JPH03215316A - Production of electrofused magnesia - Google Patents
Production of electrofused magnesiaInfo
- Publication number
- JPH03215316A JPH03215316A JP904790A JP904790A JPH03215316A JP H03215316 A JPH03215316 A JP H03215316A JP 904790 A JP904790 A JP 904790A JP 904790 A JP904790 A JP 904790A JP H03215316 A JPH03215316 A JP H03215316A
- Authority
- JP
- Japan
- Prior art keywords
- melting
- raw material
- magnesia
- electrode
- furnace
- 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.)
- Pending
Links
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 title claims abstract description 56
- 239000000395 magnesium oxide Substances 0.000 title claims abstract description 28
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- 239000002994 raw material Substances 0.000 claims abstract description 26
- 238000002844 melting Methods 0.000 claims abstract description 19
- 230000008018 melting Effects 0.000 claims abstract description 19
- 230000001590 oxidative effect Effects 0.000 claims abstract description 7
- 239000013078 crystal Substances 0.000 claims description 18
- 239000007789 gas Substances 0.000 abstract description 9
- 239000000463 material Substances 0.000 abstract description 9
- 239000000112 cooling gas Substances 0.000 abstract description 7
- 238000000034 method Methods 0.000 abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 4
- 238000010309 melting process Methods 0.000 abstract description 4
- 239000004020 conductor Substances 0.000 abstract description 3
- 238000001816 cooling Methods 0.000 abstract description 3
- 229910002804 graphite Inorganic materials 0.000 abstract description 3
- 239000010439 graphite Substances 0.000 abstract description 3
- 238000005422 blasting Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 238000007664 blowing Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野コ
本発明は耐火材料の原料となる電融マグネシアの製造方
法に関する.
[従来の技術]
電気炉内に予め底敷きとして原料であるマグネシアタリ
ンカまたは天然マグネシアを装入し、その上に黒鉛製の
通電材を配置する.次いで、電極を降下して前記通電材
に接触させた後、さらに原料を装入して1チャージ分の
量が装入される.原料が所定量装入された後、電極に電
源が印加されて当初は通電材を通して通電され、原料熱
が加えられる.原料が溶解されると通電材がなくても、
溶解部分を通して通電され原料の溶解が進む.原料の溶
解が進むにしたがって、電極が引き上げられ、溶解部分
が凝固するとともに、順次新しい溶解部分が上方に形成
され、電極が所定の高さに達したところでて溶解工程が
終わる.
溶解工程が終了した後、前記溶解、凝固された電融部分
を取り出し、破砕、精製の工程を経て電融マグネシア製
品として出荷される.
[発明が解決しようとする課題]
電融マグネシアの柱状晶は、粒界面が少ない.したがっ
て不純物が少ないので、耐火材の原料としての評価が高
く、高価に取り引きされている.しかしながら、従来法
によって製造された電融マグネシアは等軸晶が多く、柱
状晶の生成率は少ないので、通常は等軸部分と一緒に混
合されて製品として出荷されている.
本発明はかかる事情に鑑みてなされたもので、柱状晶の
生成率が高い電融マグネシアの製造方法を提供しようと
するものである.
