JPH11237350A - Method and apparatus for analysis of slug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method and an apparatus by which the composition of a slug generated inside a refining furnace in the refining process of especially ion and steel can be analyzed quickly and with high accuracy, by sampling a molten slug sample from the refining furnace, and holding the molten slug sample in a molten state so as to be subjected to an X-ray fluorescence analysis, an emission spectral analysis or an atomic absorption analysis. SOLUTION: When a molten slug of iron and steel is subjected to an X-ray fluorescence analysis, a sample mounting part 20 is removed from an X-ray fluorescence analyzer body 10, and the molten slug is sampled by a slug sampler so as to be injected into the recessed part 31 of a tungsten plate 32. At this time, an electrification chuck 32 is electrified, and the tungsten plate is heated due to its resistance. While the slug is being maintained in a molten state, the sample mounting part 20 is moved to the lower part of the analyzer body 10. Then, the sample mounting part 20 is decompressed. When it becomes the same vacuum as the inside of the analyzer body 10, a shutter 17 is opened, X-rays are radiated to a sample S from an X-ray tube 13, and fluorescent X-rays which are generated from the sample S are spectrally diffracted by an X-ray spectroscope 14 so as to be detected by a detector 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for analyzing slag generated in the course of refining metal, and more particularly to a method and an apparatus for analyzing slag which can analyze slag generated during refining of steel very quickly and accurately. It relates to an analyzer.

[0002]

2. Description of the Prior Art Controlling slag generated during a metal refining process has a significant effect on the composition of the metal to be refined, and its control is an important issue, and therefore, slag is analyzed through the refining process. In analyzing the slag, a glass bead fluorescent X-ray analysis method is generally used because multiple elements are simultaneously analyzed with high accuracy. In this method, a homogenous glassy sample is prepared by melting a pulverized slag using a flux about 10 times that of a slag, and a fluorescent X-ray analysis is performed on the sample. Since it is in a state and is diluted with a flux, it is characterized by a small effect of coexisting elements and high analysis accuracy.However, it is at least necessary to grind, weigh, and melt slag for sample preparation. There is a problem that it takes 30 minutes and cannot be used for controlling a process in which the refining process is completed in a short time such as steel refining.

[0003] In order to solve this problem, a briquette method, that is, a method in which slag is pulverized and then formed and then subjected to X-ray fluorescence analysis, has been proposed. Although there is an advantage that the analysis time is shortened because the operation is omitted, it is still possible to reduce the analysis time.
It is difficult to reduce to less than a minute.

Japanese Patent Application Laid-Open No. 54-153694 discloses that a blast furnace slag having a surface roughness of 25 μm or less and a surface temperature of 600 to 700 ° C. is immersed in a blast furnace slag flowing through a gutter. There is disclosed a method in which the slag is solidified, pulled up, impacted and separated, and the separated slag pieces are directly subjected to fluorescent X-ray analysis. Further, Japanese Patent Application Laid-Open No.
No. 89 discloses a method in which a metal plate having a smooth surface is immersed in molten slag to solidify the slag, and the obtained smooth surface is directly subjected to X-ray fluorescence analysis. Since these methods directly analyze the slag in a solidified state, the analysis time can be considerably shortened.

[0005]

However, even in these methods, it takes several minutes to adjust a high-temperature slag sample into an analysis sample, and it is necessary to use the above-described refining reaction performed in a short time. Not enough. Furthermore, in converter refining of steel, for example, molten steel and slag in a furnace are vigorously stirred by blowing oxygen, gas bubbling, etc., and molten steel is mixed in slag collected from the furnace. There are many. When analysis is performed using a slag sample containing such molten steel, the fluorescence X of Fe
Analysis errors also occur due to the excitation of each component in the slag by the line. Furthermore, in the X-ray fluorescence analysis, the area actually analyzed is only about 10 μm in the surface layer due to problems such as the penetration depth of the X-rays and absorption of the X-ray fluorescence by the matrix. Therefore, in the process of cooling the slag, the portion in contact with the atmosphere or the steel sheet often changes to a composition different from the slag composition in the furnace.

