JP3235884B2 - Method for quantitative analysis of oxygen in readily reducible metal oxides contained in steelmaking slag - Google Patents
Method for quantitative analysis of oxygen in readily reducible metal oxides contained in steelmaking slagInfo
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- JP3235884B2 JP3235884B2 JP31936492A JP31936492A JP3235884B2 JP 3235884 B2 JP3235884 B2 JP 3235884B2 JP 31936492 A JP31936492 A JP 31936492A JP 31936492 A JP31936492 A JP 31936492A JP 3235884 B2 JP3235884 B2 JP 3235884B2
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- oxygen
- sample
- slag
- reducible metal
- amount
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- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、製鋼段階で脱炭吹錬等
によって生成される製鋼スラグに含まれている易還元性
金属酸化物の酸素量を測定する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the amount of oxygen in readily reducible metal oxides contained in steelmaking slag produced by decarburization blowing in a steelmaking stage.
【０００２】[0002]
【従来の技術】転炉，真空脱ガス装置等でステンレス鋼
等の合金鋼を脱炭吹錬するとき、溶鋼中の炭素が吹錬酸
素と反応しＣＯガスとなって溶鋼から除去されると同時
に、有用成分であるＣｒ，Ｆｅ，Ｍｎ等も一部が次の反
応に従って酸化される。 ４［Ｃｒ］＋３Ｏ2 →２（Ｃｒ2 Ｏ3 ） ２［Ｆｅ］＋Ｏ2 →２（ＦｅＯ） ［Ｍｎ］＋Ｏ2 →（ＭｎＯ2 ）2. Description of the Related Art When decarburizing and blowing alloy steel such as stainless steel using a converter or a vacuum degassing apparatus, carbon in molten steel reacts with blowing oxygen to form CO gas and is removed from the molten steel. At the same time, useful components such as Cr, Fe, and Mn are partially oxidized according to the following reaction. 4 [Cr] + 3O 2 → 2 (Cr 2 O 3 ) 2 [Fe] + O 2 → 2 (FeO) [Mn] + O 2 → (MnO 2 )
【０００３】酸化物となったＣｒ，Ｆｅ，Ｍｎ等の金属
元素は、溶鋼表面に浮遊しているスラグに移行する。ス
ラグ中の金属元素は、製鋼の最終段階で酸化物から金属
状態に還元され、メタルとして溶鋼に回収される。回収
は、Ｃｒ，Ｆｅ，Ｍｎ等の金属元素がＳｉによって容易
に金属状態に還元されることを利用し、たとえば真空精
練時に所定量のＳｉを取鍋内溶鋼に添加することにより
行われている。Ｓｉによる還元反応は、次の通りであ
る。 ２（Ｃｒ2 Ｏ3 ）＋３Ｓｉ→４［Ｃｒ］＋３（ＳｉＯ2 ） ２（ＦｅＯ）＋Ｓｉ→２［Ｆｅ］＋（ＳｉＯ2 ） （ＭｎＯ2 ）＋Ｓｉ→［Ｍｎ］＋（ＳｉＯ2 ）[0003] Metal elements such as Cr, Fe and Mn that have become oxides migrate to slag floating on the surface of molten steel. The metal elements in the slag are reduced from oxides to a metal state in the final stage of steel making, and are recovered as molten metal in molten steel. Recovery is performed by utilizing the fact that metal elements such as Cr, Fe, and Mn are easily reduced to a metal state by Si, for example, by adding a predetermined amount of Si to molten steel in a ladle during vacuum refining. . The reduction reaction by Si is as follows. 2 (Cr 2 O 3 ) + 3Si → 4 [Cr] +3 (SiO 2 ) 2 (FeO) + Si → 2 [Fe] + (SiO 2 ) (MnO 2 ) + Si → [Mn] + (SiO 2 )
【０００４】金属状態になったＣｒ，Ｆｅ，Ｍｎ等は溶
鋼に取り込まれ、溶鋼が成分調整される。成分調整を高
精度で行うためには、最終段階でスラグから溶鋼に移行
する金属元素を定量的に把握しておく必要がある。ま
た、最近では、Ｓｉ含有量に関する規格が極めて厳しい
鋼種が使用され始めている。このような高精度の成分調
整やＳｉ含有量が厳格に管理された鋼種に対応するため
には、Ｓｉによって還元される易還元性金属元素がスラ
グ中に含まれている量を正確に把握することが必要であ
る。スラグに含まれている易還元性金属元素の量は、Ｃ
ｒ2 Ｏ3 ，ＦｅＯ，ＭｎＯ2 等の金属酸化物中の酸素量
から算出される。また、算出された酸素量は、還元剤と
して必要なＳｉの添加量を定めるときの基準になる。[0004] Cr, Fe, Mn and the like in a metal state are taken into molten steel, and the composition of the molten steel is adjusted. In order to perform the component adjustment with high accuracy, it is necessary to quantitatively grasp the metal elements that migrate from slag to molten steel in the final stage. Also, recently, steel grades with extremely strict standards regarding the Si content have begun to be used. In order to cope with such a high-precision component adjustment and a steel type in which the Si content is strictly controlled, the amount of the easily reducible metal element reduced by Si contained in the slag is accurately grasped. It is necessary. The amount of easily reducible metal elements contained in slag is C
It is calculated from the amount of oxygen in a metal oxide such as r 2 O 3 , FeO, MnO 2 . Further, the calculated amount of oxygen is used as a reference when determining the amount of Si required as a reducing agent.
