JP2001228083A - Method for directly analyzing molten metal - Google Patents
Method for directly analyzing molten metalInfo
- Publication number
- JP2001228083A JP2001228083A JP2000042097A JP2000042097A JP2001228083A JP 2001228083 A JP2001228083 A JP 2001228083A JP 2000042097 A JP2000042097 A JP 2000042097A JP 2000042097 A JP2000042097 A JP 2000042097A JP 2001228083 A JP2001228083 A JP 2001228083A
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- Japan
- Prior art keywords
- molten metal
- light
- reflected
- reflected light
- laser
- 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.)
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- Investigating Or Analysing Materials By Optical Means (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、原子吸光分析法を
用いて溶融金属中の成分を直接且つ迅速に分析する方法
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for directly and rapidly analyzing components in a molten metal by using an atomic absorption spectrometry.
【０００２】[0002]
【従来の技術】溶融金属の直接分析は、金属の製精錬工
程の制御を迅速且つ円滑に行う手段として実用化が期待
されている。しかし、金属の製精錬工程は高温であり、
又、粉塵が多く、測定環境としては劣悪であり、溶融金
属の直接分析をこれらの測定環境に対応させるには、エ
ンジニアリング上の問題が多く、その実用化は殆どなさ
れていないのが現状である。2. Description of the Related Art Direct analysis of molten metal is expected to be put to practical use as a means for quickly and smoothly controlling a metal refining process. However, the metal refining process is hot,
In addition, there is a lot of dust and the measurement environment is inferior. To make the direct analysis of the molten metal compatible with these measurement environments, there are many engineering problems, and at present it has hardly been put to practical use. .
【０００３】従来、金属成分の迅速分析法としては、固
体試料を直接分析する発光分析法が知られており、又、
信頼性の高い分析法としては、固体試料等を酸等により
溶解し、得られた溶液試料を分析する原子吸光分析法が
知られている。Conventionally, as a rapid analysis method for a metal component, an emission analysis method for directly analyzing a solid sample has been known.
As a highly reliable analysis method, an atomic absorption analysis method in which a solid sample or the like is dissolved with an acid or the like and the obtained solution sample is analyzed is known.
【０００４】この原子吸光分析法の測定原理は、溶液試
料の蒸気層に吸光を起こす波長の光を通過させ、その通
過時に吸光される光量から蒸気層に存在する原子の量を
求めるものであり、吸光現象は下記の（１）式で表すこ
とができる。但し、（１）式において、Ａ：吸光度、
Ｉ：吸光後の光強度、Ｉ0 ：吸光前の光強度、μ：吸光
係数（波長に固有）、Ｃ：対象元素濃度、Ｌ：光の通過
する蒸気層長さである。 Ａ＝−log（Ｉ/Ｉ0 ）＝μＣＬ…（１） このように、原子吸光分析法は装置構成が簡単であり、
又、理論も単純であり、且つ、本質的に高精度分析法で
あるので、原子吸光分析法を用いた溶融金属の直接分析
方法が多数提案されている。The principle of the atomic absorption spectrometry is to allow light having a wavelength causing absorption to pass through a vapor layer of a solution sample, and to determine the amount of atoms present in the vapor layer from the amount of light absorbed at the time of passing. The light absorption phenomenon can be expressed by the following equation (1). However, in the formula (1), A: absorbance,
I: light intensity after light absorption, I 0 : light intensity before light absorption, μ: extinction coefficient (specific to wavelength), C: concentration of target element, L: length of vapor layer through which light passes. A = −log (I / I 0 ) = μCL (1) As described above, the atomic absorption analysis method has a simple device configuration,
Further, since the theory is simple and the analysis method is essentially a high-precision analysis method, many methods for directly analyzing a molten metal using an atomic absorption analysis method have been proposed.
【０００５】例えば、特表平９−５００７２５号公報に
は、溶融金属の表面に焦点を合わせて光線を照射して反
射させ、溶融金属表面のガス層で吸収される光量を測定
することで、溶融金属中の成分を測定する方法が開示さ
れている。同号公報によれば、金属浴表面の極めて小さ
い領域に光を集中させることができるので、金属浴表面
での移動の影響を実質的に排除可能であり、従って、流
動する表面を有する溶融金属についてさえ、光線を良好
に反射させ得るとしている。For example, Japanese Unexamined Patent Publication No. 9-500725 discloses that a light beam is focused on a surface of a molten metal, reflected and irradiated, and the amount of light absorbed by a gas layer on the surface of the molten metal is measured. A method for measuring a component in a molten metal is disclosed. According to the same publication, light can be concentrated on an extremely small area of the metal bath surface, so that the effect of movement on the metal bath surface can be substantially eliminated, and therefore, molten metal having a flowing surface It is said that even with regard to, light can be reflected well.
【０００６】[0006]
【発明が解決しようとする課題】溶融金属表面が静止し
た状態であれば鏡面のような挙動を示し、そこへ照射し
た光は設計上の所定の位置に反射するので、十分に強い
反射光が得られるが、溶融金属表面が揺らいで波が生じ
ている状態では、反射光が設計上の所定の位置へ戻るの
は間歇的となる。金属の製精錬工程においては溶融金属
表面で静止面を作ることは困難であり、又、底部に開口
部を有するプローブを用い、プローブを浸漬させて浴表
面の揺らぎを抑えたとしても、プローブの内面側を不活
性ガス雰囲気とするために不活性ガスをプローブ内面側
に流入させると、その影響で溶融金属表面は揺らぎ、静
止面を維持することはできない。これらの事象を考える
と、特表平９−５００７２５号公報に開示された方法で
は、流動する溶融金属での実用化は極めて困難であると
云わざるを得ない。If the surface of the molten metal is in a stationary state, it behaves like a mirror surface, and the light applied to the surface is reflected at a predetermined position in the design. However, in the state where the surface of the molten metal fluctuates and waves are generated, it is intermittent that the reflected light returns to a predetermined design position. In the metal refining process, it is difficult to form a stationary surface on the molten metal surface, and even if a probe with an opening at the bottom is used and the probe is immersed to suppress the fluctuation of the bath surface, If an inert gas is introduced into the inner surface of the probe to make the inner surface an inert gas atmosphere, the surface of the molten metal fluctuates due to the influence of the inert gas, and a stationary surface cannot be maintained. Considering these phenomena, it must be said that the method disclosed in Japanese Patent Publication No. 9-500725 is extremely difficult to put into practical use with flowing molten metal.