[0006] Such a problem is not limited to the above-mentioned X-ray fluorescence analysis, but is a common problem when slag is rapidly analyzed.
Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and a method and an apparatus for quickly and accurately analyzing a slag composition generated in a smelting furnace in a metal refining process, particularly in a steel refining process. The purpose is to provide.

[0007]

In order to solve the above-mentioned problems, the present invention provides a method for analyzing slag, which comprises extracting a molten slag sample from a refining furnace, and holding the molten slag sample in a molten state by X-ray fluorescence. Analysis, emission spectroscopy or
It is to be subjected to atomic absorption analysis.

A slag analyzer for carrying out the above method comprises an analyzer body for performing X-ray fluorescence analysis, emission spectroscopy analysis or atomic absorption analysis, and a sample mounting portion. The sample mounting portion is configured to be attachable / detachable via a window and a shutter, and the sample mounting portion has a mechanism for mounting to the analyzer main body and an exhaust port connected to a vacuum system. It is assumed that the housing is provided with a molten slag sample heating means and a slag melting and holding mechanism having a slag holding portion is housed in the housing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail by taking X-ray fluorescence analysis as an example. FIG. 1 is a sectional view showing an example of an apparatus for performing X-ray fluorescence analysis of molten slag according to the present invention. As shown here, the X-ray fluorescence analyzer according to the present invention comprises a main body 10 of the X-ray fluorescence analyzer that performs X-ray fluorescence analysis.
And a sample mounting section 20 for setting the molten slag sample in the above-mentioned analyzer in a molten state, and the sample mounting section 20 is detachable from the main body 10.

The main body 10 includes an X-ray tube 13, an X-ray spectral crystal 14, and a detector 1 in a housing 11 having an exhaust port 12 connected to a vacuum system, similarly to a normal X-ray fluorescence analyzer.
5 is provided. In addition, the main body includes a window 16 made of, for example, a Mylar film or the like at the bottom thereof,
The X-ray emitted from the X-ray tube and the fluorescent X-rays generated from the sample S pass through the main body 1 while passing through the gas generated from the sample S.
0 to prevent contamination of the inside of the apparatus. Further, the inside of the X-ray fluorescence analyzer main body 10 is always kept at a vacuum even when a shutter 17 is provided at the lower part of the main body and the sample mounting part 20 is removed or the inside of the main body is not exhausted yet. Is available. Although not shown, a connecting means for integrally fixing the sample mounting portion 20 is provided below the main body 10.

On the other hand, like the X-ray fluorescence analyzer main body 10, the sample mounting section 20 has an exhaust port 2 connected to a vacuum system.
2 and a window 23 at the top.
Further, the slag melting and holding mechanism 3
0, so that the molten slag pumped from a refining furnace or the like can be maintained in a molten state.

As shown in FIG. 2, the slag melting and holding mechanism 30 has a structure in which a recess is provided in a part of a tungsten plate 32 so that slag S can be accommodated therein. (Not shown), and the resistance is applied to the tungsten plate 32 by passing an electric current, so that the temperature required to keep the slag S in a molten state is maintained.

When the molten slag is directly subjected to the fluorescent X-ray analysis according to the present invention, the sample mounting section 20 is detached from the main body 10 of the fluorescent X-ray analyzer, moved to a position before the refining furnace, and a slag sampler such as a ladle is used. A molten slag is collected (not shown) and injected into the recess 31 of the tungsten plate 32. At this time, the tungsten plate is resistance-heated by supplying a current to a power supply chuck 33 that supports the tungsten plate 32, and the sample mounting part 20 is connected to the fluorescent X-ray analyzer main body 10 while maintaining the slag in a molten state.
To move down.

