JP2007327660A - Three-phase ac electrode type circular electric furnace and its cooling method - Google Patents
Three-phase ac electrode type circular electric furnace and its cooling method Download PDFInfo
- Publication number
- JP2007327660A JP2007327660A JP2006157322A JP2006157322A JP2007327660A JP 2007327660 A JP2007327660 A JP 2007327660A JP 2006157322 A JP2006157322 A JP 2006157322A JP 2006157322 A JP2006157322 A JP 2006157322A JP 2007327660 A JP2007327660 A JP 2007327660A
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- side wall
- phase
- electric furnace
- 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.)
- Granted
Links
- 238000001816 cooling Methods 0.000 title claims abstract description 57
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 21
- 238000003723 Smelting Methods 0.000 claims abstract description 17
- 230000002093 peripheral effect Effects 0.000 claims abstract description 16
- 238000012546 transfer Methods 0.000 claims abstract description 11
- 229910052742 iron Inorganic materials 0.000 claims abstract description 10
- 238000002844 melting Methods 0.000 claims description 46
- 230000008018 melting Effects 0.000 claims description 46
- 239000000498 cooling water Substances 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 26
- 239000000155 melt Substances 0.000 claims description 20
- 229910000863 Ferronickel Inorganic materials 0.000 claims description 10
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 8
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 238000004070 electrodeposition Methods 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 abstract description 45
- 238000000576 coating method Methods 0.000 abstract description 45
- 239000000203 mixture Substances 0.000 abstract description 14
- 239000002184 metal Substances 0.000 abstract description 13
- 229910052751 metal Inorganic materials 0.000 abstract description 13
- 229910000831 Steel Inorganic materials 0.000 abstract description 7
- 239000010959 steel Substances 0.000 abstract description 7
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 abstract description 5
- 239000000463 material Substances 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 230000003628 erosive effect Effects 0.000 abstract 2
- 230000010485 coping Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 7
- 238000004088 simulation Methods 0.000 description 6
- 239000012530 fluid Substances 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- -1 ferrous metals Chemical class 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Images
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
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
- Furnace Housings, Linings, Walls, And Ceilings (AREA)
Abstract
Description
本発明は、三相交流電極式円形電気炉とその冷却方法に関し、さらに詳しくは、鉄鋼及び非鉄金属熔融製錬に用いる三相交流電極式円形電気炉において、局所的な炉側壁の熔損の進行を防止するため、炉側壁内周部に形成するコーティングの厚み、生成領域等の生成状態を適切に制御することができ、さらに、電気炉の電力負荷変動、又は原料鉱石の組成変動にも対応することができる冷却機能をもった三相交流電極式円形電気炉とその冷却方法に関する。 The present invention relates to a three-phase AC electrode type circular electric furnace and a cooling method thereof, and more particularly, in a three-phase AC electrode type circular electric furnace used for melting and smelting steel and non-ferrous metals, In order to prevent the progress, it is possible to appropriately control the thickness of the coating formed on the inner peripheral part of the furnace side wall, the generation state of the generation region, etc., and also to the electric load fluctuation of the electric furnace or the composition fluctuation of the raw ore The present invention relates to a three-phase AC electrode type circular electric furnace having a cooling function that can cope with it and a cooling method thereof.
従来から、鉄鋼及び非鉄金属熔融製錬に用いる三相交流電極式円形電気炉においては、原料鉱石等の熔融に伴ない炉内に形成される熔融物（以下、炉内熔融物と呼称する場合がある。）による炉壁の熔損を防止することが、安全上、及び生産効率上の重要な課題であった。このため、電気炉を構成する炉側壁の熔損を防止するため、種々の炉側壁を強制冷却する方法が採用されている。 Conventionally, in a three-phase AC electrode type circular electric furnace used for steel and non-ferrous metal melting and smelting, a melt formed in the furnace accompanying the melting of raw ore (hereinafter referred to as an in-furnace melt) It was an important issue in terms of safety and production efficiency to prevent the melting of the furnace wall. For this reason, in order to prevent melting of the furnace side wall constituting the electric furnace, various methods for forcibly cooling the furnace side wall are employed.
例えば、（イ）電気炉の炉側壁の外周部に設けられた鉄板（以下、炉側壁外鉄板と呼称する場合がある。）の外表面上の全面に、シャワー冷却水を流し、炉側壁を保護する方法、或いは、（ロ）冷却水を通水した銅製冷却部品等に代表される高効率熱伝導媒体を炉側壁の全面に配置することにより、炉側壁を構成する耐火物を直接的に冷却して炉側壁を保護する方法が挙げられる。 For example, (b) shower cooling water is poured over the entire outer surface of an iron plate (hereinafter sometimes referred to as an outer iron plate on the furnace side wall) provided on the outer peripheral portion of the furnace side wall of the electric furnace. (B) A high-efficiency heat transfer medium represented by a copper cooling part that has passed through cooling water is disposed on the entire surface of the furnace side wall, so that the refractory constituting the furnace side wall is directly The method of cooling and protecting a furnace side wall is mentioned.
