JPH0453922B2 - - Google Patents
Info
- Publication number
- JPH0453922B2 JPH0453922B2 JP60192751A JP19275185A JPH0453922B2 JP H0453922 B2 JPH0453922 B2 JP H0453922B2 JP 60192751 A JP60192751 A JP 60192751A JP 19275185 A JP19275185 A JP 19275185A JP H0453922 B2 JPH0453922 B2 JP H0453922B2
- Authority
- JP
- Japan
- Prior art keywords
- chromium
- furnace
- ore
- hot metal
- tuyere
- 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
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 86
- 239000011651 chromium Substances 0.000 claims description 85
- 229910052804 chromium Inorganic materials 0.000 claims description 85
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 22
- 229910052760 oxygen Inorganic materials 0.000 claims description 22
- 239000001301 oxygen Substances 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 17
- 239000002893 slag Substances 0.000 claims description 16
- 239000003575 carbonaceous material Substances 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 8
- 238000007664 blowing Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 238000002844 melting Methods 0.000 description 11
- 230000008018 melting Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 238000003723 Smelting Methods 0.000 description 6
- 239000000571 coke Substances 0.000 description 6
- 238000006722 reduction reaction Methods 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910000604 Ferrochrome Inorganic materials 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000000567 combustion gas Substances 0.000 description 3
- 239000012159 carrier gas Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 229910001021 Ferroalloy Inorganic materials 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- 240000006829 Ficus sundaica Species 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- UOUJSJZBMCDAEU-UHFFFAOYSA-N chromium(3+);oxygen(2-) Chemical class [O-2].[O-2].[O-2].[Cr+3].[Cr+3] UOUJSJZBMCDAEU-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000010436 fluorite Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000013980 iron oxide Nutrition 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Manufacture Of Iron (AREA)
Description
〔産業上の利用分野〕
本発明は、電力を製錬用のエネルギーとして使
用することなく含クロム溶銑を製造する方法にお
いて、クロム源の一部としてクロム鉱石を使用し
このクロム鉱石の溶融還元も同時に行えるように
した熱経済的な含クロム溶銑の製造法に関する。
〔従来の技術〕
従来より、ステンレス鋼製造用の含クロム溶銑
の製造法としては、電気炉による方法が一つの技
術体系を形成している。この方法は、製鋼用アー
ク炉に、クロム源、コークス、フラツクスおよび
必要に応じて副材料を装入して溶解し、含クロム
溶銑を得るものである。そのさいのクロム源とし
ては、高炭素フエロクロムが使用されるのが通常
である。この高炭素フエロクロムを製造するのに
も電気炉が使用され、この場合にはクロム鉱石の
半還元ペレツト等が使用されたり焼結鉱が使用さ
れたりする。この従来法によると電力消費量が非
常に大きいので、近年、クロム鉱石を炭材等の還
元材によつて直接的に溶融還元する方法の開発が
推進されている。その傾向としては、転炉によつ
てクロム鉱石の溶融還元を行う方向に注力されて
いるようである。例えば特開昭58−77548号公報、
特開昭59−145758号公報、特開昭59−150059号公
報、特開昭59−150060号公報、特開昭59−150061
