JP2020163256A - Selection method and selection device of used refractory material - Google Patents

Abstract

To provide a method and a device for selecting a highly accurate valuable material from a used refractory material.SOLUTION: A selection method comprises: (a crushing process) of crushing a used refractory material; (a grain size adjustment process) of adjusting the used refractory material crushed by the crushing process to a prescribed grain size range; (a sticking foreign matter removal process) of removing a foreign matter sticking to a surface of the refractory material by spraying gas; and (a component separation process) of separating the used refractory material grain to a plurality of groups as a main component is the group based on the result obtained by performing component analysis by a laser induction breakdown spectrometry to the used refractory material grain from which the foreign matter has been removed.SELECTED DRAWING: Figure 3

Description

The present invention relates to a used refractory sorting method and a sorting device, and more particularly to a sorting method and a sorting device for sorting and recovering valuable resources from used blast furnace gutter refractories generated in a steel mill.

Various refractories are used in the steel process, especially in the ironmaking process and the steelmaking process. Moreover, not only one type of refractory is used alone, but also a plurality of types of refractories are combined according to their characteristics. Widely used.

For example, FIG. 1 is a cross-sectional view showing a general usage state of a blast furnace gutter. As shown in this figure, in the blast furnace gutter 1, the refractory material 3 is attached to the inside of the iron skin 2 which is the outer shell. The refractory material 3 mainly has an upper and lower two-layer structure of the metal line material 4 and the slag line material 5, so that the metal line material 4 mainly contacts the hot metal and the slag line material 5 mainly contacts the slag. It has been distributed. Since the used refractory (hereinafter, used refractory) is generally disassembled using a heavy machine, the metal line material 4 and the slag line material 5 are mixed and discharged.

The metal line material 4 contains alumina (Al ₂ O ₃ ) as a main component, and the slag line material 5 contains silica (SiC) as a main component. Since both of these have high value as raw materials, it would be an industrial advantage if the metal line material 4 and the slag line material 5 could be individually recovered from the used refractory and reused as recycled materials.

Therefore, various methods have been proposed for sorting used refractories. For example, Patent Document 1 and Patent Document 2 describe a method of crushing and adjusting the particle size of a used refractory and then repeating sorting by magnetic force a plurality of times, and a method of further combining sorting by color. Further, Patent Document 3 describes a method in which a refractory is artificially colored in advance and sorted by the color after use. In addition, Patent Document 4 describes a method of selecting used refractories by using a solid-gas fluidized bed using powder as a fluidized medium and utilizing the difference in specific gravity.

Further, Patent Document 5 discloses a technique of pulverizing, adjusting the particle size, and further separating each composition by density separation and magnetic force selection. Patent Document 6 discloses a method for sorting particles by analysis by optical means. Patent Document 7 discloses a method for sorting metals by fluorescent X-rays. Patent Document 8 discloses a method for selecting a powdery or granular object. Patent Document 9 discloses a method of selecting based on the result of component analysis using laser-induced breakdown spectroscopy.

Japanese Unexamined Patent Publication No. 2003-83683 Japanese Unexamined Patent Publication No. 2003-08845 Japanese Unexamined Patent Publication No. 2013-212481 Japanese Unexamined Patent Publication No. 2016-77956 Japanese Unexamined Patent Publication No. 2016-168523 Special Table 2014-512267 Japanese Patent Application Laid-Open No. 10-216651 Japanese Unexamined Patent Publication No. 2011-41903 JP-A-2018-122226 Public Relations

Here, the metal line material 4 and the slag line material 5 both contain a small amount of iron, but the amount thereof is small and the difference in the amount is small. Therefore, selection by magnetic force disclosed in Patent Documents 1 and 2. It is difficult. Next, in the method of selecting by color described in Patent Document 3 and the method of selecting particles by optical means as described in Patent Document 6, both the metal line material 4 and the slag line material 5 are used. Since it contains carbon, it is gray or black, and there are some parts where the colored parts are not exposed after crushing, so it was not suitable for sorting this type of refractory. Further, the sorting using the difference in specific gravity described in Patent Document 4 is not suitable for sorting refractories having a particle size of about 10 mm or less.

Further, since the used refractory is usually stored in an outdoor yard after being crushed, the used refractory is often wetted by rainfall in rainy weather, and the color tone changes due to the wetness, and Patent Document 3 It was difficult to sort by the color that can be described in. In the sorting using the difference in specific gravity described in Patent Document 4 and Patent Document 5, the apparent specific gravity of the wet refractory changes, which makes sorting difficult, or the fluidized bed medium adheres to the wet refractory. Then, it is transported to the outside of the device as it is, and it is necessary to replenish the fluidized bed medium on a regular basis, which is a problem. Further, although it is possible to sort metals by the method using fluorescent X-rays described in Patent Document 7 and Patent Document 8, in the sorting of non-ferrous metals such as refractories, slight differences in composition are separated. It was difficult to do.
The above-mentioned points can be solved by using the component separation method described in Patent Document 9, but the following points have been sought to be improved even when the component separation is used. That is, foreign matter such as slag may adhere to the surface of the used refractory during yard storage and handling of the refractory, and the composition of the foreign matter may be mistaken for the composition of the refractory, so that the composition can be measured appropriately. Without this, it may be difficult to ensure the separation accuracy.
Therefore, with the above method, the accuracy of sorting valuable materials from used refractories was still not sufficient.