【０００５】金属酸化物中の酸素を定量する方法とし
て、スラグ試料を蛍光Ｘ線分析する方法が知られてい
る。蛍光Ｘ線分析においては、精練中の転炉，電気炉，
取鍋等から採取した溶融スラグをガラスビード法，プレ
ス成形法等で分析用試料に作製している。ガラスビード
法では、たとえば図１に示すように、凝固したスラグを
粉砕した後、秤量し、スラグ０．２ｇを炭酸ナトリウム
等の融剤２．０ｇと共に白金ルツボに入れ、ビードサン
プラーで加熱・撹拌し、均一に溶融・冷却する。この方
法によるとき、分析用試料を得るまでに２５分程度の作
業が必要となる。[0005] As a method for quantifying oxygen in a metal oxide, there is known a method in which a slag sample is subjected to fluorescent X-ray analysis. In fluorescent X-ray analysis, the converter, electric furnace,
Molten slag collected from a ladle or the like is made into a sample for analysis by a glass bead method, press molding method, or the like. In the glass bead method, for example, as shown in FIG. 1, solidified slag is pulverized, weighed, 0.2 g of slag is put into a platinum crucible together with 2.0 g of a flux such as sodium carbonate, and heated and stirred with a bead sampler. And uniformly melt and cool. According to this method, it takes about 25 minutes to obtain an analysis sample.
【０００６】他方、プレス成形法では、採取された適量
のスラグをアルミニウム製キャップに充填し、１５〜２
０トンのプレスで加圧成形することにより、分析用試料
を作製している。プレス成形法は、ガラスビード法に比
較して分析用試料を得るまでの時間が短いものの、粉砕
した粒子のバラツキ等に起因する測定誤差を解消するた
め同一試料で２回の分析が必要となる。そのため、結果
として分析結果を得るまでに２０分程度かかる。On the other hand, in the press molding method, an appropriate amount of slag collected is filled in an aluminum cap, and the slag is filled with 15 to 2 parts.
A sample for analysis is prepared by pressure molding with a 0 ton press. Although the press molding method requires less time to obtain a sample for analysis than the glass bead method, the same sample needs to be analyzed twice in order to eliminate measurement errors due to variations in crushed particles and the like. . Therefore, it takes about 20 minutes to obtain an analysis result as a result.
【０００７】[0007]
【発明が解決しようとする課題】蛍光Ｘ線分析法は、ガ
ラスビード法及びプレス成形法の何れにおいても試料の
秤量から分析値の算出までに２０〜２５分を必要とす
る。しかも、試料に含まれている金属酸化物が単独の酸
化物形態であると仮定し、金属と酸化物との化学量論的
な関係から定まる係数を酸化物の定量値に乗じることに
より、酸素分析値を算出している。たとえば、後に掲げ
た表１に示した組成をもつ転炉スラグから採取した試料
Ａの酸素量は、メタル分を全て酸化物とし次のように算
出される。 蛍光Ｘ線酸素量＝ MnO×0.226 ＋ Cr2O3×0.316 ＋ FeO
×0.223 ＋Fe×0.287＝ 2.6×0.226 ＋45.6×0.316 ＋
2.05×0.223 ＋3.08×0.287＝１６．３The fluorescent X-ray analysis method requires 20 to 25 minutes from the weighing of a sample to the calculation of an analysis value in both the glass bead method and the press molding method. Furthermore, assuming that the metal oxide contained in the sample is in the form of a single oxide, and multiplying the quantitative value of the oxide by a coefficient determined from the stoichiometric relationship between the metal and the oxide, Analytical values are calculated. For example, the oxygen content of the sample A collected from the converter slag having the composition shown in Table 1 listed below is calculated as follows, using all the metal components as oxides. X-ray fluorescence oxygen = MnO × 0.226 + Cr 2 O 3 × 0.316 + FeO
× 0.223 + Fe × 0.287 = 2.6 × 0.226 + 45.6 × 0.316 +
2.05 × 0.223 + 3.08 × 0.287 = 16.3
【０００８】そのため、金属状態のＣｒ，Ｆｅ，Ｍｎ等
が含まれている試料や、酸素価が異なる金属酸化物が含
まれている試料等では、必然的に測定誤差が発生する。
メタル分を除去して酸素量を算出する理論計算酸素量
は、たとえば表１の試料Ａについて次のように算出され
る。 理論計算酸素量＝ MnO×0.226 ＋ Cr2O3×0.316 ＋ FeO
×0.223＝２．６×０．２２６＋４５．６×０．３１６
＋２．０５×０．２２３＝１５．５ すなわち、蛍光Ｘ線酸素量は１６．３であり、理論計算
酸素量１５．５と比較して０．８％の誤差を生じる。[0008] For this reason, in a sample containing metallic Cr, Fe, Mn or the like, or a sample containing metal oxides having different oxygen values, a measurement error necessarily occurs.
