Method and device for measuring quality of steel scrap

Abstract

To provide a method for measuring the quality of steel scrap, and to enable the selection of steel scrap having a quality suitable for use as a raw material for electric furnace steelmaking.SOLUTION: A measuring device 10 used in a measuring method of the present invention includes a detection unit 1 and a display unit 2. The detection unit 1 detects component elements of steel scraps S and contents of the component elements in the steel scraps S. The display unit 2 displays the component elements of the steel scraps S from the detection unit 1 and the contents of the component elements in the steel scraps S. Based on the detection results displayed on the display unit 2, it is determined whether the steel scraps S are suitable as a raw material for electric furnace steelmaking.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for measuring the quality of steel scrap and a measuring apparatus therefor.

Background Art

[0002] In recent years, as the trend towards decarbonization accelerates, in the steel industry, the spread of steelmaking using electric furnaces instead of conventional blast furnaces is desired. Steelmaking using an electric furnace can generally suppress the CO2 emissions to about one-fourth of those of blast furnace steelmaking. Electric furnace steelmaking uses steel scrap as a raw material, generates an arc between the steel scrap and an electrode, and melts the steel scrap with the arc heat to produce steel. Since the steel scrap used as a raw material is an accumulation of various steel products, it generally contains impurity elements.

[0003] Among the impurity elements contained in steel scrap, those that are difficult to remove in a normal steelmaking process and accumulate in steel are called tramp elements (such as Cu and Sn). The tramp elements contained in steel are factors causing troubles in the manufacturing process of steel materials and deterioration of the quality of steel materials by melting the steel scrap.

[0004] On the other hand, the spread of electric furnace steelmaking requires wide correspondence to the demand for high-quality steel materials including the automotive industry. For this purpose, it is necessary to supply steel scrap having a quality suitable as a raw material for electric furnace steelmaking, that is, the content of tramp elements does not exceed a predetermined set amount. Here, the "predetermined set amount" is an amount set as the allowable amount of tramp elements contained in steel scrap in order to make the steel scrap adaptable to electric furnace steelmaking for high-quality steel materials.

[0005] However, the circulation volume of scraps such as new cut scraps with the above quality (scraps whose origin, such as processing scraps from factories, is known) is limited. Therefore, there is a demand to expand the utilization of urban waste scraps (see Fig. 1) generated during building demolition. For this purpose, it is necessary to select steel scraps with the above quality from urban waste scraps.

[0006] As a method for selecting steel scraps from urban waste scraps, for example, a method described in Patent Document 1 has been proposed. According to this method, non-ferrous components such as copper wires and plastics are removed from urban waste scraps mixed with non-ferrous components based on the weight of the scraps and the presence or absence of magnetism, etc., to select steel scraps.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the scrap sorting method described in Patent Document 1, only the weight of the scrap and the presence or absence of magnetism in the steel scrap can be determined, so it is impossible to determine whether the tramp elements in the steel scrap exceed the predetermined set amount. That is, the scrap sorting method described in Patent Document 1 cannot select steel scraps having a quality suitable as raw materials for electric furnace steelmaking for high-quality steel.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a method for measuring the quality of steel scraps and enable the selection of steel scraps having a quality suitable as raw materials for electric furnace steelmaking from urban waste scraps.

Means for Solving the Problems

[0010] According to one aspect of the present invention, a detection unit that detects component elements of steel scrap and the content of the component elements in the steel scrap, and a measuring device including a display unit by the detection unit, displays the component elements of the steel scrap and the content of the component elements in the steel scrap.

Advantages of the Invention

[0011] According to the measuring device of the present invention, the component elements and their contents in the steel scrap are displayed. An operator can know from the display whether the Trump element in the steel scrap is contained in an amount exceeding the predetermined set amount. As a result, the operator can easily determine whether the steel scrap to be measured has the quality suitable as a raw material for electric furnace steelmaking.