Therefore, the present invention provides a method and an apparatus for selecting valuable resources from used refractories with high accuracy, and particularly separates used refractories containing light elements such as C, O, Na and Mg by component. It is an object of the present invention to provide a method and an apparatus for sorting with high accuracy.

As a result of diligent research on the means for solving the above problems, the inventors have made a clear difference in the composition of the metal line material 4 and the slag line material 5, as shown in Table 1 below. It was found that selection based on the type and component ratio of the contained components is effective, and it is particularly necessary to accurately detect the emission spectrum of Mg, which is a light element. In addition, blast furnace slag, which is a typical impurity, can be selected from the characteristic that it contains a large amount of CaO. Furthermore, when analyzing the components of used refractories, it is necessary to adjust the particle size appropriately according to the analysis method.

It was confirmed that the sorting by component analysis is effective according to the above procedure, but when actually sorting the used refractories, it is important to solve the above-mentioned problem of foreign matter adhering to the used refractories. become. As a result of diligent investigation by the inventors on this point, it was found that it is effective to blow off the foreign matter adhering to the used refractory by blowing a gas prior to the component analysis.

Further, as shown in Table 1, the slag line material 5 contains Al ₂ O ₃ and SiC, and in order to reuse them as valuable resources, it is preferable to further select and recover them. Therefore, as a result of diligent studies on a method for sorting the slag line material 5 into an Al ₂ O ₃ refractory and a SiC refractory, the slag line 5 is further pulverized and the obtained powder is sorted by magnetic force. Found to be effective. That is, the powder containing Al ₂ O ₃ as a main component contains a small amount of Fe, whereas the powder containing SiC as a main component does not contain any Fe. Therefore, when the slag line material 5 was pulverized, a mixed powder of Al ₂ O ₃ based powder and SiC based powder was obtained, and it was conceived that a trace amount of Fe could be detected by a predetermined magnetic force.
The present invention is based on the above findings.

The gist of the present invention is as follows.

(1) A method for sorting used refractories.
The crushing process for crushing the used refractory and
A particle size adjusting step for adjusting the used refractory crushed by the crushing step to a predetermined particle size range, and a particle size adjusting step.
A step of spraying a gas onto the used refractory particles whose particle size has been adjusted to remove foreign substances from the surface of the refractory.
Based on the results obtained by performing component analysis on the used refractory particles from which the foreign matter has been removed by using laser-induced breakdown spectroscopy, the used refractory particles have the same main components. A component separation step that separates into multiple groups as a group,
A method for sorting used refractories, which comprises.

(2) The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
The method for sorting used refractories according to (1) above.

(3) A method for sorting used refractories.
The crushing process for crushing the used refractory and
A particle size adjusting step for adjusting the used refractory crushed by the crushing step to a predetermined particle size range, and a particle size adjusting step.
A step of spraying a gas onto the used refractory particles whose particle size has been adjusted to remove foreign substances from the surface of the refractory.
Based on the results obtained by component analysis of the used refractory particles from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory particles have the same main components. A component separation step that separates into multiple groups as a group,
A pulverization step of pulverizing refractory particles belonging to at least one of the plurality of groups into refractory powder, and
A method for sorting used refractories, which comprises a magnetic force sorting step of sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force.

(4) The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
In the crushing step, refractory particles belonging to the group of slag line materials are crushed into slag line material powder.
In the magnetic force sorting step, the slag line material powder is sorted into Al ₂ O ₃ powder and SiC powder using magnetic force.
The method for sorting used refractories according to (3) above.

(5) The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
In the crushing step, refractory particles belonging to the group of metal line materials are crushed into metal line material powder.
In the magnetic force sorting step, the metal line material powder is sorted into Al ₂ O ₃ powder and SiC powder using magnetic force.
The method for sorting used refractories according to (3) or (4) above.

(6) The method for sorting used refractories according to any one of (3) to (5) above, wherein the magnetic force sorting step uses a magnet having a magnetic flux density of 0.6 T or more.

(7) The component separation step includes separating the refractory grains containing bare metal iron from the refractory grains by using magnetic force before or after the component analysis.
The method for sorting used refractories according to any one of (1) to (6) above.

(8) A used refractory sorting device
A crushing means for crushing the used refractory and
A particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range, and
A means for removing foreign matter from the surface of the refractory by spraying a gas onto the used refractory particles whose particle size has been adjusted.
Based on the results obtained by component analysis of the used refractory particles from which the foreign matter has been removed by a laser-induced breakdown spectroscope, the used refractory particles have the same main components. A component separation means that separates into multiple groups as a group,
A used refractory sorting device, characterized in that it contains.

(9) The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The used refractory sorting device according to (8) above.

(10) A used refractory sorting device
A crushing means for crushing the used refractory and
A particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range, and
A means for removing foreign matter from the surface of the refractory by spraying a gas onto the used refractory particles whose particle size has been adjusted.
Based on the results obtained by component analysis of the used refractory particles from which the foreign substances have been removed by a laser-induced breakdown spectrometer, the used refractory particles have the same main components. A component separation means that separates into multiple groups as a group,
A pulverizing means for pulverizing refractory particles belonging to at least one of the plurality of groups into refractory powder, and
A magnetic force sorting means for sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force.
A used refractory sorting device, characterized in that it contains.

(11) The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The crushing means grinds refractory particles belonging to the group of slag line materials into slag line material powder.
The magnetic force sorting means sorts the slag line material powder into Al ₂ O ₃ powder and SiC powder by using magnetic force.
The used refractory sorting device according to (10) above.