（イ）の方法として、例えば、フェロニッケル製錬用の三相交流電極式円形電気炉でのシャワー冷却水による炉側壁の保護方法においては、電気炉の熔解能力を一般的に評価する炉床電力密度（ただし、電気炉電力／電気炉炉床面積で定義され、単位はｋＷ／ｍ２で表される。）が高い場合、或いは原料鉱石の組成等の変動により炉内熔融物の融点が低い場合には、通常、シャワー冷却水による炉側壁の冷却能力が不足するので、炉側壁内周部に形成されるコーティング層の厚みが縮小し、耐火物の熔損が進行する。特に、炉側壁の中で熱負荷が大きい部分、例えば、電気炉に設けられた各電極から最も距離が短い炉側壁部分において、炉側壁内周部に形成されたコーティングと耐火物の熔損が生じ、電気炉寿命が短縮される原因につながる。この方法の改善策としては、炉側壁表面を任意に区画化して、温度上昇が高い区画のシャワー冷却水の流量を増加させ、コーティングの厚さを制御する方法が開示されている（例えば、特許文献１参照。）。 As a method of (a), for example, in a method for protecting a furnace side wall with shower cooling water in a three-phase AC electrode type circular electric furnace for ferronickel smelting, a hearth for generally evaluating the melting ability of the electric furnace When the power density (however, defined as electric furnace power / electric furnace hearth area, the unit is expressed in kW / m 2 ) or when the melting point of the melt in the furnace is changed due to fluctuations in the composition of the raw ore, etc. When the temperature is low, the cooling capacity of the furnace side wall with shower cooling water is usually insufficient, so that the thickness of the coating layer formed on the inner peripheral portion of the furnace side wall is reduced, and the refractory melts. In particular, in the portion of the furnace side wall where the heat load is large, for example, in the furnace side wall portion where the distance from each electrode provided in the electric furnace is the shortest, the coating formed on the inner peripheral portion of the furnace side wall and the refractory melted. This leads to a shortened life of the electric furnace. As an improvement measure of this method, a method is disclosed in which the furnace sidewall surface is arbitrarily partitioned to increase the flow rate of shower cooling water in a section where the temperature rise is high, and the thickness of the coating is controlled (for example, patents). Reference 1).
（ロ）の方法して、例えば、高効率熱伝導媒体による炉側壁の保護方法において、炉床電力密度が低い場合、或いは原料鉱石の組成等の変動により炉内熔融物の融点が高い場合には、炉側壁の冷却能力が高いがために、炉側壁内周部の全体に渡ってコーティングが増大することが生じる。特に、炉側壁の中で熱負荷が小さい範囲、例えば、電気炉に備えられた各電極から最も離れた炉側壁部分において、コーティングが局部的に過大に成長付着するため、電気炉内の有効容積が縮小され、電気炉の熔解処理能力が制約される。 In the method of (b), for example, in the method of protecting the furnace side wall with a high-efficiency heat conduction medium, when the hearth power density is low, or when the melting point of the melt in the furnace is high due to fluctuations in the composition of the raw ore, etc. However, since the cooling capacity of the furnace side wall is high, the coating increases over the entire inner periphery of the furnace side wall. In particular, since the coating locally grows and adheres excessively in a range where the heat load is small in the furnace side wall, for example, in the furnace side wall part farthest from each electrode provided in the electric furnace, the effective volume in the electric furnace is increased. Is reduced and the melting capacity of the electric furnace is limited.
以上の状況から、三相交流電極式円形電気炉を構成する炉側壁の熔損を防止するため、炉側壁を強制冷却する方法において、局所的な炉側壁の熔損の進行を防止するため、炉側壁内周部に形成するコーティングの厚み、生成領域等の生成状態を適切に制御することができ、さらに、電気炉の電力負荷変動、又は原料鉱石の組成変動にも対応することができる電気炉の冷却方法が求められている。 From the above situation, in order to prevent melting of the furnace side wall constituting the three-phase AC electrode type circular electric furnace, in the method of forcibly cooling the furnace side wall, in order to prevent the progress of local melting of the furnace side wall, Electricity that can appropriately control the thickness of the coating formed on the inner peripheral part of the furnace side wall, the generation state of the generation region, etc., and can also cope with fluctuations in the electric power load of the electric furnace or the composition of the raw ore There is a need for a method of cooling the furnace.
本発明の目的は、上記の従来技術の問題点に鑑み、鉄鋼及び非鉄金属熔融製錬に用いる三相交流電極式円形電気炉において、局所的な炉側壁の熔損の進行を防止するため、炉側壁内周部に形成するコーティングの厚み、生成領域等の生成状態を適切に制御することができ、さらに、電気炉の電力負荷変動、又は原料鉱石の組成変動にも対応することができる冷却機能をもった三相交流電極式円形電気炉とその冷却方法を提供することにある。 In view of the above-mentioned problems of the prior art, the object of the present invention is to prevent local progress of the melting of the side wall of the furnace in the three-phase AC electrode type circular electric furnace used for steel and non-ferrous metal melting and smelting. Cooling that can appropriately control the thickness of the coating formed on the inner peripheral part of the furnace side wall, the generation state of the generation region, etc., and can also cope with fluctuations in the electric power load of the electric furnace or composition fluctuations of the raw ore The object is to provide a three-phase AC electrode type circular electric furnace having a function and a cooling method thereof.
本発明者らは、上記目的を達成するために、外周部に炉側壁耐火物層が敷設された原料鉱石の熔解処理に用いる三相交流電極式円形電気炉の炉側壁の冷却方法について、鋭意研究を重ねた結果、炉側壁の特定の領域内に所望の冷却機能を有する高効率熱伝導媒体を局所的に配置したところ、コーティングの厚み、生成領域等の生成状態を制御することにより、局所的な炉側壁の熔損の進行を防止することができ、さらに、電気炉の電力負荷変動、原料鉱石の組成変動等にも対応することができることを見出し、本発明を完成した。 In order to achieve the above object, the inventors of the present invention have earnestly studied a method for cooling a furnace side wall of a three-phase AC electrode type circular electric furnace used for melting raw material ore having a furnace side wall refractory layer laid on the outer periphery. As a result of repeated research, when a high-efficiency heat transfer medium having a desired cooling function is locally disposed in a specific region of the furnace side wall, the generation state of the coating thickness, the generation region, etc. is controlled, and the local state is controlled. The present invention has been completed by finding that it is possible to prevent typical furnace side wall melting and to cope with fluctuations in the electric power load of the electric furnace, composition fluctuations in the raw ore, and the like.
