JP6357670B2 - Reusing used refractories - Google Patents

Description

  The present invention relates to a method for reusing used refractories that reuses used refractories that have been used in steel factories and the like, refractory raw materials, and refractories obtained thereby.

  Generally, in steel factories and the like, refractories such as refractory bricks and irregular refractories are lined in refining furnaces such as converters and electric furnaces, and incidental facilities such as ladle and firewood. Since such a refractory is worn out by melting damage caused by molten steel or slag, it is replaced with a new refractory when the remaining thickness is reduced. On the other hand, used refractory materials generated by re-covering are difficult to reuse because bullion adheres to the surface or bullion, iron oxide, slag, etc. infiltrate inside. Until now, most of them have been discarded.

  On the other hand, in recent years, a method for reusing used refractories has been proposed in order to realize effective use of resources and reduction of raw material costs. However, in general, used refractories are in a state in which various materials are mixed, so that they are only used for refractories with relatively mild use conditions such as repair materials and irregular refractories. Specifically, Patent Document 1 uses a crushed product of used refractory mixed with a spray repair material, and Patent Document 2 uses a crushed product of used refractory as a thermal spray repair material. A method is described.

  Patent Document 3 describes a method in which used refractories are classified by material and by presence / absence of an infiltrated infiltrated layer by manual selection and added to an indeterminate material by classifying and managing crushed products. Has been. In addition, in the case of an amorphous material, lower oxides such as slag and FeO infiltrate and cause a reduction in fire resistance and durability when used as a refractory raw material. The method of separating the infiltrated layer from the used amorphous refractory and the method of using it for the amorphous material are described. Furthermore, Patent Document 7 describes a method of removing a portion containing a large amount of impurities in a refractory material by color-selecting a refractory material having a purity of 90% or more. However, generally used refractories are often reused by mixing a plurality of refractory raw materials including those of low purity. For this reason, it is difficult to apply the method described in Patent Document 7 to used refractories.

JP 2005-188798 A JP-A-7-187830 JP 2003-212667 A JP 2003-88845 A Japanese Patent No. 4499940 Japanese Patent Laid-Open No. 52-115811 JP 2008-687 A

  In general, refractories are formed by using multiple materials with different chemical components at the same time. Therefore, when reusing used refractories, not only removing impurities but also separating materials is an important issue. Become. Specifically, the deteriorated portion is disassembled when the refractory is replaced, and at this time, a plurality of used refractory scraps of different materials are generated. Refractories made of different materials are properly used in the form of the part to be used, use of the working surface or use of the back surface. For this reason, partial dismantling of the refractory for each material is considered an effective method for separating the materials.

  However, the dismantling work for each material significantly deteriorates the efficiency of the dismantling work. In addition, since most of the refractories are integrated by intrusion of impurities such as bullion and seizure of adhesive such as mortar, it is difficult to disassemble and recover each material. For this reason, in order to separate used refractories by material, it is necessary to further dismantle and separate used refractories by manual work, and process used refractories that are generated in large quantities in steel factories, etc. Was difficult.

  From such a background, when a used refractory is used as a raw material, the used refractory has been made into a raw material in a state containing components other than chemical components that are originally necessary. In addition, when used refractories of different materials are mixed and used, the mixing ratio varies depending on the previous refractory remaining condition and the refractory repair range, and the collected used refractories are the same. Due to the difference in the mixing ratio even in the lot, the performance of the refractory manufactured using the used refractory as a raw material varies greatly. For this reason, such a refractory has been limited to a site or application where there is no problem even if the quality is inferior to that of the refractory originally used.

  The present invention has been made in view of the above, and an object of the present invention is to provide a method for reusing used refractories that can separate a large amount of used refractories for each material with high accuracy without relying on manual work. It is to provide.

  The method of reusing used refractories according to the present invention is a method of reusing used refractories that recycles used refractories, wherein the chemical components of the used refractories are based on the difference in color tone. It includes a separate collection step for separating and collecting each different material.