【０００７】本発明は上記事情に鑑みなされたもので、
その目的とするところは、溶融金属の表面が静止面とな
らない場合においても、原子吸光分析法を用いて溶融金
属中の成分を直接且つ迅速に分析する方法を提供するこ
とである。[0007] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a method for directly and quickly analyzing components in a molten metal using atomic absorption spectrometry even when the surface of the molten metal does not become a stationary surface.
【０００８】[0008]
【課題を解決するための手段】第１の発明による溶融金
属の直接分析方法は、溶融金属表面にレーザ光を照射し
てその反射光を受光し、その光路にある金属蒸気により
生じる原子吸光に基づき、対象元素の溶融金属中の濃度
を求める溶融金属の直接分析方法において、分析すべき
元素の吸収波長に調整した測定用レーザ光と、前記溶融
金属では原子吸光を生じない波長に調整した比較用レー
ザ光とを、同一光路を用いて溶融金属表面に照射して反
射させ、反射光強度を１０ミリ秒以下の周期で連続的に
測定して、各々の反射光強度から吸光度を求めることを
特徴とするものである。According to a first aspect of the present invention, there is provided a method for directly analyzing a molten metal, the method comprising: irradiating a laser beam on a surface of a molten metal to receive a reflected light thereof; Based on the method for direct analysis of molten metal to determine the concentration of the target element in the molten metal, the measurement laser light adjusted to the absorption wavelength of the element to be analyzed and a comparison adjusted to a wavelength that does not cause atomic absorption in the molten metal The laser light for irradiation is applied to the surface of the molten metal using the same optical path and reflected, and the reflected light intensity is continuously measured at a cycle of 10 ms or less, and the absorbance is determined from each reflected light intensity. It is a feature.
【０００９】第２の発明による溶融金属の直接分析方法
は、溶融金属表面にレーザ光を照射してその反射光を受
光し、その光路にある金属蒸気により生じる原子吸光に
基づき、対象元素の溶融金属中の濃度を求める溶融金属
の直接分析方法において、分析すべき元素の吸収波長に
調整した測定用レーザ光と、前記溶融金属では原子吸光
を生じない波長に調整した比較用レーザ光とを、溶融金
属表面での照射面が直径５ｍｍ以上となるようにして、
同一光路を用いて溶融金属表面に照射して反射させ、各
々の反射光強度から吸光度を求めることを特徴とするも
のである。In the method for directly analyzing a molten metal according to the second invention, the surface of the molten metal is irradiated with a laser beam to receive the reflected light, and the molten metal is melted on the basis of the atomic absorption generated by the metal vapor in the optical path. In the direct analysis method of the molten metal to determine the concentration in the metal, the measurement laser light adjusted to the absorption wavelength of the element to be analyzed, and the comparison laser light adjusted to a wavelength that does not cause atomic absorption in the molten metal, The irradiation surface on the molten metal surface has a diameter of 5 mm or more,
The method is characterized in that the molten metal surface is irradiated and reflected using the same optical path, and the absorbance is obtained from each reflected light intensity.
【００１０】溶融金属の表面においては、溶融金属から
その表面に存在する気相へ向かって、溶融金属の各成分
の蒸発現象が常に生じている。従って、この気相中に存
在する各金属元素の濃度は、温度等の他の条件が同一な
らば溶融金属での各成分の濃度と平衡関係になる。そこ
で、本発明では、レーザ光を利用して、この気相に存在
する各金属元素の濃度を原子吸光分析によって測定し、
これに基づいて溶融金属の各元素の濃度を推定する。On the surface of the molten metal, the evaporation phenomenon of each component of the molten metal always occurs from the molten metal toward the gas phase existing on the surface. Therefore, the concentration of each metal element present in the gas phase has an equilibrium relationship with the concentration of each component in the molten metal if other conditions such as temperature are the same. Therefore, in the present invention, using a laser beam, the concentration of each metal element present in the gas phase is measured by atomic absorption analysis,
Based on this, the concentration of each element of the molten metal is estimated.
【００１１】但し、溶融金属表面が揺らいで波立つ時、
その波はランダムに生じてランダムな方向に移動し、且
つ、その波面の曲率も時々刻々変化する。そのような金
属表面の或る一点にレーザ光を照射した時、その反射光
の方向もランダムとなる。そのため、照射されたレーザ
光が定常的に予め設置した受光位置に反射するというこ
とはなく、受光しない状態も生ずる。この状態における
測定は、本来の目的である吸光現象を測定しておらず、
ノイズの測定をしているだけとなる。又、溶融金属は通
常高温状態にあり、その輻射光は強く、これがノイズ信
号として測定されるため、溶融金属の表面に揺らぎがな
い状態でも溶融金属での原子吸光分析法は、溶液の原子
吸光分析法に較べてＳ／Ｎ比が悪く、これが、更に金属
浴面での揺らぎにより劣化する。However, when the surface of the molten metal fluctuates and undulates,
The waves occur randomly and move in random directions, and the curvature of the wavefront changes from moment to moment. When a certain point on such a metal surface is irradiated with laser light, the direction of the reflected light is also random. Therefore, the irradiated laser light does not constantly reflect at the light receiving position set in advance, and a state where no light is received may occur. Measurement in this state does not measure the original purpose of the light absorption phenomenon,
It just measures noise. In addition, the molten metal is usually in a high temperature state, the radiated light is strong, and this is measured as a noise signal.Therefore, even if the surface of the molten metal does not fluctuate, the atomic absorption spectrometry with the molten metal can perform the atomic absorption The S / N ratio is poor as compared with the analysis method, which is further deteriorated by fluctuations on the metal bath surface.
