of low boiling point components containing elements such as iron and silicon and clogging the exhaust gas pipe system of the reactor, after heating the above reaction raw materials, the reaction products and the atmosphere are forcedly cooled. The vapor of the low boiling point component is forcibly cooled, deposited on the furnace wall, and collected.
本発明による装置は、このように、反応原料の
加熱の後、反応生成物と雰囲気とを強制冷却し
て、上記低沸点成分の蒸気を強制的に冷却する冷
却帯を備えており、低沸点成分を炉壁に析出付着
させて、補集し、かくして、本発明の装置によれ
ば、上記低沸点成分の蒸気が排ガス菅系において
析出付着することがないので、炭化ケイ素ウイス
カーの連続製造を安定して行なうことができる。 As described above, the apparatus according to the present invention is equipped with a cooling zone that forcibly cools the reaction product and the atmosphere after heating the reaction raw materials, and forcibly cools the vapor of the low-boiling point component. The components are deposited and deposited on the furnace wall and collected. Thus, according to the apparatus of the present invention, the vapor of the low boiling point component does not deposit and deposit in the exhaust gas pipe system, so that continuous production of silicon carbide whiskers is possible. It can be done stably.
この後、必要に応じて、反応生成物を放冷し、
好ましくは、反応生成物に含まれる余剰の炭素を
酸化焼却することによつて、通常、綿状の炭化ケ
イ素ウイスカーを得ることができる。 After this, if necessary, the reaction product is allowed to cool,
Preferably, excess carbon contained in the reaction product is oxidized and incinerated to obtain typically flocculent silicon carbide whiskers.
以下、本発明による装置を図面に基づいて具体
的に説明する。第１図は本発明による装置の正面
断面図、第２図は第１図に示す装置の平面断面図
である。 Hereinafter, the apparatus according to the present invention will be specifically explained based on the drawings. FIG. 1 is a front sectional view of an apparatus according to the invention, and FIG. 2 is a plan sectional view of the apparatus shown in FIG.
反応炉１０は角管状に形成されており、上記反
応原料を炉内に挿入する端部である挿入帯１１，
反応原料を予め所定温度まで予熱する予熱帯１
２、反応原料を所定の反応温度に加熱するための
加熱帯１３、反応後に反応生成物及び雰囲気ガス
を冷却するための冷却帯１４、及び冷却された反
応生成物を炉から取出すための取出帯１５を有す
る。 The reactor 10 is formed into a rectangular tube shape, and has an insertion zone 11, which is an end portion through which the reaction raw material is inserted into the reactor.
Preheating zone 1 that preheats the reaction raw materials to a predetermined temperature
2. A heating zone 13 for heating the reaction raw materials to a predetermined reaction temperature, a cooling zone 14 for cooling the reaction product and atmospheric gas after the reaction, and a take-out zone for taking out the cooled reaction product from the furnace. It has 15.
挿入帯１１の入口には入口扉１６が、また、挿
入帯と予熱帯１２との間には中扉１７がそれぞれ
開閉可能に且つ炉断面を横切るように配設され
て、挿入帯と予熱帯の雰囲気が必要に応じて遮断
される。同様に、冷却帯１４と取出帯１５との間
にも、それぞれの雰囲気を必要に応じて遮断する
ために、開閉可能に且つ炉断面を横切るように中
扉１８が設けられている。 An inlet door 16 is provided at the entrance of the insertion zone 11, and an inner door 17 is provided between the insertion zone and the preheating zone 12 so as to be openable and closable and to cross the furnace cross section. atmosphere is shut off as necessary. Similarly, an inner door 18 is provided between the cooling zone 14 and the take-out zone 15 so as to be openable and closable and to cross the furnace cross section in order to shut off the respective atmospheres as necessary.
上記挿入帯は、不活性ガス導入管２７と排出管
２６とを備え、予熱帯に挿入された反応原料と共
に搬入された空気は例えば窒素と置換され、反応
原料は不活性ガス雰囲気下におかれる。 The insertion zone is equipped with an inert gas introduction pipe 27 and an exhaust pipe 26, and the air carried in together with the reaction materials inserted into the preheating zone is replaced with, for example, nitrogen, and the reaction materials are placed in an inert gas atmosphere. .