The theoretical calculated oxygen amount for calculating the oxygen amount by removing the metal component is calculated, for example, for the sample A in Table 1 as follows. Theoretical calculation amount of oxygen = MnO × 0.226 + Cr 2 O 3 × 0.316 + FeO
× 0.223 = 2.6 × 0.226 + 45.6 × 0.316
+ 2.05 × 0.223 = 15.5 That is, the fluorescent X-ray oxygen amount is 16.3, which causes an error of 0.8% as compared with the theoretically calculated oxygen amount of 15.5.
【０００９】また、特開平１−１７２５３０号公報で
は、クロム鉱石中のＦｅＯとＦｅ2 Ｏ3 との割合を特定
する方法が開示されている。しかし、この方法は、Ｃｒ
2 Ｏ3の算出を対象にしておらず、スラグに含まれてい
る易還元性金属酸化物の酸素濃度を求める方法としては
不十分である。しかも、測定時間が１〜２時間と長く、
迅速性に欠ける。本発明は、このような問題を解消すべ
く案出されたものであり、試料スラグに含まれている易
還元性金属酸化物を炭素と反応させ、発生したＣＯ等の
ガスを分析することにより、試料スラグ中の酸素濃度を
迅速且つ高精度に直接測定し、還元に必要な正確なＳｉ
量を得ることを目的とする。Japanese Patent Application Laid-Open No. 1-172530 discloses a method for specifying the ratio between FeO and Fe 2 O 3 in chromium ore. However, this method uses Cr
It is not intended to calculate 2 O 3 , and is insufficient as a method for determining the oxygen concentration of the easily reducible metal oxide contained in the slag. Moreover, the measurement time is as long as 1-2 hours,
Lack of speed. The present invention has been devised to solve such a problem. By reacting easily reducible metal oxides contained in a sample slag with carbon, and analyzing the generated gas such as CO. , Measure oxygen concentration in sample slag directly and quickly with high accuracy,
The aim is to get the quantity.
【００１０】[0010]
【課題を解決するための手段】本発明の酸素定量分析方
法は、その目的を達成するため、製鋼スラグから採取さ
れた試料を不活性雰囲気中で連続的に加熱しながら炭素
源と反応させ、炭素と結合して系外に排出される酸素量
を時系列的に測定し、前記試料に含まれ且つ溶融状態で
Ｓｉによって還元される易還元金属酸化物の酸素量を測
定結果の積分値から求めることを特徴とする。不活性雰
囲気中で試料を連続的に加熱する際、酸素抽出の開始か
ら終了までの昇温速度を０．０１〜２０℃／秒とするこ
とが好ましい。炭素源としては、粒状又は粉末状の活性
炭や各種炭化物等があり、黒鉛ルツボに試料スラグと共
に装入される。黒鉛ルツボの内壁も、炭素源として利用
される。Means for Solving the Problems In order to achieve the object, the oxygen quantitative analysis method of the present invention reacts a sample collected from steelmaking slag with a carbon source while continuously heating the sample in an inert atmosphere. The amount of oxygen bound to carbon and discharged out of the system is measured in time series, and the amount of oxygen in the easily reduced metal oxide contained in the sample and reduced by Si in the molten state is determined from the integrated value of the measurement result. It is characterized by seeking. When the sample is continuously heated in an inert atmosphere, the rate of temperature increase from the start to the end of oxygen extraction is preferably 0.01 to 20 ° C./sec. Examples of the carbon source include granular or powdered activated carbon and various carbides, which are charged into a graphite crucible together with a sample slag. The inner wall of the graphite crucible is also used as a carbon source.