(12) The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The crushing means pulverizes refractory particles belonging to the group of metal line materials into metal line material powder.
The magnetic force sorting means sorts the metal line material powder into Al ₂ O ₃ powder and SiC powder by using magnetic force.
The used refractory sorting device according to (10) or (11) above.

(13) The used refractory sorting device according to any one of (10) to (12) above, wherein the magnetic force sorting means has a magnet having a magnetic flux density of 0.6 T or more.

(14) The component separating means can further separate the refractory particles containing bare metal iron from the refractory particles by using magnetic force.
The used refractory sorting device according to any one of (8) to (13) above.

According to the present invention, valuable materials can be sorted with high accuracy from used refractories.

It is sectional drawing which shows the use state of a general blast furnace gutter. It is a flowchart of the used refractory sorting method which concerns on one Embodiment of this invention. Based on the results obtained by component analysis of used refractory grains by laser-induced breakdown spectroscopy, the refractory grains are separated into a plurality of groups as a group having the same main component. It is a conceptual diagram which shows the structure of the separation means. It is a figure which shows the example of the emission spectrum of the refractory grain of a metal line material detected by a spectrometer. It is a figure which shows the example of the emission spectrum of the refractory grain of a slag line material detected by a spectrometer. It is a figure which shows the example of the emission spectrum of the impurity refractory grain detected by the spectrometer.

(Method of sorting used refractories)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a flowchart of a method for sorting used refractories according to an embodiment of the present invention.

As shown in FIG. 2, the method for selecting used refractories according to the present invention crushes used refractories (crushing step) and adjusts the used refractories crushed by the crushing step to a predetermined particle size range. (Particle size adjustment step), gas is sprayed onto the used refractory particles whose particle size has been adjusted to remove foreign substances (gas spraying step), and the results obtained by component analysis of the used refractory particles are obtained. Based on this, the refractory particles are separated into a plurality of groups as a group having the same main component (component separation step).
Hereinafter, each step will be described in detail.

First, in the crushing process, the used refractory is crushed. This crushing can be performed using a heavy machine such as a jaw crusher or a bucket crusher. This crushing step is intended to make the used refractory a particle size suitable for component separation described later.

Next, in the particle size adjusting step, the used refractory crushed by the crushing step is adjusted to a predetermined particle size range. When the laser-induced breakdown spectroscopy described later is used, the particle size range is 5 mm or more and 100 mm or less, and more preferably 10 mm or more and 40 mm or less. It is preferable that the width of the particle size distribution is narrow in order to improve the accuracy of the subsequent component separation.

Specifically, the particle size of the used refractory can be adjusted by using a sieve. For example, when the particle size range of the used refractory is 10 mm or more and 40 mm or less, first, the crushed used refractory is sieved using a sieve having a mesh size of 40 mm. Then, the used refractory that has passed through a sieve having an opening size of 40 mm is passed through a sieve having an opening size of 10 mm. The used refractory material remaining on the sieve having a mesh size of 10 mm is treated as used refractory material particles 30 (hereinafter, also referred to as refractory material particles 30) having a predetermined particle size range.

First, in a sieve having an opening size of 40 mm, it is preferable that the used refractory remaining on the sieve is crushed again to further reduce the particle size, and then subjected to the above-mentioned particle size adjustment again.

Subsequently, in the gas spraying step, gas is sprayed onto the used refractory particles 30 whose particle size has been adjusted to remove foreign substances adhering to the refractory. In many cases, the foreign matter adhering to the refractory is mainly blast furnace slag and other types of refractory powder (mainly), and the size of the foreign matter is about 2 mm or less. .. When removing such foreign substances, examples of the type of gas suitable for use include air and nitrogen, the gas supply piping pressure is in the range of 0.05 to 1 MPa, and the flow rate is 0.05 to 10 Nm ³ / min. In order to prevent the used refractory from falling from the belt conveyor, 0.05 to ⁵ Nm ³ / min is desirable. The size of the nozzle (opening diameter) is 1 to 20 mm, and a plurality of nozzles may be provided. Further, a slit-shaped nozzle having a similar opening area can also be used. In addition, when the foreign matter or refractory is wet, or by adjusting the flow rate and nozzle size according to the type and size of the foreign matter, there is no problem in component analysis and position identification due to the rolling of the refractory particles. Can be a range.
After that, in the component separation step, based on the results obtained by performing the component analysis, the group is separated into a plurality of groups as a group having the same main component. When the used refractory grain 30 is a used blast furnace slag refractory grain, the refractory grain 30a belonging to the metal line material group (hereinafter, metal line material refractory grain 30a), as a group having the same main component, It is separated into a plurality of groups including the refractory grain 30b belonging to the group of slag line material (hereinafter, slag line material refractory grain 30b). As described above, there is a clear difference in the component composition between the metal line material and the slag line material, and therefore selection can be performed based on the contained components themselves and the component ratio. Further, the refractory material of the blast furnace gutter usually has slag attached in the process of being used, and 30c of refractory material containing impurities such as blast furnace slag (hereinafter, “impurity refractory material 30c”) is also contained. It can be selected based on the components themselves and the component ratio.
Hereinafter, the selection of used blast furnace gutter refractory grains will be described as a typical example.