次に、予熱帯１２の導入側には、非酸化性ガ
ス、例えば、水素導入管２１及び２８が配設され
ており、反応原料の移送方向と同じ方向に流れる
ように、水素ガスが予熱帯及び加熱帯に供給され
る。上記予熱帯及び加熱帯には、ケイ素含有原
料、炭素粉末及び反応触媒を含む反応原料をそれ
ぞれ所定温度に予熱し、又は加熱するための加熱
手段として電気ヒーター４１が炉壁に取付けられ
ている。 Next, non-oxidizing gas, for example, hydrogen introduction pipes 21 and 28 are arranged on the introduction side of the pre-heating zone 12, and hydrogen gas is introduced into the pre-heating zone so that it flows in the same direction as the transfer direction of the reaction raw materials. and supplied to the heating zone. In the preheating zone and the heating zone, an electric heater 41 is attached to the furnace wall as a heating means for preheating or heating the silicon-containing raw material, the carbon powder, and the reaction raw material containing the reaction catalyst to a predetermined temperature, respectively.
また、冷却帯１４には、その導入側及び搬出側
にそれぞれ冷却用不活性ガス導入管２９及び３１
が配設され、搬出側寄りに冷却用不活性ガス排出
管２５及び３０が配設されていて、冷却用不活性
ガスが冷却帯に導入されて、雰囲気ガス及び反応
生成物を強制冷却し、雰囲気ガスに含まれる前記
低沸点成分の蒸気を炉壁に析出付着させる。 The cooling zone 14 also has cooling inert gas introduction pipes 29 and 31 on its inlet and outlet sides, respectively.
is provided, and cooling inert gas exhaust pipes 25 and 30 are provided near the discharge side, and the cooling inert gas is introduced into the cooling zone to forcibly cool the atmospheric gas and reaction products. The vapor of the low boiling point component contained in the atmospheric gas is deposited on the furnace wall.
必要に応じて、低沸点成分の蒸気の冷却析出効
果率を高めるために、冷却帯には炉壁に沿つて冷
却器（図示せず）、例えば、冷却板を取替可能に
配設し、この冷却板の内部に冷却水を流通して、
所定の温度に冷却してもよい。 If necessary, a cooler (not shown), such as a cooling plate, is replaceably disposed along the furnace wall in the cooling zone in order to increase the efficiency of cooling and precipitation of the vapor of low boiling point components. Cooling water is distributed inside this cooling plate,
It may be cooled to a predetermined temperature.
本発明による装置においては、冷却帯１４は、
第２図に示されているように、管状の反応炉内に
おいて、加熱帯１３よりも大きい炉内断面積を有
して、大きい炉内容積を有するように形成され、
冷却帯において、炉壁や冷却器に低沸点成分が層
をなして析出付着しても、反応容器が反応炉内を
支障なく移送され得るように、十分な空間を有せ
しめる。 In the device according to the invention, the cooling zone 14 is
As shown in FIG. 2, the tubular reactor is formed to have a larger internal cross-sectional area and a larger internal volume than the heating zone 13,
In the cooling zone, sufficient space is provided so that even if low-boiling components are deposited and deposited in layers on the furnace wall or cooler, the reaction vessel can be transferred through the reactor without any trouble.
この冷却帯は、一定期間の運転後に、炉壁や冷
却器に析出付着した低沸点成分を除去し得ると共
に、連続製造の効率を高めるために、取替式に反
応炉に配設されていてもよい。しかし、炉体自体
を取替可能とすることなく、炉壁を外側炉壁と内
側炉壁とからなる二重構造とし、内側炉壁を炉体
に対して取替可能に構成することもできる。 This cooling zone is replaceable in the reactor in order to remove low-boiling components deposited on the furnace walls and cooler after a certain period of operation, and to improve the efficiency of continuous production. Good too. However, without making the furnace body itself replaceable, it is also possible to make the furnace wall a double structure consisting of an outer furnace wall and an inner furnace wall, and configure the inner furnace wall to be replaceable with respect to the furnace body. .
上記冷却帯の搬出側端部は取出帯１５に接続さ
れている。取出帯にも、その導入側と搬出側にそ
れぞれ不活性ガス導入管３２と排出管３３とが配
設され、反応生成物はこの取出帯にて不活性ガス
雰囲気下におかれ、必要に応じて更に冷却された
後、反応炉より取出される。 The discharge side end of the cooling zone is connected to the take-out zone 15. The take-out zone is also provided with an inert gas introduction pipe 32 and a discharge pipe 33 on the inlet side and the discharge side, respectively, and the reaction product is placed under an inert gas atmosphere in this take-out zone, and is discharged as necessary. After further cooling, it is taken out from the reactor.
次に、かかる装置による炭化ケイ素ウイスカー
の連続製造について説明する。 Next, continuous production of silicon carbide whiskers using such an apparatus will be explained.
