JPS6214210B2 - - Google Patents
Info
- Publication number
- JPS6214210B2 JPS6214210B2 JP58138084A JP13808483A JPS6214210B2 JP S6214210 B2 JPS6214210 B2 JP S6214210B2 JP 58138084 A JP58138084 A JP 58138084A JP 13808483 A JP13808483 A JP 13808483A JP S6214210 B2 JPS6214210 B2 JP S6214210B2
- Authority
- JP
- Japan
- Prior art keywords
- dephosphorization
- steel
- cac
- molten steel
- slag
- 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
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 31
- 239000010959 steel Substances 0.000 claims description 31
- 238000000034 method Methods 0.000 claims description 14
- 239000011651 chromium Substances 0.000 claims description 13
- 230000004907 flux Effects 0.000 claims description 10
- 229910052804 chromium Inorganic materials 0.000 claims description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 7
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 12
- 239000011574 phosphorus Substances 0.000 description 12
- 229910052698 phosphorus Inorganic materials 0.000 description 12
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 11
- 239000002893 slag Substances 0.000 description 11
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 8
- 239000011775 sodium fluoride Substances 0.000 description 7
- 239000011734 sodium Substances 0.000 description 6
- 235000013024 sodium fluoride Nutrition 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 230000002829 reductive effect Effects 0.000 description 4
- 239000011575 calcium Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 229910004261 CaF 2 Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 230000005587 bubbling Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000005997 Calcium carbide Substances 0.000 description 1
- 229910019589 Cr—Fe Inorganic materials 0.000 description 1
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- VVTSZOCINPYFDP-UHFFFAOYSA-N [O].[Ar] Chemical compound [O].[Ar] VVTSZOCINPYFDP-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 229910001610 cryolite Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- CLZWAWBPWVRRGI-UHFFFAOYSA-N tert-butyl 2-[2-[2-[2-[bis[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]amino]-5-bromophenoxy]ethoxy]-4-methyl-n-[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]anilino]acetate Chemical compound CC1=CC=C(N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)C(OCCOC=2C(=CC=C(Br)C=2)N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)=C1 CLZWAWBPWVRRGI-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Description
本発明は、クロム含有鋼、とくにCr3.0％以上
を含む各種低合金鋼、耐熱鋼、ステンレス鋼等の
脱燐方法に関する。
鋼中の燐（Ｐ）は一般に鋼品質を損なう有害な
元素である。とくに、オーステナイト系ステンレ
ス鋼では応力腐食割れ、高温割れなどの点で、Ｐ
の含有量は可及的に低いことが望まれる。
鋼の精錬におけるＰの除去は、通常は酸化精錬
期に、ＰをP2O5に酸化し、これを4CaO・P2O5と
してスラグ中に固定する、所謂酸化脱燐により行
なうのが一般であるが、クロム含有鋼、とくに
Crを3.0％以上含む鋼では、このような酸化脱燐
を行つても、Crの優先酸化を生じるため所要の
脱燐を達成することは実施上不可能である。この
対策として、Ｐ含有量の低い原材料を厳選すると
ともに、炉壁ライニングに低燐の耐火物を使用し