【００１２】従って、反射光強度を一定時間測定して、
測定時間中の単純な平均値から反射光強度を求めるので
はなく、短時間に分割して反射光強度を測定し、上記の
ような受光していない期間の測定値、又は受光効率が低
くてＳ／Ｎ比が悪い期間の測定値を除外すること等によ
り高精度の測定が可能となる。又、測定周期を短くする
ことで経時変化が明確になり、各々の測定値が受光して
いた時のデータか否かが明確になる。但し、測定周期を
短くするほど一定時間内での測定値が増加し、解析は煩
雑になるが、計算機を用いれば解析可能である。Therefore, the intensity of the reflected light is measured for a certain time,
Instead of calculating the reflected light intensity from a simple average value during the measurement time, measure the reflected light intensity by dividing it into short time periods, and the measured value during the period when light is not received as described above, or the light receiving efficiency is low. High-precision measurement is possible by excluding measured values during a period in which the S / N ratio is poor. Further, by shortening the measurement cycle, the change with time becomes clear, and it becomes clear whether or not each measured value is data when light was received. However, as the measurement period is shortened, the measured value within a certain time increases, and the analysis becomes complicated. However, the analysis can be performed by using a computer.
【００１３】或る瞬間に溶融金属表面の或る点における
傾きが、照射光を所定の受光位置に反射させる状態にな
った時、溶融金属表面の傾きが受光位置に反射光が届か
なくなるまでに変化する時間は、溶融金属の粘性と、受
光位置が反射光を受けることが可能である立体角とによ
り決まる。但し、受光位置の立体角を大きくすることは
エンジニアリング上制約が大きく、前記時間は実質的に
は溶融金属の粘性に依存する。そして、各種の溶融金属
の粘性においては金属浴表面の波面の形状を金属元素に
より変化させる程の大きな差がなく、波面の周期は何れ
の溶融金属においても１〜１００ミリ秒であることが分
かった。従って、１０ミリ秒以下の周期で反射光強度を
測定することにより、各測定値が有効なものであるか、
無駄の多いものであるか等の判断が可能となる。When the inclination of the molten metal surface at a certain point at a certain moment causes the irradiation light to be reflected to a predetermined light receiving position, the inclination of the molten metal surface until the reflected light does not reach the light receiving position is reached. The changing time is determined by the viscosity of the molten metal and the solid angle at which the light receiving position can receive the reflected light. However, increasing the solid angle of the light receiving position has a great engineering restriction, and the time substantially depends on the viscosity of the molten metal. And, in the viscosity of various molten metals, there is no large difference that changes the shape of the wavefront of the metal bath surface by the metal element, and the period of the wavefront is 1 to 100 milliseconds in any molten metal. Was. Therefore, by measuring the reflected light intensity at a period of 10 milliseconds or less, whether each measured value is valid,
It is possible to determine whether or not it is wasteful.
【００１４】以上説明したように溶融金属からの反射光
を測定する周期としては１０ミリ秒以下が適正であり、
精度の高い測定が可能となる。As described above, the period for measuring the reflected light from the molten metal is suitably 10 ms or less.
Highly accurate measurement is possible.
【００１５】又、このように反射効率が一定でないの
で、反射光強度の変化が原子吸光によるものか、揺らぎ
による反射効率の変化によるものなのかの判断ができな
くなるため、光路及び照射面を測定用レーザ光と全く同
一とすることで、反射効率の変化を測定用レーザ光と全
く同一になるようにした比較用レーザ光の反射光強度を
測定して、反射効率の変化を修正することで、測定精度
を向上させることができる。Since the reflection efficiency is not constant as described above, it is impossible to determine whether the change in the reflected light intensity is due to the atomic absorption or the change in the reflection efficiency due to fluctuations. By measuring the reflected light intensity of the comparison laser light that makes the change in the reflection efficiency exactly the same as the measurement laser light by making it exactly the same as the measurement laser light, and correcting the change in the reflection efficiency. , Measurement accuracy can be improved.
【００１６】又、上記のように揺らいでいる波面にレー
ザ光を照射した時、或る一点から離れた他の場所での波
面の傾斜は異なり、その場所からの反射光は別の方向に
向かう。即ち、反射点の数を増やすことにより、受光位
置に達する反射光が多くなり、従来技術で説明した特表
平９−５００７２５号公報のように溶融金属の表面に焦
点を合わせるのではなく、逆に、照射される部分の面積
を広くする方が受光位置に達する反射光が増加する。When the wavefront oscillating as described above is irradiated with the laser beam, the inclination of the wavefront at another place away from a certain point is different, and the reflected light from that place goes in another direction. . That is, by increasing the number of reflection points, the amount of reflected light reaching the light receiving position increases, and instead of focusing on the surface of the molten metal as disclosed in Japanese Patent Application Publication No. 9-500725 described in the related art, the reflected light is inverted. In addition, as the area of the irradiated portion is increased, the amount of reflected light reaching the light receiving position increases.