[0012] Therefore, the same measurement method enables the selection of steel scrap having the above quality from among urban waste scrap. As a result, the same measurement method can expand the utilization of urban waste scrap, and ultimately can contribute to the realization of a decarbonized society by expanding the utilization of electric furnace steelmaking (electric furnace shift).

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description will not be repeated. Also, in the following description, terms such as "upper", "lower", "lateral", and "longitudinal" that indicate positions or directions may be used. These terms are used for convenience in order to facilitate understanding of the embodiments and are not limited to the positions or directions during actual implementation.

[0015] FIG. 1 shows an example of steel scrap S. FIG. 1 is a diagram showing an example of urban waste scrap that is the measurement object of the measurement method according to the present invention. The steel scrap S is transported to a scrap yard by, for example, the illustrated dump truck D and then stockpiled at the yard. Various quality scraps are mixed in the steel scrap S. The measurement method of the present invention is capable of selecting only those having a quality suitable as a raw material for electric furnace steelmaking for high-quality steel from among these steel scraps S.

[0016] Referring to FIG. 2, a measuring device 10 that can be used in the measurement method of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the measuring device 10 that can be used in the measurement method of the present invention.

[0017] From FIG. 2, the measuring device 10 includes a detection unit 1 and a display unit 2. The detection unit 1 detects the component elements of the steel scrap S and the content of the component elements in the steel scrap S, and outputs them as detection results. The display unit 2 displays the detection results from the detection unit 1.

[0018] The detection unit 1 typically detects the component elements of the steel scrap S and the content of those elements in the steel scrap S by means of fluorescent X-ray analysis, and outputs the detection results. The fluorescent X-ray analysis irradiates the steel scrap S, which is the object to be analyzed, with X-rays from the X-ray tube 1a (arrow D1 in the figure), and the detector 1b detects the energy value and the energy amount of the characteristic X-rays specific to the elements coming out of the steel scrap S (arrow D2 in the figure). The control unit (not shown) collates the energy value of the characteristic X-rays detected by the detection unit 1 with the correspondence table between each element registered in advance in the storage unit (not shown) and its energy value, thereby determining the types of elements present in the steel scrap, and quantifies the content of that element in the steel scrap S from the energy amount of the characteristic X-rays. The detection results are stored in the storage unit by the control unit.

[0019] The display unit 2 is typically a liquid crystal monitor. The control unit causes the display unit 2 to display the component elements contained in the steel scrap S and the content of those component elements, which are the detection results. The display unit 2 may be incorporated into the measuring device 10 and configured integrally with the measuring device 10, or may be configured separately from the measuring device 10.

[0020] As shown by the phantom line in FIG. 2, the measuring device 10 may be further configured to include a determination unit 3 that determines the quality of the steel scrap S.

[0021] Based on the detection results from the detection unit 1, the determination unit 3 determines whether or not the contents of Cu and Sn in the steel scrap S exceed the preset predetermined set amounts for the reasons described below. Here, the predetermined set amounts may be configured to be set in advance in the storage unit, or may be configured to be set each time by the measurer during measurement. At this time, the display unit 2 may be further configured to display, in addition to the detection results, the determination result of the quality of the steel scrap S by the determination unit 3.

[0022] The predetermined set amount is preferably set to 0.03% by mass for Cu and 0.002% by mass for Sn. These set amounts correspond to the upper limits of the contents of Cu and Sn in the steel material produced in the blast furnace.

[0023] With the above configuration, the measuring device 10 has the following effects.

[0024] The measuring device 10 causes the display unit 2 to display the component elements and their contents in the steel scrap S as the detection result of the detection unit 1 of the steel scrap S.

[0025] Here, as described above, when the trump element is contained in the steel scrap S, it becomes a factor in the occurrence of troubles in the steel manufacturing process and the deterioration of the quality of the steel material. The trump elements are specifically elements such as Cu, Sn, Ni, and Cr. In particular, Cu and Sn inhibit the workability of the steel material and cause flaws on the surface of the steel material in the manufacturing process (from "Recycling of Iron" by Yoshimasa Mizukami, "Measurement and Control", Vol. 36, No. 10, issued in 1997). Therefore, it is necessary to control the contents of Cu and Sn in the steel scrap S to be below the predetermined set amounts to ensure the quality of the steel scrap S.