号公報、特開昭59−150062号公報等は転炉による
クロム鉱石の溶融還元を開示している。また特開
昭50−116363号公報は特殊な混合層を使用してク
ロム鉱石の溶融還元を行う方法を開示する。
一方、本願と同一出願人に係る特願昭59−
18219号（特開昭60−162718号公報）において、
特殊な竪型炉を使用し、この竪型炉の羽口にクロ
ム源の一部としての粉状のクロム鉱石を吹込むこ
とによつてその溶融還元を図る方法を提案した。
この出願人の提案に係る竪型炉による方法の骨子
は、炉の上部に原料装入口をそして炉の下部付近
に上下二段の羽口をもつ竪型炉を用いて含クロム
溶銑を製造するものであり、上部の原料装入口か
らクロム源、鉄源、炭材および造滓材を装入し、
該上下の羽口から熱風を吹込むと同時に、羽口か
ら粉状クロム鉱石および発熱材を炉内に供給する
ことにより、この粉状クロム鉱石を溶融還元しな
がら含クロム溶銑を得るものである。
〔発明の目的〕
本発明は、前記の特願昭59−18219号（特開昭
60−162718号公報）に提案した竪型炉によるクロ
ム鉱石の溶融還元法の一層の改善を図つたもので
ある。特に、この堅型炉の二段羽口付近での反応
挙動について未解決であつた問題を解決して、ク
ロム鉱石を良好な熱効率のもとで溶融還元する方
法を提供しようとするものである。
〔目的を達成する手段〕
本発明は、炉の上部に原料装入口をそして炉の
下部付近に上下二段の羽口をもつ竪型炉を用いて
含クロム溶銑を製造するにさいし、該上部の原料
装入口から鉄源、炭材、造滓材およびクロム源を
装入し、該上下の羽口から高温酸素富化空気を吹
込むと同時に、上段羽口から粉状クロム鉱石およ
び粉状造滓材を炉内に供給することにより、この
粉状クロム鉱石を溶融還元しながら含クロム溶銑
を製造する方法において、該上下二段の羽口から
吹込む高温酸素富化空気の吹込み速度を100ｍ／
ｓ以上に制御すすことを特徴とする。
第１図に本発明法を実施する竪型炉の例を示し
た。図示のように、この竪型炉は全体としては縦
長のシヤフトからなり、この炉の上部には、原料
装入口１が、また下部には上段羽口２と下段羽口
３とからなる二段羽口が設けられている。４は熱
風炉であり、この熱風炉４で得られた熱風が各羽
口２と３に供給される。そのさい、酸素源５によ
つて、熱風に酸素を富化することができるように
なつている。上段羽口２にはこの高温酸素富化空
気と共に容器６内の粉状クロム鉱石１５と容器７
内の粉状造滓材１６がキヤリヤガス８によつて供
給され、これらが炉内に吹き込まれる。なお必要
に応じてフエロアロイ粉例えば高炭素フエロクロ
ム粉やフエロシリコン粉、更にはSiCやCaCや
CaC等の酸素と反応して発熱する粉状物質もキヤ
リヤガス８によつて炉内に供給されるようになつ
ている。なお図において、１０〜１２は、クロム
源としての高炭素フエロクロム、鉄源としての鋼
屑、炭材としてのコークス、造滓材としての石灰
石や螢石などを収容する容器群であり、これらの
炉頂装入原料は計量器１３によつて所定の量とな
るように計量されながら原料装入口１から炉内に
装入される。
本発明者らは、このような竪型炉によるクロム
鉱石の吹き込みにさいし、上段羽口から炉内に吹
込む粉状クロム鉱石をどのようにしたら熱効率的
に良好に溶融還元せしめることができるかという
点を重点項目にして実験を重ねた。すなわち、粉
状造滓材と共に上段羽口から炉内に吹き込まれた
粉状クロム鉱石は、上段羽口前のコークス燃焼領
域で溶融し、その溶融物がコークス充填層を滴下
する間に還元されることになるであろうが、この
還元反応は吸熱反応である。したがつて、熱の媒
体である下段羽口前で生成されたコークスの燃焼
ガスから、溶融クロム鉱石が還元されている領域
に向けて、熱が効率よく供給されないと、クロム
鉱石の溶融還元反応は著しく阻害され、クロムの
収率が低下すると共に安定的な含クロム溶銑の製
造が困難となる。このような現象は本発明者らの
度重なる実験検討の結果、上段羽口前で溶融状態
となつたクロム鉱石が炉の断面に対して限られた
狭い範囲を選択的に滴下するような条件のときに
発生することが判明した。
本発明の骨子は、このような条件が生じないよ
うに、上段羽口から炉内に吹き込まれて溶融状態
となつた溶融クロム鉱石の滴下領域を炉の断面に
対して巾広く分布させることにある。これを達成
するのに最も有効且つ簡易な手段は、本発明者ら
の数多くの実験の結果、上下段羽口から吹込む高
温酸素富化空気の速度（Vb）を、
（Vb）≧100（ｍ／ｓ）
となるように制御することであることが明らかと
なつた。
第２図は、実験炉を用いた含クロム溶銑製造実
験の途中において炉内の状況がそのまま保存でき
るように炉を急冷し、その後に炉を解体して調査
した結果、知見することができた羽口付近の炉内
の状況を図解したものである。第２図に示される
ように、含クロム溶銑製造途中では、上段羽口２
および下段羽口３の炉内側前面に、冶金用コーク
ス等の炭材が燃焼するレースウエイ２０なる空間
が形成され、このレースウエイ２０を取り巻くよ
うに、上段羽口２から溶融状態となつたクロム鉱
石が炭材の充填層を滴下する領域２１が存在す
る。この領域２１においては、クロム鉱石等の溶
融酸化物中に存在するクロム酸化物や鉄酸化物が
炭材中の炭素によつて還元され、クロム濃度の高
い溶融金属を生成すると共に、溶融酸化物中のク
ロム濃度は低下する。この結果として、炉の底部
にクロム濃度の低い溶融酸化物とクロム濃度の高
い溶融金属が滴下し、また、炉上部より装入され
た鋼屑等の溶融物も滴下し最終的に炉底に含クロ
ム溶銑が溜まることになる。第２図において、２
２は溶融酸化物が溜まつている領域を、２３は含
クロム溶銑が溜まつている領域を、そして２４は
炉上部より装入した鋼屑等が溶融し滴下する領域
を示している。
このような含クロム溶銑製造時の炉内状況にお
いて、上下段羽口から炉内に吹込む高温酸素富化
空気の速度（Vb）を、（Vb）＜100（ｍ／ｓ）の条
件としたときには、クロム鉱石の溶融物は、炉の
断面に対して限られた狭い範囲を選択的に滴下し
ていることがわかつた。このために下段羽口３の
前で生成した炭材の燃焼ガスから、の滴下領域２
１への、クロム鉱石の溶融還元に必要な反応熱が
効率良く供給されず、この結果として炉内でのク