【００１７】揺らぎにより生じる溶融金属表面の波は曲
率半径が１〜２ｍｍ程度のものが多い。それらが伝播し
て金属浴表面は複雑な凹凸を生じているが、その１つの
凸部に着目すると、その凸部にレーザ光を照射した場
合、凸部内のどこか１点からの反射光を受光すると、そ
の近傍以外の凸部からの反射光は受光されない。受光量
を多くするには他の凸部又は凹部からの反射光を受光で
きるように、他の凹部及び凸部にもレーザ光を照射する
ことが必要であり、少なくとも或る１つの凸部の周囲を
取り囲み、凸部と同等の幅を含む範囲にレーザ光を照射
することで、受光量を増加させることが可能となる。Many waves on the surface of the molten metal caused by fluctuations have a radius of curvature of about 1 to 2 mm. As they propagate, the surface of the metal bath has complicated irregularities. Focusing on one of the projections, when the projection is irradiated with laser light, reflected light from some point in the projection is reflected. When the light is received, the reflected light from the convex portions other than the vicinity is not received. In order to increase the amount of received light, it is necessary to irradiate the other concave portion and the convex portion with laser light so that the reflected light from the other convex portion or the concave portion can be received. By irradiating the laser light to the area surrounding the periphery and including the width equivalent to the convex part, the amount of received light can be increased.
【００１８】凸部の代表的な大きさが１〜２ｍｍの幅で
あるため、凸部の周囲を取り囲み、凸部と同等の幅を含
む範囲に照射するためには、照射面を直径５ｍｍ以上と
すれば良く、このようにすることで、測定精度を上げる
ことができる。尚、このように照射面を広げて測定する
ことにより反射頻度が増大するため、先に述べた１０ミ
リ秒以下の周期での測定により更に測定精度は良好とな
るが、このような短周期測定を行わなくても実用的には
十分な測定精度を得られる。Since the typical size of the projection is a width of 1 to 2 mm, in order to surround the circumference of the projection and irradiate the area including the width equivalent to the projection, the irradiation surface must have a diameter of 5 mm or more. By doing so, the measurement accuracy can be improved. In addition, since the reflection frequency is increased by performing the measurement by expanding the irradiation surface in this manner, the measurement accuracy is further improved by the above-described measurement at a cycle of 10 milliseconds or less. In practice, sufficient measurement accuracy can be obtained without performing the above.
【００１９】[0019]
【発明の実施の形態】以下、本発明の実施の形態を添付
図面を参照して説明する。図１は本発明を実施した分析
装置の概要図である。Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of an analysis device embodying the present invention.
【００２０】図１に示すように、分析装置は、原子吸光
を生じさせる波長のレーザ光を発振するための測定用レ
ーザ光源１と、どの元素についても原子吸光しない波長
のレーザ光を発振するための比較用レーザ光源２と、測
定用レーザ光源１及び比較用レーザ光源２からのレーザ
光を集光して同一光路とするための集光光学系３と、集
光光学系３で集光したレーザ光を、溶融金属５表面へ照
射するための照射光学系４と、照射されたレーザ光の、
溶融金属５表面からの反射光を受光するための受光光学
系６と、受光光学系６で受光したレーザ光を分光し、分
光したレーザ光の強度を測定するための分光測定部７
と、分光測定部７で測定したレーザ光の強度からレーザ
光が途中通過する溶融金属５の表面近傍の気相、即ち蒸
気層９における測定対象元素の濃度を求め、更に溶融金
属５中の測定対象元素の濃度を求め、これらの測定値を
記憶する計算機８と、を備えている。As shown in FIG. 1, the analyzer comprises a measuring laser light source 1 for oscillating a laser beam having a wavelength causing atomic absorption and a laser beam having a wavelength which does not cause atomic absorption for any element. , A condensing optical system 3 for condensing the laser beams from the measuring laser light source 1 and the comparing laser light source 2 into the same optical path, and condensing by the condensing optical system 3. An irradiation optical system 4 for irradiating the surface of the molten metal 5 with a laser beam;
A light receiving optical system 6 for receiving light reflected from the surface of the molten metal 5, and a spectrum measuring unit 7 for separating the laser light received by the light receiving optical system 6 and measuring the intensity of the split laser light.
From the intensity of the laser beam measured by the spectrometer 7, the concentration of the element to be measured in the gas phase near the surface of the molten metal 5 through which the laser beam passes, ie, the vapor layer 9, is determined. A calculator 8 for determining the concentration of the target element and storing these measured values.
【００２１】ここで、照射光学系４は、溶融金属５表面
へのレーザ照射面が直径５ｍｍ以上となるように調整し
て照射する機能を有しており、又、分光測定部７は、分
光したレーザ光の強度を１０ミリ秒以下の指定時間の周
期で測定する機能を有しており、本実施の形態では、溶
融金属５表面への照射面は直径５ｍｍ以上とし、又、分
光したレーザ光の強度を１０ミリ秒以下の指定時間の周
期で測定することとする。Here, the irradiation optical system 4 has a function of adjusting and irradiating the surface of the molten metal 5 with a laser so that the laser irradiation surface has a diameter of 5 mm or more. Has a function of measuring the intensity of the laser beam at a specified time period of 10 milliseconds or less. In the present embodiment, the irradiation surface on the surface of the molten metal 5 has a diameter of 5 mm or more. The light intensity is measured at a specified time period of 10 milliseconds or less.
