JP2015196901A - Method for controlling blowing in revolving furnace for steel making - Google Patents
Method for controlling blowing in revolving furnace for steel making Download PDFInfo
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本発明は、製鋼用転炉における吹錬制御方法に関し、具体的には、転炉において酸素ガスを供給して吹錬を開始する前の諸々の関連データを用いて、吹錬末期の溶鋼中のＣ濃度を目標値に的中させるように、酸素供給量や冷却材使用量を調整して吹錬する、いわゆる静的吹錬制御方法における目標値への的中精度を向上する方法に関する。 The present invention relates to a blowing control method in a steelmaking converter, and more specifically, using various related data before supplying oxygen gas in the converter and starting blowing, The present invention relates to a method for improving the accuracy of hitting a target value in a so-called static blowing control method in which the oxygen supply amount and the coolant usage amount are adjusted and blown so that the C concentration of the target is correct.
転炉で溶銑を吹錬して溶鋼を製造する際、一般的に、静的吹錬制御（スタティックコントロール）と動的吹錬制御（ダイナミックコントロール）とを組み合わせて、吹錬終了時の溶鋼Ｃ濃度や溶鋼温度を目標値に合わせるようにしている。 When producing molten steel by blowing hot metal in a converter, in general, a combination of static blowing control (dynamic control) and dynamic blowing control (dynamic control), the molten steel C at the end of blowing The concentration and molten steel temperature are adjusted to the target values.
静的吹錬制御は、吹錬を開始する前における当該吹錬に関連する諸データを用いて、主として脱炭量と溶鋼温度変化量とを統計的計算式により推定して、酸素の供給量やスクラップ等の冷却材の使用量を定める方法である。 In static blowing control, the amount of oxygen supplied is estimated by statistically calculating mainly the amount of decarburization and the temperature change of molten steel using various data related to the blowing before the start of blowing. This is a method for determining the amount of coolant used such as scrap.
一方、動的吹錬制御は、吹錬の末期にサブランスを用いて吹錬中の溶鋼Ｃ濃度と溶鋼温度とを測定し、その後の酸素供給必要量や冷却材添加量を計算して、吹錬終了時の溶鋼Ｃ濃度と溶鋼温度の目標値への的中精度を高める方法である。 On the other hand, dynamic blowing control measures the concentration of molten steel C and the molten steel temperature during blowing using a lance at the final stage of blowing, calculates the required amount of oxygen supply and the amount of coolant added after that, This is a method of increasing the accuracy of the molten steel C concentration at the end of refining and the target value of molten steel temperature.
この内、静的吹錬制御は、予定する吹錬に用いる諸データを収集して予め用意してある統計的に作成された計算式に入力し、吹錬末期のＣ濃度や溶鋼温度を計算して当該予定吹錬に用いる酸素使用量を決めたり、スクラップ配合率を調整したりするだけであるので、吹錬目標に的中させるためのランニングコストは低い。その一方で、吹錬開始前の諸データから吹錬終了時の結果を予測するため、諸々の誤差が相乗的に影響し合いつつ蓄積されるので、的中精度を高めることが難しい。 Among them, static blowing control collects various data to be used for scheduled blowing and inputs it into a statistical formula prepared in advance to calculate the C concentration and molten steel temperature at the end of blowing. Thus, since only the amount of oxygen used for the scheduled blowing is determined or the scrap blending ratio is adjusted, the running cost for hitting the blowing target is low. On the other hand, since various errors are accumulated while synergistically affecting each other in order to predict the result at the end of blowing from various data before the start of blowing, it is difficult to increase the accuracy.
そこで、吹錬が末期に至ってから、吹錬開始前および吹錬経過中の諸要因の影響による吹錬予測計算からの実績値のズレを、サブランスで実測することにより補正し、吹錬終了時の溶鋼Ｃ濃度と溶鋼温度を目標値に的中させる精度を向上させることが、一般的に行われている。 Therefore, after the end of blowing, the deviation of the actual values from the blown prediction calculation due to the influence of various factors before the start of blowing and during the blowing process is corrected by measuring with sub-lance, and at the end of blowing It is common practice to improve the accuracy with which the molten steel C concentration and the molten steel temperature are set to the target values.
ただし、このサブランスによる実測は、サブランスプローブの使用を必要とするために、ランニングコストがかかる。この他、サブランスによる測定タイミングが適切でないと、サブランスを用いた測定後の酸素供給量の調整が吹錬終了までに間に合わなかったり、逆に、酸素供給必要量が多過ぎてその後の吹錬終点目標値への的中精度を低下させてしまったりする問題を生じる。 However, the actual measurement using the sublance requires the use of the sublance probe, and thus requires a running cost. In addition, if the measurement timing by the sublance is not appropriate, the adjustment of the oxygen supply amount after measurement using the sublance will not be in time for the end of blowing, or conversely, the oxygen supply requirement is too much and the subsequent blowing end point There arises a problem that the accuracy to the target value is lowered.
サブランスによる測定タイミングは、静的吹錬制御による予測計算値に基づいて決定されているので、静的吹錬制御の精度は動的吹錬制御を組み合わせて吹錬を行う場合にも重要である。そこで、従来から静的吹錬制御の精度向上の取組が多数行われてきた。 Since the measurement timing by sublance is determined based on the predicted calculation value by static blowing control, the accuracy of static blowing control is important even when blowing by combining dynamic blowing control. . Therefore, many efforts have been made to improve the accuracy of static blowing control.
静的吹錬制御では、少なくとも吹錬末期の溶鋼Ｃ濃度と溶鋼温度とを、当該吹錬に用いる溶銑やスクラップに含まれる諸成分の含有質量や供給する酸素必要量に基づいて計算し、当該吹錬での目標値に合うように酸素必要量とスクラップ等の冷却材使用量を調整する。 In static blowing control, at least the molten steel C concentration and molten steel temperature at the end of blowing are calculated based on the contained mass of various components contained in the hot metal and scrap used in the blowing and the required amount of oxygen to be supplied, Adjust the amount of oxygen required and the amount of coolant such as scrap to match the target value for blowing.
この溶銑に含まれる諸成分の含有質量は、高炉から溶銑が出銑された後や、溶銑を脱硫する予備処理の後等に溶銑サンプルを採取して分析し、別途計測した溶銑重量に乗算して求めることが普通である。溶銑を脱硫する予備処理では、脱硫反応が低酸素条件で有利に進行することから、酸化鉄や気体酸素等の酸素源を供給しない。 The mass content of the various components contained in this hot metal is taken and analyzed after hot metal is extracted from the blast furnace, after pretreatment for desulfurizing the hot metal, and multiplied by the separately measured hot metal weight. It is normal to ask. In the pretreatment for desulfurizing the hot metal, since the desulfurization reaction proceeds advantageously under low oxygen conditions, oxygen sources such as iron oxide and gaseous oxygen are not supplied.
例えば、特許文献１，２に記載された発明でも、その静的吹錬制御に用いる溶鋼Ｃ濃度と溶鋼温度の計算式には溶銑中諸成分の濃度と溶銑重量とがインプットされ、酸素使用量との関係から最終的な溶鋼Ｃ濃度と溶鋼温度とが計算されている。 For example, even in the inventions described in Patent Documents 1 and 2, the concentration of various components in the hot metal and the weight of the hot metal are input to the calculation formula of the molten steel C concentration and the molten steel temperature used for the static blowing control, and the amount of oxygen used Thus, the final molten steel C concentration and molten steel temperature are calculated.