  The method for reusing used refractories according to the present invention is the above-described invention, wherein the separation and collection step separates and collects used refractories for each material based on a difference in color using a color separator. Including steps.

  The method for reusing a used refractory according to the present invention is characterized in that, in the above invention, the method further comprises a crushing step of crushing the used refractory before performing the separation and recovery step.

  The reuse method of the used refractory according to the present invention is characterized in that, in the above invention, the crushing step includes a step of removing powder having a particle size of 1 mm or less contained in the used refractory.

  The used refractory recycling method according to the present invention is characterized in that, in the above invention, the used refractory for each recovered material is reused as a refractory raw material.

  The method for reusing used refractories according to the present invention is the above-mentioned invention, wherein the used refractories include a used carbon-containing shaped refractory and a carbon-free shaped refractory, and a used carbon-containing shaped refractory. It includes a step of collecting the refractory and reusing it as a carbon-containing shaped refractory raw material.

  The method for reusing used refractories according to the present invention is the above-described invention, wherein the used refractory does not include a carbon-containing refractory, includes a plurality of used carbon-free refractories, It includes a step of recovering a carbon-free refractory and reusing it as a refractory raw material.

  The refractory raw material according to the present invention is obtained by separating and collecting used refractories for each material having different chemical components by the method for reusing used refractories as described above. It is characterized by that.

  The refractory according to the present invention is a refractory obtained by separating and collecting used refractories for each material having different chemical components by the method for reusing used refractories described above. It is manufactured using raw materials.

  According to the reuse method of a used refractory according to the present invention, a large amount of used refractory can be sorted for each material with high accuracy without relying on manual work. Moreover, according to the refractory raw material which concerns on this invention, it can be used for a product as an appropriate raw material for every material. Furthermore, according to the refractory according to the present invention, it is possible to effectively use the used refractory and to reduce the deterioration of the refractory and the variation in the quality as much as possible.

  Generally, a refractory is formed by combining various chemical components mainly including chemical components such as aluminum oxide, magnesium oxide, and silicon oxide. In particular, many refractories containing carbon are now used depending on the application. In addition, regarding refractory raw materials, a wide variety of raw materials are used from expensive high-purity raw materials to inexpensive natural low-purity raw materials, and the price of refractories varies greatly depending on the combination thereof.

  Used refractories are damaged by melts and deposits, and some of the remaining used parts are affected by these infiltrations and chemical reactions with refractories. This altered portion is often a low melting point compound such as a lower metal oxide, and causes a decrease in heat resistance when the used refractory is reused as a refractory raw material. When reusing an irregular refractory, a technique for separating the altered portion has been practiced for a long time, utilizing the fact that many of the altered portions have greatly different colors from the original portion.

  A high-density regular refractory compared to an irregular refractory, particularly a regular refractory containing carbon, has few such infiltrated layers and altered layers, and the effect of fractionation of altered portions is small. In addition, even when using only refractories containing no carbon, it is common to use multiple types of materials in combination, leaving a state where materials with different chemical components remain mixed even if the altered part is separated. Yes. As described above, in the conventional recycling method based on altered parts, materials with different chemical components are collected in a mixed state. Therefore, when using a used refractory as a refractory raw material, it is lower than the last time it was used. It must be used as a refractory or through a low-efficiency, high-cost sorting process by hand.

  The refractory has a unique color according to its chemical composition. For example, a refractory containing carbon is close to black, a refractory mainly composed of aluminum oxide or silicon oxide is white, and a refractory mainly composed of magnesia exhibits a color tone such as brown or ivory. Therefore, the method for reusing used refractories according to the present invention separates and collects used refractories for each material using the difference in color tone of refractories due to chemical components.

  Thereby, a large amount of used refractories can be sorted for each material with high accuracy without depending on manual work. In addition, only used refractories that have the chemical components required for reuse can be used as raw materials, and can be used as appropriate raw materials for each material.Therefore, even if used refractories are used as raw materials, there is a decrease in quality and variations in quality. You can get fewer products.