Laser-induced breakdown spectroscopy is the most suitable method for component analysis of wet refractories. This is because laser-induced breakdown spectroscopy does not require sample preparation, and can perform very high-speed measurements, usually several microseconds to several milliseconds per spot, and has high work efficiency. Furthermore, laser-induced breakdown spectroscopy has a wide element measurement range including light elements such as O, Na and Mg, and the analysis of the component composition of the metal line material and the slag line material shown in Table 1 Suitable for. Furthermore, light elements such as H, Be, Li, and N can also be measured, and substances containing these can be analyzed, so that used refractories and the like can be accurately discriminated.

In FIG. 3, based on the results obtained by performing component analysis of used refractory particles by laser-induced breakdown spectroscopy, the refractory particles are divided into a plurality of groups as a group having the same main component. It is a conceptual diagram which shows the structure of the component separation means to separate. Hereinafter, with reference to FIG. 3, the used refractory particles 30 are subjected to component analysis by laser-induced breakdown spectroscopy using a component separation means, and the refractory particles 30 are based on the results obtained. Will be described as a component separation step of separating the group into a plurality of groups as a group having the same main component.

The component separating means 6 shown in FIG. 3 includes a vibration feeder 7, a belt conveyor 8a, a gas blowing device 8b, an image camera 9, a short pulse laser 10, a spectrometer 11, an analysis controller 12, and an air jet. 13 and drop chutes 14a to 14c are provided. Here, the gas blowing device 8b can blow gas at a pressure of 0.05 to 0.5 MPa, and fits the width of 1 to 20, preferably 4 to 12, or the existing belt conveyor 8a. It has a number of nozzles that can be installed at intervals of 10 to 100 mm in the width direction of the belt conveyor, and is separated from the upper surface of the refractory particles on the belt conveyor by 50 to 1000 mm, preferably 100 mm, and is used as a refractory material on the belt conveyor. It has features such as air hitting all of the grains almost evenly, and foreign matter adhering to the surface can be removed without causing the refractory grains to roll significantly.

In the component separating means 6, the used refractory particles 30 adjusted to a predetermined particle size range are evenly supplied by the vibration feeder 7 without being stacked on the belt conveyor 8a. The position of the used refractory particles 30 supplied on the belt conveyor 8a is detected by the image camera 9 on the belt conveyor 8a. Based on the transport position information by the image camera 9 and the information on the movement amount of the belt conveyor 8a tracked from the rotation pulse sensor information of the encoder or the like attached to the drive motor (not shown) of the belt conveyor 8a. The short pulse laser 10 is accurately irradiated to each of the used refractory particles 30 being transported, the emission spectrum of the high temperature plasma generated from the irradiation point is detected by the spectrometer 11, and the analysis controller is based on the detection information. 12 is used to determine whether the refractory grain 30 corresponds to any of the metal line material refractory grain 30a, the slag line material refractory grain 30b, or the impurity refractory grain 30c.

4 to 6 are diagrams showing examples of emission spectra of metal line material refractory particles, slag line material refractory particles, and impurity refractory particles detected by a spectrometer. Here, when the composition of the metal line material and the slag line material is compared with reference to Table 1, the metal line material contains Al ₂ O ₃ as a main component, and the slag line material contains SiC as a main component. .. Further, the metal line material contains MgO, but the slag line material does not contain MgO. Therefore, by comparing the result of the component composition obtained by the analysis of the emission spectrum with the above findings (Table 1), the refractory grain 30 is the metal line material refractory grain 30a or the slag line material refractory grain 30b. It is possible to determine which one is applicable. For example, in the example of the emission spectrum of the refractory grain of the metal line material shown in FIG. 4, since Al has a peak and the spectrum of Mg can be confirmed, Al ₂ O ₃ is contained as a main component and Mg O is contained. It can be determined that the metal line material is the refractory grain 30a. On the other hand, in the example of the emission spectrum of the slag line material refractory grain shown in FIG. 5, since the spectrum of Mg does not exist, it can be determined that the slag line material refractory grain 30b contains SiC as a main component. Further, in the example of the emission spectrum of the impurity refractory particles shown in FIG. 6, since there is a peak in Ca, it can be determined that the impurity refractory particles such as blast furnace slag are 30c.

The used refractory grain 30 determined by the analysis controller 12 to be either the metal line material refractory grain 30a, the slag line material refractory grain 30b, or the impurity refractory grain 30c is dropped by using the air jet 13. The positions of the shoots 14a to 14c are controlled and separated. The metal line material refractory grain 30a is separated into a falling chute 14a, the slag line material refractory grain 30b is separated into a falling chute 14b, and the impurity refractory grain 30c is separated into a falling chute 14c. Although the air jet 13 is used in the illustrated example, the position of the drop chute 14a to 14c can be controlled by using a paddle.
Based on the results obtained by performing component analysis on the used refractory grain 30 whose particle size has been adjusted in this way, the refractory grain 30 is divided into the metal line material refractory grain 30a and the slag line material refractory. It can be separated into either the particle 30b or the impurity refractory particle 30c.