すなわち、本発明の第１の発明によれば、外周部に炉側壁耐火物層が敷設された原料鉱石の熔解処理に用いるための三相交流電極式円形電気炉において、
三相交流電極により炉内に発生する高温雰囲気下で、熱負荷が大きくなる炉側壁の領域内に、炉側壁を構成する耐火物層の局所的な熔損を防止するに十分な程度に冷却できる高効率熱伝導媒体を局所的に配置することを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。
That is, according to the first invention of the present invention, in the three-phase AC electrode type circular electric furnace for use in the melting treatment of the raw material ore in which the furnace side wall refractory layer is laid on the outer peripheral portion,
Cooling to a sufficient extent to prevent local melting of the refractory layer constituting the furnace side wall in the area of the furnace side wall where the heat load increases under the high temperature atmosphere generated in the furnace by the three-phase AC electrode There is provided a method for cooling a three-phase AC electrode type circular electric furnace characterized by locally arranging a high-efficiency heat conduction medium that can be produced.
また、本発明の第２の発明によれば、第１の発明において、前記高効率熱伝導媒体を局所的に配置する場所は、前記電気炉に垂直に設けられる各電極位置に対応して、水平断面上では電極からの水平距離が最も短い円周上の範囲であり、かつ垂直断面上では炉底から炉内熔融物層の上面に渡る範囲であることを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a second invention of the present invention, in the first invention, the location where the high-efficiency heat conduction medium is locally disposed corresponds to the position of each electrode provided perpendicular to the electric furnace, Three-phase AC electrode type characterized in that the horizontal distance from the electrode on the horizontal section is the shortest circumferential range, and on the vertical section is the range from the furnace bottom to the top surface of the melt layer in the furnace A method for cooling a circular electric furnace is provided.
また、本発明の第３の発明によれば、第２の発明において、前記高効率熱伝導媒体を配置する炉側壁の割合は、円周長さ全体の３０〜４０％であることを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a third aspect of the present invention, in the second aspect, the ratio of the furnace side wall on which the high-efficiency heat conduction medium is arranged is 30 to 40% of the entire circumferential length. A method for cooling a three-phase AC electrode type circular electric furnace is provided.
また、本発明の第４の発明によれば、第１の発明において、前記高効率熱伝導媒体は、炉側壁の内周部に沿って、炉側壁を構成する耐火物層の内部に埋設されることを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a fourth aspect of the present invention, in the first aspect, the high-efficiency heat conduction medium is embedded in the refractory layer constituting the furnace side wall along the inner peripheral portion of the furnace side wall. A cooling method for a three-phase AC electrode type circular electric furnace is provided.
また、本発明の第５の発明によれば、第１の発明において、前記高効率熱伝導媒体は、冷却水を通水する銅製冷却部品であることを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a fifth aspect of the present invention, in the first aspect, the high-efficiency heat conduction medium is a copper cooling part that allows cooling water to flow therethrough. A method for cooling a furnace is provided.
また、本発明の第６の発明によれば、第１〜５いずれかの発明において、さらに、電気炉の炉側壁外鉄板に沿ってシャワー冷却水を流す冷却手段を併用することを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a sixth invention of the present invention, in any one of the first to fifth inventions, a cooling means for flowing shower cooling water along the outer iron plate of the furnace side wall of the electric furnace is further used. A method for cooling a three-phase AC electrode type circular electric furnace is provided.
また、本発明の第７の発明によれば、第１〜６いずれかの発明において、前記電気炉は、酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用であることを特徴とする三相交流電極式円形電気炉の冷却方法が提供される。 According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the electric furnace is for ferronickel smelting used for reduction melting treatment of nickel oxide ore. A method of cooling a phase AC electrode type circular electric furnace is provided.
また、本発明の第８の発明によれば、第１〜７いずれかの発明の冷却方法を実施する三相交流電極式円形電気炉が提供される。 Moreover, according to the 8th invention of this invention, the three-phase alternating current electrode type circular electric furnace which implements the cooling method of the invention in any one of the 1st-7th is provided.
本発明の三相交流電極式円形電気炉の冷却方法は、鉄鋼及び非鉄金属熔融製錬に用いる三相交流電極式円形電気炉において、炉側壁を構成する耐火物層の局所的な熔損を防止するに十分な程度に冷却できる高効率熱伝導媒体を、前記電気炉の炉側壁の熱負荷が大きい領域に局所的に配置することによって、炉側壁内周部に形成するコーティングの厚み、生成領域等の生成状態を適切に制御することができ、さらに、電気炉の電力負荷変動、又は原料鉱石の組成変動にも対応することができる冷却機能を有するので、その工業的価値は極めて大きい。 The cooling method of the three-phase AC electrode type circular electric furnace of the present invention is a three-phase AC electrode type circular electric furnace used for melting smelting of steel and non-ferrous metals. The thickness and generation of the coating formed on the inner periphery of the furnace side wall is locally arranged in a region where the heat load on the furnace side wall of the electric furnace is large, which can be cooled sufficiently to prevent Since it has a cooling function that can appropriately control the generation state of the region and the like, and can also cope with fluctuations in the electric power load of the electric furnace or the composition fluctuation of the raw ore, its industrial value is extremely large.
以下、本発明の三相交流電極式円形電気炉とその冷却方法を詳細に説明する。
本発明の三相交流電極式円形電気炉とその冷却方法は、外周部に炉側壁耐火物層が敷設された原料鉱石の熔解処理に用いるための三相交流電極式円形電気炉において、三相交流電極により炉内に発生する高温雰囲気下で、熱負荷が大きくなる炉側壁の領域内に、炉側壁を構成する耐火物層の局所的な熔損を防止するに十分な程度に冷却できる高効率熱伝導媒体を局所的に配置することを特徴とする。これにより、炉側壁の熱負荷が大きい領域で、炉側壁内周部に形成するコーティングの生成状態を制御することができるので、局所的な炉側壁の熔損の進行を防止することができ、さらに、電気炉の電力負荷変動、又は原料鉱石の組成変動に適切に対応することができる。
Hereinafter, the three-phase AC electrode type circular electric furnace of the present invention and its cooling method will be described in detail.