て溶解・精錬を行う方法がこれまで講ぜられてき
た。しかし、クロム源である原材料は、前記理由
および回転材としての繰返し溶解のために、低燐
レベルのものを調達することは極めて困難となつ
ている。また、一般の発生鋼屑は、燐の著しい偏
析を随伴するので多く配合することはできない。
近時は、前記酸化脱燐方式に代え、
3Ca++＋2P---→Ca3P2
で示される反応を利用した還元脱燐について研究
が進められ、CaやCaC2にCaF2などを配合したフ
ラツクスを脱燐剤として使用する方法が提案され
てはいるが、反応効率などに問題があり、いまだ
に実生産ベースでの十分な成果をみるに到つてい
ない。
本発明は浄記事情に鑑みてなされたものであ
り、Crを3.0％以上含む鋼の還元脱燐による反応
効率等にすぐれた脱燐方法を提供する。
本発明の脱燐方法は、クロム含有溶鋼に、脱燐
剤として、カルシウムカーバイト（CaC2）、石灰
（CaO）、および弗化ソーダ（NaF）もしくは氷晶
石（Na3AlF6）からなる混合フラツクスを添加し
て脱燐を行うものである。
本発明に脱燐剤として使用されるフラツクス
は、被処理溶鋼量に対し、0.5〜５％のCaC2と、
0.2〜３％のCaOと、0.1〜１％のNaFもしくは
Na3AlF6とからなる配合率にて構成される。
CaC2は、下式
3CaC2＋2P→Ca3P2＋6C
で示されるように直接脱燐反応に関与する。その
反応効率を十分なものとするために、少くとも
0.5％の添加が必要である。上限を５％とするの
は、それより多いと、鋼浴温度の低下に伴い、反
応の円滑な進行が妨げられるからである。
上記CaC2による脱燐反応を促進するために
は、流動性に富むスラグを形成することが必要で
あり、このためには、CaC2とともに、造滓剤と
してCaO、および滓化促進剤としてNaFもしくは
Na3AlF6の複合使用を要する。反応に効果的なこ
れらの配合量は、CaOは0.2〜３％であり、NaF
もしくはNa3AlF6は0.1〜１％である。すなわ
ち、CaOは、適当な塩基度を有する適量のスラグ
の形成のために、少くとも0.2％を必要とし、か
つ迅速な滓化と、十分な流動性付与のためにNaF
もしくはNa3AlF6を0.1％以上必要とするのであ
る。またCaOの上限を３％、NaFもしくは
Na3AlF6の上限を１％とするのは、それを越えて
添加する必要がないばかりか、鋼浴温度の降下に
伴うスラグ流動性の低下により、却つて反応の円
滑な進行が妨げられるからである。
本発明において、Cr3.0％以上を含む被処理溶
鋼は、好ましくはＣ濃度0.5〜3.0％、Si濃度0.5％
以下に調整される。Ｃ濃度を0.5％以上とするの
は、それより低いと、溶鋼の融点と関連して、フ
ラツクスの投与に伴う降温のため鋼浴の十分な流
動性を確保するのが困難となるからである。ま
た、Fe−Ｃ−Ｐ系において、脱燐反応の進行に
好ましいＣ濃度は0.5〜3.0％、更に好ましくは1.0
〜2.0％の範囲にもとめられる。一方、Si濃度の
上限を0.5％とするのは、その酸化生成物SiO2に
より、脱燐剤として投与されるフラクス中の
CaC2が消耗され、脱燐効率の低下をきたすから
である。
本発明において、被処理鋼浴に投与されたフラ
ツクスは流動性に富むスラグを形成する。生成し
たスラグによる脱燐反応は、ガスバブリング撹
拌、あるいはインペラー撹拌などの強力な撹拌作
用下に、スラグと溶鋼との十分な接触面を与える
ことにより効率よく進行する。例えば、アルゴン
−酸素脱炭吹精炉（AOD炉）において、脱炭吹
錬に先立ち、フラツクスを投与するとともにAr
ガスの吹込みによる撹拌を行うことにより、極め
て良好な脱燐反応の完結をみる。その脱燐率は、
60％前後もしくはそれ以上に達する。
なお、脱燐処理ののちは、鋼浴中への復燐を防
ぐために、十分に除滓すべきである。
本発明の実施例として、AOD炉での18−８系
ステンレス鋼の精錬における脱燐試験結果を第１
表に示す。各チヤーヂの溶鋼量は5.8〜11.0トン
であり、脱燐処理前の溶鋼にＣ濃度は0.5〜3.0
％、Si濃度は0.5％以下、処理前の鋼浴温度は
1500〜1570℃である。フラツクスは、溶鋼量に対
し、CaC20.5〜5.0％、CaO0.2〜３％、NaF0.1〜
１％である。なお、脱燐処理は、Ar25〜40Nm3／
分のバブリング撹拌下、約５〜８分を要して行つ
た。脱燐処理後、ほぼ完全に排滓し、ついで常法
により脱炭およびその後の精錬を行つた。
第１表に示されるように、脱燐率は60％前後な
いしそれ以上と高く、かつ安定しており、十分な
低燐レベルに達することがわかる。
なお、従来の還元脱燐法として、CaC2−NaF2
系フラツクスを使用し、精錬炉内の雰囲気中の酸
化性ガス（O2、SO2、CO2、水蒸気等）の合計含
有量が８％未満または60mmHg未満になるように
雰囲気制御することにより脱燐率を改善した脱燐
方法（特開昭52−133803号）によると、その実施
例として、誘導溶解炉中、100Kgの溶融フエロク
ロム（７％−63％Cr−Fe）に、脱燐スラグ５Kg
（CaC2：3.5Kg、CaF2：１Kg、CaO：0.5Kg）を投
与し、炉内雰囲気の酸化性ガス量の制御下に行つ
た脱燐処理（ｎ＝６）における脱燐率は下記のと
おり（同公開特許公報第３頁〜４頁）であり、や
やバラツキが大きく、平均脱燐率は48.7％であ
る。
The present invention relates to a method for dephosphorizing chromium-containing steel, particularly various low-alloy steels containing 3.0% or more of Cr, heat-resistant steels, stainless steels, and the like. Phosphorus (P) in steel is a harmful element that generally impairs steel quality. In particular, austenitic stainless steel suffers from stress corrosion cracking, high temperature cracking, etc.