  In particular, carbon-containing fixed refractories and non-carbon-containing fixed refractories are often used in combination as the working surface side material and the back side material, respectively, but when carbon is included, most of the refractories exhibit a black color. When carbon is not contained, it often exhibits a light color, and is suitable for separation by the difference in color tone according to the present invention.

  By separating and collecting used refractories for each material based on the difference in color using a color sorter, it is possible to separate and collect used refractories by color at high efficiency and at low cost. Specifically, when using a color sorter to separate and collect used refractories based on the difference in color tone, set the color tone you want to separate as a threshold value, and set the used refractory as a boundary. Separate by color. That is, the used refractory is classified into two types of materials based on the difference in color tone. Further, when it is necessary to separate used refractories, the color tone to be separated is reset as a threshold, and the above-described used refractories after separation are further separated by color tone based on the reset threshold. That is, the sorted used refractory is further sorted into two types of materials based on the difference in color tone. The same effect can be obtained even if this operation is repeated according to the number of necessary materials (sorting), or color sorters used at each stage are installed in series. An example of the configuration of the color sorter will be described. When an object continuously discharged from a belt conveyor or a slide is photographed by a camera and the color information is processed by a computer, the color sorter is based on the preset threshold value. There is a method of discriminating between a sampling object and a non-collecting object, and changing the trajectory of the non-collecting object with an air gun located behind the flight route.

  The used refractories crushed for the purpose of removing bullion can also be separated by a color separator. Even if the surface of the refractory is discolored due to high temperature or usage conditions, the inside of the refractory is often maintained in its original color, and the inside of the refractory can be seen by crushing. The accuracy of sorting by difference is improved. In such crushed materials of refractory used, fine powder with a particle size of 5 mm or less is removed by sieving with an opening of 5 mm or less, centrifugal classification, or air classification in a crushing process before being separated and collected according to the color difference. It is adjusted to what you did. However, when a lot of fine powder that may be affected by wind when sorting is contained in the crushed material of the used refractory, the sorting accuracy is lowered. For this reason, in the crushing treatment of the used refractory, sieving with an opening of 1 mm, centrifugal classification or air classification is performed. It is desirable to remove it.

  When using a color sorter that performs separation determination by applying compressed air to the target after separation judgment based on color difference, the optimum mass range is determined by the pressure and flow rate of the compressed air, so the particle size It is desirable to make the difference between the maximum value and the minimum value of the distribution within a range of about 5 to 15 mm. If the maximum particle size of the used refractory when using the color separator is too small, the reuse application is limited.

  The used refractories separated and recovered by the method for reusing used refractories according to the present invention are obtained as raw materials for products such as refractory raw materials. The obtained used refractories can be reused as refractories and other raw materials by performing separation management according to the respective chemical components and raw materials used. At this time, the used and collected refractories that have been separated and collected are reused as refractories and other raw materials through re-grinding to a required particle size, particle size adjustment, heat treatment, chemical treatment, and the like. Thus, by using (reusing) the used refractory obtained by separating and collecting the used refractory according to the present invention as a refractory raw material or a raw material for other products, Products such as goods can be manufactured.

[Example 1]
Used refractories were collected from a place where the used refractories generated during the repair of hot metal containers at a steel factory were stored exclusively. Alumina-waxite-SiC-carbon brick is used as the refractory on the working surface side of the hot metal container, and waxy brick is used as the refractory on the back side. The recovered refractory is a mixture of these. Further, these used refractories are stored after being ground to a particle size of about 40 mm or less with a cone crusher and removed with a magnetic separator for the purpose of use for civil engineering work.

  Moreover, in the present Example 1, the presetting which sets the threshold value of a color tone was performed about the color sorter used for the classification for every material of used refractory. In this pre-setting, first, select several samples of the material to be collected and samples of the material to be removed from the used refractories after the above-mentioned magnetic selection, and color-separate each of these samples one by one. Go through the machine. As a result, the color tone (hue) determination of each sample was performed by the color classifier, and an image when the color tone of each sample was determined by the color classifier was displayed on the screen as a still image. The image at the time of color tone determination displayed in this way was confirmed for each sample.