[問題点を解決するための手段及び作用コ本発明による
電融マグネシアの製造方法は、原料であるマグネシアク
リン力または天然マグネシアを電気炉で溶解する電融マ
グネシアの製造方法において、前記電気炉の炉底か冷却
用ガスとして非酸化性ガスまたは非酸化性ガスの含有ガ
スを吹き込んで、炉内の溶融ゾーンの周囲を冷却し、電
融マグネシアの柱状晶生成率を増加させることを特徴と
する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing fused magnesia, which is a raw material for refractory materials. [Prior art] Magnesia tarinka or natural magnesia, which is a raw material, is charged in advance as a bottom layer into an electric furnace, and a graphite conductive material is placed on top of it. Next, after the electrode is lowered and brought into contact with the current-carrying material, raw materials are further charged in an amount equivalent to one charge. After a predetermined amount of raw material has been charged, power is applied to the electrodes, initially through the current-carrying material, and heat is applied to the raw material. Once the raw materials are melted, even if there is no current-carrying material,
Electricity is passed through the melting part and the raw material melts. As the melting of the raw material progresses, the electrode is pulled up, and as the melted portion solidifies, new melted portions are sequentially formed upward, and the melting process ends when the electrode reaches a predetermined height. After the melting process is completed, the melted and solidified electrofused portion is taken out, crushed and purified, and shipped as an electrofused magnesia product. [Problem to be solved by the invention] The columnar crystals of electrofused magnesia have few grain boundaries. Therefore, since it contains few impurities, it is highly valued as a raw material for refractory materials and is traded at a high price. However, since electrofused magnesia produced by conventional methods has many equiaxed crystals and a low production rate of columnar crystals, it is usually mixed together with the equiaxed portion and shipped as a product. The present invention has been made in view of the above circumstances, and aims to provide a method for producing fused magnesia with a high production rate of columnar crystals. [Means and effects for solving the problems] The method for producing electro-fused magnesia according to the present invention is a method for producing electro-fused magnesia in which magnesia curing power or natural magnesia as a raw material is melted in an electric furnace. It is characterized by blowing a non-oxidizing gas or a gas containing a non-oxidizing gas into the bottom of the furnace as a cooling gas to cool the area around the melting zone in the furnace and increase the rate of columnar crystal formation of fused magnesia. .
柱状晶を発達させるためには、原料の純度の他、固液界
面における温度勾配とその安定性が重要な要因となる。In addition to the purity of the raw materials, the temperature gradient at the solid-liquid interface and its stability are important factors for the development of columnar crystals.
従来例においては、前記温度勾配が小さく、また安定し
ていないので、柱状晶の発達が阻害され、その生成率が
小さくなっている.そこで、本発明においては、前記温
度勾配を従来よりも大きくかつ、安定させるため電気炉
炉底から冷却用ガスを供給して、溶融ゾーンの表面にお
ける固液界面を冷却して前記温度勾配を増加させ、また
冷却用ガスの供給量を調節して、温度勾配を安定させ、
柱状晶の発達を促進しようとするものである.
冷却ガスとして通常、空気が最も使用に便利であるが、
炉内の例えばカーボンと反応して発熱し、冷却作用が不
十分となるときは不活性ガスを混入して発熱作用を抑え
る必要がある.さらに冷却効果を高める必要があるとき
は、酸素を含まないガスを使用することも考えられる.
[実施例コ
添付の図面を参照しながら本発明の実施例について詳細
に説明する.第1図は本発明の方法を実施する電気炉の
縦断面図である.図中、1は原料3が溶解されて凝固し
た電磁マグネシア、2は溶融帯、4は電極、5は炉壁、
6は炉内に空気を吹き込むブロワーである.上記のよう
に構成された電気炉の作用について、説明する。In the conventional example, since the temperature gradient is small and unstable, the development of columnar crystals is inhibited and the production rate is low. Therefore, in the present invention, in order to make the temperature gradient larger and more stable than before, cooling gas is supplied from the bottom of the electric furnace to cool the solid-liquid interface on the surface of the melting zone, thereby increasing the temperature gradient. and adjust the supply amount of cooling gas to stabilize the temperature gradient.
This is intended to promote the development of columnar crystals. Although air is usually the most convenient cooling gas to use,
When reacting with, for example, carbon in the furnace and generating heat, making the cooling effect insufficient, it is necessary to mix in an inert gas to suppress the heat generation effect. If it is necessary to further enhance the cooling effect, it may be possible to use a gas that does not contain oxygen. [Embodiments] Examples of the present invention will be described in detail with reference to the attached drawings. Figure 1 is a longitudinal sectional view of an electric furnace in which the method of the present invention is carried out. In the figure, 1 is electromagnetic magnesia obtained by melting and solidifying the raw material 3, 2 is a molten zone, 4 is an electrode, 5 is a furnace wall,
6 is a blower that blows air into the furnace. The operation of the electric furnace configured as described above will be explained.
ti4に通電する前の準備工程では、電気炉内に予め底
敷きとして原料であるマグネシアクリン力または天然マ
グネシアを5〜2(lawφ程度に破砕して装入し、そ
の上に黒鉛製の通電材を配置する。次いで、電極4を降
下して前記通電材に接触させた後、さらに原料3を装入
して1チャージ分の量が装入された後、通電が始まる.