ロム鉱石の溶融還元が順調に進行せず、発熱材の
吹き込み量を増加させない限り、クロムの収率は
不良となつた。
これに対して、他の操業条件は同一にして、高
温酸素富化空気の速度（Vb）を、（Vb）≧100
（ｍ／ｓ）とした場合には、クロム鉱石の溶融物
が滴下する流域が炉の断面に対して幅広く分布し
ていた。このために、この滴下流域２１へ炭材の
燃焼ガスから効率的に熱が供給され、第３図に示
すように、炉内に供給された熱量のうち、クロム
鉱石の溶融還元に有効に利用された熱量の割合、
すなわち熱効率は、（Vb）＜100（ｍ／ｓ）の条件
で実験を行つた場合に比べて高くなり、クロムの
収率は高率を示し、また発熱材を吹き込まずとも
これと同等のクロム収率が得られることがわかつ
た。
なお、炉内に吹き込む高温酸素富化空気の速度
（Vb）は、次式で算出できる。
Vb＝BV／｛π・（DT／２）2｝
ただし、BV；羽口一本当りに吹き込まれる高
温酸素富化空気の流量（m3／ｓ），DT；羽口径
（ｍ），π；円周率である。
以下に実験炉による実施結果を述べる。
実験例 １
第１図から示したような炉内径が0.6ｍの竪型
炉の上部から第１表に示すような量で炉頂装入原
料を装入し、内径がそれぞれ16mmの上下段羽口か
ら、各1Nm3／minの流量で、温度が800℃、酸素
濃度が28.5％の高温酸素富化空気を、284ｍ／ｓ
の速度で炉内に吹き込み、且つ上段羽口からは、
第２表に示す粉末の混合物を炉内に吹き込んだ。
この結果として、出滓口から取り出されたスラグ
中の未還元クロム濃度は0.8％、またクロムの収
率は97.9％と良好にクロム鉱石の溶融還元を行う
ことができ、第３表に示すような組成の含クロム
溶銑を得ることができた。
[Industrial Application Field] The present invention is a method for producing chromium-containing hot metal without using electricity as energy for smelting, in which chromium ore is used as part of the chromium source and the smelting reduction of the chromium ore is also carried out. This invention relates to a thermoeconomic method for producing chromium-containing hot metal that can be carried out simultaneously. [Prior Art] Conventionally, as a method for producing chromium-containing hot metal for producing stainless steel, a method using an electric furnace has formed one technological system. In this method, a chromium source, coke, flux, and optionally auxiliary materials are charged into a steelmaking arc furnace and melted to obtain chromium-containing hot metal. High carbon ferrochrome is usually used as the chromium source in this case. An electric furnace is also used to produce this high carbon ferrochrome, and in this case semi-reduced pellets of chromium ore or sintered ore are used. Since this conventional method consumes a very large amount of electricity, in recent years, the development of a method for directly melting and reducing chromium ore using a reducing agent such as carbonaceous material has been promoted. The trend seems to be to focus on smelting and reducing chromium ore using converters. For example, Japanese Patent Application Laid-Open No. 58-77548,
JP-A-59-145758, JP-A-59-150059, JP-A-59-150060, JP-A-59-150061
JP-A-59-150062, etc. disclose melting and reduction of chromium ore using a converter. Furthermore, Japanese Patent Application Laid-Open No. 116363/1983 discloses a method for melting and reducing chromium ore using a special mixed layer. On the other hand, a patent application filed in 1983 by the same applicant as the present application
In No. 18219 (Japanese Unexamined Patent Publication No. 162718/1983),
We proposed a method of melting and reducing chromium ore as part of the chromium source by using a special vertical furnace and injecting powdered chromium ore as part of the chromium source into the tuyeres of this vertical furnace.
