JP6287905B2 - Used refractory sorting method and used refractory sorting device - Google Patents

Description

The present invention relates to a method for sorting used refractories based on color differences, and in particular, it is possible to accurately sort and collect valuable materials from used refractories generated in steelworks. The present invention relates to a method for sorting used refractories.
The present invention also relates to a used refractory sorting apparatus for sorting used refractories based on color difference.

  Various refractories are used in the iron and steel process, especially in the ironmaking and steelmaking processes. Moreover, not only one type of refractory is used alone, but also multiple types of refractories are combined in accordance with the characteristics. It is widely used.

For example, as shown in FIG. 1, in a tundish 1 which is an intermediate container for temporarily holding molten steel in continuous casting, a lining made of a refractory material is formed on the inner surface of an iron skin 3 formed in a box shape or a boat shape. 4 is provided. The lining 4 is composed of two layers of an Al ₂ O ₃ rich work material 5 and an SiO ₂ rich permanent material 6.

  Refractories used in such applications are worn by contact with hot metal, molten steel, slag, and the like, and are dismantled and disposed of when they are less than a specified thickness. However, disposal of used refractories as industrial waste as it is is not only expensive, but it would otherwise dispose of reusable refractories, which is undesirable from the viewpoint of resource conservation. . Therefore, there is a need to recycle used refractories in some form.

However, used refractories contain multiple refractories as described above, and also contain components other than refractories such as bullion and slag. Is difficult. In order to effectively use the used refractory, it is necessary to sort out the contained materials. In particular, expensive materials such as Al ₂ O ₃ rich work materials are separated and recovered with high purity. If possible, it is extremely practical.

  Therefore, various methods for selecting used refractories and recovering reusable materials have been proposed. For example, Patent Document 1 proposes a method for sorting used refractories by color difference sorting. Patent Document 2 proposes a method for performing color difference selection after magnetic separation, and Patent Document 3 proposes a method for sequentially performing crushing, magnetic selection, classification, and color difference selection.

  Color difference sorting is a method (Patent Literature 4) for sorting a plurality of objects included in a processing object based on the difference in color. In the above method proposed in Patent Literatures 1 to 3, a refractory material is used. Color difference selection is performed by utilizing the fact that the color tone varies depending on the material and the degree of deterioration. By using color difference sorting, it is possible to automatically determine the type of refractory and to sort a large amount of used refractory efficiently.

Japanese Patent Laid-Open No. 52-115811 Japanese Patent No. 3704301 Japanese Patent No. 3645843 Japanese Patent Laid-Open No. 51-027568

However, although it has become possible to automatically sort used refractories by using the sorting method described in Patent Documents 1 to 3, the separation accuracy is still not sufficient. In particular, in order to effectively use expensive refractories such as Al ₂ O ₃ rich work materials contained in used refractories, further improvement in separation accuracy is desired.

  The present invention has been developed in view of the above circumstances, and an object thereof is to provide a used refractory sorting method and a used refractory sorting apparatus capable of sorting used refractories with high accuracy. And

  As a result of diligent research to achieve the above object, the inventors have found that the cause of the decrease in separation accuracy in color difference selection is the variation in water content of the used refractory and the resulting color variation. I found out.

  Color difference sorting is a method of sorting based on the difference in color. Specifically, the color of a refractory is observed under a certain light source using a color image sensor or the like, and the refractory based on the result. Sort out. And in the case of selection, the criteria (threshold etc.) determined beforehand according to the color of the refractory contained are used. Therefore, in order to select the refractories with high accuracy, it is necessary that the color tone of each refractory is constant in addition to the clear color difference between the refractories mixed.

  However, general refractories have the property that the color tone changes depending on the water content. Therefore, when the moisture content of the refractory is deviated from the moisture content when the determination criteria used for selection are determined, the color changes, and the type of the refractory cannot be properly determined.

  Furthermore, since the refractory is porous, the moisture content tends to vary depending on the environment. For example, used refractories discharged at steelworks are often stored in outdoor yards. For this reason, there is a difference in the wetness during rainfall and the degree of dryness in fine weather between the outside and the inside of the mountain pile, and the refractory near the mountain surface is easy to dry, so the water content is low. Since the refractory in the center of the refractory is difficult to dry, the water content is high.

  Thus, in the separation of the refractory using the color difference selection, the water content of the refractory is not constant, resulting in variations in color, resulting in a decrease in separation accuracy. Therefore, if the moisture content of the refractory can be made constant and variations in color tone of the refractory can be eliminated, it is considered that the accuracy of color difference selection can be improved.