ケイ素含有原料、炭素含有原料及び反応触媒か
らなる反応原料は、適宜の反応容器４２又は匣
鉢、例えば、ムライト、アルミナ等からなるセラ
ミツクス製容器や黒鉛製容器に充填されて、反応
炉に挿入帯１１から順次挿入され、不活性ガス雰
囲気下におかれる。次いで、挿入帯から予熱帯１
２に移送された反応原料は、この予熱帯で所定温
度まで予熱された後、加熱帯１３にて反応原料の
移送方向と並流に流通される非酸化性ガス、例え
ば、水素ガスの雰囲気下に所定の反応温度に加熱
されて、炭化ケイ素ウイスカーを生成する。 The reaction raw materials consisting of a silicon-containing raw material, a carbon-containing raw material, and a reaction catalyst are filled into a suitable reaction vessel 42 or a sagger, such as a ceramic vessel made of mullite, alumina, etc., or a graphite vessel, and inserted into the reactor. They are inserted sequentially starting from No. 11 and placed under an inert gas atmosphere. Next, from the insertion zone to the preheating zone 1
After being preheated to a predetermined temperature in the preheating zone 2, the reaction raw material transferred to No. 2 is heated in a heating zone 13 under an atmosphere of non-oxidizing gas, such as hydrogen gas, which is passed in parallel with the direction of transfer of the reaction raw material. is heated to a predetermined reaction temperature to produce silicon carbide whiskers.
上記加熱帯における反応温度及び反応時間につ
いては、既に先に説明されている。反応容器に充
填された反応原料は、加熱帯に所定時間滞留する
ように、前記挿入帯から順次に間欠的に反応炉内
に挿入される。 The reaction temperature and reaction time in the heating zone have already been explained above. The reaction raw materials filled in the reaction vessel are sequentially and intermittently inserted into the reactor from the insertion zone so as to stay in the heating zone for a predetermined period of time.
冷却帯１４には、前記したように、冷却用不活
性ガス導入管２９及び３１とガス排出管２５及び
３０とが配設されて、反応原料は、上記したよう
に、加熱帯にて所定の反応温度への加熱によつて
炭化ケイ素ウイスカーを生成した後、この冷却帯
で不活性ガスによつて強制冷却され、上記加熱反
応によつて副生した低沸点成分の蒸気を炉壁に析
出させて補集し、かくして、低沸点成分の蒸気の
ガス排出管系における析出付着を防止するのであ
る。 As described above, the cooling zone 14 is provided with the cooling inert gas introduction pipes 29 and 31 and the gas discharge pipes 25 and 30, and the reaction raw materials are heated to a predetermined level in the heating zone as described above. After silicon carbide whiskers are generated by heating to the reaction temperature, they are forcibly cooled by inert gas in this cooling zone, and the vapor of low boiling point components produced by the above heating reaction is deposited on the furnace wall. This prevents vapors of low boiling point components from depositing in the gas exhaust pipe system.
前述したように、予熱帯及び加熱帯に供給され
た水素も、反応原料の加熱後は、冷却帯に導入さ
れた不活性ガスや冷却帯で除去されない非凝縮性
副生ガスと共に、冷却帯の搬出側のガス排出管２
５及び３０から反応炉外に排出される。 As mentioned above, after the reaction materials are heated, the hydrogen supplied to the pre-heating zone and the heating zone, together with the inert gas introduced into the cooling zone and the non-condensable by-product gas that is not removed in the cooling zone, flows into the cooling zone. Gas exhaust pipe 2 on the unloading side
5 and 30 are discharged from the reactor.
以上のようにして、得られた炭化ケイ素ウイス
カーは、冷却帯の搬出側を経て、取出帯１５に移
送され、取出帯から取出された反応生成物は、次
いで、マツフル炉内にて未反応炭素原料を酸化焼
却し、このようにして炭化ケイ素ウイスカーを得
ることができる。 The silicon carbide whiskers obtained in the above manner are transferred to the extraction zone 15 via the extraction side of the cooling zone, and the reaction product extracted from the extraction zone is then treated with unreacted carbon in the Matsufuru furnace. The raw material can be oxidized and incinerated, thus obtaining silicon carbide whiskers.
発明の効果
以上のように、本発明の装置によれば、反応原
料の加熱帯における加熱によつて発生した低沸点
成分の蒸気を冷却帯にて強制冷却して、析出さ
せ、これを補集するので、これら蒸気がガス排出
管系に付着することが防止される。従つて、本発
明によれば、長期にわたつて連続して、且つ、安
定に炭化ケイ素ウイスカーを製造することができ
る。Effects of the Invention As described above, according to the apparatus of the present invention, the vapor of low boiling point components generated by heating the reaction raw materials in the heating zone is forcibly cooled in the cooling zone, precipitated, and collected. This prevents these vapors from adhering to the gas exhaust pipe system. Therefore, according to the present invention, silicon carbide whiskers can be produced continuously and stably over a long period of time.