[0026] Based on the detection results displayed on the display unit 2, it is confirmed and judged by the measurer whether the steel scrap S, as a trump element, particularly whether Cu and Sn exceed the predetermined set amounts. Thus, it is judged whether the quality suitable for the raw material of electric furnace steelmaking for high-quality steel materials is ensured. That is, the measuring method of the present invention enables the selection of the steel scrap S having the above quality from among urban waste scraps. Therefore, the measuring method of the present invention can expand the utilization of urban waste scraps, and ultimately can contribute to the realization of a decarbonized society by expanding the utilization of electric furnace steelmaking (electric furnace shift).

[0027] The measuring device 10 equipped with the determination unit 3 makes the above determination. That is, the determination unit 3 determines whether the steel scrap S has the above quality by checking whether the contents of Cu and Sn, which are trump elements particularly affecting the strength reduction of steel materials, exceed the predetermined set amounts. Therefore, the measuring device 10 enables reliable selection of the steel scrap S having the above quality from among urban waste scraps, excluding artificial judgment.

[0028] By causing the measuring device 10 equipped with the determination unit 3 to display the determination result regarding the above quality for the detection result on the display unit 2 in addition to the detection result, it is possible to reliably and efficiently determine whether the steel scrap S has the above quality. Therefore, the measuring device 10 enables reliable and efficient selection of the steel scrap S having the above quality from among urban waste scraps.

[0029] Furthermore, by adopting the fluorescent X-ray analysis method in the detection unit 1, the measuring device 10 can quickly detect the contents of component elements in the steel scrap S in a non-destructive state. Specifically, the measuring device 10 can detect the component elements and their contents in the steel scrap S by irradiating the surface of the measurement part of the steel scrap S to be measured with X-rays after performing a peeling treatment on the measurement part with a file or the like. Thereby, the measuring device 10 enables reliable and efficient selection of the steel scrap S having the above quality.

[0030] From the above, the measurement method of the present invention enables reliable and efficient selection of the steel scrap S having the above quality suitable as a raw material for electric arc furnace steelmaking from among urban waste scraps. As a result, the measurement method of the present invention can expand the use of urban waste scraps, and ultimately, can contribute to the realization of a decarbonized society by expanding the use of electric arc furnace steelmaking (electric arc furnace shift). suitable as a raw material of

[0031] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist thereof. The drawings schematically show each component mainly for easy understanding, and the thickness, length, number, interval, etc. of each illustrated component are different from the actual ones for convenience of drawing creation. Also, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the configuration of the present invention.

Description of Reference Numerals

[0032] S Steel scrap S 1 Detection unit 1 1a X-ray tube 1a 1b Detector 1b 2 Display unit 2 3 Judgment unit 3 10 Measuring device 10

Claims

1. A detection unit that detects component elements of steel scrap and the content of the component elements in the steel scrap, and a measuring device including a display unit that displays the detection result by the detection unit, for displaying the component elements of the steel scrap and the content of the component elements in the steel scrap. A method for measuring the quality of steel scrap, characterized by the above.

2. The detection unit detects the component elements and the content by X-ray fluorescence analysis. The measuring method according to claim 1, characterized by the above.

3. A detection unit that detects component elements of steel scrap and the content of the component elements in the steel scrap, a determination unit that determines the quality of the steel scrap based on the content of Cu and Sn in the steel scrap, and a display unit that displays the determination result by the determination unit. A measuring device for the quality of steel scrap, characterized by the above.

4. The determination unit determines that the steel scrap is a good product when the content of Cu in the steel scrap is 0.03% by mass or less and the content of Sn is 0.002% by mass or less. The measuring device according to claim 3, characterized by the above.

5. The detection unit detects the component elements and the content by X-ray fluorescence analysis. The measuring device according to claim 3 or claim 4, characterized by the above.

Images