While the slag holding mechanism 30 is being removed for receiving the molten slag, the shutter 17 is closed and the inside of the X-ray fluorescence analyzer 10 is kept at a vacuum. After moving to the lower part of the main body, the sample mounting part 20 is fixed integrally with the main body 10 by connecting means provided at the lower part of the main body, for example, a lifter 34 and an O-ring 35, and operates a vacuum system connected to the exhaust hole 22 to exhaust air. Then, the inside of the sample mounting portion 20 including the slag melting and holding mechanism 30 is decompressed. When the inside of the sample mounting portion 20 has the same degree of vacuum as the inside of the X-ray fluorescence analyzer main body 10, the shutter 17 is opened, and the X-ray tube 13 A line is emitted to the sample S, and fluorescent X-rays generated from the sample are separated by an X-ray spectroscope 14 and detected by a detector 15.

[0015]

EXAMPLES Table 1 shows the results of analyzing the composition of slag generated in a furnace in a vacuum decarburization furnace using the present invention. Table 1 also shows, as a conventional method, a case where a slag was pulverized to form a glass bead and subjected to fluorescent X-ray analysis for comparison. As is clear from Table 1, the analysis results according to the present invention are in good agreement with the conventional method. In addition, the time from the sampling to the end of the analysis was 2 minutes in total.

[0016]

[Table 1]

After analyzing the molten slag sample according to the present invention, the slag is cooled, and the longitudinal section is analyzed by EPMA. As a result, the distribution of Fe is shown below (bottom) of the slag sample S as schematically shown in FIG. ). This indicates that the Fe component (molten steel) settles at the bottom of the sample during the analysis process due to the difference in specific gravity, and indicates that the slag can be analyzed without the molten steel. Since the area analyzed by the fluorescent X-ray analysis is at most within several tens of μm, it was confirmed that the slag analysis can be performed according to the present invention without being affected by the molten steel dispersed in the sample at all. did it.

In this embodiment, the ladle is used for sampling the slag. However, the present invention is not limited to this, and the heating means for melting the slag is an electric heating method. However, the present invention is not limited to this. A resistance heating method, an infrared irradiation heating method, or the like can also be used. Although the X-ray fluorescence analyzer was used as the analyzer, the present invention is not limited to this. For example, a laser emission spectrometer may be used.

[0019]

As described above, according to the present invention, since the slag in the refining process of the metal is subjected to the analysis in the molten state as described above, the composition can be analyzed very quickly and accurately. became. As a result, the results of the slag analysis can be used for controlling processes in which the refining process is completed in a very short time, such as converter refining of steel and vacuum decarburization refining, and the accuracy of the refining process has been further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an apparatus for implementing the present invention.

FIG. 2 shows a slag melting and holding mechanism used in the present invention.
It is a perspective view of an example.

FIG. 3 is a distribution diagram of Fe in a sample after analysis according to the present invention.

[Explanation of symbols]

 10: X-ray fluorescence analyzer main body 11: Housing 12: Exhaust port 13: X-ray tube 14: X-ray spectral crystal 15: Detector 16: Window 17: Shutter 20: Sample mounting part 21: Housing 22: Exhaust Mouth 23: Window 30: Slag melting and holding mechanism 31: Recess 32: Tungsten plate 33: Electric chuck 34: Lifter 35: O-ring S: Molten slag

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01N 21/64 G01N 1/28 W K

Claims (2)

[Claims] 1. A slag analysis method comprising: collecting a molten slag sample from a refining furnace; and subjecting the molten slag sample to a fluorescent X-ray analysis, an emission spectroscopic analysis, or an atomic absorption analysis while maintaining the molten slag sample in a molten state. . 2. X-ray fluorescence analysis, emission spectroscopy or
An analyzer main body for performing atomic absorption analysis, and a sample mounting portion, wherein the analyzer main body is configured to be able to attach and detach the sample mounting portion via a window and a shutter, and the sample mounting portion is the analyzer. In a housing having a mechanism for attaching to a main body and an exhaust port connected to a vacuum system, a molten slag sample heating means is provided, and a slag melting and holding mechanism having a slag holding portion is housed. Slag analyzer.