しかし、それらの計算式は直近の同種の吹錬のデータを集めて統計的に解析して作成されたものであって、その式を用いて行う吹錬において、溶銑Ｃ濃度は４質量％以上の高炭素濃度から０．１質量％以下等の低炭素濃度まで大きく変化するために、その濃度変化予定量に誤差があるとそれが吹錬終了時の溶鋼Ｃ濃度に及ぼす影響は大きいはずである。 However, these calculation formulas were created by collecting and statistically analyzing the latest data of the same type of blowing, and in the blowing performed using the formula, the hot metal C concentration is 4% by mass or more. Because there is a large change from a high carbon concentration to a low carbon concentration such as 0.1% by mass or less, if there is an error in the expected amount of concentration change, it should have a large effect on the molten steel C concentration at the end of blowing. is there.
ところが、溶銑Ｃ濃度の分析精度は、吹錬予定が定まった後から吹錬を開始するまでの、吹錬制御計算のために使うことができる時間の中では、後述するように、精度が低いのが実情である。 However, the analysis accuracy of hot metal C concentration is low, as will be described later, in the time that can be used for the blowing control calculation after the blowing schedule is determined until the blowing is started. Is the actual situation.
従来は、この分析精度の低さを承知していながら、静的吹錬制御のために用意した統計的計算式に溶銑サンプルの分析値を入力し、その分析誤差をこの吹錬に用いる他の諸データのバラツキの中に含めてしまって、その分析誤差の影響を吹錬末期に適用する動的吹錬制御での調整操作に任せて計算していた。 In the past, while knowing the low accuracy of this analysis, the analysis value of the hot metal sample was input to the statistical formula prepared for static blowing control, and the analysis error was used for other blowing. It was included in the variation of various data, and the effect of the analysis error was left to the adjustment operation in the dynamic blowing control applied at the end of blowing.
また、静的吹錬制御に用いる統計的な計算式を用意する際に、その分析誤差の影響を含んだまま統計的に解析処理して用意し、そのように用意した統計的な計算式を用いてその後の静的吹錬制御を行ってきた。 In addition, when preparing a statistical calculation formula used for static blowing control, it is prepared by statistical analysis processing including the influence of the analysis error, and the prepared statistical calculation formula is It has been used for subsequent static blowing control.
また、近年では転炉で溶銑を溶鋼に吹錬するに先立って、溶銑を脱珪する予備処理や溶銑を脱珪し脱燐する予備処理が行われるようになっている。これらの脱珪予備処理や脱燐予備処理は、いずれも酸化反応を利用するものであるので、酸化鉄や気体酸素等の酸素源の供給が必須である。そして、溶銑に酸素源を供給すれば溶銑中のＳｉやＰが酸化されてそれらの濃度が減少するほか、付随的にＣやＦｅも酸化されてしまうのが普通である。 In recent years, prior to blowing hot metal into molten steel in a converter, pretreatment for desiliconizing the hot metal and pretreatment for desiliconizing and dephosphorizing the hot metal have been performed. Since these desiliconization pretreatment and dephosphorization pretreatment both use an oxidation reaction, it is essential to supply an oxygen source such as iron oxide or gaseous oxygen. When an oxygen source is supplied to the hot metal, Si and P in the hot metal are oxidized to reduce their concentration, and C and Fe are usually oxidized incidentally.
しかし、これらの酸素源を供給して行う予備処理を施した溶銑に関しても、溶銑サンプルのＣ濃度分析精度が低いという実情は上述したのと同じである。したがって、それらの溶銑を転炉で溶鋼に吹錬する際にも、上記の酸素源を供給しない予備処理における場合と同じ問題があった。 However, with respect to the hot metal that has been subjected to the pretreatment performed by supplying these oxygen sources, the fact that the C concentration analysis accuracy of the hot metal sample is low is the same as described above. Therefore, when these hot metal was blown into molten steel in a converter, there was the same problem as in the preliminary treatment in which the oxygen source was not supplied.
本発明の目的は、製鋼用転炉における静的吹錬制御の制御精度の向上方法を提供すること、より具体的には、溶銑Ｃ濃度の分析精度が、吹錬予定が定まった後から吹錬を開始するまでの短時間のうちでは低いことに起因した吹錬制御精度への悪影響を解消し、もって、Ｃ濃度が０．５０質量％以下の溶鋼になった後における溶鋼Ｃ濃度の予測精度を向上させる方法を提供することである。 An object of the present invention is to provide a method for improving the control accuracy of static blowing control in a steelmaking converter. More specifically, the analysis accuracy of hot metal C concentration is determined after the blowing schedule is determined. Eliminating the adverse effects on the blow control accuracy due to the low time until the start of smelting, and thus the prediction of the molten steel C concentration after the C concentration becomes 0.50% by mass or less. It is to provide a method for improving accuracy.
本発明は、以下に列記の通りである。 The present invention is listed below.
（１）高炉から出銑された溶銑に対して、酸素源を供給して脱珪や脱燐を行う溶銑予備処理を施すことなく、該溶銑を転炉へ装入し、酸素ガスを供給して溶鋼を製造する製鋼用転炉における吹錬制御方法であって、
前記酸素ガスの供給を開始する前の該溶銑のＣ濃度として、該溶銑の温度と該溶銑に含まれている元素のうち少なくともＳｉ，ＭｎおよびＴｉの濃度分析値とに基づいて計算されるＣ濃度（Ｃ１）を用いて、
前記酸素ガスの供給によって該溶銑のＣ濃度が０．５０質量％以下の溶鋼になった後の該溶鋼中のＣ濃度が目標値に的中するよう、該酸素ガスの供給量を制御すること
を特徴とする製鋼用転炉における吹錬制御方法。
(1) The hot metal discharged from the blast furnace is charged into the converter and supplied with oxygen gas without performing hot metal pretreatment for supplying silicon with oxygen source and desiliconization or dephosphorization. A method for controlling blowing in a steelmaking converter for producing molten steel,
The C concentration of the hot metal before starting the supply of the oxygen gas is calculated based on the temperature of the hot metal and the concentration analysis values of at least Si, Mn, and Ti among the elements contained in the hot metal. Using the concentration (C 1 ),
Controlling the supply amount of the oxygen gas so that the C concentration in the molten steel after the molten steel having the molten steel C concentration of 0.50% by mass or less by the supply of the oxygen gas hits the target value. A blowing control method for a steelmaking converter characterized by the above.