The gist of the method using a vertical furnace proposed by this applicant is to produce chromium-containing hot metal using a vertical furnace that has a raw material charging port in the upper part of the furnace and two stages of upper and lower tuyere near the bottom of the furnace. The chromium source, iron source, carbon material, and slag material are charged from the upper raw material charging port.
By blowing hot air through the upper and lower tuyeres and at the same time supplying powdered chromium ore and heat generating material from the tuyeres into the furnace, chromium-containing hot metal is obtained while melting and reducing the powdered chromium ore. . [Object of the Invention] The present invention is based on the aforementioned Japanese Patent Application No. 59-18219.
This is an attempt to further improve the smelting reduction method for chromium ore using a vertical furnace, which was proposed in Japanese Patent Publication No. 60-162718. In particular, we aim to solve the unresolved problems regarding the reaction behavior near the two-stage tuyere of this vertical furnace and provide a method for melting and reducing chromium ore with good thermal efficiency. . [Means for Achieving the Object] The present invention provides a method for producing chromium-containing hot metal using a vertical furnace having a raw material charging port in the upper part of the furnace and upper and lower tuyeres near the lower part of the furnace. Iron source, carbon material, slag material, and chromium source are charged from the raw material charging port of In a method of producing chromium-containing hot metal by melting and reducing powdery chromium ore by supplying slag material into a furnace, the blowing speed of high-temperature oxygen-enriched air that is blown from the upper and lower two stages of tuyeres is 100m/
It is characterized by being controlled more than s. FIG. 1 shows an example of a vertical furnace for carrying out the method of the present invention. As shown in the figure, this vertical furnace consists of a vertically long shaft as a whole, and the upper part of this furnace has a raw material charging port 1, and the lower part has two stages consisting of an upper tuyere 2 and a lower tuyere 3. A tuyere is provided. 4 is a hot air stove, and hot air obtained from this hot air stove 4 is supplied to each tuyere 2 and 3. At this time, the oxygen source 5 makes it possible to enrich the hot air with oxygen. The powdered chromium ore 15 in the container 6 and the container 7 are delivered to the upper tuyere 2 together with this high-temperature oxygen-enriched air.