【００１１】[0011]
【作 用】酸素分析装置を用いた酸素定量方法では、不
活性ガス雰囲気中で黒鉛ルツボに活性炭，炭化物と共に
充填した酸化物を不活性ガス雰囲気中で連続加熱昇温
し、Ｃとの間の還元反応によって発生するＣＯガスを赤
外線吸収法で測定する。ＣＯガスは、次の反応によって
発生するものと考えられる。ただし、次式の還元反応
は、２価の金属元素Ｍで代表させている。 ＭＯ＋Ｃ＝Ｍ＋ＣＯ ＭＯ＋Ｃ＝ＭＣ＋ＣＯ ＭＯ＋ＭＣ＝２Ｍ＋ＣＯ[Action] In an oxygen determination method using an oxygen analyzer, an oxide filled with activated carbon and carbide in a graphite crucible in an inert gas atmosphere is continuously heated and heated in an inert gas atmosphere. The CO gas generated by the reduction reaction is measured by an infrared absorption method. The CO gas is considered to be generated by the following reaction. However, the reduction reaction of the following formula is represented by the divalent metal element M. MO + C = M + CO MO + C = MC + CO MO + MC = 2M + CO
【００１２】試料スラグに含まれているＣｒ，Ｆｅ，Ｍ
ｎ等の易還元性金属酸化物は、比較的低温で還元反応を
開始し、金属元素から分離した酸素が抽出される。他
方、Ｓｉにより還元できないＣａ，Ｍｇ，Ｓｉ等の酸化
物（難還元性金属酸化物）は、高温で還元反応が開始さ
れるため、易還元性金属酸化物からの酸素抽出が終了し
た後で難還元性金属酸化物からの酸素抽出が始まる。易
還元性金属酸化物と難還元性金属酸化物との還元反応が
温度条件によって明確に異なることを利用することによ
り、試料スラグに含まれている易還元性金属酸化物を酸
素定量することができる。すなわち、易還元性金属酸化
物からの酸素抽出が終了した時点までに測定された酸素
強度を積分するとき、易還元性金属酸化物の酸素量，換
言すれば酸化状態のＣｒ，Ｆｅ，Ｍｎ等を金属状態に還
元するのに必要なＳｉ量が得られる。[0012] Cr, Fe, M contained in the sample slag
An easily reducible metal oxide such as n starts a reduction reaction at a relatively low temperature, and oxygen separated from the metal element is extracted. On the other hand, oxides such as Ca, Mg, and Si (reducible metal oxides) that cannot be reduced by Si start a reduction reaction at a high temperature, and therefore, after the oxygen extraction from the easily reducible metal oxide is completed. Oxygen extraction from the non-reducible metal oxide begins. By making use of the fact that the reduction reaction between easily reducible metal oxides and hardly reducible metal oxides differs depending on the temperature conditions, oxygen quantification of the easily reducible metal oxides contained in the sample slag can be performed. it can. That is, when integrating the oxygen intensity measured up to the time when the extraction of oxygen from the reducible metal oxide is completed, the oxygen amount of the reducible metal oxide, in other words, the oxidized state of Cr, Fe, Mn, etc. The amount of Si required to reduce to the metal state is obtained.
【００１３】たとえば、試料スラグの炭素還元によって
発生したＣＯガスを赤外線吸収法で定量するとき、図２
に示した酸素抽出曲線が得られる。酸素抽出曲線は、分
析時間及び加熱温度に伴って上昇するが、時点ｔ1 に達
する１８００℃近傍の温度Ｔ1 で一旦降下し、次いで再
度立ち上がった後、時点ｔ2 で酸素強度０となる。時点
ｔ1 における分析酸素強度の極小値Ｉ1 は明瞭に検出さ
れ、易還元性金属酸化物の還元反応が難還元性金属酸化
物の還元反応から明確に区別される。分析開始から時点
ｔ1 まで易還元性金属酸化物に由来する酸素が検出さ
れ、期間 (ｔ1 →ｔ2)で難還元性金属酸化物に由来する
酸素が検出される。そこで、期間（０→ｔ1)の酸素分析
強度を積分し、図２で斜線を付した面積を濃度換算する
ことにより、易還元性金属酸化物から抽出された酸素量
が測定される。極小値Ｉ1 は、試料スラグを徐々に昇温
するほど顕著に表れる。昇温速度が２０℃／秒を超える
ようになると、極小値Ｉ1 が上昇する傾向がみられ、易
還元性金属酸化物からの酸素抽出と難還元性金属酸化物
からの酸素抽出との分解度が低下する。しかし、過度に
小さな昇温速度は分析の迅速化に反することから、実操
業を考慮して０．０１℃／秒以上の昇温速度にすること
が望ましい。For example, when the CO gas generated by the carbon reduction of the sample slag is quantified by the infrared absorption method, FIG.