（２）高炉から出銑された溶銑に対して、酸素源を供給して脱珪や脱燐を行う溶銑予備処理を施した後、該溶銑予備処理後の溶銑を転炉へ装入し、酸素ガスを供給して溶鋼を製造する製鋼用転炉における吹錬制御方法であって、
前記溶銑予備処理における溶銑Ｃ濃度の低下量（ΔＣ）を該溶銑予備処理条件に基づいて計算し、
前記酸素ガスの供給を開始する前の該溶銑のＣ濃度として、前記溶銑予備処理を施す前の該溶銑のＣ濃度としての、該溶銑の温度と該溶銑に含まれている元素のうち少なくともＳｉ，ＭｎおよびＴｉの濃度分析値とに基づいて計算されるＣ濃度（Ｃ１）から、前記溶銑予備処理における溶銑中のＣ濃度低下量（ΔＣ）を減じたＣ濃度（Ｃ２）を用いて、
前記酸素ガスの供給によって該溶銑のＣ濃度が０．５０質量％以下の溶鋼になった後の該溶鋼中のＣ濃度が目標値に的中するよう、該酸素ガスの供給量を制御すること
を特徴とする製鋼用転炉における吹錬制御方法。
(2) The hot metal discharged from the blast furnace is subjected to a hot metal pretreatment for supplying an oxygen source to perform desiliconization and dephosphorization, and then the hot metal after the hot metal pretreatment is charged into a converter. A blowing control method in a steelmaking converter for producing molten steel by supplying oxygen gas,
The amount of decrease in hot metal C concentration (ΔC) in the hot metal pretreatment is calculated based on the hot metal pretreatment conditions,
As the C concentration of the hot metal before starting the supply of the oxygen gas, as the C concentration of the hot metal before the hot metal pretreatment, the temperature of the hot metal and at least Si among the elements contained in the hot metal Using the C concentration (C 2 ) obtained by subtracting the C concentration decrease amount (ΔC) in the hot metal in the hot metal pretreatment from the C concentration (C 1 ) calculated based on the concentration analysis values of Mn, Ti and Ti ,
Controlling the supply amount of the oxygen gas so that the C concentration in the molten steel after the molten steel having the molten steel C concentration of 0.50% by mass or less by the supply of the oxygen gas hits the target value. A blowing control method for a steelmaking converter characterized by the above.
本発明に係る製鋼用転炉における吹錬制御方法により、脱炭吹錬計算に用いる溶銑Ｃ濃度を分析値から計算値に換えて精度を高め、もって、脱Ｃ吹錬を最適化することが可能となる。 According to the present invention, the control method for blowing steel in a converter for steelmaking is to improve the accuracy by changing the hot metal C concentration used for decarburization blowing calculation from the analytical value to the calculated value, thereby optimizing the de-C blowing. It becomes possible.
本発明を実施するための形態を説明する。以降の説明では、各元素の濃度または含有量に関する「％」は特に断りがない限り「質量％」を意味する。 A mode for carrying out the present invention will be described. In the following description, “%” regarding the concentration or content of each element means “mass%” unless otherwise specified.
１．本発明を実施するために必要な設備
本発明は、スクラップ等とともに転炉に装入した溶銑中のＣを除去して溶鋼を製造する際に、溶銑やスクラップ等に含有される成分や温度といった当該吹錬に関係する諸データを収集し、それらの諸データに基づいて、直近の同種の吹錬実績等を参照しつつ、当該吹錬によって製造する溶鋼の成分や温度の目標値に合わせるために必要なスクラップ配合率や副原料などの冷却材使用量と、酸素供給量とを予測して調整する、転炉の静的吹錬制御方法である。
1. Equipment necessary for carrying out the present invention The present invention relates to components and temperatures contained in hot metal, scrap, etc., when producing molten steel by removing C in the hot metal charged in the converter together with scrap, etc. To collect various data related to the blowing, and to match the target values of the components and temperature of the molten steel produced by the blowing while referring to the latest similar blowing results, etc. based on the data This is a static blowing control method for a converter that predicts and adjusts the amount of coolant used, such as scrap mixing ratio and auxiliary materials, and the oxygen supply amount.
したがって、溶銑量やスクラップ量並びに副原料等の秤量器、酸素流量計を有する酸素供給設備、吹錬関係諸データの収集設備、および直近の吹錬実績等を参考にして必要酸素供給量や冷却材投入量等を計算するために統計的に作成された計算式を有する演算装置といった、一般的な転炉の静的吹錬制御を行うために必要な諸設備を使用する。 Therefore, the required oxygen supply amount and cooling with reference to the scale of hot metal, scrap, and auxiliary materials, oxygen supply equipment with an oxygen flow meter, equipment for collecting various data related to blowing, and the latest results of blowing Various facilities necessary for performing static blowing control of a general converter such as an arithmetic unit having a calculation formula statistically created to calculate the material input amount and the like are used.
他に、溶鋼Ｃ濃度が０．５０％以下の吹錬末期に溶鋼Ｃ濃度と溶鋼温度とを測定するサブランスと、その測定値に基づいてその後の酸素供給必要量や冷却材投入量等を計算する一般的な動的吹錬制御関係の設備を有していることが望ましい。 In addition, the sublance that measures the molten steel C concentration and molten steel temperature at the end of the blowing process where the molten steel C concentration is 0.50% or less, and the subsequent oxygen supply requirement and coolant input amount, etc. are calculated based on the measured values. It is desirable to have equipment related to general dynamic blowing control.
２．本発明の実施方法
（１）初めに、従来の静的吹錬制御方法に関して説明する。
2. Implementation Method of the Present Invention (1) First, a conventional static blowing control method will be described.
従来は、高炉から出銑された溶銑から、または溶銑脱硫を施した場合にはその脱硫処理後の溶銑から、サンプルを採取し、発光分光分析法や赤外線燃焼法等の短時間で含有濃度を求めることができる分析方法を用いて、Ｃ，Ｓｉ，Ｍｎ，Ｐ，Ｓ，Ｔｉ等の濃度を知り、それらの濃度をそのまま上記した統計的な計算式に入力して、吹錬目標の溶鋼Ｃ濃度や溶鋼温度に合わせるように、酸素供給量等を調整していた。 Conventionally, samples are taken from the hot metal discharged from the blast furnace or from the hot metal after the desulfurization treatment when the hot metal desulfurization is performed, and the content concentration is measured in a short time such as emission spectroscopic analysis or infrared combustion method. Using the analysis method that can be obtained, know the concentrations of C, Si, Mn, P, S, Ti, etc., and enter those concentrations as they are into the above statistical calculation formula, and then the molten steel C as the blowing target The oxygen supply amount and the like were adjusted to match the concentration and molten steel temperature.
しかし、Ｃ濃度が３．３％以上の溶銑領域では、上記分析方法によるＣ濃度の分析値はバラツキが大きく、同一のサンプルに対して複数回分析すると、最大値と最小値とで０．２％程度相違しており、サンプリングから吹錬開始までの１５〜６０分間程度の短時間という制約条件下では、上記分析方法の分析精度を高めることが困難であった。 However, in the hot metal region where the C concentration is 3.3% or more, the analysis value of the C concentration by the above analysis method varies widely, and when the same sample is analyzed a plurality of times, the maximum value and the minimum value are 0.2. %, And it was difficult to improve the analysis accuracy of the above analysis method under the constraint of a short time of about 15 to 60 minutes from sampling to the start of blowing.
（２）そこで、本発明者らは、溶銑の飽和Ｃ濃度がＳｉ，Ｍｎ，Ｐ，Ｓ等の濃度と溶銑の温度とから計算されることを参考にして、脱硫処理を施した後の溶銑からサンプルを採取して従来と同様に発光分光分析法や赤外線燃焼法による分析を行い、得られたＳｉ，Ｍｎ，Ｐ，Ｓの質量濃度と、そのサンプリング時の温度とから溶銑Ｃ濃度を推測することを着想した。 (2) Therefore, the present inventors refer to the fact that the saturated C concentration of the hot metal is calculated from the concentrations of Si, Mn, P, S, etc. and the temperature of the hot metal, and then the hot metal after the desulfurization treatment is performed. A sample is taken from the sample and analyzed by emission spectroscopic analysis or infrared combustion as in the past, and the hot metal C concentration is estimated from the obtained mass concentration of Si, Mn, P, S and the temperature at the time of sampling. Inspired to do.