The three-phase AC electrode type circular electric furnace and the cooling method thereof according to the present invention are a three-phase AC electrode type circular electric furnace for use in melting raw material ore having a furnace side wall refractory layer laid on the outer periphery. High enough to prevent local melting of the refractory layer that constitutes the furnace side wall in the area of the furnace side wall where the thermal load increases under high temperature atmosphere generated in the furnace by the AC electrode An efficient heat conducting medium is locally arranged. Thereby, in the region where the thermal load on the furnace side wall is large, it is possible to control the generation state of the coating formed on the inner peripheral part of the furnace side wall, so that the progress of local melting of the furnace side wall can be prevented, Furthermore, it is possible to appropriately cope with power load fluctuations of the electric furnace or composition fluctuations of the raw ore.
本発明において、電気炉の炉側壁の熱負荷が大きい領域内に、炉側壁を構成する耐火物層の局所的な熔損を防止するに十分な程度に冷却できる高効率熱伝導媒体を局所的に配置することが重要である。すなわち、炉内に形成される熔融物に接する炉側壁に高効率熱伝導媒体を設置することによって、熱移動により炉内熔融物を凝固させて、コーティングを形成することができる。しかも、炉側壁の熱負荷が大きい領域内から効率よく熱移動を行ない、その領域内の炉側壁の熱負荷を特に軽減して、炉側壁全体の熱負荷を均等化する働きがある。したがって、コーティングの局所的な過度の成長、及び耐火物の熔損の進行を防止することができる。 In the present invention, a high-efficiency heat conduction medium that can be cooled sufficiently to prevent local melting of the refractory layer constituting the furnace side wall is locally provided in a region where the heat load on the furnace side wall of the electric furnace is large. It is important to place in That is, by installing a high-efficiency heat conduction medium on the furnace side wall in contact with the melt formed in the furnace, the melt in the furnace can be solidified by heat transfer to form a coating. In addition, heat transfer is efficiently performed from within a region where the heat load on the furnace side wall is large, and the heat load on the furnace side wall in that region is particularly reduced, thereby serving to equalize the heat load on the entire furnace side wall. Therefore, local excessive growth of the coating and progression of refractory melting can be prevented.
例えば、従来のシャワー冷却水による炉側壁の保護方法に比べて、局所的な炉側壁の熔損が抑えられ、また、高効率熱伝導媒体を炉側壁の全面に配置する炉側壁の保護方法に比べて、コーティングの局部的な成長付着を抑えられるので、電気炉の炉床電力密度を上昇させて熔解処理能力を向上することが達成される。 For example, compared to the conventional method for protecting the furnace side wall with shower cooling water, local melting of the furnace side wall can be suppressed, and a method for protecting the furnace side wall in which a high-efficiency heat conduction medium is arranged on the entire surface of the furnace side wall. In comparison, since the local growth adhesion of the coating can be suppressed, it is possible to increase the hearth power density of the electric furnace and improve the melting processing capacity.
さらに詳しくは、酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用の三相交流電極式円形電気炉において、従来のシャワー冷却水による炉側壁の保護方法による電気炉操業での炉床電力密度、及び炉側壁への熱負荷が大きい範囲、例えば、電極に最も近い炉側壁内周部に形成されるコーティング厚みを、各々１．０とした場合、或いは電気炉の炉床面積を一定とし炉床電力密度を１．８とした場合においても、熱負荷が大きい範囲での炉側壁内周部に形成されるコーティング厚みは１．０となるので、電気炉寿命を従来以上に延長することが可能となる。一方、炉側壁の熱負荷が小さい場合でも、電極から最も離れた炉側壁の過冷却を防ぎ、炉内へのコーティングの過大な成長を防止し、効率的な操業を維持することが可能となる。さらに、原料鉱石の組成変動により、炉内熔融物の融点が低下した場合においても、熱負荷が大きい範囲での炉側壁耐火物を熔損することなく、炉側壁内周部に形成されるのコーティング厚みを適切に維持することができる。 More specifically, in a three-phase AC electrode circular electric furnace for ferronickel smelting used for reduction melting treatment of nickel oxide ore, the hearth power density in the electric furnace operation by the conventional method of protecting the furnace side wall with shower cooling water , And in the range where the heat load on the furnace side wall is large, for example, when the coating thickness formed on the inner periphery of the furnace side wall closest to the electrode is 1.0, or the furnace floor area of the electric furnace is constant. Even when the floor power density is 1.8, the coating thickness formed on the inner peripheral portion of the furnace side wall in the range where the heat load is large is 1.0, so that the life of the electric furnace can be extended more than before. It becomes possible. On the other hand, even when the heat load on the furnace side wall is small, it is possible to prevent overcooling of the furnace side wall farthest from the electrodes, prevent excessive growth of the coating in the furnace, and maintain efficient operation. . Furthermore, even when the melting point of the melt in the furnace is lowered due to the fluctuation of the composition of the raw ore, the coating formed on the inner periphery of the furnace side wall without damaging the furnace side wall refractory in a large heat load range The thickness can be maintained appropriately.
上記高効率熱伝導媒体を局所的に配置する場所としては、特に限定されるものではないが、炉側壁での高効率熱伝導媒体の配置場所は、電気炉に垂直に設けられる各電極位置に対応して、水平断面上では電極からの水平距離が最も短い円周上の範囲であり、かつ垂直断面上では炉底から炉内熔融物層の上面に渡る範囲であることが望ましい。すなわち、三相交流電極式円形電気炉においては、例えば、電極位置、原料鉱石の装入場所、熔融物のタッピングホール等の配置によって、炉側壁の熱負荷が大きい領域は異なるが、通常、電気炉に備えられた各電極からの水平距離が最も短い円周上の範囲で、しかも炉底から炉内熔融物層の上面に渡る高さの範囲である。 The place where the high-efficiency heat conduction medium is locally disposed is not particularly limited, but the place where the high-efficiency heat conduction medium is disposed on the furnace side wall is at each electrode position provided perpendicular to the electric furnace. Correspondingly, it is desirable that the horizontal distance from the electrode on the horizontal section is the shortest circumferential range, and the vertical section is the range extending from the furnace bottom to the top surface of the melt layer in the furnace. That is, in a three-phase AC electrode type circular electric furnace, the region where the heat load on the furnace side wall is large differs depending on, for example, the position of the electrode, the raw ore charging place, the tapping hole of the melt, etc. The horizontal distance from each electrode provided in the furnace is the shortest circumferential range and the height range from the furnace bottom to the upper surface of the melt layer in the furnace.