  Next, a temporary threshold value related to the color tone is set for the color classifier, and an attention area that exceeds (or is less than) the temporary threshold value in the above-described image at the time of the color tone determination is defined as another area. Display on the screen in a different color. At the same time, the image occupation ratio of this attention area is displayed on the screen. Subsequently, by adjusting each or all of red (R), green (G), and blue (B) of the image, the color separation is performed so that the sample of the material to be removed can be completely separated and removed by the color sorter. The machine threshold (the above-mentioned temporary threshold) is adjusted. Thus, each sample mentioned above was again passed one by one to the color sorter after adjusting the threshold value, and it was confirmed whether or not the color sorter sorted each sample as desired. If the desired sample separation is not performed, the above-described threshold adjustment is performed again. On the other hand, when the sample separation was performed as desired, each sample described above was passed through the color sorter, and it was confirmed whether or not the sample of the material desired to be removed could be separated and removed. If the separation / removal cannot be performed as desired, the above-described threshold adjustment is performed again. If the separation / removal can be performed as desired, the threshold at this point is set as the threshold of the color separation device.

  After performing the above-mentioned presetting, the used refractories after magnetic separation are classified with a predetermined sieve mesh, and then black crushed material, white crushed material, and intermediate color crushed material with a preset color sorter And separated. At this time, the used refractories in Example 1 were separated into a white crushed material, a black crushed material, and a mixture of intermediate colored crushed materials with a set threshold as a boundary. Furthermore, the mixture after the separation was further separated into a black crushed product and a neutral crushed product with the reset threshold as a boundary. In this way, the used refractories were collected by separating into white crushed material and black crushed material (material separation) according to the material, and the intermediate color crushed material was removed from the above mixture. Thereafter, each of these recovered products and removed products was visually confirmed to confirm whether or not they were separated as desired. When it was not possible to sort as desired, the above-described pre-setting was performed again, and when it was possible to sort as desired, this sorting process was terminated.

  In the first embodiment, in addition to the threshold setting of the color sorter described above, in order to correspond to the particle size of the used refractory to be separated, the compressed air to the separation target is determined according to the determination range of the particle size. Adjust the ejection range (for example, the injection range of several nozzles that simultaneously inject compressed air to the separation target having the particle size at both ends of the judgment range) or adjust the compressed air injection time (for example, classification with a large particle size) Various settings related to the classification were made, such as adjusting the blowing time when adjusting the target, and adjusting the ejection timing.

  Here, in the present Example 1, the intermediate crushed material exhibits a color tone between white and black. Specifically, the slag and the metal that could not be removed by the magnetic separator are removed. It was an impurity. For comparison, there were prepared ones that were not subjected to separation by a color separator, ones that did not remove intermediate color impurities, and ones that only removed intermediate color impurities. These used refractories are further dried and pulverized into refractory raw materials (for example, carbon-containing regular refractory raw materials), and the obtained refractory raw materials are used to newly form carbon-containing fixed forms such as hot metal transport container refractories. A refractory, specifically an alumina-waxite-SiC-carbon brick, was produced. In the production of the brick, the blending ratio of the used refractory was set to 30% or 50% in terms of the amount of material used internally.

Part of the used refractory is collected before use and analyzed for chemical components, and then the composition value of the brick as a base material together with new raw materials is 50% alumina (Al ₂ O ₃ ), silica (SiO 2 ₂ ) Brick was produced with the goal of 30%. The new raw material used band shale as the alumina source and waxite as the silica source. In addition, graphite and SiC were used to make up for other than the recycled material mixture from the used refractory.