It is desired that the content of is as low as possible. P removal during steel refining is generally carried out during the oxidation refining period by oxidative dephosphorization, which oxidizes P to P 2 O 5 and fixes it in the slag as 4CaO P 2 O 5 . However, chromium-containing steel, especially
In steel containing 3.0% or more of Cr, even if such oxidative dephosphorization is performed, preferential oxidation of Cr occurs, so it is practically impossible to achieve the required dephosphorization. As a countermeasure to this problem, methods have been taken so far to carefully select raw materials with low P content and to use low-phosphorus refractories for the furnace wall lining during melting and refining. However, it is extremely difficult to procure a raw material that is a chromium source with a low phosphorus level due to the above reasons and repeated melting as a rotating material. In addition, it is not possible to incorporate a large amount of commonly generated steel scrap because it is accompanied by significant segregation of phosphorus. Recently, instead of the oxidative dephosphorization method described above, research has been progressing on reductive dephosphorization using the reaction shown by 3Ca ++ + 2P --- →Ca 3 P 2 , and by combining Ca or CaC 2 with CaF 2 etc. Although a method has been proposed in which the resulting flux is used as a dephosphorizing agent, there are problems with reaction efficiency, and sufficient results have not yet been achieved in actual production. The present invention has been made in view of the purification situation, and provides a method for dephosphorizing steel containing 3.0% or more of Cr by reductive dephosphorization with excellent reaction efficiency. The dephosphorization method of the present invention includes adding calcium carbide (CaC 2 ), lime (CaO), and sodium fluoride (NaF) or cryolite (Na 3 AlF 6 ) to chromium-containing molten steel as a dephosphorizing agent. Dephosphorization is performed by adding mixed flux. The flux used as a dephosphorizing agent in the present invention contains 0.5 to 5% CaC 2 based on the amount of molten steel to be treated,
0.2-3% CaO and 0.1-1% NaF or
It is composed of a compounding ratio of Na 3 AlF 6 . CaC 2 directly participates in the dephosphorization reaction as shown by the following formula: 3CaC 2 +2P→Ca 3 P 2 +6C. In order to make the reaction efficiency sufficient, at least
0.5% addition is required. The reason why the upper limit is set to 5% is that if the content is more than 5%, the smooth progress of the reaction will be hindered as the steel bath temperature decreases. In order to promote the dephosphorization reaction by CaC 2 described above, it is necessary to form a highly fluid slag, and for this purpose, in addition to CaC 2 , CaO as a sludge-forming agent and NaF as a slag-forming accelerator are used. or
Requires combined use of Na 3 AlF 6 . The effective amount of these compounds for the reaction is 0.2 to 3% for CaO, and 0.2 to 3% for NaF.