脱硫処理後の溶銑に、Ｃ以外の成分と温度とから規定される飽和Ｃ濃度が含有されているかどうかは定かではないが、高炉からの出銑時には１５００℃程度あった溶銑が脱硫処理後には１４００℃以下まで低下していて、そこまでに酸素源は供給されていないので、飽和Ｃ濃度に近い濃度のＣが含有されている可能性がある。 Although it is not certain whether the hot metal after desulfurization contains a saturated C concentration defined by components other than C and the temperature, the hot metal that was around 1500 ° C at the time of discharge from the blast furnace is Since it has decreased to 1400 ° C. or lower and no oxygen source has been supplied so far, there is a possibility that C having a concentration close to the saturation C concentration is contained.
そこで、飽和Ｃ濃度を以下の式（１）の通り算出して、精密分析結果と対比した。
（鉄鋼便覧第２版３１頁より引用）
飽和Ｃ濃度
=(-0.31)・Si+0.003・Mn+(-0.33)・P+(-0.40)・S+0.00257・温度+1.3 ・・・・・・・(1)
この調査において、溶銑サンプルの精密分析値は、Ｃ：４．１〜４．７％，Ｓｉ：０．２０〜０．８０％，Ｍｎ：０．１３〜０．２３％，Ｐ：０．１２０〜０．１４０％，Ｓ：０．０２０〜０．０４０％，溶銑温度は１２３０〜１３６０℃であった。
Therefore, the saturated C concentration was calculated as in the following formula (1) and compared with the precision analysis result.
(Quoted from page 31 of the Steel Handbook 2nd edition)
Saturated C concentration
= (-0.31) ・ Si + 0.003 ・ Mn + (-0.33) ・ P + (-0.40) ・ S + 0.00257 ・ Temperature +1.3 (1)
In this investigation, the precision analysis values of the hot metal samples were C: 4.1 to 4.7%, Si: 0.20 to 0.80%, Mn: 0.13 to 0.23%, P: 0.120. -0.140%, S: 0.020-0.040%, hot metal temperature was 1230-1360 degreeC.
図１には、精密分析によるＣ濃度と上記（１）式による計算値との対応をグラフで示す。 FIG. 1 is a graph showing the correspondence between the C concentration by precise analysis and the calculated value by the above equation (1).
図１のグラフに示すように、上記（１）式による計算Ｃ濃度は、精密分析Ｃ濃度に対して、±０．０７％の範囲にあることが分かる。 As shown in the graph of FIG. 1, it can be seen that the calculated C concentration according to the above equation (1) is in the range of ± 0.07% with respect to the precise analysis C concentration.
一方、図２には、図１に示したものと同じサンプルについて、従来のオンラインでの赤外線燃焼法での分析の結果をグラフで示す。 On the other hand, in FIG. 2, the result of the analysis by the conventional on-line infrared combustion method is shown with a graph about the same sample as what was shown in FIG.
図２のグラフに示すように、従来のオンラインでの分析Ｃ濃度は、精密分析Ｃ濃度に対して、−０．３％程度低く計測されており、誤差が大きいことが確認された。 As shown in the graph of FIG. 2, the conventional on-line analytical C concentration was measured to be about −0.3% lower than the precise analytical C concentration, and it was confirmed that the error was large.
この（１）式は、特定の高炉から出銑した溶銑の温度が１００℃以上低下した条件で適用したもので、条件が異なっても同じ式を適用することが適当であるかどうかは不明である。しかし、高炉からの出銑以降で酸素源を供給していない場合は、上記した（１）式と同様な考え方で溶銑Ｃ濃度の計算式を、溶銑温度と少なくともＳｉ，Ｍｎ，Ｐ，Ｓの分析値とに基づいて、以下の（２）式のように作成することができると考えられる。 This formula (1) is applied under the condition that the temperature of the hot metal discharged from a specific blast furnace is lowered by 100 ° C or more, and it is unclear whether the same formula is appropriate even if the conditions are different. is there. However, when the oxygen source is not supplied after the blast furnace is discharged, the calculation formula for the hot metal C concentration can be calculated from the hot metal temperature and at least Si, Mn, P, and S in the same way as the above formula (1). Based on the analysis value, it can be considered that the following equation (2) can be created.
計算溶銑Ｃ濃度＝Ａ＋Ｂ×Ｔ＋Σ（αｉ×Ｑｉ ） ・・・・・・・（２）
（２）式におけるＡ，Ｂは定数であり、Ｔは溶銑温度（℃）であり、Ｑｉは溶銑成分の濃度（質量％）であり、αｉはＱｉの係数である。
Calculated hot metal C concentration = A + B × T + Σ (α i × Qi) (2)
In Equation (2), A and B are constants, T is the hot metal temperature (° C.), Qi is the concentration (mass%) of the hot metal component, and α i is a coefficient of Qi.
上記（１）式による溶銑Ｃ濃度の計算値である計算溶銑Ｃ濃度を転炉の静的吹錬制御の統計的な計算式に入力して、従来の溶銑サンプルの分析Ｃ濃度をそのまま入力した場合との、転炉の静的吹錬制御の精度向上効果を調査した。 The calculated hot metal C concentration, which is the calculated value of the hot metal C concentration according to the above formula (1), is input to the statistical calculation formula of the static blowing control of the converter, and the analysis C concentration of the conventional hot metal sample is input as it is. We investigated the accuracy improvement effect of static blowing control of converters.
この調査では、計算溶銑Ｃ濃度を用いることによる吹錬末期での溶鋼Ｃ濃度の目標値への的中精度を従来法と比較することにより、転炉の静的吹錬制御の精度向上効果を検討した。転炉の静的吹錬制御による吹錬末期での溶鋼Ｃ濃度の予測は、吹錬開始前に行うので、この吹錬末期での溶鋼Ｃ濃度の予測精度はそのまま静的吹錬制御の的中精度に置き換えられる。 In this investigation, the accuracy improvement effect of the static blowing control of the converter was compared by comparing the accuracy of the hot steel C concentration to the target value in the final stage of blowing by using the calculated hot metal concentration. investigated. Since the prediction of the molten steel C concentration at the end of blowing by the static blowing control of the converter is performed before the start of blowing, the prediction accuracy of the molten steel C concentration at the end of blowing is the same as that of static blowing control. Replaced by medium precision.
具体的には、静的制御に用いる溶銑Ｃ濃度を分析Ｃ濃度または計算Ｃ濃度として、脱Ｃ吹錬を行った。その脱Ｃ吹錬中には、動的制御を行うためにサブランスを用いて測定した時の溶鋼Ｃ濃度の目標値を予め定めているため、その目標値と実際にそのサブランスを用いて測定した溶鋼Ｃ濃度とを比較することで、本発明の実施効果を調査することができる。 Specifically, de-C blowing was performed using the hot metal C concentration used for static control as the analytical C concentration or the calculated C concentration. During the de-C blowing, since the target value of the molten steel C concentration when the measurement was performed using the sub lance to perform dynamic control was determined in advance, the target value and the actual measurement were performed using the sub lance. The implementation effect of the present invention can be investigated by comparing the molten steel C concentration.