The present invention is based on the above findings, and the gist of the present invention is as follows.
1. A method for sorting used refractories,
Crushing step of crushing the used refractory to obtain refractory particles,
A classification step of classifying the refractory particles;
A water-containing treatment step for imparting moisture to the refractory particles whose particle size has been adjusted in the classification step;
A method for sorting used refractories, comprising: a color difference sorting step of sorting the refractory grains given moisture in the water-containing treatment step based on a color difference of the refractory grains.

2. Prior to the color difference sorting step, the method for sorting used refractories according to 1 further includes a surplus moisture removing step of removing surplus moisture adhering to the refractory grains given moisture in the water-containing treatment step. .

3. A used refractory sorting device,
Crushing means for crushing the used refractories to form refractory grains;
Classification means for adjusting the particle size of the refractory particles;
Moisture treatment means for imparting moisture to the refractory grains whose particle size has been adjusted by the classification means;
A used refractory sorting apparatus, comprising: a color difference sorting unit that sorts refractory grains to which moisture has been given by the water-containing treatment unit based on a color difference of the refractory grains.

4). Prior to the sorting based on the color difference, the used refractory sorting according to 3, further comprising a surplus moisture removing means for removing surplus moisture adhering to the refractory grains to which moisture has been given in the water-containing treatment step. apparatus.

According to the present invention, by imparting moisture to the refractory grains prior to color difference sorting, it is possible to eliminate color variations depending on the moisture content and to sort used refractories with high accuracy. Such a method and apparatus for sorting used refractories are extremely useful for separating expensive refractories such as Al ₂ O ₃ rich work materials from used refractories.

It is the schematic which shows the structure of a general tundish. It is a flowchart which shows the flow of the process in one Embodiment of this invention. It is the schematic of the water-containing process means and the excess water removal means in one Embodiment of this invention.

Next, a method for carrying out the present invention will be specifically described.
In the present invention, a crushing step of crushing a used refractory to obtain refractory particles, a classification step of classifying the refractory particles, and a water content that imparts moisture to the refractory particles adjusted in particle size in the classification step The used refractory is sorted by sequentially performing a treatment step and a color difference sorting step of sorting the refractory particles given moisture in the water-containing treatment step based on the color difference of the refractory particles.

  FIG. 2 is a flowchart showing the flow of processing in one embodiment of the present invention. Specifically, the flow chart represents processing when the method for sorting used refractories according to the present invention is applied to sorting used refractories in which the above-mentioned tundish work material and permanent material are mixed. It is assumed that the used refractory is finally separated into a workpiece material, a deteriorated workpiece material and a permanent material. Hereinafter, the sorting method and sorting apparatus of the present invention will be described with reference to the flowchart of FIG.

[Used refractories]
The sorting method and sorting apparatus of the present invention are intended to treat used refractories. The used refractory is not particularly limited, and any used refractory can be used. As an example, it is possible to use a used refractory discharged at an ironworks, for example, a used refractory in which a tundish work material and a permanent material as described above are mixed.

  As the above-mentioned used refractory, a mixture of a plurality of refractories having different colors (color tones) can be treated. As the refractories having different colors, refractories made of different materials are generally used. However, even refractories made of the same material may be treated even if they have a color difference depending on the degree of deterioration. be able to.

[Crushing process]
In the method for sorting used refractories according to the present invention, first, the refractory particles to be treated are crushed to obtain refractory particles (crushing step). Since there is an upper limit on the size of an object that can be selected in the color difference selecting device used in the color difference selecting process described later, it is necessary to crush it to an appropriate size in advance. The particle size of the refractory to be crushed in the crushing process may be determined according to the color difference sorting device used, but the maximum particle size that can be separated by a general color difference sorting device is about 150 mm. Therefore, it is preferable to crush until the maximum particle size is 150 mm or less.

  Moreover, by crushing, impurities such as slag and bullion iron adhering to the surface of the used refractory can be separated to some extent. In order to obtain the separation effect, the maximum particle size of the refractory after crushing is more preferably 40 mm or less, and more preferably 30 mm or less.

[Crushing means]
The means used for crushing is not particularly limited, and any means can be used as long as it can crush the refractory to be processed into an appropriate size. Examples of suitable crushing means include a jaw crusher and a hammer crusher.