【００２２】その際に、溶融金属５表面へのレーザ照射
面は、反射点が増えて反射光が測定される時間が増える
ので、レーザ光の照度が許す限り広くすることが好まし
い。又、照射光学系４及び受光光学系６は、プリズムや
反射鏡及びレンズ等を使用して光路を形成することもで
きるが、光ファイバを用いると機器の構成が簡単になる
ので好ましい。更に、光ファイバで構成した場合には、
照射光学系４の溶融金属５側の先端部、及び受光光学系
６の溶融金属５側の先端部を１つにまとめ、プローブ
（図示せず）としても良い。At that time, the laser irradiation surface on the surface of the molten metal 5 has a larger number of reflection points and a longer time for measuring the reflected light. Therefore, it is preferable to make the surface as wide as the illuminance of the laser light permits. Further, the irradiation optical system 4 and the light receiving optical system 6 can form an optical path using a prism, a reflecting mirror, a lens, or the like, but the use of an optical fiber is preferable because the configuration of the device is simplified. Furthermore, when the optical fiber is configured,
The tip of the irradiation optical system 4 on the side of the molten metal 5 and the tip of the light receiving optical system 6 on the side of the molten metal 5 may be combined into a single probe (not shown).
【００２３】原子吸光分析において、分析すべき元素が
単原子の蒸気の状態でない場合には吸光現象は生じな
い。従って、分析すべき元素が反応して化合物となるの
を防ぐために、少なくともレーザ光を照射する範囲は不
活性ガス雰囲気とする必要がある。この場合、溶融金属
５の表面全体を不活性ガス雰囲気としても良く、又、プ
ローブ等を用いる場合には、プローブから不活性ガスを
吹き込み、測定範囲のみを不活性ガス雰囲気としても良
い。In the atomic absorption analysis, if the element to be analyzed is not in the state of a monatomic vapor, no light absorption phenomenon occurs. Therefore, in order to prevent the element to be analyzed from reacting to form a compound, it is necessary that at least the laser beam irradiation range be an inert gas atmosphere. In this case, the entire surface of the molten metal 5 may be in an inert gas atmosphere. When a probe or the like is used, an inert gas may be blown from the probe and only the measurement range may be in an inert gas atmosphere.
【００２４】蒸気層９における測定元素の濃度を算出す
る際の、比較用レーザ光による修正は、例えば、以下の
ようにして行うことができる。但し、測定用レーザ光の
吸光度をＡ、吸光前の光強度即ち照射光強度をＩ0 、吸
光後の光強度即ち反射光強度をＩとし、又、比較用レー
ザ光の吸光前の光強度即ち照射光強度をＩH0、吸光後の
光強度即ち反射光強度をＩH とする。The correction by the comparative laser beam when calculating the concentration of the measurement element in the vapor layer 9 can be performed, for example, as follows. However, the absorbance of the measurement laser light is A, the light intensity before absorption, ie, the irradiation light intensity is I 0 , the light intensity after absorption, ie, the reflected light intensity is I, and the light intensity of the comparison laser light before absorption, ie, The irradiation light intensity is defined as I H0 , and the light intensity after absorption, that is, the reflected light intensity is defined as I H.
【００２５】この場合、比較用レーザ光で修正しない場
合の測定用レーザ光の吸光度（Ａ）は前述した（１）式
で表され、反射光強度（Ｉ）と照射光強度（Ｉ0 ）との
比（Ｉ／Ｉ0 ）は溶融金属表面の揺らぎにより大きく変
化する。即ち（１）式により対象元素濃度（Ｃ）を求め
ると、対象元素濃度（Ｃ）の誤差が大きくなる。In this case, the absorbance (A) of the measuring laser light, which is not corrected by the comparative laser light, is expressed by the above-mentioned equation (1), and the reflected light intensity (I) and the irradiation light intensity (I 0 ) (I / I 0 ) greatly changes due to fluctuations in the surface of the molten metal. That is, when the target element concentration (C) is obtained by the equation (1), the error of the target element concentration (C) increases.
【００２６】しかし、溶融金属表面の揺らぎによる反射
光の減少程度は、比較用レーザ光も測定用レーザ光と同
一であるので、比較用レーザ光の反射光強度（ＩH ）と
照射光強度（ＩH0）との比（ＩH ／ＩH0）も減少する。
比較用レーザ光は元素には吸光されない波長を有してい
るので、比（ＩH ／ＩH0）は溶融金属表面の揺らぎに起
因していることになる。However, the degree of reduction of the reflected light due to the fluctuation of the surface of the molten metal is the same as that of the measuring laser light for the comparative laser light, so that the reflected light intensity (I H ) of the comparative laser light and the irradiation light intensity (I H ) I H0 ) (I H / I H0 ) also decreases.
Since the comparison laser beam has a wavelength that is not absorbed by the element, the ratio (I H / I H0 ) is due to the fluctuation of the molten metal surface.
【００２７】そこで、比（Ｉ／Ｉ0 ）を比（ＩH ／
ＩH0）で除算すれば、測定用レーザ光が蒸気層９を通過
した際の原子吸光量を正確に把握することができる。即
ち、下記の（２）式により測定用レーザ光の吸光度
（Ａ）を修正することで、蒸気層９における測定対象元
素の濃度を測定することができる。尚、（２）式におけ
るμ、Ｃ、Ｌは前述の（１）式と同一である。 Ａ=−log［（Ｉ/Ｉ0）/（ＩH/ＩH0）］=μＣＬ…（２） 又、（２）式を用いて修正したとしても、比（ＩH ／Ｉ
H0）が小さい場合の測定値は、反射光が少なく、本来信
頼性に欠ける。そこで、測定した反射光強度の全てを用
いて対象元素濃度（Ｃ）を求めるのではなく、溶融金属
表面の揺らぎによる影響が少ない時期、即ち、比（ＩH
／ＩH0）が高い時期に測定した反射光強度から対象元素
濃度（Ｃ）を算出することが好ましい。具体的には、例
えば比（ＩH ／ＩH0）が０．１以上若しくは０．２以上
等の測定時期に測定した反射光強度、又は、比（ＩH ／
ＩH0）を高い順に並べて上位の４０％若しくは３０％等
の時期に測定した反射光強度に基づき算出する等の方法
がある。Therefore, the ratio (I / I 0 ) is changed to the ratio (I H /
By dividing by I H0 ), the amount of atomic absorption when the measurement laser beam passes through the vapor layer 9 can be accurately grasped. That is, the concentration of the element to be measured in the vapor layer 9 can be measured by correcting the absorbance (A) of the measurement laser beam according to the following equation (2). Note that μ, C, and L in Expression (2) are the same as those in Expression (1). A = −log [(I / I 0 ) / (I H / I H0 )] = μCL (2) Further, even if the ratio is corrected by using the expression (2), the ratio (I H / I
The measured value when H0 ) is small has little reflected light and is inherently unreliable. Therefore, the target element concentration (C) is not obtained by using all of the measured reflected light intensities, but the time when the influence of the fluctuation of the molten metal surface is small, that is, the ratio (I H)
It is preferable to calculate the target element concentration (C) from the reflected light intensity measured at the time when (/ I H0 ) is high. Specifically, for example, the ratio (I H / I H0) the reflected light intensity measured in the measurement period, such as 0.1 or more or 0.2 or more, or the ratio (I H /
I H0 ) are arranged in descending order, and are calculated based on the reflected light intensity measured at the time of the upper 40% or 30%.