電極4に電源が印加されると、最初は通電材を通して電
極4に通電され原料3にジュール熱が加えられる.原料
3が溶解されると通電材がなくても、溶解部分を通して
通電され原料3の溶解が進む.前記通電中は、ブロワー
6により炉底部から冷却用ガスを吹き込む.
原料3の溶解が進むにしたがって、電極4が引き上げら
れ、溶解部分が凝固するとともに、順次新しい溶解部分
が上方に形成され、電極が所定の高さに達したところで
溶解工程が終わる。その後、炉内で放冷されたあと、凝
固ブロックとして取り出す。In the preparation process before energizing ti4, the raw material magnesia clin or natural magnesia is crushed and charged to about 5 to 2 (lawφ) as a bottom layer in the electric furnace, and a graphite current-carrying material is placed on top of it. Next, after the electrode 4 is lowered and brought into contact with the current-carrying material, the raw material 3 is further charged, and after the amount equivalent to one charge has been charged, energization is started.
When power is applied to the electrode 4, electricity is first applied to the electrode 4 through the current-carrying material, and Joule heat is applied to the raw material 3. When the raw material 3 is melted, even if there is no current-carrying material, electricity is applied through the melted part and the melting of the raw material 3 progresses. During the energization, the blower 6 blows cooling gas from the bottom of the furnace. As the melting of the raw material 3 progresses, the electrode 4 is pulled up, the melted portion solidifies, and new melted portions are sequentially formed upward, and the melting process ends when the electrode reaches a predetermined height. After that, it is left to cool in the furnace and then taken out as a solidified block.
第2図は上記のようにして取り出された凝固ブロック1
0である.図中、14は凝固した電融マグネシア1の周
囲に溶解中に加熱されて焼結した焼結層、11は本発明
がその生成率の増大を目的としている柱状晶部分、12
は等軸晶部分、13は凝固の際に生じる引け巣である。Figure 2 shows the coagulation block 1 taken out as described above.
It is 0. In the figure, 14 is a sintered layer that is heated and sintered around the solidified electrofused magnesia 1 during melting, 11 is a columnar crystal portion whose production rate is aimed at by the present invention, and 12
13 is an equiaxed crystal portion, and 13 is a shrinkage cavity generated during solidification.
前記凝固ブロック10は、焼結層14を取り除かれたあ
と、破砕、精製の工程で柱状晶部分11が分離され、等
軸晶部分12とともに電融マグネシア製品として出荷さ
れる.第1表は本実施例と従来例について、柱状晶の発
生率を比較したものである.
第1表の空気吹き込み量の単位は、上記電気炉の断面積
*2, Hr当たり、標準状態の空気の体積■3てある
.同表に見られるように、従来例に比して、本実施例に
よる柱状晶生成率増加の効果は明らかである,
第
1
表
[発明の効果]
本発明の方法によれば、原料の溶解中に電気炉の炉底か
ら冷却用ガスを吹き込み、炉内の溶融ゾーンの周囲を冷
却するので、製品である電融マグネシアに柱状晶の生成
率が増加される.After the sintered layer 14 is removed from the solidified block 10, the columnar crystal portions 11 are separated in a crushing and refining process, and are shipped together with the equiaxed crystal portions 12 as fused magnesia products. Table 1 compares the incidence of columnar crystals between this example and the conventional example. The unit of air blowing amount in Table 1 is the volume of air in the standard state x3 per hour of the cross-sectional area of the electric furnace *2. As seen in the table, the effect of increasing the columnar crystal formation rate in this example is clear compared to the conventional example. Table 1 [Effect of the invention] According to the method of the present invention, Cooling gas is blown into the furnace from the bottom of the electric furnace to cool the area around the melting zone, increasing the rate of columnar crystal formation in the product, electrofused magnesia.