The oxygen extraction curve shown in FIG. The oxygen extraction curve rises with the analysis time and the heating temperature, but once drops at a temperature T 1 near 1800 ° C., which reaches the time point t 1 , and then rises again, after which the oxygen intensity becomes zero at the time point t 2 . Minimum value I 1 of the analytical oxygen intensity at time t 1 is clearly detected, the reduction reaction of the readily reducible metal oxide is clearly distinguished from the reduction reaction of irreducible metal oxide. Oxygen derived from the easily reducible metal oxide is detected from the start of the analysis to time t 1, and oxygen derived from the hardly reducible metal oxide is detected during the period (t 1 → t 2 ). Therefore, the oxygen analysis intensity during the period (0 → t 1 ) is integrated, and the area shaded in FIG. 2 is converted into a concentration, whereby the amount of oxygen extracted from the easily reducible metal oxide is measured. The minimum value I 1 becomes more noticeable as the temperature of the sample slag is gradually increased. When the heating rate exceeds 20 ° C./sec, the minimum value I 1 tends to increase, and the decomposition of oxygen extraction from easily reducible metal oxides and oxygen extraction from hardly reducible metal oxides is observed. Degree decreases. However, an excessively small heating rate is contrary to the rapid analysis, and therefore it is preferable to set the heating rate to 0.01 ° C./sec or more in consideration of actual operation.
【００１４】[0014]
【実施例】実施例１：酸素定量されるスラグとして、表
１に示す組成をもつ４種類のステンレス鋼の転炉スラグ
を使用した。なお、表１における理論計算酸素量は、ス
ラグ中のメタルを沃素アルコールで分離除去した後、蛍
光Ｘ線分析で得られた測定値を係数倍した値である。EXAMPLES Example 1 Four types of stainless steel converter slag having the compositions shown in Table 1 were used as slags to be subjected to oxygen determination. The theoretical calculated oxygen amount in Table 1 is a value obtained by multiplying a measured value obtained by X-ray fluorescence analysis after separating and removing metal in slag with iodine alcohol.
【表１】 [Table 1]
【００１５】試料Ａのスラグから分析試料を用意した。
分析試料を０．０５ｇ秤量し、空焼きした容量２．５ｍ
ｌの二重黒鉛ルツボに同量の空焼きした活性炭素と共に
入れ、種々の昇温速度で加熱した。そして、分析酸素強
度の極小値Ｉ1 に与える昇温速度の影響を調査した。分
析酸素強度の極小値Ｉ1 は、調査結果を示す図３から明
らかなように、昇温速度の上昇に従って高くなってい
る。このことから、難還元性金属酸化物からの酸素抽出
と易還元性金属酸化物からの酸素抽出とを高い分解度で
区別するためには、昇温速度を低く設定する必要がある
ことが判る。An analysis sample was prepared from the slag of sample A.
0.05 g of analytical sample was weighed and calcined in a capacity of 2.5 m
1 l of double graphite crucible together with the same amount of calcined activated carbon was heated at various heating rates. Then, to investigate the effects of heating rate to be applied to the minimum value I 1 of the analysis oxygen intensity. Minimum value I 1 of the analysis oxygen strength, as is apparent from FIG. 3 showing the investigation results are higher with increasing heating rate. From this, it can be seen that in order to distinguish the oxygen extraction from the hardly reducible metal oxide from the oxygen extraction from the easily reducible metal oxide with a high degree of decomposition, it is necessary to set the temperature rising rate low. .