Or Na 3 AlF 6 is 0.1-1%. That is, CaO is required at least 0.2% for the formation of a suitable amount of slag with suitable basicity, and NaF is required for rapid slag formation and sufficient fluidity.
Alternatively, 0.1% or more of Na 3 AlF 6 is required. Also, the upper limit of CaO is 3%, NaF or
Setting the upper limit of Na 3 AlF 6 to 1% is not only because it is not necessary to add more than that, but also because the smooth progress of the reaction is hindered by the decrease in slag fluidity as the steel bath temperature falls. It is from. In the present invention, the molten steel to be treated containing 3.0% or more of Cr preferably has a C concentration of 0.5 to 3.0% and a Si concentration of 0.5%.
Adjusted below. The reason why the C concentration is set to 0.5% or more is because if it is lower than that, it will be difficult to ensure sufficient fluidity of the steel bath due to the temperature drop associated with the administration of flux, which is related to the melting point of molten steel. . In addition, in the Fe-C-P system, the preferable C concentration for the progress of the dephosphorization reaction is 0.5 to 3.0%, more preferably 1.0%.
It can be kept in the range of ~2.0%. On the other hand, the reason why the upper limit of the Si concentration is set at 0.5% is that the oxidation product SiO 2 in the flux administered as a dephosphorizing agent is
This is because CaC 2 is consumed and the dephosphorization efficiency decreases. In the present invention, the flux applied to the steel bath to be treated forms a highly fluid slag. The dephosphorization reaction by the generated slag proceeds efficiently by providing a sufficient contact surface between the slag and molten steel under strong stirring action such as gas bubbling stirring or impeller stirring. For example, in an argon-oxygen decarburization blowing furnace (AOD furnace), flux is administered and Ar
By stirring with gas injection, the dephosphorization reaction was completed very well. Its dephosphorization rate is
It reaches around 60% or more. After the dephosphorization treatment, the slag should be thoroughly removed to prevent phosphorus from returning to the steel bath. As an example of the present invention, the results of a dephosphorization test in the refining of 18-8 stainless steel in an AOD furnace are shown in the first example.
Shown in the table. The amount of molten steel in each charge is 5.8 to 11.0 tons, and the C concentration in the molten steel before dephosphorization is 0.5 to 3.0.
%, Si concentration is below 0.5%, steel bath temperature before treatment is
The temperature is 1500-1570℃. The flux is CaC 2 0.5-5.0%, CaO 0.2-3%, NaF 0.1-5.0% relative to the amount of molten steel.
It is 1%. In addition, the dephosphorization treatment is carried out using Ar25~40Nm 3 /
It took about 5 to 8 minutes under bubbling stirring for about 5 minutes. After the dephosphorization treatment, the slag was almost completely removed, and then decarburization and subsequent refining were carried out by conventional methods. As shown in Table 1, the dephosphorization rate is high at around 60% or more, and is stable, indicating that a sufficiently low phosphorus level is reached. In addition, as a conventional reductive dephosphorization method, CaC 2 −NaF 2
By using system flux, the atmosphere is controlled so that the total content of oxidizing gases (O 2 , SO 2 , CO 2 , water vapor, etc.) in the atmosphere in the smelting furnace is less than 8% or less than 60 mmHg. According to a dephosphorization method that improves the phosphorus rate (Japanese Patent Application Laid-open No. 133803/1983), as an example, 5 kg of dephosphorization slag is added to 100 kg of molten ferrochrome (7%-63% Cr-Fe) in an induction melting furnace.
(CaC 2 : 3.5Kg, CaF 2 : 1Kg, CaO: 0.5Kg) was administered and the dephosphorization treatment (n=6) was carried out under the control of the amount of oxidizing gas in the furnace atmosphere. The dephosphorization rate was as follows. (pages 3 to 4 of the same publication), and there is a somewhat large variation, and the average dephosphorization rate is 48.7%.