The powdered slag materials 16 inside are supplied by carrier gas 8 and are blown into the furnace. If necessary, ferroalloy powder such as high carbon ferrochrome powder, ferrosilicon powder, SiC, CaC, etc.
Powdered substances such as CaC that react with oxygen and generate heat are also supplied into the furnace by the carrier gas 8. In the figure, numerals 10 to 12 are containers containing high-carbon ferrochrome as a chromium source, steel scrap as an iron source, coke as a carbon material, limestone and fluorite as a slag material, etc. The raw material to be charged at the top of the furnace is charged into the furnace from the raw material charging port 1 while being weighed by a measuring device 13 to a predetermined amount. The present inventors investigated how to melt and reduce powdered chromium ore, which is injected into the furnace from the upper tuyere, in a thermally efficient manner when injecting chromium ore using such a vertical furnace. We conducted repeated experiments with this point in mind. That is, the powdered chromium ore that is injected into the furnace from the upper tuyere together with the powdered slag material is melted in the coke combustion area in front of the upper tuyere, and is reduced while the melt drips through the coke packed bed. However, this reduction reaction is an endothermic reaction. Therefore, if heat is not efficiently supplied from the coke combustion gas generated in front of the lower tuyere, which is the heat medium, to the area where the molten chromium ore is being reduced, the smelting reduction reaction of the chromium ore will occur. is significantly inhibited, reducing the yield of chromium and making it difficult to produce stable chromium-containing hot metal. As a result of repeated experimental studies by the inventors, this phenomenon is caused by conditions in which chromium ore, which has become molten in front of the upper tuyere, selectively drips in a narrow area with respect to the cross section of the furnace. It was found that this occurs when The gist of the present invention is to distribute the dripping area of molten chromium ore, which has been blown into the furnace from the upper tuyere into a molten state, over a wide area with respect to the cross section of the furnace, in order to prevent such conditions from occurring. be. The most effective and simple means to achieve this is to increase the velocity (Vb) of high-temperature oxygen-enriched air blown from the upper and lower tuyeres to (Vb) ≧ 100 ( m/s). Figure 2 shows that during an experiment to produce chromium-containing hot metal using an experimental furnace, the furnace was rapidly cooled so that the conditions inside the furnace could be preserved, and then the furnace was dismantled and investigated. This diagram illustrates the situation inside the furnace near the tuyere. As shown in Figure 2, during the production of chromium-containing hot metal, the upper tuyere 2
A space called a raceway 20 in which carbonaceous materials such as metallurgical coke are burned is formed at the front of the lower tuyere 3 inside the furnace. There is a region 21 where the ore drips a packed bed of carbonaceous material. In this region 21, chromium oxides and iron oxides present in molten oxides such as chromium ore are reduced by carbon in the carbonaceous material, producing molten metal with a high chromium concentration, and The chromium concentration in it decreases. As a result, molten oxide with a low chromium concentration and molten metal with a high chromium concentration drip onto the bottom of the furnace, and molten materials such as steel scrap charged from the top of the furnace also drip and eventually reach the bottom of the furnace. Chromium-containing hot metal will accumulate. In Figure 2, 2
2 is a region where molten oxides are accumulated, 23 is a region where chromium-containing hot metal is accumulated, and 24 is a region where steel scraps etc. charged from the upper part of the furnace are melted and dripped. Under such conditions inside the furnace during the production of chromium-containing hot metal, the velocity (Vb) of high-temperature oxygen-enriched air blown into the furnace from the upper and lower tuyeres was set to (Vb) < 100 (m/s). At times, the chromium ore melt was found to selectively drip over a narrow area relative to the furnace cross-section. For this purpose, from the combustion gas of the carbonaceous material generated in front of the lower tuyere 3, the dripping area 2
1, the reaction heat necessary for melting and reducing the chromium ore is not efficiently supplied, and as a result, the melting and reducing of the chromium ore in the furnace does not progress smoothly, unless the amount of exothermic material blown is increased. The yield of chromium was poor. On the other hand, keeping other operating conditions the same, the velocity (Vb) of high-temperature oxygen-enriched air is set to (Vb) ≧100.