【００２８】このようにして溶融金属５を直接分析する
ことで、溶融金属５の表面が静止面とならない場合にお
いても、正確且つ迅速に溶融金属の成分を分析すること
ができる。By directly analyzing the molten metal 5 in this manner, the components of the molten metal 5 can be accurately and quickly analyzed even when the surface of the molten metal 5 does not become a stationary surface.
【００２９】尚、上記説明では、レーザ光線の溶融金属
５表面への照射面を５ｍｍ以上とし、且つ、分光したレ
ーザ光強度を１０ミリ秒以下の指定時間の周期で測定す
るとしたが、本発明では両者を同時に行う必要はなく、
どちらか一方を適用することが可能であり、一方のみの
適用であってもその効果を発揮させることができる。In the above description, the irradiation surface of the laser beam on the surface of the molten metal 5 is set to 5 mm or more, and the intensity of the separated laser light is measured at a period of a specified time of 10 ms or less. Then it is not necessary to do both at the same time,
Either one can be applied, and even if only one is applied, the effect can be exhibited.
【００３０】[0030]
【実施例】高周波溶解炉にて炭素質坩堝中で溶鋼５ｋｇ
を溶解し、溶鋼中にＭｎを０〜１．５ｗｔ％相当量添加
し、溶鋼温度を１６００℃として、本発明による溶鋼中
Ｍｎの直接分析方法を実施した。[Example] 5 kg of molten steel in a carbonaceous crucible in a high-frequency melting furnace
Was melted, Mn was added to the molten steel in an amount equivalent to 0 to 1.5 wt%, and the temperature of the molten steel was set to 1600 ° C., and the direct analysis method of Mn in the molten steel according to the present invention was performed.
【００３１】測定用レーザ光としては、ＹＡＧレーザの
第２高調波の発振光（０．５３ｎｍ）によりサファイア
レーザ光を励起して波長連続レーザ光とし、この波長連
続レーザ光の第２高調波について波長を調整して発振さ
せるシステムから発振される波長可変レーザ光を使用
し、その発振波長をＭｎの原子吸光波長中心である４０
３．３０７ｎｍから若干ずらした、４０３．３１７ｎｍ
に調整した。このレーザ光の出力は１０ｍＶである。
又、比較用レーザ光としては、青色半導体レーザ光の発
振波長４３０．０ｎｍのものを使用した。As the measuring laser light, the sapphire laser light is excited by the second harmonic oscillation light (0.53 nm) of the YAG laser to produce continuous wavelength laser light. A wavelength tunable laser beam oscillated from a system that oscillates by adjusting the wavelength is used, and the oscillation wavelength is set to the atomic absorption wavelength center of Mn of 40 nm.
403.317 nm, slightly shifted from 3.307 nm
Was adjusted. The output of this laser light is 10 mV.
As the comparative laser light, a blue semiconductor laser light having an oscillation wavelength of 430.0 nm was used.
【００３２】上記２種のレーザ光源を９０度となる位置
関係に置き、４５度入射光について４０３ｎｍは反射
し、４３０ｎｍは透過する光学フィルタを両レーザ光の
交差点に置き、４０３ｎｍのレーザ光と４３０ｎｍレー
ザ光とが同一光路となる状況を作り、それらの光をレン
ズで集光して０．３ｍｍ直径の光ファイバに入射した。
光ファイバの反対側端面はプローブのコネクタで固定
し、プローブにレンズの位置を微調整する機構を取り付
け、プローブを溶鋼面直上に設置してレンズと光ファイ
バ端面との距離を調整して溶鋼面での照射面の広さを調
整した。照射面は１５ｍｍ直径及び２ｍｍ直径の２水準
とした。又測定時、プローブ内にＮ2 ガスを流して空気
の混入による酸化を防止した。The above two laser light sources are placed in a positional relationship of 90 degrees, and an optical filter that reflects 403 nm and transmits 430 nm for the 45-degree incident light is placed at the intersection of the two laser lights. A situation was created in which the laser light and the laser light had the same optical path, and the light was condensed by a lens and incident on an optical fiber having a diameter of 0.3 mm.
The opposite end face of the optical fiber is fixed with a probe connector, a mechanism for finely adjusting the position of the lens is attached to the probe, and the probe is placed directly above the molten steel surface to adjust the distance between the lens and the end face of the optical fiber and the molten steel surface The width of the irradiation surface was adjusted. The irradiation surface had two levels of 15 mm diameter and 2 mm diameter. At the time of measurement, N 2 gas was flown into the probe to prevent oxidation due to air mixing.