Brick produced using a rotating drum tester was subjected to an erosion test. Brick production conditions and test results are shown in Tables 1 and 2 below. For the erosion test, synthetic slag prepared so that the ratio of CaO to SiO ₂ (CaO / SiO ₂ ) was 2.2 was used. Further, the slag was prepared so that the total content of FeO and MnO was 17%. The erosion test was performed by heating a sample lined on a rotating drum tester with a burner while rotating, and after reaching a test temperature of 1500 ° C., a synthetic slag was added and held for 3 hours. For the evaluation, the change in thickness of the sample before and after the test was measured, and an erodibility index with the change in thickness of the base material as 100 was used. An erosion index of less than 100 indicates good erosion, and an erosion index of greater than 100 indicates poor erosion.

  In Tables 1 and 2, the example of “with” impurity removal and “with” material separation is the classification of used refractory into white crushed material, black crushed material and intermediate color impurities, and the intermediate color after separation. In this example, impurities are removed. The example of “None” for impurity removal and “None” for material separation is an example in which the used refractory is not separated by a color separator. The example of “existence” of impurity removal and “absence” of material classification is an example in which only intermediate color impurities are removed from the used refractory. In this example, the white crushed material and the black crushed material were collected without being separated. The example of “None” for impurity removal and “Yes” for material classification is an example in which the intermediate color impurities are not removed from the used refractory. In this example, a white crushed material and a mixture of black crushed material and intermediate color impurities were collected in a separated state. The distinction between the examples is the same as in the first embodiment.

  Table 3 shown below summarizes the results of the erosion test. From the comparison between Comparative Example 1 and Invention Example 1, Comparison between Comparative Example 2 and Invention Example 2, and Comparison between Comparative Example 3 and Invention Example 4, the erosion index was obtained when the color separation treatment was performed. It was found that the distribution range is narrowed, the average value of the erosion index is reduced, and the corrosion resistance is improved. Also, by comparing the present invention example 1 with the present invention example 2, when the fine powder of 1 mm or less is removed in advance before the color separation treatment, the distribution range of the erosion index is further narrowed, and the corrosion resistance is further improved. Was discovered. On the other hand, from the comparison between Invention Example 1, Invention Example 2 and Invention Example 5, the corrosion resistance did not change between the case where the particle size of the fine powder removed in advance was 5 mm or less and the case where the particle size was 1 mm or less. From this, it was found that if the particle size of the fine powder to be removed in advance is 5 mm or less, the corrosion resistance is sufficiently improved. However, it is desirable that the particle size of the fine powder to be removed in advance is 1 mm or less from the viewpoint of increasing the collection amount of the used refractory after the separation to increase the efficiency of the separation and collection.

Furthermore, by comparing the present invention example 2 with the present invention example 3, by narrowing the particle size distribution range during the color separation treatment, the standard deviation of the erodibility index is reduced from 7.2 to 5.3, and the erodibility is reduced. It was found that the average value of the index also decreased from 106 to 103. Furthermore, by comparing Comparative Example 3 with Invention Examples 1 to 4, it was found that the corrosion resistance comparable to that of the conventional 30% can be obtained even if the amount of reuse material added is 50% by color separation processing. It was. In addition, when the particle size range is narrowed, the erosion index is almost the same as that of the base material even if the amount of reused material is 50%. It has been found that refractories can be applied. Further, by comparing the comparative example 2 and the comparative example 4, if the material separation of the present invention is not performed, the erodibility index when only the impurities are removed may be almost the same as when the impurities are not removed. It was discovered. In addition, by comparing the comparative example 2 and the reference example , if the material separation of the present invention is performed, the average value of the erosion index and It has been found that since the standard deviation is reduced, the corrosion resistance can be improved. In addition, the standard deviation of the erosion index is not changed by comparison between Example 2 of the present invention and the reference example , but the average value is reduced from 108 to 106. From this, the material separation of the present invention is classified. It has been found that the corrosion resistance is improved by removing impurities after the removal. From these results, improvement of corrosion resistance was not obtained only by removing impurities according to the prior art, and the effectiveness of the material separation of the present invention was confirmed.

[Example 2]
Used refractories collected during tundish repair at a steel factory were collected. An alumina amorphous refractory is used as the refractory on the working surface side of the tundish, and alumina brick and wax stone brick are used as the refractory on the back side. The recovered used refractory is a mixture of these. These used refractories were pulverized to a particle size of about 40 mm or less with a cone crusher, and the metal was removed with a magnetic separator.