実施例
以下に実施例と共に比較例を挙げて本発明を説
明するが、本発明はこれら実施例によつて何ら制
限されるものではない。EXAMPLES The present invention will be explained below by giving Examples and Comparative Examples, but the present invention is not limited to these Examples in any way.
実施例
製造装置として図示したように、加熱帯及び冷
却帯を備えたトレープツシヤー式加熱炉を用い、
反応炉内に水素ガスを反応原料の移送方向と並流
に流通させると共に、加熱帯における温度を1600
℃として、冷却帯に冷却用窒素ガスを送入して、
炭化ケイ素ウイスカーの連続製造を行なつた。Example As shown in the figure, a Tröpscher heating furnace equipped with a heating zone and a cooling zone was used as the manufacturing device.
Hydrogen gas is passed through the reactor in parallel with the direction of reaction raw material transfer, and the temperature in the heating zone is set to 1600°C.
°C, by introducing cooling nitrogen gas into the cooling zone,
Continuous production of silicon carbide whiskers was carried out.
即ち、炭素匣鉢にケイ素含有原料と非表面積
250m2／ｇ、平均粒子径14nm、嵩密度190ｇ／cm3
及び触媒としての少量の酸化ニツケルを充填し、
加熱帯において上記反応原料を95％水素／５％窒
素雰囲気下に1600℃の温度に２時間加熱し、この
後、冷却帯にて窒素ガスにて冷却する条件にて１
か月間の連続運転を行なつた。 i.e. silicon-containing raw material and non-surface area in a carbon sagger.
250m 2 /g, average particle size 14nm, bulk density 190g/cm 3
and a small amount of nickel oxide as a catalyst,
The above reaction raw materials were heated to a temperature of 1600°C in a 95% hydrogen/5% nitrogen atmosphere for 2 hours in a heating zone, and then cooled with nitrogen gas in a cooling zone for 1 hour.
It was operated continuously for months.
この間、冷却帯の炉壁に設けた覗き窓から炉内
を観察したところ、冷却帯の炉壁には低沸点成分
の折出が認められたが、排ガス管系には殆ど析出
が認められず、連続運転を安定に続けることがで
きた。 During this period, when the inside of the furnace was observed through a viewing window installed in the furnace wall of the cooling zone, precipitation of low boiling point components was observed on the furnace wall of the cooling zone, but almost no precipitation was observed in the exhaust gas pipe system. , it was possible to continue stable continuous operation.
また、このようにして得られた炭化ケイ素ウイ
スカーは、フツ酸可溶分が２％以下であつて、し
かも、その形状は針状であつて、針状比の高いも
のであつた。 Furthermore, the silicon carbide whiskers thus obtained had a hydrofluoric acid soluble content of 2% or less, and were acicular in shape, with a high acicular ratio.
比較例
上記実施例において、反応炉内に冷却帯を設け
て、ここでの反応生成物及び雰囲気の強制冷却を
行なわなかつた以外は、上記実施例と同様にして
炭化ケイ素ウイスカーを連続製造したところ、運
転を開始してから僅か１時間後には、低沸点成分
の蒸気の析出付着による排ガス管系の閉塞が始ま
り、炉内圧力が上昇したため、予備の排ガス管系
を併用せざるを得なかつた。しかも、このように
予備の排ガス管系を併用しても、それらも、その
２日後に閉塞傾向を示し、連続操業における安全
運転の確保が困難であつた。Comparative Example Silicon carbide whiskers were continuously produced in the same manner as in the above example, except that a cooling zone was provided in the reactor and the reaction products and atmosphere were not forcedly cooled. Just one hour after the start of operation, the exhaust gas piping system began to become clogged due to deposits of vapor containing low-boiling components, and the pressure inside the furnace rose, so a backup exhaust gas piping system had to be used. . Furthermore, even if such a backup exhaust gas pipe system was used in combination, they also tended to become clogged two days later, making it difficult to ensure safe operation during continuous operation.
第１図は本発明による装置の実施例を示す正面
断面図、第２図は第１図に示す装置の平面断面図
である。
１０……反応炉、１１……挿入帯、１２……予
熱帯、１３……加熱帯、１４……冷却帯、１５…
…取出帯、１７及び１８……中間扉、２６……不
活性ガス排出管、２１……水素導入管、２５……
冷却用不活性ガス排出管、２７……不活性ガス導
入管、２８……水素導入管、２９……冷却用不活
性ガス導入管、２５……冷却用不活性ガス排出
管、３１……冷却用不活性ガス導入管、４２……
反応容器。
FIG. 1 is a front sectional view showing an embodiment of the apparatus according to the present invention, and FIG. 2 is a plan sectional view of the apparatus shown in FIG. 10... Reactor, 11... Insertion zone, 12... Pre-heating zone, 13... Heating zone, 14... Cooling zone, 15...