【００１６】試料Ａのスラグから得られた分析試料を、
同様な黒鉛ルツボに入れて加熱し、炭素還元した。昇温
速度を３℃／秒，１２℃／秒及び２０℃／秒に設定した
加熱条件下で、それぞれ図４〜６に示す酸素抽出曲線が
得られた。何れの曲線においても、酸素抽出曲線に極小
値がみられる。しかし、昇温速度が２０℃／秒のときの
酸素抽出曲線は、図６に示すように複数の凹凸をもって
おり、しかも谷が浅いものであった。試料Ａ〜Ｄの各ス
ラグにつき、それぞれ分析用試料を二つ用意した。各試
料スラグを所定の昇温速度で加熱し、易還元性金属酸化
物の酸素濃度を測定した結果を表２に示す。表２におい
ては、理論計算酸素量を対比して示した。表２から明ら
かなように、本発明に従って得られた積分値は、昇温速
度２０℃／秒を除き、理論計算酸素量に対する一致性が
高いことが判る。The analytical sample obtained from the slag of Sample A is
It was placed in a similar graphite crucible and heated to reduce carbon. Under heating conditions in which the heating rate was set at 3 ° C./sec, 12 ° C./sec, and 20 ° C./sec, the oxygen extraction curves shown in FIGS. In each curve, a minimum value is observed in the oxygen extraction curve. However, the oxygen extraction curve at a heating rate of 20 ° C./sec had a plurality of irregularities and a shallow valley as shown in FIG. For each slag of Samples A to D, two samples for analysis were prepared. Table 2 shows the results obtained by heating each sample slag at a predetermined heating rate and measuring the oxygen concentration of the easily reducible metal oxide. In Table 2, the theoretical calculated oxygen amount is shown in comparison. As is clear from Table 2, it can be seen that the integrated values obtained according to the present invention are highly consistent with the theoretically calculated oxygen content except for the heating rate of 20 ° C./sec.
【表２】 [Table 2]
【００１７】極小値Ｉ1 を示す時点ｔ1 で採取した試料
を、高周波誘導結合アルゴンプラズマ分光分析法（ＩＣ
Ｐ）で分析した。なお、採取した試料に含まれているＣ
ｒ，Ｆｅ，Ｍｎ等を硫酸及び硫酸−フッ酸の混酸で分解
しすることにより湿式分析試料を調製した。ＩＣＰ分析
の結果、時点ｔ1 の試料スラグに含まれているＣｒ，Ｆ
ｅ，Ｍｎ等の９５％が金属状態に還元されていることが
確認された。これによっても、極小値Ｉ1 を示す時点ｔ
1 までの分析酸素強度を積分し酸素量を算出する方法
は、試料スラグに含まれている易還元性金属酸化物の酸
素濃度を測定する上で有効な方法といえる。易還元性金
属酸化物の炭素還元は、図２に示すように８００℃以下
の低温側ではほとんど進行しない。たとえば、８００℃
以下の低温域を１〜２秒の短時間で通過させても、酸素
定量分析に影響は現れず、分析操作の迅速化が図られ
る。表３は、試料スラグを８００℃に瞬時に加熱した
後、昇温速度４℃／秒で連続的に加熱し、分析酸素強度
を積分して求めた酸素量を示す。図７は、このときの酸
素抽出曲線を示す。A sample taken at time t 1 showing the minimum value I 1 was subjected to high-frequency inductively coupled argon plasma spectroscopy (IC
P). In addition, C contained in the collected sample
A wet analysis sample was prepared by decomposing r, Fe, Mn, and the like with sulfuric acid and a mixed acid of sulfuric acid and hydrofluoric acid. As a result of ICP analysis, Cr, F contained in the sample slag at time t 1
It was confirmed that 95% of e, Mn and the like were reduced to the metal state. Accordingly, the time t at which the minimum value I 1 is reached is obtained.
The method of calculating the amount of oxygen by integrating the analytical oxygen intensity up to 1 can be said to be an effective method for measuring the oxygen concentration of the easily reducible metal oxide contained in the sample slag. As shown in FIG. 2, the carbon reduction of the easily reducible metal oxide hardly proceeds at a low temperature of 800 ° C. or lower. For example, 800 ° C
Even if it passes through the following low temperature range in a short time of 1 to 2 seconds, no influence is exerted on the oxygen quantitative analysis, and the analysis operation can be sped up. Table 3 shows the amount of oxygen determined by instantaneously heating the sample slag to 800 ° C., then continuously heating the sample slag at a rate of 4 ° C./sec, and integrating the analyzed oxygen intensity. FIG. 7 shows an oxygen extraction curve at this time.
【表３】 [Table 3]
【００１８】表３から明らかなように、この場合にも本
発明に従った算出値は、理論計算酸素量に高精度で一致
していることが判る。この方式によるとき、試料の秤量
及びセッティングを含めても分析に必要な時間は７分程
度であり、操業中におけるスラグ分析に十分適用され
る。なお、実際に易還元性金属酸化物の酸素が抽出され
ている箇所のみの昇温速度をコントロールすることによ
っても、精度良く酸素を定量することができた。As is evident from Table 3, the calculated value according to the present invention also matches the theoretically calculated oxygen amount with high accuracy in this case as well. According to this method, the time required for the analysis including the weighing and setting of the sample is about 7 minutes, and is sufficiently applied to the slag analysis during the operation. It should be noted that oxygen could be quantified with high accuracy by controlling the rate of temperature increase only in the portion where oxygen of the easily reducible metal oxide was actually extracted.