  Moreover, in the present Example 2, about the color sorter used for the classification | category for every material of used refractory material, the prior setting which sets the threshold value of a color tone was performed similarly to the case of Example 1 mentioned above. At this time, several samples of the material to be collected and samples to be removed are selected from the used refractories after the magnetic separation in the second embodiment, and the color tone of the color separator is selected using these samples. The threshold value was set.

  After performing the above-mentioned pre-setting, classify the used refractories after magnetic separation with a predetermined sieve mesh, and set the used refractories after classification to the preset color for each material with the set threshold as a boundary. Sorting into black crushed material and non-black color crushed material, specifically, a mixture of alumina-based amorphous refractory and alumina brick and wax stone brick. Was removed. In this Example 2, the black crushed material is an impurity including adhering slag, an infiltrated layer in which a lower oxide such as slag or iron oxide has infiltrated the refractory, and a metal that cannot be removed by a magnetic separator. there were. On the other hand, the mixture after the above-described separation was further separated into an alumina-based amorphous refractory and an alumina brick and a wax stone brick by a color separation machine by using a reset threshold as a boundary. In this manner, alumina-based amorphous refractories were separated from these used refractories by a color separator and collected. Thereafter, each of these recovered products and removed products was visually confirmed to confirm whether or not they were separated as desired. When it was not possible to sort as desired, the above-described pre-setting was performed again, and when it was possible to sort as desired, this sorting process was terminated.

  In the second embodiment, as in the case of the first embodiment described above, in addition to the threshold setting of the color separator, in order to correspond to the particle size of the used refractory to be separated, according to the determination range of the particle size. Thus, various settings related to the classification were made, such as adjusting the ejection range of the compressed air to the classification target, adjusting the injection time of the compressed air, and adjusting the ejection timing.

  On the other hand, in this Example 2, for comparison, a sample that was not subjected to any separation by a color sorter and a sample that was obtained by removing only impurities were prepared. The used refractories of these comparative examples and Example 2 were further dried and pulverized to obtain refractory raw materials (for example, refractory raw materials made of carbon-free refractories). Using the obtained refractory raw materials, In addition, a carbon-free fixed refractory such as a molten steel holding container refractory, specifically, an alumina fired brick was manufactured.

  In the production of the alumina fired brick, the blending ratio of the used refractory was set to 50% or 70% in terms of the amount of inner material. A portion of the used refractory was collected before use, analyzed for chemical components, and then alumina fired brick was manufactured with a target of 55% alumina, which is the composition value of the brick as a base material together with new raw materials. . The new raw material used band shale as the alumina source and waxite as the silica source.

The alumina fired brick produced using a rotating drum tester was subjected to an erosion test. The production conditions and test results of the alumina fired brick are shown in Table 4 below. In the erosion test, a synthetic slag prepared so that the ratio of CaO to Al ₂ O ₃ (CaO / Al ₂ O ₃ ) was 1.5 was used. The erosion test was performed by heating a sample lined on a rotating drum tester with a burner while rotating, and after reaching a test temperature of 1650 ° C., synthetic slag was added and held for 2 hours. For the evaluation, the change in thickness of the sample before and after the test was measured, and an erodibility index with the change in thickness of the base material as 100 was used.

  In Table 4, an example of “with” impurity removal and “with” material separation is the classification of used refractory into alumina-based amorphous refractories, alumina bricks, wax stone bricks and black impurities, and black after separation. In this example, the impurities are removed. The example of “None” for impurity removal and “None” for material separation is an example in which the used refractory is not separated by a color separator. The example of “existence” of impurity removal and “absence” of material classification is an example in which only black impurities are removed from the used refractory. In this example, the alumina-based amorphous refractory and the alumina brick and the waxy brick were recovered without being separated. Such distinction between the examples is the same as in the second embodiment.