(m/s), the region where the chromium ore melt dripped was widely distributed with respect to the cross section of the furnace. For this purpose, heat is efficiently supplied from the combustion gas of the carbonaceous material to this dripping region 21, and as shown in Fig. 3, the amount of heat supplied to the furnace is effectively used for melting and reducing the chromium ore. percentage of heat consumed,
In other words, the thermal efficiency is higher than when the experiment is conducted under the condition of (Vb) < 100 (m/s), and the yield of chromium is high. It was found that good yields were obtained. Note that the velocity (Vb) of high-temperature oxygen-enriched air blown into the furnace can be calculated using the following formula. Vb=BV/{π・(D T /2) 2 } Where, BV: Flow rate of high-temperature oxygen-enriched air blown into each tuyere (m 3 /s), D T : Tuyere diameter (m), π: Pi. The results of the experiment using the experimental reactor are described below. Experimental example 1 A vertical furnace with an inner diameter of 0.6 m as shown in Fig. 1 was charged with top charging material in the amount shown in Table 1 from the top of the furnace, and the upper and lower stages with an inner diameter of 16 mm were charged into the upper and lower stages. From the mouth, high-temperature oxygen-enriched air with a temperature of 800℃ and an oxygen concentration of 28.5% is pumped at a flow rate of 1Nm 3 /min at 284m/s.
Blow into the furnace at a speed of , and from the upper tuyeres,
A mixture of powders shown in Table 2 was blown into the furnace.
As a result, the unreduced chromium concentration in the slag taken out from the slag was 0.8%, and the chromium yield was 97.9%, making it possible to successfully melt and reduce chromium ore, as shown in Table 3. We were able to obtain chromium-containing hot metal with a similar composition.
【表】【table】
【表】【table】
【表】
実験例 ２
上段羽口から発熱材を吹き込まず、第４表に示
したように粉状クロム鉱石と造滓材だけを吹き込
んだ以外は、前記実験例１と実質上同じ条件で含
クロム溶銑を製造した。
この結果、クロムの収率は97.2％であり、発熱
材を吹き込まずともクロム鉱石と溶融還元は効率
良く行うことができた。得られた含クロム溶銑の
組成は第５表に示す結果となつた。また、スラグ
中の未還元クロム濃度は1.0％であつた。[Table] Experimental Example 2 The experiment was carried out under substantially the same conditions as in Experimental Example 1, except that no exothermic material was injected from the upper tuyere and only powdered chromium ore and slag material were injected as shown in Table 4. Produced chrome hot metal. As a result, the yield of chromium was 97.2%, and chromium ore and smelting reduction could be carried out efficiently without blowing in a heat generating material. The composition of the obtained chromium-containing hot metal was as shown in Table 5. Furthermore, the unreduced chromium concentration in the slag was 1.0%.