[Classification process]
When the refractory is crushed in the crushing step, a powder having a particle size that is too small to be sorted by the color sorter is generated. Therefore, the refractory particles obtained by the crushing step are classified in the classification step, and the powder having a constant particle size or less (small particle refractory powder) is removed. Thereby, the separation accuracy in the color difference selection process can be further improved. Since the minimum particle size that can be separated by a general color difference selection device is about 2 mm, classification is preferably performed so that the minimum particle size is 2 mm or more. In order to stably obtain sufficient separation accuracy, the minimum particle diameter is more preferably 5 mm or more, and further preferably 10 mm or more.

[Classification means]
The means used for classification is not particularly limited, and any means can be used as long as it can separate a refractory having a predetermined particle size or less. An example of usable classification means is a sieve.

  Since the small particle size refractory powder removed by classification contains the work material, the small particle size refractory powder is further separated using an air table, air jig, fluidized bed density segregation method, etc. It is preferable to collect the workpiece material contained in the particle size refractory powder.

[Water treatment process]
The refractory particles (large particle size refractory particles) from which the small particle size refractory has been removed in the classification step are then given moisture in the water treatment step. The water treatment is intended to eliminate variation in the water content of the refractory grains, and therefore it is preferable that all refractory grains to be treated are sufficiently wet. In the color difference selection process, since the selection is usually performed based on the color of the surface of the refractory grain, it is sufficient that the surface of the refractory grain is in a sufficiently wet state, and moisture is contained inside the refractory grain. There is no need to infiltrate.

[Moisture treatment means]
The means used for the water-containing treatment is not particularly limited, and any means can be used as long as it can impart moisture to the refractory grains. From the standpoint of making all the refractory particles to be treated sufficiently wet, for example, a water tank for immersing the refractory particles in water and spraying means for spraying water on the refractory particles ( It is preferable to use an apparatus equipped with a nozzle or the like. However, as described above, since the surface of the refractory particles only needs to be in a sufficiently wet state, it is not necessary to immerse in a water tank for a long time, and when spraying means is used. Moisture can be sufficiently imparted by simply spraying water onto the refractory particles being conveyed by a belt conveyor or the like. In the case of using the spraying means, from the viewpoint of reliably moistening the surface of all the refractory particles, it is preferable to apply water using a plurality of spraying means, and using the plurality of spraying means, two directions, four More preferably, water is applied from a plurality of directions such as directions.

[Excess water removal process]
In the present invention, prior to the color difference selection step, it is preferable to further provide a surplus moisture removing step for removing surplus moisture adhering to the refractory grains to which moisture has been imparted in the water treatment step. If excessive moisture adheres to the surface of the refractory particles in the form of water drops, water film, etc., the light is reflected and scattered by the water drops, water film, etc. in the color difference sorting process. The color of the grain surface may not be measured correctly. By removing excess water in advance, such measurement problems can be avoided and the separation accuracy can be improved.

[Excess water removal means]
The means used for removing excess water is not particularly limited, and any means can be used as long as it can remove excess water such as water droplets and water film adhering to the refractory particles. For example, a sponge or other water-absorbing material or a brush that comes into contact with the refractory particles to absorb or wipe off excess moisture, a device that blows air from a nozzle or slit to remove excess moisture, or a refractory particle on the mesh It is possible to suitably use a material that shakes moisture by applying vibration in a state where it is placed on the surface. Note that it is not preferable to remove excess moisture using a heating means because moisture necessary for making the refractory surface wet is removed and the color of the refractory grains becomes unstable.

  FIG. 3 is a schematic view of an embodiment of the present invention in which the water-containing treatment means and the excess water removing means are used in combination. In this embodiment, while the refractory particles 10 after removing the refractory powder having a small particle size in the classification process are conveyed to the color difference selecting means (not shown) by the belt conveyor 11, the water-containing treatment and the removal of excess water are continuously performed. Implemented.

  The refractory particles 10 are conveyed in the direction of the arrow in the figure, and first, a water-containing treatment is performed by water 13 sprayed from a spray nozzle 12 as a water-containing treatment means. Next, excess water present on the surface of the refractory particles is removed by the air 15 blown from the air nozzle 14. Thereafter, the refractory particles are conveyed to the color difference sorting means and sorted according to the color of the surface. Thus, since it can process continuously by processing on the belt conveyor 11, a used refractory can be sorted out efficiently. In addition, it is not necessary to provide a separate place for the water-containing treatment means and the surplus water removing means, so that the apparatus can be miniaturized.