In the component separation step of the present invention, it is preferable to separate the refractory grains containing the bare metal iron from the refractory grains 30 by using magnetic force before or after the above component analysis. In general, refractories in blast furnace gutters are designed so that slag and hot metal adhere to them less, but slag containing bare metal and iron adhere to them in the process of use. In the reuse of refractory materials, the refractory particles to which such slag containing metal iron is attached are separated from the refractory particles by using magnetic force using the magnetism of the metal iron contained in the slag. Is preferable. The use of magnetic force includes, for example, the use of a magnetic force separator having a magnetic field having a magnetic flux density of 0.1 T to 1 T. The suitable magnetic flux density is 0.3T to 0.6T. A drum type or a belt hanging type can be used for this magnetic force separator. Preferably, by using the drum type magnetic force separating means, it is possible to prevent the slag from being dropped more effectively.
In this way, by separating the refractory particles containing the bare metal iron from the refractory particles by using magnetic force, it is possible to reduce the possibility that slag is mixed in the valuable material.

Through the above steps, the used blast furnace gutter refractory can be reliably sorted into the metal line material and the slag line material. In the present invention, the refractory particles thus separated can be further subdivided according to the presence or absence of magnetism.

That is, subsequently, in the present embodiment, the refractory particles 30 belonging to at least one of the plurality of groups are pulverized into the refractory powder (crushing step). More specifically, among the refractory grains 30 separated into the metal line material refractory grain 30a and the slag line material refractory grain 30b by the above-mentioned component separation step, the refractory belonging to the slag line material refractory grain 30b. The grains are further crushed into refractory powder (hereinafter referred to as slag line material powder). As described above, since the slag line material contains Al ₂ O ₃ and SiC, when the refractory grain 30b of the slag line material is further finely crushed into powder, Al ₂ O ₃ is the main component. It can be a mixed powder of Al ₂ O ₃ based powder and SiC based powder containing SiC as a main component.

The pulverization can be performed using, for example, a hammer mill, an impact crusher, a roller mill, or the like.

The powder after crushing the refractory grain 30b of the slag line material should have a particle size range that can be separated into Al ₂ O ₃ powder and SiC powder, and according to the investigation by the inventors. The particle size is preferably 2 mm or less, more preferably 1 mm or less. On the other hand, if the particle size is pulverized to less than 100 μm, the handleability as a powder deteriorates, so the particle size is preferably 100 μm or more.

The refractory powder thus crushed is sorted into magnetic powder and non-magnetic powder using magnetic force (magnetic force sorting step). Here, Al ₂ O ₃ is derived from natural ore and therefore contains a small amount of Fe, whereas SiC does not exist in nature and is artificially produced, so that it does not contain any Fe. Has. As described above, in order to detect a small amount of Fe contained in Al ₂ O ₃ , it is necessary to select the magnetic force using a sufficient magnetic force. As a result of investigation by the inventors, it is preferable to use a magnetic field sorting means having a magnetic field with a magnetic flux density of 0.6 T or more, and more preferably, a magnetic force sorting means having a magnetic field with a magnetic flux density of 1 T or more is used.

As the magnetic force sorting means, for example, a magnetic force sorting means designed by devising a magnetic circuit so that a large number of poles having 1T or more are locally arranged may be used. The type of the magnetic force sorting means can be a drum type, a belt type, a belt hanging type, a high-gradient magnetic force sorting means using a magnetic media, or the like.

Using the above magnetic force sorting means, it is possible to sort a magnetic Al ₂ O ₃ powder containing a small amount of Fe and a non-magnetic SiC powder containing no Fe from the slag line material powder. it can. In this way, SiC can be recovered with higher purity by performing magnetic force selection after component separation.

The above crushing step and magnetic force sorting step may be applied to refractory grains belonging to the group of metal line materials. Of the refractory grains 30 separated into the metal line material group and the slag line material group by the above-mentioned component separation step, the refractory particles belonging to the metal line material refractory grain 30a are further pulverized into refractory powder ( Hereinafter, metal line material powder). The metal line material contains Al ₂ O ₃ and SiC, and when the refractory grain 30a of the metal line material is crushed, Al ₂ O ₃ based powder containing Al ₂ O ₃ as a main component and SiC as a main component are used. A metal line material powder, which is a mixed powder with the SiC powder, can be obtained, and Al ₂ O ₃ can be recovered with higher purity by performing magnetic force sorting similar to that of the slag line material powder. it can.

In this way, valuable materials can be sorted with high accuracy from used refractories. It has been difficult to separate the metal line material and the slag line material by color separation and fluorescent X-ray analysis, which are conventional sorting methods. On the other hand, the component separation means by the laser-induced breakdown spectroscopy, which is the method of the present invention, enables the separation of the metal line material and the slag line material. At that time, by spraying gas on the refractory, valuable materials can be sorted with high accuracy even in a used refractory in a wet state where foreign matter is attached to the surface without adding a step such as drying.

(Used refractory sorting device)
Next, an apparatus for selecting valuable resources from used refractories according to the present invention will be described. The used refractory sorting device (hereinafter referred to as a refractory sorting device) according to the present invention has a crushing means for crushing the used refractory and a used refractory crushed by the crushing means in a predetermined particle size range. Based on the results obtained by performing component analysis, the particle size adjusting means for adjusting the particle size, the means for removing foreign substances adhering to the refractory to the used refractory particles whose particle size has been adjusted, and the results obtained by component analysis. It includes a component separation means for separating the refractory particles into a plurality of groups as a group having the same main component.

In the used refractory sorting apparatus of the present invention, the means used for crushing the used refractory is not particularly limited, and any used refractory to be treated can be crushed to an appropriate size. Can be used. For example, heavy machinery such as a jaw crusher and a bucket crusher can be used.

When the particle size range is suitable for the component separation means by laser-induced breakdown spectroscopy described later, the particle size is 5 mm or more and 100 mm or less, and more preferably 10 mm or more and 40 mm or less. It is preferable that the particle size distribution is relatively narrow in order to improve the accuracy of the subsequent component separation.