【００３３】受光光学系は光ファイバのみとし、分光測
定部ではフィルタを用いて分光した。即ち、プローブ内
に１ｍｍ直径の受光用光ファイバを取り付けて溶鋼面か
らの反射光を受光し、光ファイバの他端から出た光をレ
ンズにより平行光として、４５度入射光について４０３
ｎｍは反射し、４３０ｎｍは透過する光学フィルタによ
り各々のレーザ光を分光し、光電子増倍管（ホトマル）
に導き、その強度を２ミリ秒単位で測定した。測定は２
秒間行い１０００データ収集した。The light receiving optical system was an optical fiber only, and the spectroscopic measurement section separated light using a filter. That is, a light receiving optical fiber having a diameter of 1 mm is mounted in the probe to receive light reflected from the molten steel surface, and light emitted from the other end of the optical fiber is converted into parallel light by a lens.
Each laser beam is separated by an optical filter that reflects nm and transmits 430 nm, and a photomultiplier tube (Photomaru)
And the intensity was measured in units of 2 milliseconds. Measurement is 2
Performed for a second and collected 1000 data.
【００３４】測定した１０００データのうち、比較用レ
ーザ光の反射光強度の高い時期、即ち、比（ＩH ／
ＩH0）が高い順に並べて上位から４０％の時期に測定し
たデータを有効データとみなし、上記（２）式により吸
光度（Ａ）を定めた。Of the 1000 data measured, the period when the reflected light intensity of the comparative laser beam is high, that is, the ratio (I H /
The data measured in the order of I H0 ) in descending order of 40% from the top was regarded as effective data, and the absorbance (A) was determined by the above equation (2).
【００３５】照射面が１５ｍｍ直径の時の反射光強度の
測定結果を図２に示し、照射面が２ｍｍ直径の時の反射
光強度の測定結果を図３に示す。これらの図から明らか
なように、照射面が２ｍｍ直径の場合には、反射光を受
けた時には反射光強度が強くなり、受光感度を下げる必
要があったが、反射光を受ける頻度に差があり、測定時
間に無駄が多いことが確認された。一方、照射面が１５
ｍｍ直径の場合には、測定期間の全域に渡って反射光が
得られ、測定精度がより一層高くなった。FIG. 2 shows the measurement results of the reflected light intensity when the irradiation surface has a diameter of 15 mm, and FIG. 3 shows the measurement results of the reflection light intensity when the irradiation surface has a diameter of 2 mm. As is clear from these figures, when the irradiation surface has a diameter of 2 mm, the intensity of the reflected light increases when receiving the reflected light, and it is necessary to reduce the light receiving sensitivity. It was confirmed that there was much waste in the measurement time. On the other hand, the irradiation surface is 15
In the case of the mm diameter, reflected light was obtained over the entire area of the measurement period, and the measurement accuracy was further improved.
【００３６】図４は、照射面が１５ｍｍ直径の時に測定
された吸光度（Ａ）と溶鋼中Ｍｎ濃度との関係を示す図
である。図４に示すように、吸光度（Ａ）と溶鋼中Ｍｎ
濃度との相関は高く、正確に分析できることが分かっ
た。FIG. 4 is a diagram showing the relationship between the absorbance (A) measured when the irradiation surface has a diameter of 15 mm and the Mn concentration in molten steel. As shown in FIG. 4, absorbance (A) and Mn in molten steel
It was found that the correlation with the concentration was high and the analysis could be performed accurately.
【００３７】[0037]
【発明の効果】本発明によれば、溶融金属の表面が静止
面とならない場合においても、正確且つ迅速に溶融金属
の成分を分析することが可能となり、その結果、金属の
製精錬工程をより理想的に行えるようになり、品質向上
や省エネルギー等に大きく貢献し、工業上有益な効果が
もたらされる。According to the present invention, even if the surface of the molten metal does not become a stationary surface, it is possible to analyze the components of the molten metal accurately and quickly, and as a result, the refining process of the metal can be further improved. It can be ideally performed, greatly contributes to quality improvement, energy saving, etc., and brings about industrially beneficial effects.
【図１】本発明を実施した分析装置の概要図である。FIG. 1 is a schematic diagram of an analysis device embodying the present invention.
【図２】照射面が１５ｍｍ直径の時の実施例における反
射光強度の測定結果を示す図である。FIG. 2 is a diagram showing a measurement result of a reflected light intensity in an example when an irradiation surface has a diameter of 15 mm.
【図３】照射面が２ｍｍ直径の時の実施例における反射
光強度の測定結果を示す図である。FIG. 3 is a diagram showing measurement results of reflected light intensity in an example when the irradiation surface has a diameter of 2 mm.
【図４】実施例における吸光度と溶鋼中Ｍｎ濃度との関
係を示す図である。FIG. 4 is a diagram showing a relationship between absorbance and Mn concentration in molten steel in Examples.