[Color difference selection process]
In the color difference selection step, the refractory contained in the refractory grains is selected using the fact that it has a different color tone depending on the material and the degree of deterioration. The specific sorting conditions may be determined according to the type of refractory contained in the used refractory to be processed, the purpose of reuse after sorting, and the like. In the embodiment shown in the flowchart of FIG. 2, the used refractories are sorted into a work material, a deteriorated work material, and a permanent material.

[Color difference selection means]
As the color difference selecting means, any means can be used as long as the refractory grains can be selected based on the color difference. As a general color difference selecting means that can be used, for example, one having a structure as described in Patent Document 4 can be cited. Specifically, it is as follows. First, refractory particles are conveyed by a plate called a chute (or a belt conveyor), and color information for each particle contained in the refractory particles is captured by a camera in the middle. Next, based on a preset selection criterion, for example, a valuable material that is collected and reused is distinguished from other unnecessary materials, and the air gun is discharged when the unnecessary materials are thrown out of the chute (belt). Shoot down and sort by. Needless to say, color selection means having a structure and mechanism other than those described above can be used.

  Next, the present invention will be specifically described based on examples. The following examples show preferred examples of the present invention, and the present invention is not limited to the examples. Modifications can be made within the scope that can meet the spirit of the present invention, and such embodiments are also included in the technical scope of the present invention.

An experiment was conducted to select a work material from a used tundish refractory containing an Al ₂ O ₃ rich work material and a SiO ₂ rich permanent material. The selection method is as follows. First, 100 kg of used refractory actually stored in the field in the outdoor yard was crushed to a particle size of 30 mm or less using a cone crusher, and the refractory particles after crushing were classified using a mesh 10 mm sieve. . The refractory particles on the sieve are divided into two, one is subjected to water treatment and excess water removal and then subjected to color difference selection (Example), and the other is not subjected to water treatment and excess water removal. The color difference selection was performed as it was (comparative example). The hydrous treatment was carried out in the form of a water spray in which water was sprayed from the nozzle to the refractory particles. Excess water was removed by sieving by placing the refractory particles on a mesh with an opening of 10 mm and applying vibration.

  In the color difference sorting, the refractory particles are fed at a belt speed of 2 m / s using a conveyor length of 2 mm and a width of 430 mm, and the RGB color information of the refractory particles is read by a camera with air nozzles arranged at a pitch of 5 mm. The permanent material and the deteriorated workpiece material were removed.

  In order to evaluate the separation accuracy, the ratio of the work material contained in the selected product was measured by visual sorting for each of the example and the comparative example. As a result, in the comparative example in which the water treatment and the excess water removal were not performed, the work material ratio was 76% by mass, whereas in the example in which the water treatment and the excess water removal were performed, the work material ratio As a result, the separation accuracy was remarkably improved.

  As described above, according to the present invention, it is possible to improve the separation accuracy of used refractories using color difference sorting by a very simple method of applying moisture, and therefore, a large amount is discharged at a steelworks or the like. This is extremely useful in that the used refractories can be used effectively.

DESCRIPTION OF SYMBOLS 1 Tundish 2 Nozzle 3 Iron skin 4 Lining 5 Work material 6 Perm material 10 Refractory grain 11 Belt conveyor 12 Spray nozzle 13 Water 14 Air nozzle 15 Air

Claims (4)

A method for sorting used refractories,
Crushing step of crushing the used refractory to obtain refractory particles,
A classification step of classifying the refractory particles;
A water-containing treatment step for imparting moisture to the refractory particles whose particle size has been adjusted in the classification step;
A method for sorting used refractories, comprising: a color difference sorting step of sorting the refractory grains given moisture in the water-containing treatment step based on a color difference of the refractory grains.   The used refractory sorting according to claim 1, further comprising a surplus moisture removing step for removing surplus moisture adhering to the refractory grains to which moisture has been given in the water-containing treatment step, prior to the color difference sorting step. Method. A used refractory sorting device,
Crushing means for crushing the used refractories to form refractory grains;
Classification means for adjusting the particle size of the refractory particles;
Moisture treatment means for imparting moisture to the refractory grains whose particle size has been adjusted by the classification means;
A used refractory sorting apparatus, comprising: a color difference sorting unit that sorts refractory grains to which moisture has been given by the water-containing treatment unit based on a color difference of the refractory grains. The used refractory according to claim 3, further comprising surplus moisture removing means for removing surplus moisture adhering to the refractory grains given moisture by the moisture treatment means prior to the selection based on the color difference. Sorting device.

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