Further, the means used for adjusting the particle size of the used refractory is not particularly limited, and any means can be used as long as it can be adjusted to the used refractory particles in a predetermined particle size range. Sieve can be mentioned as a particle size adjusting means that can be used. For example, when the particle size range of a used refractory is 10 mm or more and 40 mm or less, it is first sieved with a mesh size of 40 mm. Then, the used refractory that has passed through a sieve having an opening size of 40 mm is passed through a sieve having an opening size of 10 mm. The used refractory material remaining on the sieve having a mesh size of 10 mm is treated as the used refractory material grain 30 having a predetermined particle size range.

Further, with respect to the used refractory particles 30 whose particle size has been adjusted, foreign matter adhering to the surface of the wet refractory or the like affects the component analysis accuracy, so the foreign matter on the surface is removed by spraying gas. Perform component analysis. Foreign matter is removed to the extent that the surface of used refractory grains is exposed by 50% or more, and the mixture is subjected to component analysis. When removing foreign matter from the surface of used refractory particles, a suitable gas flow rate and nozzle arrangement can be set by conducting a trial run in advance and observing the foreign matter removal state. In the trial run, the used refractory particles from which the foreign matter has been removed can be moistened and then sprayed with blast furnace slag powder, and the foreign matter removal state can be confirmed visually or by component analysis value. For used refractory particles that were actually tested, set the gas flow rate and nozzle arrangement so that the surface of the used refractory particles was exposed by 50% or more, and sprayed the gas under those conditions, the results were obtained. Was achieved. Based on the results obtained by performing component analysis, a component separation means for separating into a plurality of groups as a group having the same main component will be described. The component separation means is also not particularly limited, and any means can be used. When the used refractory grain 30 is a used blast furnace refractory grain, the refractory grain 30a belonging to the metal line material group (hereinafter, metal line material refractory grain 30a) and slag are classified as a group having the same main component. It is separated into a plurality of groups including the refractory grain 30b belonging to the line material group (hereinafter, slag line material refractory grain 30b). As described above, there is a clear difference in the component composition between the metal line material and the slag line material, and therefore selection can be performed based on the contained components themselves and the component ratio. Further, the refractory material of the blast furnace gutter usually has slag attached in the process of being used, and 30c of refractory material containing impurities such as blast furnace slag (hereinafter referred to as 30c of refractory material containing impurities) is also contained. It can be selected based on the components themselves and the component ratio.

As the component separating means of the present embodiment, for example, the component separating means 6 shown in FIG. 3 can be used. The component separation means 6 is a component separation means that separates refractory particles into a plurality of groups as a group having the same main component based on the result obtained by component analysis by laser-induced breakdown spectroscopy. Yes, as shown in FIG. 3, a vibration feeder 7, a belt conveyor 8a, a gas spraying device 8b for removing foreign matter adhering to a fireproof object, an image camera 9, a short pulse laser 10, a spectrometer 11, and a spectroscope 11. It is composed of an analysis controller 12, an air jet 13, and drop chutes 14a to 14c.
Based on the results obtained by performing component analysis on the used refractory grains 30 whose particle size has been adjusted using the component separating means 6, the refractory grains 30 are combined with the metal line material refractory grains 30a and slag. It can be separated into either line material refractory particles 30b or impurity refractory particles 30c.

Further, the component separating means preferably includes a magnetic force separator because the refractory particles containing the bare metal iron are separated from the refractory particles by using magnetic force. More specifically, in the reuse of refractory materials, the refractory particles of slag containing such metal iron are obtained from the refractory grain 30 by utilizing the magnetism of the metal iron contained in the slag. It is preferable to separate using. For example, a magnetic force separator having a magnetic field having a magnetic flux density of 0.1 T to 1 T may be used. The suitable magnetic flux density is 0.3T to 0.6T. A drum type or a belt hanging type can be used for this magnetic force separator. Preferably, by using the drum type magnetic force separating means, it is possible to prevent the slag from being dropped more effectively.
In this way, by separating the refractory particles containing the bare metal iron from the refractory particles by using magnetic force, it is possible to reduce the possibility that slag is mixed in the valuable material.

The refractory sorting apparatus of the present invention further includes a pulverizing means for pulverizing refractory particles belonging to at least one of the plurality of groups into refractory powder. More specifically, by the above-mentioned component separation means, one or both of the metal line material refractory particles 30a and the slag line material refractory particles 30b are further pulverized into refractory powder, for example. , Hammer mill, impact crusher, roller mill, etc.

The refractory sorting apparatus of the present invention further includes a magnetic force sorting means that sorts the refractory powder into magnetic powder and non-magnetic powder using magnetic force. As the magnetic force sorting means, it is preferable to use a magnetic field sorting means having a magnetic field having a magnetic flux density of 0.6 T or more, and more preferably, a magnetic force sorting means having a magnetic field having a magnetic flux density of 1 T or more is used.

As the above-mentioned magnetic force sorting means, for example, a magnetic force sorting means designed by devising a magnetic circuit so that a large number of poles having 1T or more are locally arranged may be used. The type of the magnetic force sorting means can be a drum type, a belt type, a belt hanging type, a high-gradient magnetic force sorting means using a magnetic media, or the like.