高炉から出銑した溶銑２５０〜２７５トンを溶銑脱硫処理したのみで溶銑脱珪や溶銑脱燐処理を行わずにスクラップ０〜５０トンとともに２５０トン転炉へ装入した。溶銑の成分のオンライン分析値は、Ｃ：４．４〜４．７％，Ｓｉ：０．４０〜０．７０％，Ｍｎ：０．３０〜０．４５％，Ｐ：０．１１０〜０．１４０％，Ｓ：０．０２０〜０．０３０％，溶銑温度：１２５０〜１３４０℃であった。一方、前記した（１）式による計算溶銑Ｃ濃度は、４．４〜４．８％であった。 Only 250 to 275 tons of hot metal discharged from the blast furnace was subjected to hot metal desulfurization treatment, and without any hot metal desiliconization or hot metal dephosphorization treatment, it was charged into a 250 ton converter together with 0 to 50 tons of scrap. The on-line analysis values of the hot metal components are as follows: C: 4.4 to 4.7%, Si: 0.40 to 0.70%, Mn: 0.30 to 0.45%, P: 0.110 to 0.8. 140%, S: 0.020 to 0.030%, hot metal temperature: 1250 to 1340 ° C. On the other hand, the calculated hot metal C concentration according to the above equation (1) was 4.4 to 4.8%.
静的制御には、本発明の実施例も従来例も、酸素原単位計算、熱量計算および副原料使用量の計算を行い、動的制御のためにサブランスを用いて測定する際の溶鋼温度と溶鋼Ｃ濃度とが目標値に合うように、冷却材や副原料を転炉上に設置したバンカーから炉内へ適宜投入した。 For static control, both the embodiment of the present invention and the conventional example perform calculation of oxygen intensity, calorific value, and usage of auxiliary raw material, and the molten steel temperature when measured using a sub lance for dynamic control and Coolant and auxiliary materials were appropriately charged into the furnace from a bunker installed on the converter so that the molten steel C concentration matched the target value.
上吹き酸素は、（１）式の計算溶銑Ｃ濃度を用いた場合も従来のオンライン分析を用いた場合も、ともに、装入溶銑トンあたり３．５〜４．０Ｎｍ３／ｍｉｎとし、その酸素供給時間は１０〜１２分間であった。底吹きガスにはＮ２またはＣＯ２を使用し、装入溶銑トンあたり０．０４〜０．２０Ｎｍ３／ｍｉｎとした。 The top blown oxygen is 3.5 to 4.0 Nm 3 / min per ton of molten iron both when the calculated hot metal C concentration of the formula (1) is used and when the conventional online analysis is used. Feeding time was 10-12 minutes. N 2 or CO 2 was used as the bottom blowing gas, and the amount was 0.04 to 0.20 Nm 3 / min per ton of molten iron.
なお、この種の吹錬において重要な管理目標である吹錬終点の溶鋼中［Ｐ］は、いずれの条件においても、０．０１０〜０．０１６％程度であり、（１）式の計算溶銑Ｃ濃度を用いた場合も従来のオンライン分析を用いた場合もともに同程度に目標を達成できていた。 Note that [P] in the molten steel at the end of the blowing, which is an important management target in this type of blowing, is about 0.010 to 0.016% under any condition, and the calculated hot metal of the formula (1) The target was achieved to the same extent both when the C concentration was used and when the conventional online analysis was used.
図３には、（１）式の計算溶銑Ｃ濃度を用いた場合（実施例）と従来のオンライン分析を用いた場合（比較例）とを上記した条件で実施した場合の、サブランス投入時点での目標Ｃ濃度と実際にその時に測定した溶鋼Ｃ濃度との差を、ヒストグラムで対比して示す。目標としたサブランス投入時のＣ濃度は、０．２〜０．５％の範囲内にある０．３５％等の特定Ｃ濃度である。 FIG. 3 shows the time when the sublance was charged when the calculated hot metal C concentration of the formula (1) was used (Example) and when the conventional online analysis was used (Comparative Example) under the above-described conditions. The difference between the target C concentration of the steel and the molten steel C concentration actually measured at that time is shown in a histogram. The target C concentration at the time when the sublance is turned on is a specific C concentration such as 0.35% within a range of 0.2 to 0.5%.
図３にヒストグラムで示すように、比較例では動浴Ｃ濃度の誤差は最大で±０．２０％程度あるのに対し、（１）式の計算溶銑Ｃ濃度を用いた実施例では±０．１１％まで減少していた。 As shown by the histogram in FIG. 3, the error of the dynamic bath C concentration is about ± 0.20% at maximum in the comparative example, whereas in the example using the calculated hot metal C concentration of the equation (1), ± 0.00%. It decreased to 11%.
この結果から、溶銑の分析誤差の影響は、ほぼそのまま吹錬末期のサブランス測定時の溶鋼Ｃ濃度の誤差となって残っており、酸素供給による脱Ｃ反応の酸素反応効率が安定している条件においては当然であるが、溶銑分析値の精度の影響により注意を払うべきであったことが確認された。 From this result, the influence of hot metal analysis error remains as it is as an error in molten steel C concentration at the time of sublance measurement at the end of blowing, and the oxygen reaction efficiency of de-C reaction by oxygen supply is stable As a matter of course, it was confirmed that attention should be paid to the influence of the accuracy of the hot metal analysis value.
一方、溶銑に酸素源を供給して脱珪、脱燐を行った場合には、その予備処理時に供給した酸素とＣ，Ｓｉ，Ｍｎ，Ｔｉのほか、Ｆｅと反応した比率を考慮しなければならない。したがって、上記した（１）式の考え方をそのまま適用することができない。しかし、予備処理時に供給酸素が種々の元素と反応した量を、多重回帰により解析して溶銑中のＣ濃度低下量（ΔＣ）を推定する（３）式を作成し、（１）式の値（Ｃ１）から（３）式の値（ΔＣ）を差し引くことにより、溶銑Ｃ濃度（Ｃ２）を計算することができると考えられる。 On the other hand, when desiliconization and dephosphorization are performed by supplying an oxygen source to the hot metal, oxygen and C, Si, Mn, Ti supplied during the preliminary treatment, as well as the ratio of reaction with Fe must be considered. Don't be. Therefore, the concept of the above formula (1) cannot be applied as it is. However, the amount of the oxygen supplied reacting with various elements during the pretreatment is analyzed by multiple regression to estimate the amount of decrease in C concentration (ΔC) in the hot metal, formula (3) is created, and the value of formula (1) It is considered that the hot metal C concentration (C 2 ) can be calculated by subtracting the value (ΔC) of the equation (3) from (C 1 ).
溶銑中のＣ濃度低下量（ΔＣ）＝Σ（βｉ・Ｒｉ）＋δ・温度・・・・・（３）
（３）式におけるＲｉは溶銑予備処理における操業パラメータであり、βｉはＲｉに乗ずる係数であり、δは温度に乗ずる係数である。
C concentration reduction amount in molten iron (ΔC) = Σ (βi · Ri) + δ · temperature (3)
In Equation (3), Ri is an operation parameter in hot metal pretreatment, βi is a coefficient by which Ri is multiplied, and δ is a coefficient by which temperature is multiplied.
今回の調査で考慮した、脱燐処理時の脱Ｃ量計算のための諸パラメータを、表１にまとめて示す。装入Ｃ：３．７〜４．７％，装入Ｓｉ：０．３０〜０．７％，装入Ｔｉ：０．０８〜０．４０％，溶銑温度：１２５０〜１３４０℃である。 Table 1 summarizes various parameters for calculating the amount of C removed during the dephosphorization process, which were taken into consideration in this survey. Charge C: 3.7 to 4.7%, Charge Si: 0.30 to 0.7%, Charge Ti: 0.08 to 0.40%, Hot metal temperature: 1250 to 1340 ° C.