  Table 5 shown below summarizes the results of the erosion test. As shown in Table 5, the effects of the prior art for removing impurities can be seen from the comparison between Comparative Example 1 and Comparative Example 2, but the erosion index of Comparative Example 1 and Comparative Example 2 is 20% or more with respect to the base material. It was big. Further, from the comparison between Comparative Example 2 and Example 1 of the present invention and the comparison between Comparative Example 3 and Example 2 of the present invention, when the material separation is performed by the color separation process, the distribution range of the erodibility index is narrowed and the erosion property is decreased. It has been found that the corrosion resistance can be improved since the average value of the index decreases.

  Further, from the comparison between Comparative Example 2 and Comparative Example 3 and the comparison between Invention Example 1 and Invention Example 2, when the mass ratio of the recycled material is increased, the distribution range of the erosion index is widened. It was found that the average value increased. Further, from the comparison of Comparative Example 2, Comparative Example 3, Invention Example 1 and Invention Example 2, the material is separated by color separation treatment, so that the material ratio is 70% even if the mass ratio of the recycled material is 70%. It has been found that the average value and maximum value of the erodibility index are smaller than those obtained by adding 50% of non-sorted materials, the distribution range of the erosion index is narrow, and the same level of corrosion resistance as the base material can be obtained. It was.

  As described above, according to the method for reusing used refractories according to the present invention, by separating and collecting used refractories for each material based on color tone, a large amount can be obtained with high accuracy without relying on manual work. Used refractories can be sorted by material. Moreover, when using a used refractory as a raw material, the dispersion | variation in quality accompanying the change of a material mixing ratio can be reduced, and the product with stable performance can be obtained.

  In addition, by stabilizing the variation in quality, it can be applied to parts and facilities where a refractory made from a used refractory can not be applied conventionally. In addition, since it becomes easy to apply the used refractory to other applications, the reuse scope and the reusable amount of the used refractory are increased, and the waste disposal cost is reduced by reducing the waste. The cost of the manufacturing industry can be reduced by increasing the amount of used refractory used as an inexpensive raw material.

  The embodiment to which the invention made by the present inventors is applied has been described above, but the present invention is not limited by the description and the drawings that constitute a part of the disclosure of the present invention. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

Claims (6)

A method of reusing used refractories that reuses used refractories, using a color separator and having the used refractories according to the chemical components contained in the used refractories In accordance with the inherent color difference, in addition to removing impurities, the used refractory is separated and collected for each material having a different chemical composition, and includes a separate collection step.
The separation and collection step includes: setting a color tone threshold for separating the used refractory in the color sorter; and separating the used refractory by the color sorter with the set threshold as a boundary. Separating the used refractory according to the total number of the material and the impurities to be collected in the used refractory.   The method for reusing a used refractory according to claim 1, further comprising a crushing step of crushing the used refractory before performing the separation and recovery step.   The said crushing step includes the step of removing the powder with a particle size of 1 mm or less contained in the said used refractory, The reuse method of the used refractory according to claim 2 characterized by the above-mentioned.   The used refractory according to any one of claims 1 to 3, further comprising a reuse step of reusing the used refractory for each recovered material as a refractory raw material. How to reuse The used refractories include a used carbon-containing shaped refractory and a carbon-free shaped refractory,
In the separation and collection step, the used refractory is separated into the carbon-containing fixed refractory and the carbon-free fixed refractory used by the color separator, and the used carbon-containing fixed sized material is separated. Collecting the refractory,
5. The reuse of used refractories according to claim 4, wherein the reuse step includes a step of reusing the collected used carbon-containing fixed refractory as a carbon-containing fixed refractory raw material. Method. The used refractory does not include a carbon-containing refractory, and includes a plurality of used carbon-free refractories,
In the separation and collection step, the used refractory is separated into each of a plurality of used carbon-free refractories by the color separator, and the collected used carbon-free refractories are collected. Including steps,
5. The method for reusing a used refractory according to claim 4, wherein the reusing step includes a step of reusing the collected used carbon-free refractory as a refractory raw material.