第1図は本発明の方法を実施する電気炉の縦断面図、第
2図は凝固ブロックの縦断面図である.1・・・電融マ
グネシア、2・・・溶融ゾーン、3・・・原料、4・・
・電極、5・・・炉壁、6・・・プロワ10・・凝固ブ
ロック、11・・・柱状晶部分、12・・・等軸晶部分
、13・・・引け巣、1
4・・・焼結層.Fig. 1 is a longitudinal sectional view of an electric furnace for carrying out the method of the present invention, and Fig. 2 is a longitudinal sectional view of a solidification block. 1... Electrofused magnesia, 2... Melting zone, 3... Raw material, 4...
- Electrode, 5... Furnace wall, 6... Prower 10... Solidification block, 11... Columnar crystal portion, 12... Equiaxed crystal portion, 13... Shrinkage cavity, 1 4... Sintered layer.
Claims (1)
電気炉で溶解する電融マグネシアの製造方法において、
原料の溶解中に前記電気炉の炉底から非酸化性ガスまた
は非酸化性ガス含有ガスを吹き込み、炉内の溶融ゾーン
の周囲を冷却して、電融マグネシアの柱状晶を増加させ
ることを特徴とする電融マグネシアの製造方法。In the method for producing fused magnesia, which involves melting the raw material magnesia clinker or natural magnesia in an electric furnace,
A non-oxidizing gas or a non-oxidizing gas-containing gas is blown from the bottom of the electric furnace during melting of the raw materials to cool the area around the melting zone in the furnace, thereby increasing columnar crystals of fused magnesia. A method for producing electrofused magnesia.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP904790A JPH03215316A (en) | 1990-01-18 | 1990-01-18 | Production of electrofused magnesia |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP904790A JPH03215316A (en) | 1990-01-18 | 1990-01-18 | Production of electrofused magnesia |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH03215316A true JPH03215316A (en) | 1991-09-20 |
Family
ID=11709730
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP904790A Pending JPH03215316A (en) | 1990-01-18 | 1990-01-18 | Production of electrofused magnesia |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH03215316A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006265058A (en) * | 2005-03-25 | 2006-10-05 | Tateho Chem Ind Co Ltd | Magnesium oxide single crystal and its manufacturing method |
CN100341815C (en) * | 2002-06-21 | 2007-10-10 | 董波 | Smelting technique of high-purity electrosmelted magnesite clinker |
CN103922615A (en) * | 2014-03-27 | 2014-07-16 | 沈阳化工大学 | Method for preparing high-grade electrical-grade magnesium oxide from low-grade fused magnesium oxide |
-
1990
- 1990-01-18 JP JP904790A patent/JPH03215316A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100341815C (en) * | 2002-06-21 | 2007-10-10 | 董波 | Smelting technique of high-purity electrosmelted magnesite clinker |
JP2006265058A (en) * | 2005-03-25 | 2006-10-05 | Tateho Chem Ind Co Ltd | Magnesium oxide single crystal and its manufacturing method |
WO2006104027A1 (en) * | 2005-03-25 | 2006-10-05 | Tateho Chemical Industries Co., Ltd. | Magnesium oxide single crystal and method for producing same |
KR100895118B1 (en) * | 2005-03-25 | 2009-04-28 | 다테호 가가쿠 고교 가부시키가이샤 | Magnesium oxide single crystal and method for producing same |
US7691200B2 (en) | 2005-03-25 | 2010-04-06 | Tateho Chemical Industries Co., Ltd | Magnesium oxide single crystal and method for producing the same |
JP4676796B2 (en) * | 2005-03-25 | 2011-04-27 | タテホ化学工業株式会社 | Magnesium oxide single crystal and method for producing the same |
CN103922615A (en) * | 2014-03-27 | 2014-07-16 | 沈阳化工大学 | Method for preparing high-grade electrical-grade magnesium oxide from low-grade fused magnesium oxide |
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