上記（３）式に関し、表１に記載した諸要件に関して多重回帰による解析を行って実験式を作成し、脱Ｐ銑を用いた脱Ｃ吹錬をする際に、その静的制御における溶銑Ｃ濃度の値に前記した（１）式による計算溶銑Ｃ濃度（Ｃ１）から（３）式による溶銑中のＣ濃度低下量（ΔＣ）を減じた溶銑Ｃ濃度（Ｃ２）を用いた場合と、その溶銑Ｃ濃度の値に溶銑脱Ｐ処理後にサンプルを採取して従来の燃焼法により分析した値を用いた場合とについて、前記した脱硫予備処理のみ行った場合の調査と同様に比較調査を行った。その具体的な方法とその実施結果を比較しつつ説明する。 With respect to the above formula (3), the empirical formula is created by analyzing the various requirements described in Table 1 by multiple regression, and when performing de-C blowing using de-P soot, hot metal C in the static control When the hot metal C concentration (C 2 ) obtained by subtracting the C concentration decrease amount (ΔC) in the hot metal according to the equation (3) from the calculated hot metal C concentration (C 1 ) according to the above equation (1) is used as the concentration value, In the case of using the value obtained by collecting a sample after the hot metal desulfurization P treatment and analyzing it by the conventional combustion method as the value of the hot metal C concentration, a comparative investigation is conducted in the same manner as in the case of performing only the desulfurization pretreatment described above. went. The specific method and its implementation result will be compared and described.
脱燐予備処理では、高炉から出銑した溶銑２５０〜２７５トンを溶銑脱硫処理した後、スクラップ０〜５０トンとともに転炉へ装入した。その溶銑の成分のオンライン分析値は、先に溶銑脱珪や溶銑脱燐処理を行わない場合について記載したものと同じである。 In the dephosphorization preliminary treatment, 250 to 275 tons of hot metal discharged from the blast furnace was subjected to hot metal desulfurization treatment, and then charged to the converter together with 0 to 50 tons of scrap. The on-line analysis value of the hot metal component is the same as that described above for the case where the hot metal desiliconization or hot metal dephosphorization treatment is not performed.
上吹き酸素は装入溶銑トンあたり、１．０〜１．５Ｎｍ３／ｍｉｎとし、その酸素供給時間は６〜１４ｍｉｎであった。底吹きガスにはＮ２を使用し、流量は装入溶銑トンあたり０．２５Ｎｍ３／ｍｉｎとした。上底吹きガスを吹込み、生石灰および冷却材を投入して行う溶銑脱燐処理を経た脱燐銑を、スクラップ０〜５０トンとともに転炉へ装入した。溶銑脱燐処理後の溶銑成分のオンライン分析値は、［Ｃ］：３．３〜３．８％，［Ｓｉ］：≦０．０１％，［Ｍｎ］：０．１１〜０．３０％，［Ｐ］：０．０１８〜０．０５５％であった。 The top-blown oxygen was 1.0 to 1.5 Nm 3 / min per ton of charged molten iron, and the oxygen supply time was 6 to 14 min. N 2 was used as the bottom blowing gas, and the flow rate was 0.25 Nm 3 / min per ton of molten iron charged. The dephosphorizer after the hot metal dephosphorization process in which the top bottom blowing gas was blown and quick lime and coolant were added was charged into the converter together with 0 to 50 tons of scrap. The on-line analysis values of the hot metal component after the hot metal dephosphorization treatment are [C]: 3.3 to 3.8%, [Si]: ≦ 0.01%, [Mn]: 0.11 to 0.30%, [P]: 0.018 to 0.055%.
前述のように脱燐銑については（１）式のままでは適用できないため、（１）式と（３）式とを組み合わせて用いる。本発明では、直近９００チャージの溶銑脱燐処理時のデータについて、表１に示すパラメータを用いてＣ濃度低下量（ΔＣ）に関する多重線型回帰による解析を行った。得られた係数を用いて、この吹錬時の脱燐処理時Ｃ濃度低下量（ΔＣ）を一次線型結合の形で数式化して求めた。回帰に使用したＣ濃度低下量は、直近データそれぞれについて、サブランス測定時の目標Ｃ濃度とその際の溶鋼Ｃ濃度の実績との差が０となるように脱燐処理後Ｃ濃度を求め、この値と計算溶銑Ｃ濃度（Ｃ１）との差から求めた。 As described above, since dephosphorization cannot be applied with the formula (1), the formula (1) and the formula (3) are used in combination. In the present invention, the data at the time of the latest 900 charge hot metal dephosphorization treatment was analyzed by multi-linear regression on the C concentration decrease amount (ΔC) using the parameters shown in Table 1. Using the obtained coefficient, the amount of decrease in C concentration (ΔC) during dephosphorization treatment during blowing was calculated and expressed in the form of a linear linear bond. The amount of C concentration decrease used for the regression was obtained for each of the latest data by calculating the C concentration after dephosphorization so that the difference between the target C concentration at the time of sublance measurement and the actual result of the molten steel C concentration at that time was zero. The value was calculated from the difference between the calculated hot metal C concentration (C 1 ).
なお、脱燐処理時脱炭量の推定方法については、表１のパラメータを用いた多重線型回帰に限るわけではない。排ガス情報等のパラメータを追加したり、理論的な脱炭量の式を構築しフィッティングを行ったりしてもよい。これにより得られた計算脱燐銑Ｃ濃度（Ｃ２）は、３．３〜３．８％であった。 Note that the method for estimating the amount of decarburization during the dephosphorization process is not limited to the multiple linear regression using the parameters in Table 1. Parameters such as exhaust gas information may be added, or a theoretical decarburization amount formula may be constructed to perform fitting. The calculated dephosphorization C concentration (C 2 ) thus obtained was 3.3 to 3.8%.
上吹き酸素は、静的吹錬制御に供する酸素供給開始前の溶銑中Ｃ濃度に、計算脱燐銑Ｃ濃度（Ｃ２）を用いた場合も従来の脱燐銑のオンライン分析値を用いた場合も、ともに、装入溶銑トンあたり３．５〜４．０Ｎｍ３／ｍｉｎとし、その酸素供給時間は１０〜１２分間であった。底吹きガスにはＮ２またはＣＯ２を使用し、装入溶銑トンあたり０．０４〜０．２０Ｎｍ３／ｍｉｎとした。 Top blowing oxygen, the C concentration in the molten iron before the start of oxygen supply to be subjected to static blowing control, when using the calculated de Rinzuku C concentration (C 2) was also used online analytical values of the conventional dephosphorization pig iron In both cases, the oxygen supply time was 10 to 12 minutes at 3.5 to 4.0 Nm 3 / min per ton of charged molten iron. N 2 or CO 2 was used as the bottom blowing gas, and the amount was 0.04 to 0.20 Nm 3 / min per ton of molten iron.
なお、この種の吹錬において重要な管理目標である吹錬終点の溶鋼中［Ｐ］は、いずれの条件においても０．００６〜０．０１６％程度であり、（１）式の計算溶銑Ｃ濃度を用いた場合も従来のオンライン分析を用いた場合も、ともに、同程度に目標を達成できていた。 In addition, [P] in the molten steel at the end point of blowing, which is an important management target in this type of blowing, is about 0.006 to 0.016% in all conditions, and calculated hot metal C in the formula (1) Both the concentration and the conventional on-line analysis achieved the same target.