【表】【table】
【表】
実験例 ３
内径35mmの上下段羽口から高温酸素富化空気の
速度を68ｍ／ｓとして吹き込んだ以外は前記実験
例１と実質上同じ条件で含クロム溶銑を製造し
た。すなわち羽口内径を実験例１よりも大きく
し、実験例１と同じ1Nm3／minの流量の高温酸
素富化空気をより低速度（68ｍ／ｓ）で吹き込ん
だ。この場合のスラグ中の未還元クロム濃度は
3.3％であり、クロムの収率は91.6％であつた。
また得られた含クロム溶銑の組成は第６表に示す
結果となつた。[Table] Experimental Example 3 Chromium-containing hot metal was produced under substantially the same conditions as in Experimental Example 1, except that high-temperature oxygen-enriched air was blown at a speed of 68 m/s from upper and lower tuyeres with an inner diameter of 35 mm. That is, the inner diameter of the tuyere was made larger than in Experimental Example 1, and high-temperature oxygen-enriched air at the same flow rate of 1 Nm 3 /min as in Experimental Example 1 was blown at a lower velocity (68 m/s). In this case, the unreduced chromium concentration in the slag is
The yield of chromium was 91.6%.
The composition of the obtained chromium-containing hot metal was as shown in Table 6.
【表】
これらの実験例の結果から次のこと明らかであ
る。実験例３のように高温酸素富化空気の吹き込
み流速が遅いと、たとえ発熱材を使用しても、ス
ラグ中の未還元クロム濃度が高くなり、クロム収
率も十分なものとは言えない。これに対して、実
験例１のように、高温酸素富化空気の吹き込み速
度を速くすると、同量の高温酸素富化空気の吹き
込み量でもスラグ中の未還元クロム濃度は低くな
り、クロム収率が高くなる。また、実験例２のよ
うに、高温酸素富化空気の吹き込み速度が速い場
合には、とくに発熱材を使用しなくてもスラグ中
の未還元クロム濃度は十分に低くなり、高いクロ
ム収率となる。[Table] From the results of these experimental examples, the following is clear. If the flow rate of high-temperature oxygen-enriched air is slow as in Experimental Example 3, even if a heat generating material is used, the unreduced chromium concentration in the slag will be high and the chromium yield will not be sufficient. On the other hand, as in Experimental Example 1, when the blowing speed of high-temperature oxygen-enriched air is increased, the unreduced chromium concentration in the slag decreases even with the same amount of high-temperature oxygen-enriched air blown, and the chromium yield increases. becomes higher. In addition, as in Experimental Example 2, when the blowing speed of high-temperature oxygen-enriched air is high, the unreduced chromium concentration in the slag is sufficiently low even without using a heat generating material, resulting in a high chromium yield. Become.
第１図は本発明法に実施するのに好適な竪型炉
の略断面図、第２図は上下段羽口付近の炉内状況
を示す略断面図、第３図は高温酸素富化空気の吹
き込み速度とエネルギー効率との関係図であり、
同図におけるエネルギー効率は入熱に対してクロ
ム鉱石の溶融還元に有効に利用された熱量の割合
を示すものである。
１……炉上部の原料装入口、２……上段羽口、
３……下段羽口、４……熱風炉、５……酸素源、
１５……粉状クロム鉱石、２０……レースウエ
イ、２１……溶融クロム鉱石の滴下領域、２２…
…溶融酸化物が溜まつている領域、２３……含ク
ロム溶銑の溜まつている領域、２４……炉上部よ
り装入した鋼屑等が溶融し滴下する領域。
Fig. 1 is a schematic cross-sectional view of a vertical furnace suitable for implementing the method of the present invention, Fig. 2 is a schematic cross-sectional view showing the inside of the furnace near the upper and lower tuyeres, and Fig. 3 is a high-temperature oxygen-enriched air This is a diagram showing the relationship between blowing speed and energy efficiency.
The energy efficiency in the figure indicates the ratio of the amount of heat effectively used for melting and reducing the chromium ore to the heat input. 1... Raw material charging port in the upper part of the furnace, 2... Upper tuyere,
3...Lower tuyere, 4...Hot stove, 5...Oxygen source,
15... Powdered chromium ore, 20... Raceway, 21... Dripping area of molten chromium ore, 22...
...area where molten oxides are accumulated, 23...area where chromium-containing hot metal is accumulated, 24...area where steel scraps etc. charged from the upper part of the furnace melt and drip.