【００１９】実施例２： 表１に示した試料Ａ〜Ｄの転炉スラグをそれぞれ秤量
し、同量の炭素源と共に空焼きした二重黒鉛ルツボに入
れた。炭素源としては、ＳｉＣ，Ｃｒ3 Ｃ2 ，Ｃｒ7 Ｃ
3 及びカーボンブラックの４種類を使用した。すなわ
ち、試料Ａ〜Ｄ及び４種類の炭素源に応じて、合計１６
通りの実験を行った。各試料スラグを昇温速度４℃／秒
で連続加熱し、酸素抽出曲線を求めた。たとえば、炭素
源としてＣｒ3 Ｃ2 を使用したとき、図８に示す酸素抽
出曲線が得られた。この酸素抽出曲線から易還元性金属
の酸素濃度を求めたところ、表４に示す結果が得られ
た。表４から明らかなように、本発明に従って算出され
た酸素量は、理論計算酸素量とよく一致していた。ま
た、算出結果は、炭素源の種類に拘らず、ほぼ一定した
値を示した。Example 2 Converter slags of Samples A to D shown in Table 1 were respectively weighed and placed in a double graphite crucible which was calcined with the same amount of carbon source. As the carbon source, SiC, Cr 3 C 2 , Cr 7 C
3 and 4 types of carbon black were used. That is, depending on the samples A to D and the four types of carbon sources, a total of 16
The same experiment was performed. Each sample slag was continuously heated at a heating rate of 4 ° C./sec, and an oxygen extraction curve was determined. For example, when Cr 3 C 2 was used as a carbon source, an oxygen extraction curve shown in FIG. 8 was obtained. When the oxygen concentration of the easily reducible metal was determined from the oxygen extraction curve, the results shown in Table 4 were obtained. As is apparent from Table 4, the oxygen amount calculated according to the present invention was in good agreement with the theoretically calculated oxygen amount. In addition, the calculation result showed a substantially constant value regardless of the type of the carbon source.
【００２０】[0020]
【発明の効果】以上に説明したように、本発明において
は、Ｃｒ，Ｆｅ，Ｍｎ等の易還元性金属酸化物の炭素還
元反応とＳｉ，Ｃａ，Ａｌ等の難還元性金属酸化物の炭
素還元反応とが明確に異なる温度領域で進行することを
利用し、高温側で還元される難還元性金属酸化物に由来
する酸素から区別した状態で易還元性金属酸化物から抽
出される酸素を定量している。定量結果は、理論計算酸
素量に対し一致性が高い値を示す。このようにして、本
発明によるとき、製鋼スラグに含まれている易還元性金
属酸化物の酸素濃度が高精度で迅速に測定される。その
結果、取鍋精練時等で還元剤として添加されるＳｉ量が
正確に把握され、Ｓｉ含有量を厳格に制御した各種溶鋼
も製造することが可能になる。As described above, in the present invention, the carbon reduction reaction of easily reducible metal oxides such as Cr, Fe and Mn and the carbon reduction reaction of hardly reducible metal oxides such as Si, Ca and Al Utilizing that the reduction reaction proceeds in a distinctly different temperature range, oxygen extracted from the easily reducible metal oxide is distinguished from oxygen derived from the hardly reducible metal oxide that is reduced on the high temperature side. Has been quantified. The quantitative result shows a value that is highly consistent with the theoretically calculated oxygen amount. In this way, according to the present invention, the oxygen concentration of the easily reducible metal oxide contained in the steelmaking slag is quickly measured with high accuracy. As a result, the amount of Si added as a reducing agent at the time of ladle refining or the like can be accurately grasped, and various molten steels in which the Si content is strictly controlled can be produced.
【図１】 蛍光Ｘ線分析に使用される試料の調製工程FIG. 1 Preparation process of sample used for X-ray fluorescence analysis
【図２】 不活性雰囲気中で転炉スラグを昇温速度４℃
／秒で昇温しながら炭素還元したときの酸素抽出曲線Fig. 2 Converter slag is heated at 4 ° C in an inert atmosphere
Oxygen extraction curve when carbon is reduced while heating at a rate per second
【図３】 分析酸素強度の極小値に与える昇温速度の影
響Fig. 3 Effect of heating rate on minimum value of analytical oxygen intensity
【図４】 不活性雰囲気中で転炉スラグを昇温速度３℃
／秒で昇温しながら炭素還元したときの酸素抽出曲線FIG. 4 Heating rate of converter slag in inert atmosphere at 3 ° C.