Al ₂ O ₃ can be recovered with higher purity from the refractory grain 30a (metal line material powder) of the metal line material crushed into the refractory powder by using the above magnetic force sorting means, and the refractory powder can be recovered. SiC can be recovered with higher purity from the refractory grain 30b (slag line material powder) of the slag line material crushed into.

In this way, valuable materials can be sorted with high accuracy from used refractories.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited by the following examples, and can be appropriately modified within a range that can be adapted to the gist of the present invention, all of which are included in the technical scope of the present invention. ..

[Example 1]
Used blast furnace gutter refractories were sorted according to the flowchart shown in FIG.
That is, first, a used refractory material containing a metal line material and a slag line material was crushed with a jaw crusher. Next, the crushed used refractory is sieved with a mesh size of 40 mm, the used refractory that has passed through the sieve is collected, sieved with a mesh size of 5 mm, and the used refractory remaining on the sieve is removed. By recovering, used refractory grains having a particle size adjusted to 5 mm or more and 40 mm or less were obtained.

Then, gas was sprayed onto the used refractory particles whose particle size was adjusted to 5 mm or more and 40 mm or less, and then the components were separated. That is, the used refractory particles were evenly supplied by the vibration feeder without being stacked on the belt conveyor, and gas was sprayed on the used refractory material supplied on the belt conveyor to remove the adhered foreign matter. Later, the image camera detected the transport position of the used refractory on the belt conveyor. Here, the gas to be sprayed used had a supply pipe pressure of 0.3 MPa. The supply piping pressure can be used even if it is higher than 0.3 MPa, but if the width of the belt conveyor exceeds 100 mm because it is necessary to spray it on all the used refractories moving on the belt conveyor, It is desirable to spray from multiple blowing nozzles or slit-shaped nozzles that are long in the width direction of the belt conveyor. In addition, the flow rate is adjusted so that the rolling of the used refractory due to the spraying of gas does not continue to the position of the field of view of the image camera and the accuracy of grasping the position by the image is lowered or the used refractory does not fall off from the belt conveyor. It was adjusted. Based on the transport position information of the used refractory by this image camera and the information of the movement amount of the belt conveyor tracked from the rotation pulse sensor information of the encoder etc. attached to the drive motor of the belt conveyor, the refractory is being transported. Accurately irradiate each of the used refractory particles with a short pulse laser, detect the emission spectrum of the high-temperature plasma generated from the irradiation point with a spectrometer, and use an analysis controller based on the detection information to use the refractory. It was determined whether the grains corresponded to the metal line material refractory grains, the slag line material refractory grains, or the impurity refractory grains.

4 to 6 are diagrams showing emission spectra of metal line material refractory particles, slag line material refractory particles, and impurity refractory particles detected by a spectrometer. In the emission spectrum of the refractory grains shown in FIG. 4, since Al has a peak and the spectrum of Mg can be confirmed, it is said that the metal line material contains Al ₂ O ₃ as a main component and contains Mg O. Judgment is obtained. On the other hand, in the example of the emission spectrum of the refractory grain shown in FIG. 5, since the spectrum of Mg does not exist, it can be determined that the slag line material contains SiC as a main component. Further, in the emission spectrum shown in FIG. 6, since Ca has a peak, it can be determined that the refractory is an impurity-containing refractory such as blast furnace slag.

The refractory particles belonging to the group of metal line materials and the group of slag line materials determined by the analysis controller were separated by controlling the position of the falling chute using an air jet. As a result, the purity of both the metal line material and the slag line material was 95% by mass.
Table 2 shows a comparison of separation accuracy with the conventional method. In the method using fluorescent X-rays, the presence of the Mg spectrum could not be detected, the slag line material and the metal line material could not be distinguished, and separation was difficult. Since laser-induced breakdown spectroscopy has a wide element measurement range including light elements, it has become possible to separate refractories containing these elements by component. Among these light elements, C and O are mentioned in addition to Mg as elements that are particularly useful for discriminating used refractories.
In addition, if foreign matter adheres to the surface of a wet refractory, the accuracy of component analysis will be affected. However, by spraying gas, the foreign matter adhering to the used refractory can be removed before component analysis. , It has become possible to improve the separation accuracy.

The purity is calculated by the following formula in each drop chute in which the metal line material and the slag line material are collected.
(Equation 1)
Purity of metal line material (mass%) = mass of metal line material / (mass of metal line material + mass of slag line material + mass of impurities such as blast furnace slag)
(Equation 2)
Purity of slag line material (mass%) = mass of slag line material / (mass of metal line material + mass of slag line material + mass of impurities such as blast furnace slag)

[Example 2]
In Example 1, the refractory particles belonging to the group of slag line materials separated by component separation after gas spraying were pulverized with a hammer mill to a particle size of 2 mm or less, and the obtained slag line was obtained. The material powder was sorted into magnetic Al ₂ O ₃ powder and non-magnetic SiC powder by a magnetic force sorting means having a 1.1 T rare earth permanent magnet. The purity of the Al ₂ O ₃ powder and the SiC powder obtained by this magnetic selection was 25% by mass for the Al ₂ O ₃ powder and 92% by mass for the SiC powder, respectively. It was. In this way, valuable resources could be recovered by sorting the metal line material and the slag line material, and further sorting the Al ₂ O ₃ powder and the SiC powder.