上記高効率熱伝導媒体を配置する炉側壁の割合としては、特に限定されるものではないが、例えば、炉側壁の円周長さ全体の３０〜４０％にあたる範囲になるように、各電極位置に対応して分割して配置することが望ましい。 The ratio of the furnace side wall on which the high-efficiency heat transfer medium is arranged is not particularly limited. For example, each electrode position may be within a range corresponding to 30 to 40% of the entire circumferential length of the furnace side wall. It is desirable to divide and arrange corresponding to the above.
上記高効率熱伝導媒体としては、特に限定されるものではなく、炉側壁の内周部に所望の状態にコーティングを形成することができる冷却装置が用いられるが、この中で、耐火物中に容易に埋設することができる、冷却水等の冷媒等を用いて冷却される熱伝導性の良い金属等の材料からなる冷却部品、例えば、銅製冷却部品が好ましい。ここで、冷却部品の形状及び大きさは、特に限定されるものではなく、例えば、角柱状、円柱状等のブロック形状、管状のパイプ形状等の部品の複数個を、炉側壁の所定の範囲に配置することができる。 The high-efficiency heat conduction medium is not particularly limited, and a cooling device that can form a coating in a desired state on the inner peripheral portion of the furnace side wall is used. A cooling component made of a material such as a metal with good thermal conductivity that can be easily embedded and cooled using a coolant such as cooling water, for example, a copper cooling component is preferable. Here, the shape and size of the cooling parts are not particularly limited. For example, a plurality of parts such as a prismatic shape, a cylindrical shape such as a block shape, and a tubular pipe shape are arranged in a predetermined range on the side wall of the furnace. Can be arranged.
上記高効率熱伝導媒体は、特に限定されるものではなく、炉側壁の内周部に沿って、炉側壁を構成する耐火物内部に埋設されるように設置されることが好ましい。これにより、耐火物の冷却とともに、冷却された耐火物が炉内に形成される熔融物、或いはコーティングと直接的に接することにより、炉内の熔融物への熱伝導媒体からの熱伝導が良好に行なわれる。 The high-efficiency heat conduction medium is not particularly limited, and is preferably installed so as to be embedded inside the refractory constituting the furnace side wall along the inner peripheral portion of the furnace side wall. As a result, in addition to cooling the refractory, the cooled refractory is in direct contact with the melt formed in the furnace or the coating, so that heat conduction from the heat conduction medium to the melt in the furnace is good. To be done.
さらに、上記電気炉の冷却方法としては、高効率熱伝導媒体を炉側壁の熱負荷が大きい領域に局所的に配置するとともに、高効率熱伝導媒体を配置していない領域においては、電気炉の炉側壁外鉄板に沿ってシャワー冷却水を流す冷却手段を併用することができる。これによって、従来のシャワー冷却水による炉側壁の保護方法における問題点を解消することができる。すなわち、炉床電力密度が高い場合、或いは原料鉱石の組成等の変動により炉内熔融物の融点が低い場合にも、従来のシャワー冷却水による炉側壁の冷却能力の不足を補って、特に、炉側壁の中で熱負荷が大きい部分、例えば、電気炉に設けられた各電極から最も距離が短い炉側壁部分において、炉側壁内周部に安定したコーティングを形成して耐火物の熔損を防止することができる。 Furthermore, as a method for cooling the electric furnace, the high-efficiency heat conduction medium is locally disposed in a region where the heat load on the furnace side wall is large, and in the region where the high-efficiency heat conduction medium is not disposed, A cooling means for flowing shower cooling water along the furnace side wall iron plate can be used in combination. Thereby, the problem in the conventional method for protecting the furnace side wall with shower cooling water can be solved. That is, when the hearth power density is high, or when the melting point of the melt in the furnace is low due to fluctuations in the composition of the raw ore, etc., in addition to the lack of the cooling capacity of the furnace side wall by the conventional shower cooling water, In the furnace side wall where the heat load is large, for example, in the furnace side wall part where the distance from each electrode provided in the electric furnace is the shortest, a stable coating is formed on the inner periphery of the furnace side wall to prevent the refractory from being melted. Can be prevented.
上記電気炉としては、特に限定されるものではなく、鉄鋼及び非鉄金属熔融製錬に用いるものが挙げられるが、この中で、酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用が好ましい。ここで、フェロニッケル製錬では、原料鉱石としては、ガーニエライト鉱等の酸化ニッケル鉱石が用いられる。最も一般的に用いられるガーニエライト鉱の代表的な組成としては、乾燥鉱換算でＮｉ品位が２．１〜２．５重量％、Ｆｅ品位が１１〜２３重量％、ＭｇＯ品位が２０〜２８重量％、ＳｉＯ２品位が２９〜３９重量％、ＣａＯ品位が＜０．５重量％、灼熱減量が１０〜１５重量％であり、通常はロータリーキルンへ装入され焙焼後、電気炉中で炭素質還元剤により還元熔融され、熔融物としてフェロニッケルメタル層とスラグ層が形成される。 The electric furnace is not particularly limited, and examples thereof include those used for steel and non-ferrous metal melting and smelting. Among these, ferronickel smelting used for reduction melting treatment of nickel oxide ore is preferable. Here, in ferronickel smelting, nickel oxide ores such as garnierite ore are used as raw ores. The typical composition of the most commonly used garnierite ore is 2.1 to 2.5% by weight of Ni grade, 11 to 23% by weight of Fe grade, and 20 to 28% of MgO grade in terms of dry ore. %, SiO 2 quality 29-39 wt%, CaO quality <0.5 wt%, ignition loss is 10-15% by weight, after normally be charged into the rotary kiln roasting, carbonaceous in an electric furnace It is reduced and melted by a reducing agent, and a ferronickel metal layer and a slag layer are formed as a melt.