Oxygen extraction curve when carbon is reduced while heating at a rate per second
【図５】 不活性雰囲気中で転炉スラグを昇温速度１２
℃／秒で昇温しながら炭素還元したときの酸素抽出曲線[Fig. 5] The converter slag is heated in an inert atmosphere at a heating rate of 12
Oxygen extraction curve when carbon is reduced while increasing the temperature at ° C / sec
【図６】 不活性雰囲気中で転炉スラグを昇温速度２０
℃／秒で昇温しながら炭素還元したときの酸素抽出曲線[Fig. 6] The converter slag is heated at a heating rate of 20 in an inert atmosphere.
Oxygen extraction curve when carbon is reduced while increasing the temperature at ° C / sec
【図７】 不活性雰囲気中で転炉スラグを８００℃まで
急速加熱した後、昇温速度４℃／秒で昇温しながら炭素
還元したときの酸素抽出曲線FIG. 7 is an oxygen extraction curve obtained by rapidly heating a converter slag to 800 ° C. in an inert atmosphere and then reducing the carbon while increasing the temperature at a rate of 4 ° C./sec.
【図８】 黒鉛ルツボ及びＣｒ3 Ｃ2 を炭素源として転
炉スラグを昇温速度４℃／秒で昇温しながら炭素還元し
たときの酸素抽出曲線FIG. 8 is an oxygen extraction curve when carbon slag is reduced while increasing the temperature of a converter slag at a heating rate of 4 ° C./sec using a graphite crucible and Cr 3 C 2 as carbon sources.
Ｉ1:分析酸素強度の極小値 ｔ1:極小値が得られる時
点 Ｔ1:極小値が発生する温度I 1 : Minimum value of analytical oxygen intensity t 1 : Time when minimum value is obtained T 1 : Temperature at which minimum value occurs
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｇ０１Ｎ 33/20 Ｇ０１Ｎ 33/20 Ｅ (72)発明者 田中 清之 広島県呉市昭和町11番１号 日新製鋼株 式会社鉄鋼研究所内 (56)参考文献 特開 平１−172530（ＪＰ，Ａ) 実開 昭59−71172（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 31/00 C21C 5/28 C21C 5/46 C21C 7/00 G01N 33/20 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI G01N 33/20 G01N 33/20 E (72) Inventor Kiyoyuki Tanaka 11-1 Showa-cho, Kure-shi, Hiroshima Nisshin Steel Co., Ltd. (56) References JP-A-1-172530 (JP, A) JP-A-59-71172 (JP, U) (58) Fields investigated (Int. Cl. 7 , DB name) G01N 31 / 00 C21C 5/28 C21C 5/46 C21C 7/00 G01N 33/20
Claims (2)
雰囲気中で連続的に加熱しながら炭素源と反応させ、炭
素と結合して系外に排出される酸素量を時系列的に測定
し、前記試料に含まれ且つ溶融状態でＳｉによって還元
される易還元金属酸化物の酸素量を測定結果の積分値か
ら求めることを特徴とする製鋼スラグに含まれている易
還元性金属酸化物の酸素定量分析方法。1. A sample collected from a steelmaking slag is reacted with a carbon source while continuously heating in an inert atmosphere, and the amount of oxygen combined with carbon and discharged out of the system is measured in a time series. The oxygen content of the easily reduced metal oxide contained in the sample and reduced by Si in the molten state is determined from the integrated value of the measurement result. Oxygen quantitative analysis method.
る際、酸素抽出の開始から終了までの昇温速度を０．０
１〜２０℃／秒とする請求項１記載の酸素定量分析方
法。2. When continuously heating a sample in an inert atmosphere, the rate of temperature increase from the start to the end of oxygen extraction is set to 0.02.
2. The method according to claim 1, wherein the temperature is 1 to 20 [deg.] C./sec.
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|---|---|---|---|
| JP31936492A JP3235884B2 (en) | 1992-11-04 | 1992-11-04 | Method for quantitative analysis of oxygen in readily reducible metal oxides contained in steelmaking slag |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31936492A JP3235884B2 (en) | 1992-11-04 | 1992-11-04 | Method for quantitative analysis of oxygen in readily reducible metal oxides contained in steelmaking slag |
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|---|---|
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| JP3235884B2 true JP3235884B2 (en) | 2001-12-04 |
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| KR101246397B1 (en) * | 2011-08-30 | 2013-03-21 | 현대제철 주식회사 | Quantification method for blast furnace slag analysis |
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