【表】
また、他の還元脱燐方法として、CaC2に、燐
の活量を高めるSiを添加した混合物を溶鋼中に強
制的に添加・投入することにより脱燐効率を改善
した高クロム含有溶鋼の脱燐方法（特公昭57−
45450号）では、CaC2とSiを詰めた孔あき容器に
鉄棒を取付けて溶鋼中に投入するホスホライザー
方式、またはArガスをキヤリアガスとしてCaC2
とSiの混合物を溶鋼中に吹き込む吹き込み方式に
より25トンの18−８ステンレス溶鋼を脱燐処理し
た例が示されているが、その脱燐率は次のとおり
である（同特許公報第２頁）。[Table] In addition, as another reductive dephosphorization method, a high chromium-containing method improves dephosphorization efficiency by forcibly adding and injecting a mixture of CaC 2 and Si, which increases phosphorus activity, into molten steel. Method for dephosphorizing molten steel
No. 45450), the phosphorizer method involves attaching an iron rod to a perforated container filled with CaC 2 and Si and introducing it into molten steel, or using Ar gas as a carrier gas to remove CaC 2
An example is shown in which 25 tons of 18-8 stainless molten steel was dephosphorized by a blowing method in which a mixture of ).
【表】【table】
【表】【table】
【表】
本発明によれば、原材料の燐含有量が高くても
すぐれた脱燐効果によつて、十分な低燐レベルを
保証することができ、従つて原料事情、ことに回
転材の燐含有量の増加傾向に対処し得るととも
に、高品質が要求される用途、例えば原子力配管
材、その他の外種装置・機器用の材質の向上に大
きく寄与するものである。[Table] According to the present invention, it is possible to guarantee a sufficiently low phosphorus level due to the excellent dephosphorization effect even if the phosphorus content of the raw material is high, and therefore it is possible to ensure a sufficiently low phosphorus level even if the phosphorus content of the raw material is high. In addition to being able to cope with the increasing trend of content, it also greatly contributes to improving the quality of materials for applications that require high quality, such as nuclear power piping materials and other foreign equipment and equipment.
Claims (1)
Si濃度が0.5％以下に調整されたクロム含有溶鋼
に、溶鋼量の0.5〜５％のCaC2と、0.2〜３％の
CaOと、0.1〜１％のNaFもしくはNa3AlF6とから
なるフラツクスを添加することを特徴とするクロ
ム含有鋼の脱燐方法。1 Contains 3.0% or more Cr, C concentration is 0.5-3.0%,
Chromium-containing molten steel whose Si concentration has been adjusted to 0.5% or less is mixed with 0.5 to 5% of CaC 2 and 0.2 to 3% of the amount of molten steel.
A method for dephosphorizing chromium-containing steel, characterized by adding a flux consisting of CaO and 0.1 to 1% NaF or Na 3 AlF 6 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58138084A JPS6029444A (en) | 1983-07-27 | 1983-07-27 | Method for dephosphorizing chromium steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58138084A JPS6029444A (en) | 1983-07-27 | 1983-07-27 | Method for dephosphorizing chromium steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6029444A JPS6029444A (en) | 1985-02-14 |
| JPS6214210B2 true JPS6214210B2 (en) | 1987-04-01 |
Family
ID=15213576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58138084A Granted JPS6029444A (en) | 1983-07-27 | 1983-07-27 | Method for dephosphorizing chromium steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6029444A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0510910U (en) * | 1991-07-25 | 1993-02-12 | 株式会社イノアツクコーポレーシヨン | Soundproof floor heating panel |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4835867B2 (en) * | 2007-04-20 | 2011-12-14 | 信越化学工業株式会社 | Silicon purification method |
-
1983
- 1983-07-27 JP JP58138084A patent/JPS6029444A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0510910U (en) * | 1991-07-25 | 1993-02-12 | 株式会社イノアツクコーポレーシヨン | Soundproof floor heating panel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6029444A (en) | 1985-02-14 |
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