以下に、本発明の実施例及び比較例によって本発明をさらに詳細に説明するが、本発明は、これらの実施例によってなんら限定されるものではない。なお、実施例及び比較例で用いたコーティング厚みの評価方法は、下記の３次元熱流体シミュレーションによるコーティング厚みの算出より求めた。
［３次元熱流体シミュレーションによるコーティング厚みの算出］
酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用の三相交流電極式円形電気炉において、電気炉の電力負荷及び冷却構造による熱移動を設定して、３次元熱流体シミュレーションにより、炉側壁内周部に形成されるコーティングの状態を求め、これより、コーティング厚みを算出した。
例えば、図３に示すように炉側壁外表面から炉内溶融物に至る炉側壁内部の温度分布を求めた。その後、炉内熔融物温度と炉側壁耐火物先端温度との温度差範囲を求め、そのうち、炉内熔融物の融点（凝固点）温度以下となっている範囲をコーティング厚みとして算出した。
Hereinafter, the present invention will be described in more detail by way of examples and comparative examples of the present invention, but the present invention is not limited to these examples. In addition, the evaluation method of the coating thickness used by the Example and the comparative example was calculated | required by calculation of the coating thickness by the following three-dimensional thermal fluid simulation.
[Calculation of coating thickness by three-dimensional thermal fluid simulation]
In a three-phase AC electrode type circular electric furnace for ferronickel smelting used for reduction melting treatment of nickel oxide ore, heat transfer by electric furnace power load and cooling structure is set, and the furnace side wall The state of the coating formed on the inner periphery was determined, and the coating thickness was calculated from this.
For example, as shown in FIG. 3, the temperature distribution inside the furnace side wall from the outer surface of the furnace side wall to the melt in the furnace was obtained. Thereafter, the temperature difference range between the furnace melt temperature and the furnace side wall refractory tip temperature was determined, and the range within the melting point (freezing point) temperature of the furnace melt was calculated as the coating thickness.
（実施例１）
酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用の三相交流電極式円形電気炉において、図１に表すように、高効率熱伝導媒体を電気炉の円周部の炉側壁に局所配置した。
(Example 1)
In a three-phase AC electrode type circular electric furnace for ferronickel smelting used for reduction melting treatment of nickel oxide ore, as shown in FIG. 1, a high-efficiency heat conduction medium is locally disposed on the furnace side wall of the electric furnace. did.
図１は、本発明の電気炉の冷却方法を表す、高効率熱伝導媒体を炉側壁に局所配置した三相交流電極式円形電気炉の概略図であり、その水平断面とともに、炉側壁の垂直断面の構造の一例が表される。ここで、三相交流電極１からの距離が最も短い炉側壁領域として、三相交流電極式円形電気炉２の炉側壁の約１／３にあたる範囲に、高効率熱伝導媒体９を配置した。なお、炉側壁の垂直断面の構造に見られるように、高効率熱伝導媒体９は炉側壁耐火物５の内部に埋めこまれ、例えば、冷却水の通水により、炉内熔融物３を凝固させ、コーティングを形成する。なお、炉側壁鉄板６へのシャワー冷却水の散布は、この高効率熱伝導媒体を炉側壁に局所配置した領域を除いて行なわれている。
このとき、炉内熔融物としては、メタル温度で１４００℃、及びスラグ温度で１６００℃まで加熱され、メタル抜出し口１０とスラグ抜出し口１１より、炉外へ排出されるが、炉内熔融物からの伝導伝熱は炉側壁の内周部に形成されるコーティングと耐火物を通じて、炉側壁外鉄板に伝わるが、この間に耐火物中に局所的に配置された高効率熱伝導媒体により熱移動がなされる。
FIG. 1 is a schematic view of a three-phase AC electrode type circular electric furnace in which a high-efficiency heat conduction medium is locally disposed on the furnace side wall, which represents the cooling method of the electric furnace according to the present invention. An example of a cross-sectional structure is represented. Here, the high-efficiency
At this time, the melt in the furnace is heated to 1400 ° C. at the metal temperature and 1600 ° C. at the slag temperature, and discharged from the furnace through the
この際、上記コーティング厚みの評価方法によれば、高効率熱伝導媒体が設置された三相交流電極に最も近い炉側壁の範囲には、コーティングが形成され、耐火物の熔損を抑制することができる。すなわち、図３に一例を示すコーティング状態を３次元熱流体シミュレーションにより、コーティング厚みが増加することが確認され、これよりコーティング厚みを算出した。結果を、表１に示す。なお、表１では、従来操業（比較例１）における炉床電力密度及び炉壁内のコーティング厚みの数値をそれぞれ１．０として、相対値で示した。 At this time, according to the coating thickness evaluation method, a coating is formed in the range of the side wall of the furnace closest to the three-phase AC electrode on which the high-efficiency heat conduction medium is installed, thereby suppressing refractory melting. Can do. That is, it was confirmed by the three-dimensional thermal fluid simulation that the coating state shown in FIG. 3 is an example, and the coating thickness was calculated from this. The results are shown in Table 1. In addition, in Table 1, the numerical value of the hearth power density in the conventional operation (Comparative Example 1) and the coating thickness in the furnace wall was set to 1.0, and the relative value was shown.
（実施例２）
炉床電力密度を１８０％まで増大したこと以外は、実施例１と同様に行なった。このとき、比較例１と同じ厚さのコーティングが形成され、耐火物の熔損を抑制できることが、上記シミュレーションにより確認された。結果を、表１に示す。
(Example 2)
The same operation as in Example 1 was performed except that the hearth power density was increased to 180%. At this time, it was confirmed by the above simulation that a coating having the same thickness as that of Comparative Example 1 was formed, and that the refractory was prevented from being melted. The results are shown in Table 1.