１ 測定用レーザ光源 ２ 比較用レーザ光源 ３ 集光光学系 ４ 照射光学系 ５ 溶融金属 ６ 受光光学系 ７ 分光測定部 ８ 計算機 ９ 蒸気層 Reference Signs List 1 laser light source for measurement 2 laser light source for comparison 3 focusing optical system 4 irradiation optical system 5 molten metal 6 light receiving optical system 7 spectroscopic measurement unit 8 computer 9 vapor layer
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高岡 利夫 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 菊地 良輝 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 千野 淳 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 杉本 和巨 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 秋吉 孝則 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 Ｆターム(参考） 2G055 AA27 BA20 CA01 DA02 EA05 FA02 2G059 AA01 BB20 CC02 EE02 FF08 GG01 GG03 HH02 HH03 HH06 JJ02 JJ11 JJ12 JJ13 JJ17 KK02 MM01 MM10 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshio Takaoka 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Yoshiki Kikuchi 1-2-1-2 Marunouchi, Chiyoda-ku, Tokyo Sun Inside the Kokan Co., Ltd. (72) Atsushi Chino, Inventor 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Japan Inside Kobe Steel Pipe Co., Ltd. (72) Kazuo Sugimoto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Inside Kokan Co., Ltd. (72) Inventor Takanori Akiyoshi 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Japan Kokan Co., Ltd. F-term (reference) 2G055 AA27 BA20 CA01 DA02 EA05 FA02 2G059 AA01 BB20 CC02 EE02 FF08 GG01 GG03 HH02 HH03 HH06 JJ02 JJ11 JJ12 JJ13 JJ17 KK02 MM01 MM10
Claims (2)
反射光を受光し、その光路にある金属蒸気により生じる
原子吸光に基づき、対象元素の溶融金属中の濃度を求め
る溶融金属の直接分析方法において、分析すべき元素の
吸収波長に調整した測定用レーザ光と、前記溶融金属で
は原子吸光を生じない波長に調整した比較用レーザ光と
を、同一光路を用いて溶融金属表面に照射して反射さ
せ、反射光強度を１０ミリ秒以下の周期で連続的に測定
して、各々の反射光強度から吸光度を求めることを特徴
とする溶融金属の直接分析方法。1. A direct analysis of a molten metal in which the surface of the molten metal is irradiated with a laser beam to receive the reflected light, and the concentration of the target element in the molten metal is determined based on the atomic absorption generated by the metal vapor in the optical path. In the method, the measurement laser light adjusted to the absorption wavelength of the element to be analyzed and the comparison laser light adjusted to a wavelength that does not cause atomic absorption in the molten metal are irradiated to the molten metal surface using the same optical path. A method for direct analysis of molten metal, characterized in that reflected light intensity is continuously measured at a cycle of 10 milliseconds or less, and absorbance is determined from each reflected light intensity.
反射光を受光し、その光路にある金属蒸気により生じる
原子吸光に基づき、対象元素の溶融金属中の濃度を求め
る溶融金属の直接分析方法において、分析すべき元素の
吸収波長に調整した測定用レーザ光と、前記溶融金属で
は原子吸光を生じない波長に調整した比較用レーザ光と
を、溶融金属表面での照射面が直径５ｍｍ以上となるよ
うにして、同一光路を用いて溶融金属表面に照射して反
射させ、各々の反射光強度から吸光度を求めることを特
徴とする溶融金属の直接分析方法。2. A direct analysis of a molten metal in which the surface of the molten metal is irradiated with a laser beam to receive the reflected light, and the concentration of the target element in the molten metal is determined based on the atomic absorption generated by the metal vapor in the optical path. In the method, a laser beam for measurement adjusted to an absorption wavelength of an element to be analyzed and a comparative laser beam adjusted to a wavelength that does not cause atomic absorption in the molten metal are irradiated with a laser beam having a diameter of 5 mm or more on the surface of the molten metal. A method for direct analysis of a molten metal, comprising irradiating the surface of the molten metal with the same optical path to reflect the light, and obtaining the absorbance from the intensity of each reflected light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000042097A JP2001228083A (en) | 2000-02-21 | 2000-02-21 | Method for directly analyzing molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000042097A JP2001228083A (en) | 2000-02-21 | 2000-02-21 | Method for directly analyzing molten metal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001228083A true JP2001228083A (en) | 2001-08-24 |
Family
ID=18565214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000042097A Pending JP2001228083A (en) | 2000-02-21 | 2000-02-21 | Method for directly analyzing molten metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001228083A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012013573A (en) * | 2010-07-01 | 2012-01-19 | Ibaraki Univ | Ozone concentration meter and ozone concentration monitoring kit with the ozone concentration meter |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5188291A (en) * | 1974-12-19 | 1976-08-02 | ||
| JPH0224367U (en) * | 1988-07-30 | 1990-02-19 | ||
| JPH09500725A (en) * | 1993-07-26 | 1997-01-21 | エルケム・アクシエセルスカプ | Direct chemical analysis of molten metal |
| JPH0949795A (en) * | 1995-08-09 | 1997-02-18 | Nkk Corp | Method and device for directly analyzing molten metal |
| JPH10213541A (en) * | 1997-01-28 | 1998-08-11 | Asahi Eng Co Ltd | Oil film detector |
| JPH10260137A (en) * | 1997-03-19 | 1998-09-29 | Kawasaki Steel Corp | Method and apparatus for detection of ripple on molten metal bath face |
| JPH11108829A (en) * | 1997-09-30 | 1999-04-23 | Nkk Corp | Method and device for online analysis of molten metal |
-
2000
- 2000-02-21 JP JP2000042097A patent/JP2001228083A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5188291A (en) * | 1974-12-19 | 1976-08-02 | ||
| JPH0224367U (en) * | 1988-07-30 | 1990-02-19 | ||
| JPH09500725A (en) * | 1993-07-26 | 1997-01-21 | エルケム・アクシエセルスカプ | Direct chemical analysis of molten metal |
| JPH0949795A (en) * | 1995-08-09 | 1997-02-18 | Nkk Corp | Method and device for directly analyzing molten metal |
| JPH10213541A (en) * | 1997-01-28 | 1998-08-11 | Asahi Eng Co Ltd | Oil film detector |
| JPH10260137A (en) * | 1997-03-19 | 1998-09-29 | Kawasaki Steel Corp | Method and apparatus for detection of ripple on molten metal bath face |
| JPH11108829A (en) * | 1997-09-30 | 1999-04-23 | Nkk Corp | Method and device for online analysis of molten metal |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012013573A (en) * | 2010-07-01 | 2012-01-19 | Ibaraki Univ | Ozone concentration meter and ozone concentration monitoring kit with the ozone concentration meter |
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