...Takeout band, 17 and 18...Middle door, 26...Inert gas discharge pipe, 21...Hydrogen introduction pipe, 25...
Cooling inert gas discharge pipe, 27... Inert gas introduction pipe, 28... Hydrogen introduction pipe, 29... Cooling inert gas introduction pipe, 25... Cooling inert gas discharge pipe, 31... Cooling Inert gas introduction pipe for 42...
reaction vessel.
Claims (1)
からなる反応原料を管状の反応炉内において非酸
化性ガス雰囲気下に所定の反応温度に加熱して、
炭化ケイ素ウイスカーを生成させる装置におい
て、上記反応炉内に上記反応原料を挿入するため
の挿入帯、反応原料を予熱するための予熱帯、反
応原料を所定の反応温度に加熱するための加熱
帯、冷却用不活性ガスの導入管及び排出管を備
え、上記加熱帯よりも大きい断面積を有し、反応
生成物と雰囲気ガスとを上記冷却用不活性ガスに
て強制冷却するための冷却帯及び強制冷却された
反応生成物を取出すための取出帯が順次に形成さ
れていると共に、前記挿入帯と予熱帯との間と前
記冷却帯と取出帯との間とにそれぞれ炉断面を横
切るように中扉が開閉可能に設けられていること
を特徴とする炭化ケイ素ウイスカーの連続製造装
置。1. A reaction raw material consisting of a silicon-containing raw material, a carbon-containing raw material, and a reaction catalyst is heated to a predetermined reaction temperature in a non-oxidizing gas atmosphere in a tubular reactor,
In an apparatus for producing silicon carbide whiskers, an insertion zone for inserting the reaction raw material into the reaction furnace, a preheating zone for preheating the reaction raw material, a heating zone for heating the reaction raw material to a predetermined reaction temperature, A cooling zone, which is equipped with an inlet pipe and a discharge pipe for a cooling inert gas, has a larger cross-sectional area than the heating zone, and forcibly cools the reaction product and the atmospheric gas with the cooling inert gas; Take-out zones for taking out the forcedly cooled reaction products are sequentially formed, and between the insertion zone and the preheating zone and between the cooling zone and the take-out zone, respectively, so as to cross the furnace cross section. A continuous production device for silicon carbide whiskers, characterized in that an inner door is provided that can be opened and closed.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61305122A JPS63159298A (en) | 1986-12-20 | 1986-12-20 | Continuous production of silicon carbide whisker and apparatus therefor |
| US07/096,743 US4873070A (en) | 1986-12-17 | 1987-09-15 | Process for producing silicon carbide whiskers |
| DE8787308276T DE3777577D1 (en) | 1986-12-17 | 1987-09-18 | METHOD FOR PRODUCING SILICON CARBIDE WHISKERS. |
| EP87308276A EP0272773B1 (en) | 1986-12-17 | 1987-09-18 | Process for production silicon carbide whiskers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61305122A JPS63159298A (en) | 1986-12-20 | 1986-12-20 | Continuous production of silicon carbide whisker and apparatus therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63159298A JPS63159298A (en) | 1988-07-02 |
| JPH0448760B2 true JPH0448760B2 (en) | 1992-08-07 |
Family
ID=17941367
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61305122A Granted JPS63159298A (en) | 1986-12-17 | 1986-12-20 | Continuous production of silicon carbide whisker and apparatus therefor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63159298A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528779U (en) * | 1978-08-15 | 1980-02-25 | ||
| JPS6126600A (en) * | 1984-07-17 | 1986-02-05 | Nippon Light Metal Co Ltd | Preparation of beta type silicon carbide whisker |
| JPS61127700A (en) * | 1984-11-21 | 1986-06-14 | Tokai Carbon Co Ltd | Manufacture of sic whisker |
-
1986
- 1986-12-20 JP JP61305122A patent/JPS63159298A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528779U (en) * | 1978-08-15 | 1980-02-25 | ||
| JPS6126600A (en) * | 1984-07-17 | 1986-02-05 | Nippon Light Metal Co Ltd | Preparation of beta type silicon carbide whisker |
| JPS61127700A (en) * | 1984-11-21 | 1986-06-14 | Tokai Carbon Co Ltd | Manufacture of sic whisker |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63159298A (en) | 1988-07-02 |
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