図４には、上記した条件で本発明を実施した場合（実施例）と従来の脱燐処理後の溶銑Ｃ濃度の分析値を用いた場合（比較例）とに関し、サブランス投入時点での目標Ｃ濃度と実際にその時に測定した溶鋼Ｃ濃度との差を、ヒストグラムで対比して示す。目標としたサブランス投入時のＣ濃度は、普通銑吹錬時と同様に０．２〜０．５％の範囲内にある０．３５％等の特定Ｃ濃度である。 FIG. 4 shows the target at the time of charging the sublance when the present invention is carried out under the above-described conditions (Example) and when the analytical value of the hot metal C concentration after the conventional dephosphorization treatment is used (Comparative Example). The difference between the C concentration and the molten steel C concentration actually measured at that time is shown in a histogram. The target C concentration at the time of charging the sublance is a specific C concentration such as 0.35% within the range of 0.2 to 0.5% as in the case of ordinary soot blowing.
図４にヒストグラムで示すように、比較例では動浴Ｃ濃度の誤差は最大で±０．１８％程度あったのに対し、実施例では±０．１２％まで減少していた。 As shown in the histogram of FIG. 4, the error of the dynamic bath C concentration was about ± 0.18% at the maximum in the comparative example, but decreased to ± 0.12% in the example.
以上より、普通銑吹錬および脱燐銑を用いた脱炭吹錬において、脱炭吹錬計算に計算Ｃ濃度を使用することにより、動浴Ｃ濃度の狙い精度が向上することが確認された。 From the above, it was confirmed that the target accuracy of the dynamic bath C concentration is improved by using the calculated C concentration in the decarburization blown calculation in the decarburization blown using ordinary dredging and dephosphorization. .
上記の検討では、表１に示すパラメータを用いて多重線型回帰による解析を行い、脱燐処理時のＣ濃度低下量（ΔＣ）を一次線型結合の形で数式化して求めた。ただし、吹錬の実情に即して、Ｃ濃度低下量（ΔＣ）の計算値に大きな影響がある項目として脱Ｃ酸素効率等を含めて多重回帰などにより関係式を作成しておけば、上記の検討と同様に本発明を実施することが可能である。 In the above examination, analysis by multi-linear regression was performed using the parameters shown in Table 1, and the amount of decrease in C concentration (ΔC) at the time of dephosphorization was obtained by formulating in the form of primary linear bonds. However, if the relational expression is created by multiple regression etc. including the de-C oxygen efficiency as an item having a great influence on the calculated value of C concentration decrease (ΔC) in accordance with the actual situation of blowing, the above It is possible to carry out the present invention in the same manner as in the above discussion.
（実施例１）
高炉から出銑した溶銑２５０〜２７５トンを溶銑脱硫処理したのみで溶銑脱珪や溶銑脱燐処理を行わずに、スクラップ０〜５０トンとともに２５０トン転炉へ装入した。溶銑の成分のオンライン分析値は、Ｃ：４．４〜４．７％，Ｓｉ：０．４０〜０．７０％，Ｍｎ：０．３０〜０．４５％，Ｐ：０．１１０〜０．１４０％，Ｓ：０．０２０〜０．０３０％，溶銑温度：１２５０〜１３４０℃であった。前記した（１）式による計算溶銑Ｃ濃度（Ｃ１）は、４．４〜４．８％であった。
(Example 1)
Only 250 to 275 tons of hot metal discharged from the blast furnace was subjected to hot metal desulfurization treatment, and without any hot metal desiliconization or hot metal dephosphorization treatment, it was charged into a 250 ton converter together with 0 to 50 tons of scrap. The on-line analysis values of the hot metal components are as follows: C: 4.4 to 4.7%, Si: 0.40 to 0.70%, Mn: 0.30 to 0.45%, P: 0.110 to 0.8. 140%, S: 0.020 to 0.030%, hot metal temperature: 1250 to 1340 ° C. The calculated hot metal C concentration (C 1 ) according to the formula (1) described above was 4.4 to 4.8%.
静的制御における酸素ガス供給開始前の溶銑Ｃ濃度の値には上記の計算溶銑Ｃ濃度（Ｃ１）を用い、吹錬終了時の目標である溶鋼中Ｃ濃度：０．０６％に的中させるための酸素ガス供給量を算出した。 The calculated hot metal C concentration (C 1 ) is used as the hot metal C concentration before starting oxygen gas supply in static control, and the target C concentration in the molten steel: 0.06% is the target at the end of blowing. The oxygen gas supply amount for making it into was calculated.
上吹き酸素供給速度は、装入溶銑トンあたり３．５〜４．０Ｎｍ３／ｍｉｎとし、その酸素供給時間は１０〜１５分間であった。底吹きガスにはＮ２またはＣＯ２を使用し、装入溶銑トンあたり０．０４〜０．２０Ｎｍ３／ｍｉｎとした。 The top blowing oxygen supply rate was 3.5 to 4.0 Nm 3 / min per ton of molten molten iron, and the oxygen supply time was 10 to 15 minutes. N 2 or CO 2 was used as the bottom blowing gas, and the amount was 0.04 to 0.20 Nm 3 / min per ton of molten iron.
吹錬の途中で、静的制御計算によって溶鋼中Ｃ濃度が０．３５％と推定した時点でサブランスを用いて転炉内溶鋼の温度とＣ濃度を測定し、その後、動的吹錬制御式を用いて酸素供給量や冷却材投入量を調整して、吹錬を終了した。 During the blowing, when the C concentration in the molten steel is estimated to be 0.35% by static control calculation, the temperature and C concentration of the molten steel in the converter are measured using a sublance, and then the dynamic blowing control formula The oxygen supply amount and the coolant input amount were adjusted using, and the blowing was completed.
これらの吹錬でのサブランスによる溶鋼中Ｃ％の測定値は０．３５±０．１１％に収まっていて良好であり、その結果、吹錬終了時の溶鋼中Ｃ％は目標値である０．０６％に対して、±０．０１％の範囲内に１００％的中していた。
The measured value of C% in molten steel by sublance in these blow squeezing is good within 0.35 ± 0.11%. As a result, C% in molten steel at the end of blowing is the
（実施例２）
上記の実施例１で用いた溶銑の温度および成分範囲と同じ温度および成分範囲を有する溶銑２５０〜２７５トンを溶銑脱硫処理した後、スクラップ０〜５０トンとともに２５０トン転炉へ装入し、溶銑脱燐処理を行った。
(Example 2)
After 250 to 275 tons of hot metal having the same temperature and component range as the temperature and component range of the hot metal used in Example 1 above, hot metal desulfurization treatment was performed and charged into a 250 ton converter together with 0 to 50 tons of scrap, A dephosphorization process was performed.
その上吹き酸素流量は装入溶銑トンあたり１．０〜１．５Ｎｍ３／ｍｉｎとし、その酸素供給時間は６〜１４分間であった。底吹きガスにはＮ２を使用し、流量は装入溶銑トンあたり０．２５Ｎｍ３／ｍｉｎとした。溶銑脱燐処理後の溶銑成分のオンライン分析値は、［Ｃ］：３．３〜３．８％，［Ｓｉ］：≦０．０１％，［Ｍｎ］：０．１１〜０．３０％，［Ｐ］：０．０１８〜０．０５５％であり、前記した（１）式の値（Ｃ１）から（３）式の値（ΔＣ）を差し引いた溶銑Ｃ濃度の計算値（Ｃ２）は、３．３〜３．８％であった。 The top blowing oxygen flow rate was 1.0 to 1.5 Nm 3 / min per ton of charged molten iron, and the oxygen supply time was 6 to 14 minutes. N 2 was used as the bottom blowing gas, and the flow rate was 0.25 Nm 3 / min per ton of molten iron charged. The on-line analysis values of the hot metal component after the hot metal dephosphorization treatment are [C]: 3.3 to 3.8%, [Si]: ≦ 0.01%, [Mn]: 0.11 to 0.30%, [P]: 0.018 to 0.055%, calculated value (C 2 ) of hot metal C concentration obtained by subtracting the value (ΔC) of equation (3) from the value (C 1 ) of equation (1). Was 3.3 to 3.8%.