Claims (1)
に上下二段の羽口をもつ竪型炉を用いて含クロム
溶銑を製造するにさいし、該上部の原料装入口か
ら鉄源、炭材、造滓材およびクロム源を装入し、
該上下の羽口から高温酸素富化空気を吹込むと同
時に、上段羽口から粉状クロム鉱石および粉状造
滓材を炉内に供給することにより、この粉状クロ
ム鉱石を溶融還元しながら含クロム溶銑を製造す
る方法において、該上下二段の羽口から吹込む高
温酸素富化空気の吹込み速度を100ｍ／ｓ以上に
制御することを特徴とする含クロム溶銑の製造
法。1. When producing chromium-containing hot metal using a vertical furnace with a raw material charging port in the upper part of the furnace and upper and lower tuyeres near the bottom of the furnace, iron source and carbonaceous material are supplied from the upper raw material charging port. , charging slag material and chromium source,
By blowing high-temperature oxygen-enriched air through the upper and lower tuyeres, and at the same time supplying powdered chromium ore and powdered slag material into the furnace from the upper tuyere, the powdered chromium ore is melted and reduced. A method for producing chromium-containing hot metal, characterized in that the blowing speed of high-temperature oxygen-enriched air blown from the upper and lower two stages of tuyeres is controlled to 100 m/s or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19275185A JPS6254007A (en) | 1985-09-01 | 1985-09-01 | Production of molten chromium iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19275185A JPS6254007A (en) | 1985-09-01 | 1985-09-01 | Production of molten chromium iron |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6254007A JPS6254007A (en) | 1987-03-09 |
| JPH0453922B2 true JPH0453922B2 (en) | 1992-08-28 |
Family
ID=16296444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19275185A Granted JPS6254007A (en) | 1985-09-01 | 1985-09-01 | Production of molten chromium iron |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6254007A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60162718A (en) * | 1984-02-06 | 1985-08-24 | Nisshin Steel Co Ltd | Production of chromium-containing molten iron by vertical furnace |
-
1985
- 1985-09-01 JP JP19275185A patent/JPS6254007A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60162718A (en) * | 1984-02-06 | 1985-08-24 | Nisshin Steel Co Ltd | Production of chromium-containing molten iron by vertical furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6254007A (en) | 1987-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU628987B2 (en) | Manufacture of ferroalloys using a molten bath reactor | |
| JPS6023182B2 (en) | Melting method for medium carbon high chromium molten metal | |
| JPH04107206A (en) | Production process of chromium-incorporated molten steel | |
| JPS6250545B2 (en) | ||
| JPH0453922B2 (en) | ||
| JPS62167808A (en) | Production of molten chromium iron | |
| JPS62167809A (en) | Production of molten chromium iron | |
| JP2836192B2 (en) | Method for producing low sulfur hot metal | |
| JP2684113B2 (en) | Dephosphorization method of chromium-containing hot metal | |
| JPH06940B2 (en) | Method for smelting reduction refining of high manganese iron alloy | |
| JPH0524961B2 (en) | ||
| JP3718945B2 (en) | Method for smelting reduction of chromium ore | |
| SU729251A1 (en) | Method of steel casting in hearth steel-melting set | |
| JP2837282B2 (en) | Production method of chromium-containing hot metal | |
| JPH01195211A (en) | Method for melting and reducing iron oxide | |
| JPS59113159A (en) | Method for refining high chromium alloy by melting and reduction | |
| JPH0454722B2 (en) | ||
| JPH04128307A (en) | Production of chromium-containing molten iron | |
| JPH0362767B2 (en) | ||
| JPH01252709A (en) | Method for operating iron bath type smelting reduction furnace | |
| JPS63103012A (en) | Production of molten iron containing chromium | |
| JPH0313291B2 (en) | ||
| JPS6123244B2 (en) | ||
| JPH01294812A (en) | Production of base metal for stainless steel | |
| JPS6338506A (en) | Adding method for powdery carbon material into smelting reduction furnace |