[Example 3]
In Example 1, the fire-resistant material particles belonging to the group of metal line materials separated by component separation after gas spraying were pulverized with a hammer mill to a particle size of 2 mm or less, and the obtained metal line was obtained. The material powder was sorted into magnetic Al ₂ O ₃ powder and non-magnetic SiC powder by a magnetic force sorting means having a 1.1 T rare earth permanent magnet. The purity of the Al ₂ O ₃ powder and the SiC powder obtained by this magnetic selection was 95% by mass for the Al ₂ O ₃ powder and 90% by mass for the SiC powder, respectively. It was. In this way, valuable resources could be recovered by sorting the metal line material and the slag line material, and further sorting the Al ₂ O ₃ powder and the SiC powder.

1 Blast furnace gutter 2 Refractory 3 Refractory 4 Metal line material 5 Slag line material 6 Component separation means 7 Vibration feeder 8a Belt conveyor 8b Gas sprayer for removing powder adhering to refractory 9 Image camera 10 Short pulse laser 11 Spectrometer 12 Analysis controller 13 Air jet 14 Fall chute 30 Refractory grain 30a Metal line material Refractory grain 30b Slag line material Refractory grain 30c Impurity refractory grain

Claims (14)

It is a method of sorting used refractories.
The crushing process for crushing the used refractory and
A particle size adjusting step for adjusting the used refractory crushed by the crushing step to a predetermined particle size range, and a particle size adjusting step.
A step of spraying a gas onto the used refractory particles whose particle size has been adjusted to remove foreign substances from the surface of the refractory.
Based on the results obtained by performing component analysis on the used refractory particles from which the foreign matter has been removed by using laser-induced breakdown spectroscopy, the used refractory particles have the same main components. A component separation step that separates into multiple groups as a group,
A method for sorting used refractories, which comprises. The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
The method for sorting used refractories according to claim 1. It is a method of sorting used refractories.
The crushing process for crushing the used refractory and
A particle size adjusting step for adjusting the used refractory crushed by the crushing step to a predetermined particle size range, and a particle size adjusting step.
A step of spraying a gas onto the used refractory particles whose particle size has been adjusted to remove foreign substances from the surface of the refractory.
Based on the results obtained by component analysis of the used refractory particles from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory particles have the same main components. A component separation step that separates into multiple groups as a group,
A pulverization step of pulverizing refractory particles belonging to at least one of the plurality of groups into refractory powder, and
A method for sorting used refractories, which comprises a magnetic force sorting step of sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force. The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
In the crushing step, refractory particles belonging to the group of slag line materials are crushed into slag line material powder.
In the magnetic force sorting step, the slag line material powder is sorted into Al ₂ O ₃ powder and SiC powder using magnetic force.
The method for sorting used refractories according to claim 3. The used refractory is a used blast furnace gutter refractory.
The plurality of groups include a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component.
In the crushing step, refractory particles belonging to the group of metal line materials are crushed into metal line material powder.
In the magnetic force sorting step, the metal line material powder is sorted into Al ₂ O ₃ powder and SiC powder using magnetic force.
The method for sorting used refractories according to claim 3 or 4. The method for sorting used refractories according to any one of claims 3 to 5, wherein the magnetic force sorting step uses a magnet having a magnetic flux density of 0.6 T or more. The component separation step comprises separating the refractory grains containing the bare metal iron from the refractory grains by magnetic force before or after the component analysis.
The method for selecting used refractories according to any one of claims 1 to 6. A used refractory sorting device
A crushing means for crushing the used refractory and
A particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range, and
A means for removing foreign matter from the surface of the refractory by spraying a gas onto the used refractory particles whose particle size has been adjusted.
Based on the results obtained by component analysis of the used refractory particles from which the foreign matter has been removed by a laser-induced breakdown spectroscope, the used refractory particles have the same main components. A component separation means that separates into multiple groups as a group,
A used refractory sorting device, characterized in that it contains. The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The used refractory sorting device according to claim 8. A used refractory sorting device
A crushing means for crushing the used refractory and
A particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range, and
A means for removing foreign matter from the surface of the refractory by spraying a gas onto the used refractory particles whose particle size has been adjusted.
Based on the results obtained by performing laser-induced breakdown spectroscopic component analysis on the used refractory particles from which the foreign matter has been removed, the used refractory particles have the same main components. As a component separation means that separates into multiple groups,
A pulverizing means for pulverizing refractory particles belonging to at least one of the plurality of groups into refractory powder, and
A magnetic force sorting means for sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force.
A used refractory sorting device, characterized in that it contains. The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The crushing means grinds refractory particles belonging to the group of slag line materials into slag line material powder.
The magnetic force sorting means sorts the slag line material powder into Al ₂ O ₃ powder and SiC powder by using magnetic force.
The used refractory sorting device according to claim 10. The crushing means is for crushing a used blast furnace gutter refractory.
The component separation means separates the refractory particles into a plurality of groups including a group of metal line materials containing Al ₂ O ₃ as a main component and a group of slag line materials containing SiC as a main component. ,
The crushing means crushes refractory particles belonging to the group of metal line materials into metal line material powder.
The magnetic force sorting means sorts the metal line material powder into Al ₂ O ₃ powder and SiC powder by using magnetic force.
The used refractory sorting device according to claim 10 or 11. The used refractory sorting device according to any one of claims 10 to 12, wherein the magnetic force sorting means has a magnet having a magnetic flux density of 0.6 T or more. The component separating means can further separate the refractory particles containing the bare metal iron from the refractory particles by using a magnetic force.
The used refractory sorting device according to any one of claims 8 to 13.

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