静的制御における酸素ガス供給開始前の溶銑Ｃ濃度の値には、上記の計算溶銑Ｃ濃度（Ｃ２）を用い、吹錬終了時の目標である溶鋼中Ｃ濃度：０．０６％に的中させるための酸素ガス供給量を算出した。 The calculated hot metal C concentration (C 2 ) is used as the hot metal C concentration before starting oxygen gas supply in static control, and the target C concentration in molten steel: 0.06% is the target at the end of blowing. The amount of oxygen gas supplied to make it medium was calculated.
上吹き酸素供給速度は、装入溶銑トンあたり３．５〜４．０Ｎｍ３／ｍｉｎとし、その酸素供給時間は１０〜１２分間であった。底吹きガスにはＮ２またはＣＯ２を使用し、装入溶銑トンあたり０．０４〜０．２０Ｎｍ３／ｍｉｎとした。 The top blowing oxygen supply rate was 3.5 to 4.0 Nm 3 / min per ton of charged molten iron, and the oxygen supply time was 10 to 12 minutes. N 2 or CO 2 was used as the bottom blowing gas, and the amount was 0.04 to 0.20 Nm 3 / min per ton of molten iron.
吹錬の途中で、静的制御計算によって溶鋼中Ｃ濃度が０．３５％と推定した時点でサブランスを用いて転炉内溶鋼の温度とＣ濃度を測定し、その後、動的吹錬制御式を用いて酸素供給量や冷却材投入量を調整して、吹錬を終了した。 During the blowing, when the C concentration in the molten steel is estimated to be 0.35% by static control calculation, the temperature and C concentration of the molten steel in the converter are measured using a sublance, and then the dynamic blowing control formula The oxygen supply amount and the coolant input amount were adjusted using, and the blowing was completed.
これらの吹錬でのサブランスによる溶鋼中Ｃ％の測定値は０．３５±０．１２％に収まっていて良好であり、その結果、吹錬終了時の溶鋼中Ｃ％は目標値である０．０６％に対して、±０．０１％の範囲内に１００％的中していた。
The measured value of C% in molten steel by sublance in these blow squeezing is good within 0.35 ± 0.12%, and as a result, C% in molten steel at the end of blowing is the
Claims (2)
前記酸素ガスの供給を開始する前の該溶銑のＣ濃度として、該溶銑の温度と該溶銑に含まれている元素のうち少なくともＳｉ，ＭｎおよびＴｉの濃度分析値とに基づいて計算されるＣ濃度（Ｃ１）を用いて、
前記酸素ガスの供給によって該溶銑のＣ濃度が０．５０質量％以下の溶鋼になった後の該溶鋼中のＣ濃度が目標値に的中するように、該酸素ガスの供給量を制御すること
を特徴とする製鋼用転炉における吹錬制御方法。 The hot metal discharged from the blast furnace is supplied with an oxygen source to perform desiliconization and dephosphorization, and the hot metal is charged into the converter and oxygen gas is supplied to supply molten steel. A blowing control method in a steelmaking converter to be manufactured,
The C concentration of the hot metal before starting the supply of the oxygen gas is calculated based on the temperature of the hot metal and the concentration analysis values of at least Si, Mn, and Ti among the elements contained in the hot metal. Using the concentration (C 1 ),
The supply amount of the oxygen gas is controlled so that the C concentration in the molten steel after the molten steel having a molten steel C concentration of 0.50% by mass or less by the supply of the oxygen gas hits the target value. A blowing control method in a steelmaking converter characterized by the above.
前記溶銑予備処理における溶銑Ｃ濃度の低下量（ΔＣ）を該溶銑予備処理条件に基づいて計算し、
前記酸素ガスの供給を開始する前の該溶銑のＣ濃度として、前記溶銑予備処理を施す前の該溶銑のＣ濃度としての、該溶銑の温度と該溶銑に含まれている元素のうち少なくともＳｉ，ＭｎおよびＴｉの濃度分析値とに基づいて計算されるＣ濃度（Ｃ１）から、前記溶銑予備処理における溶銑中のＣ濃度低下量（ΔＣ）を減じたＣ濃度（Ｃ２）を用いて、
前記酸素ガスの供給によって該溶銑のＣ濃度が０．５０質量％以下の溶鋼になった後の該溶鋼中のＣ濃度が目標値に的中するように、該酸素ガスの供給量を制御すること
を特徴とする製鋼用転炉における吹錬制御方法。 The hot metal discharged from the blast furnace is supplied with an oxygen source and subjected to hot metal pretreatment for desiliconization and dephosphorization. Then, the hot metal after the hot metal pretreatment is charged into the converter, and oxygen gas is supplied. A blowing control method in a steelmaking converter for supplying molten steel by supplying,
The amount of decrease in hot metal C concentration (ΔC) in the hot metal pretreatment is calculated based on the hot metal pretreatment conditions,
As the C concentration of the hot metal before starting the supply of the oxygen gas, as the C concentration of the hot metal before the hot metal pretreatment, the temperature of the hot metal and at least Si among the elements contained in the hot metal Using the C concentration (C 2 ) obtained by subtracting the C concentration decrease amount (ΔC) in the hot metal in the hot metal pretreatment from the C concentration (C 1 ) calculated based on the concentration analysis values of Mn, Ti and Ti ,
The supply amount of the oxygen gas is controlled so that the C concentration in the molten steel after the molten steel having a molten steel C concentration of 0.50% by mass or less by the supply of the oxygen gas hits the target value. A blowing control method in a steelmaking converter characterized by the above.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5456014A (en) * | 1976-08-04 | 1979-05-04 | Voest Ag | Control of steel refining procedure |
| JPS54155113A (en) * | 1978-05-27 | 1979-12-06 | Nippon Kokan Kk <Nkk> | Blowing control hethod in pure oxygen top blowing converter |
| JPS6318013A (en) * | 1986-07-09 | 1988-01-25 | Nippon Kokan Kk <Nkk> | Method for controlling end point of converter |
| JP2001152228A (en) * | 1999-11-19 | 2001-06-05 | Kobe Steel Ltd | Method for blending main raw materials for converter |
| JP2012117090A (en) * | 2010-11-29 | 2012-06-21 | Sumitomo Metal Ind Ltd | Converter blowing method and converter blowing system |
-
2014
- 2014-04-03 JP JP2014077270A patent/JP6331601B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5456014A (en) * | 1976-08-04 | 1979-05-04 | Voest Ag | Control of steel refining procedure |
| JPS54155113A (en) * | 1978-05-27 | 1979-12-06 | Nippon Kokan Kk <Nkk> | Blowing control hethod in pure oxygen top blowing converter |
| JPS6318013A (en) * | 1986-07-09 | 1988-01-25 | Nippon Kokan Kk <Nkk> | Method for controlling end point of converter |
| JP2001152228A (en) * | 1999-11-19 | 2001-06-05 | Kobe Steel Ltd | Method for blending main raw materials for converter |
| JP2012117090A (en) * | 2010-11-29 | 2012-06-21 | Sumitomo Metal Ind Ltd | Converter blowing method and converter blowing system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105506213A (en) * | 2016-01-19 | 2016-04-20 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for lowering oxygen activity of semisteel smelting end point molten steel |
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