（比較例１）
酸化ニッケル鉱石の還元熔解処理に用いるフェロニッケル製錬用の三相交流電極式円形電気炉において、電気炉の冷却方法として、図１に表すように、従来のシャワー冷却水による炉側壁の保護方法を用いた。
(Comparative Example 1)
In a three-phase AC electrode type circular electric furnace for ferronickel smelting used for reduction melting treatment of nickel oxide ore, as shown in FIG. 1, as a cooling method of the electric furnace, a conventional method of protecting the furnace side wall with shower cooling water Was used.
図２は、シャワー冷却水による炉側壁の保護方法を用いた炉内に形成されるコーティング状態を表す電気炉の概略図であり、その水平断面とともに、炉側壁のシャワー冷却水の一例が表される。ここで、三相交流電極１を電力源とする三相交流電極式円形電気炉２において、炉内熔融物３は、メタル温度で１４００℃、及びスラグ温度で１６００℃まで加熱され、炉内熔融物３からの伝導伝熱は、コーティング４及び炉側壁耐火物５を通じて、炉側壁外鉄板６に伝わる。なお、電気炉側壁外鉄板６は、シャワー冷却水配管７より流出するシャワー冷却水８により冷却される。
FIG. 2 is a schematic view of an electric furnace showing a coating state formed in the furnace using a method for protecting the furnace side wall with shower cooling water, and an example of shower cooling water on the furnace side wall is shown along with the horizontal section thereof. The Here, in the three-phase AC electrode type circular
この際、三相交流電極１に最も近い炉側壁部分に形成されるコーティング４は薄く、炉側壁耐火物５の熔損が進行しやすい。また、炉床電力密度を増大した場合、或いは原料鉱石組成等の変動により炉内熔融物の融点が低い場合には、三相交流電極１に最も近い炉壁部分の炉側壁耐火物５の熔損はさらに進行し、その他の部分においてもコーティング４が薄いので、炉側壁耐火物５の熔損が進行しやすくなる。すなわち、図３に一例を示すコーティング状態を３次元熱流体シミュレーションにより、コーティング厚みは、実施例１に比べて低いことが確認され、これよりコーティング厚みを算出した。結果を、表１に示す。
Under the present circumstances, the
表１より、実施例１又は２では、高効率熱伝導媒体を、耐火物の熔損が進行する三相交流電極に最も近い部分である炉側壁の円周の約１／３にあたる範囲に配置したことにより、比較例１に比べて、炉側壁への熱負荷による局所的な熔損の進行を防止し、かつ電気炉の電力負荷変動に対応することができることが分かる。 From Table 1, in Example 1 or 2, the high-efficiency heat conduction medium is arranged in a range corresponding to about 1/3 of the circumference of the furnace side wall, which is the portion closest to the three-phase AC electrode where refractory melts progress. Thus, it can be seen that, compared with Comparative Example 1, it is possible to prevent the progress of local melting due to the thermal load on the furnace side wall and to cope with the electric load fluctuation of the electric furnace.
以上より明らかなように、本発明の三相交流電極式円形電気炉の冷却方法は、三相交流電極式円形電気炉において、局所的な炉側壁の熔損の進行を防止するため、炉側壁内周部に形成するコーティングを制御することができ、特に、電気炉の電力負荷変動、又は原料鉱石の組成変動に適切に対応することができるので、特に鉄鋼及び非鉄金属熔融製錬で利用される電気炉の冷却方法として好適である。 As is clear from the above, the cooling method for the three-phase AC electrode type circular electric furnace of the present invention is to prevent the local side wall of the furnace from melting in the three-phase AC electrode type circular electric furnace. It is possible to control the coating formed on the inner periphery, and in particular, it can respond appropriately to power load fluctuations of the electric furnace or composition fluctuations of the raw ore, so it is especially used in steel and non-ferrous metal melting and smelting. It is suitable as a method for cooling an electric furnace.
１ 三相交流電極
２ 三相交流電極式円形電気炉
３ 炉内熔融物
４ コーティング
５ 炉側壁耐火物
６ 炉側壁外鉄板
７ シャワー冷却水配管
８ シャワー冷却水
９ 高効率熱伝導媒体
１０ メタル抜出し口
１１ スラグ抜出し口
DESCRIPTION OF
Claims (8)
三相交流電極により炉内に発生する高温雰囲気下で、熱負荷が大きくなる炉側壁の領域内に、炉側壁を構成する耐火物層の局所的な熔損を防止するに十分な程度に冷却できる高効率熱伝導媒体を局所的に配置することを特徴とする三相交流電極式円形電気炉の冷却方法。 In the three-phase alternating current electrode type circular electric furnace for use in the melting treatment of the raw ore where the furnace side wall refractory layer is laid on the outer periphery,
Cooling to a sufficient extent to prevent local melting of the refractory layer constituting the furnace side wall in the area of the furnace side wall where the heat load increases under the high temperature atmosphere generated in the furnace by the three-phase AC electrode A cooling method for a three-phase AC electrode type circular electric furnace, wherein a high-efficiency heat conduction medium that can be produced is locally disposed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006157322A JP4912758B2 (en) | 2006-06-06 | 2006-06-06 | Three-phase AC electrode type circular electric furnace and its cooling method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006157322A JP4912758B2 (en) | 2006-06-06 | 2006-06-06 | Three-phase AC electrode type circular electric furnace and its cooling method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007327660A true JP2007327660A (en) | 2007-12-20 |
| JP4912758B2 JP4912758B2 (en) | 2012-04-11 |
Family
ID=38928243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006157322A Active JP4912758B2 (en) | 2006-06-06 | 2006-06-06 | Three-phase AC electrode type circular electric furnace and its cooling method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4912758B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010249477A (en) * | 2009-04-20 | 2010-11-04 | Hyuga Seirensho:Kk | Three-phase ac electrode type circular electric furnace and method of cooling furnace body of the same |
| JP2013127352A (en) * | 2011-11-17 | 2013-06-27 | Hyuga Seirensho:Kk | Cooling method for three-phase ac electrode type circular electric furnace and the three-phase ac electrode type circular electric furnace |
| CN107401917A (en) * | 2017-09-15 | 2017-11-28 | 巴涌 | One kind is without interpolar branch current ore-smelting electric furnace |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492706A (en) * | 1972-04-28 | 1974-01-11 | ||
| JPS4928274Y1 (en) * | 1970-10-14 | 1974-08-01 | ||
| JPS4989611A (en) * | 1972-12-27 | 1974-08-27 | ||
| JPS5035044Y1 (en) * | 1968-08-02 | 1975-10-13 | ||
| JPS52135404A (en) * | 1976-05-07 | 1977-11-12 | Shin Meiwa Ind Co Ltd | Squeezing pump |
| JPS557827Y2 (en) * | 1974-01-23 | 1980-02-21 | ||
| JPS625082A (en) * | 1985-07-01 | 1987-01-12 | ヒルサ・エス・エ− | Cooling panel for arc furnace |
| JPS6297496A (en) * | 1985-10-23 | 1987-05-06 | Honda Motor Co Ltd | Sound volume adjusting device |
| JPH05141868A (en) * | 1991-05-17 | 1993-06-08 | Tanabe:Kk | Electrical melting furnace |
| JP2004068099A (en) * | 2002-08-07 | 2004-03-04 | Hyuga Seirensho:Kk | Method for operating smelting furnace |
-
2006
- 2006-06-06 JP JP2006157322A patent/JP4912758B2/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5035044Y1 (en) * | 1968-08-02 | 1975-10-13 | ||
| JPS4928274Y1 (en) * | 1970-10-14 | 1974-08-01 | ||
| JPS492706A (en) * | 1972-04-28 | 1974-01-11 | ||
| JPS4989611A (en) * | 1972-12-27 | 1974-08-27 | ||
| JPS557827Y2 (en) * | 1974-01-23 | 1980-02-21 | ||
| JPS52135404A (en) * | 1976-05-07 | 1977-11-12 | Shin Meiwa Ind Co Ltd | Squeezing pump |
| JPS625082A (en) * | 1985-07-01 | 1987-01-12 | ヒルサ・エス・エ− | Cooling panel for arc furnace |
| JPS6297496A (en) * | 1985-10-23 | 1987-05-06 | Honda Motor Co Ltd | Sound volume adjusting device |
| JPH05141868A (en) * | 1991-05-17 | 1993-06-08 | Tanabe:Kk | Electrical melting furnace |
| JP2004068099A (en) * | 2002-08-07 | 2004-03-04 | Hyuga Seirensho:Kk | Method for operating smelting furnace |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010249477A (en) * | 2009-04-20 | 2010-11-04 | Hyuga Seirensho:Kk | Three-phase ac electrode type circular electric furnace and method of cooling furnace body of the same |
| JP2013127352A (en) * | 2011-11-17 | 2013-06-27 | Hyuga Seirensho:Kk | Cooling method for three-phase ac electrode type circular electric furnace and the three-phase ac electrode type circular electric furnace |
| CN107401917A (en) * | 2017-09-15 | 2017-11-28 | 巴涌 | One kind is without interpolar branch current ore-smelting electric furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4912758B2 (en) | 2012-04-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4912758B2 (en) | Three-phase AC electrode type circular electric furnace and its cooling method | |
| JP5445744B2 (en) | Three-phase AC electrode type circular electric furnace and its cooling method | |
| JP5408417B2 (en) | Operation method of electric furnace for ferronickel smelting | |
| JP6429190B2 (en) | Electric furnace for melting steelmaking slag | |
| JP5747286B2 (en) | Three-phase AC electrode type circular electric furnace cooling method and three-phase AC electrode type circular electric furnace | |
| JPH11223464A (en) | Electric furnace | |
| CN106062217A (en) | Method for melting minerals containing iron, titanium and vanadium | |
| CN101900491A (en) | Cooling water jacket, preparation method thereof and high temperature smelting equipment with same | |
| JP2014105348A (en) | Operation method of electric furnace for ferronickel smelting | |
| JP5963655B2 (en) | Three-phase AC electrode type circular electric furnace and its cooling method | |
| JP6689195B2 (en) | Metal manufacturing method and refractory metal manufacturing method | |
| JPWO2021045174A1 (en) | Manufacturing method of low carbon ferrochrome | |
| CN203437633U (en) | Brick-cup-free steel ladle | |
| CN206803769U (en) | A kind of furnace device of full water cooling structure | |
| CN201440041U (en) | Cooling water jacket for high-temperature smelting unit and high-temperature smelting unit with cooling water jacket | |
| CN202216548U (en) | Metallurgical slag thickness control device | |
| EP2960608A1 (en) | Method for cooling housing of melting unit and melting unit | |
| CN204174255U (en) | A kind of metallurgical electric furnace deathnium bell | |
| WO2016093197A1 (en) | Operation method for electric resistance furnaces | |
| Zaitsev et al. | Reliable steel-copper anodes for direct current electric arc furnaces manufactured by electroslag remelting under two circuits diagram | |
| JPH1047861A (en) | Electric furnace | |
| JP2019184121A (en) | Heat-recovery apparatus for high-temperature coagulation | |
| JPH07278627A (en) | Cooling piping for bottom of blast furnace and method for cooling bottom of blast furnace | |
| JP2007231388A (en) | Molten salt electrolysis method and molten salt electrolytic cell | |
| RU2016132025A (en) | A method of manufacturing a bimetallic electrode by electroslag surfacing and a method of utilizing metallurgical slag by reduction smelting using a bimetallic electrode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080402 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20110331 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110524 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110720 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120110 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120118 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4912758 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150127 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |