JP7289695B2 - Used refractory sorting method and sorting device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for sorting used refractories, and more particularly to a method and apparatus for sorting and recovering valuables from used blast furnace gutter refractories generated in ironworks.

Various refractories are used in the iron and steel process, especially in the ironmaking process and the steelmaking process. It is widely used.

For example, FIG. 1 is a cross-sectional view showing how a general blast furnace gutter is used. As shown in this figure, a blast furnace gutter 1 has a refractory 3 attached to the inside of a steel shell 2 serving as an outer shell. The refractory 3 mainly has a two-layer structure consisting of a metal line material 4 and a slag line material 5. The metal line material 4 is mainly in contact with hot metal, and the slag line material 5 is mainly in contact with slag. distributed. Used refractories (hereinafter referred to as used refractories) are generally dismantled using heavy machinery, so 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 materials are highly valuable as raw materials, it would be industrially advantageous if the metal line material 4 and the slag line material 5 could be individually recovered from the used refractories and reused as recycled materials.

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

Further, Patent Document 5 discloses a technique for separating by composition by pulverization, particle size adjustment, density separation, and magnetic force sorting. Patent Literature 6 discloses a method of sorting particles by analysis by optical means. Patent document 7 discloses a method of sorting metals using fluorescent X-rays. US Pat. No. 6,300,008 discloses a method for sorting powdery or granular objects. Patent Document 9 discloses a selection method based on the results of component analysis using laser-induced breakdown spectroscopy.

JP-A-2003-83683 JP-A-2003-088845 JP 2013-212481 A JP 2016-77956 A JP 2016-168523 A Japanese translation of PCT publication No. 2014-512267 JP-A-10-216651 Japanese Unexamined Patent Application Publication No. 2011-41903 Japanese Unexamined Patent Application Publication No. 2018-122226

Here, both the metal line material 4 and the slag line material 5 contain a small amount of iron, but the amount is small and the difference in amount is small. It is difficult. Next, in the method of sorting by color described in Patent Document 3 and the method of sorting particles by optical means as described in Patent Document 6, the metal line material 4 and the slag line material 5 are both Since it contains carbon, it has a gray or black color, and there are parts where the colored part is not exposed after crushing, so it was not suitable for sorting this kind of refractory. Furthermore, the sorting using the difference in specific gravity described in Patent Document 4 is unsuitable for sorting refractories with a particle size of about 10 mm or less.

In addition, since the used refractory is usually stored in an outdoor yard after being crushed, the used refractory often gets wet due to rainfall in rainy weather, and the moisture causes the color tone to change. It was difficult to sort by color that can be described in . In the sorting using the specific gravity difference described in Patent Document 4 and Patent Document 5, the apparent specific gravity of the wet refractory changes, making sorting difficult, and the fluidized bed medium adheres to the wet refractory. The problem is that the fluidized bed medium must be periodically replenished because the medium is then transported out of the apparatus as it is. In addition, in the method using fluorescent X-rays described in Patent Document 7 and Patent Document 8, it is possible to sort metals, but in the sorting of non-ferrous metals such as refractories, it is possible to separate slight differences in composition. was difficult to do.
The above problems can be solved by using the component separation technique described in Patent Document 9, but even with the use of component separation, the following improvements have been desired. In other words, foreign matter such as slag may adhere to the surface of used refractories during yard storage and handling of refractories. In some cases, it becomes difficult to ensure the separation accuracy.
Therefore, the accuracy of sorting out valuables from used refractories is still not sufficient with the above method.

Therefore, the present invention provides a method and apparatus for sorting valuables from used refractories with high accuracy, and in particular, 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 apparatus for sorting with high accuracy.

The inventors have diligently investigated means for solving the above problems, and found that there is a clear difference in composition between the metal line material 4 and the slag line material 5, as shown in Table 1 below. It was found that sorting based on the types and ratios of contained components is effective, and that it is necessary to accurately detect the emission spectrum of Mg, which is a light element, in particular. 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.

According to the above procedure, it was confirmed that sorting by component analysis is effective, but when actually sorting used refractories, it is important to solve the above-mentioned problem of foreign matter adhering to used refractories. become. As a result of intensive research by the inventors on this point, they have found that it is effective to blow away foreign matter adhering to the used refractory material by blowing gas prior to component analysis.

In addition, as shown in Table 1, the slag line material 5 contains Al ₂ O ₃ and SiC, and these are preferably further sorted and recovered in order to be reused as valuables. Therefore, as a result of intensive study on a method for sorting the slag line material 5 into Al ₂ O ₃ refractory and SiC refractory, the slag line material 5 is further pulverized and the obtained powder is sorted by magnetic force. I found that it is effective. That is, the powder containing Al ₂ O ₃ as the main component contains a small amount of Fe, whereas the powder containing SiC as the main component does not contain Fe at all. Therefore, when the slag line material 5 is pulverized, a mixed powder of Al ₂ O ₃ powder and SiC powder can be obtained, and it was conceived that a small amount of Fe can 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,
A crushing step of crushing the used refractory;
A particle size adjustment step of adjusting the used refractory crushed by the crushing step to a predetermined particle size range;
A step of blowing a gas onto the used refractory particles whose particle size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory grains are classified as having the same main component. A component separation step of separating into a plurality of groups as a certain group;
A method for sorting used refractories, comprising:

(2) the used refractory is a used blast furnace gutter refractory,
The plurality of groups includes 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,
A crushing step of crushing the used refractory;
A particle size adjustment step of adjusting the used refractory crushed by the crushing step to a predetermined particle size range;
A step of blowing a gas onto the used refractory particles whose particle size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory grains are classified as having the same main component. A component separation step of separating into a plurality of groups as a certain group;
a pulverizing step of pulverizing refractory grains belonging to at least one of the plurality of groups into refractory powder;
A method for sorting used refractories, comprising a magnetic force sorting step of sorting the refractory powder into magnetic powder and non-magnetic powder using a magnetic force.

(4) the used refractory is a used blast furnace gutter refractory;
The plurality of groups includes 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 pulverizing step pulverizes the refractory grains belonging to the slag line material group into slag line material powder,
In the magnetic separation step, the slag line material powder is separated into Al ₂ O ₃ -based powder and SiC-based 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 includes 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 pulverizing step pulverizes the refractory grains belonging to the metal line material group into metal line material powder,
The magnetic force sorting step uses a magnetic force to sort the metal line material powder into Al ₂ O ₃ -based powder and SiC-based powder.
The method for sorting used refractories according to (3) or (4) above.

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

(7) The component separation step includes separating refractory grains containing base metal iron from the refractory grains using a 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 device for sorting used refractories,
Crushing means for crushing the used refractory;
a particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range;
means for blowing gas onto the grains of the used refractory whose grain size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using a laser-induced breakdown spectrometer, the used refractory grains are determined to have the same main component. A component separating means for separating into a plurality of groups as a group;
A device for sorting used refractories, characterized by comprising:

(9) The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 apparatus according to (8) above.

(10) A used refractory sorting device,
Crushing means for crushing the used refractory;
a particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range;
means for blowing gas onto the grains of the used refractory whose grain size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using a laser-induced breakdown spectrometer, the used refractory grains are determined to have the same main component. A component separating means for separating into a plurality of groups as a group;
pulverizing means for pulverizing refractory grains belonging to at least one of the plurality of groups into refractory powder;
Magnetic force sorting means for sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force;
A device for sorting used refractories, characterized by comprising:

(11) The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 pulverizing means pulverizes the refractory grains belonging to the slag line material group into slag line material powder,
The magnetic force sorting means sorts the slag line material powder into Al ₂ O ₃ -based powder and SiC-based powder using magnetic force.
The used refractory sorting apparatus according to (10) above.

(12) The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 pulverizing means pulverizes the refractory grains belonging to the metal line material group into metal line material powder,
The magnetic force sorting means sorts the metal line material powder into Al ₂ O ₃ -based powder and SiC-based powder using magnetic force.
The used refractory sorting apparatus according to (10) or (11) above.

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

(14) The component separating means can further separate refractory grains containing base metal iron from the refractory grains using a magnetic force.
The used refractory sorting apparatus according to any one of (8) to (13) above.

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

It is a sectional view showing the state of use of a common blast furnace gutter. 1 is a flow chart of a method for sorting used refractories according to one embodiment of the present invention. Separating the refractory granules into a plurality of groups having the same main component based on the results obtained by performing a component analysis on the used refractory granules by laser-induced breakdown spectroscopy, FIG. 4 is a conceptual diagram showing the configuration of separating means; FIG. 3 is a diagram showing an example of an emission spectrum of metal line material refractory grains detected by a spectrometer; FIG. 3 is a diagram showing an example of an emission spectrum of slagline material refractory grains 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 for 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 one embodiment of the present invention.

As shown in FIG. 2, the used refractory sorting method according to the present invention crushes the used refractory (crushing step), and adjusts the crushed used refractory in the crushing step to a predetermined particle size range. (Particle size adjustment step), the used refractory grains whose particle size has been adjusted are blown with gas to remove foreign matter (gas blowing step), and the results obtained by performing component analysis on the used refractory grains Based on this method, the refractory grains are separated into a plurality of groups having the same main component (component separation step).
Each step will be described in detail below.

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

Next, in the particle size adjustment step, the used refractory crushed in the crushing step is adjusted to a predetermined particle size range. When laser-induced breakdown spectroscopy, which will be described later, is used, the particle size range is 5 mm or more and 100 mm or less, more preferably 10 mm or more and 40 mm or less. In addition, in order to improve the accuracy of component separation later, the narrower the width of the particle size distribution, the better.

Specifically, the particle size adjustment of this used refractory can be performed 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 with an opening size of 40 mm. After that, the used refractory that has passed through a sieve with an opening size of 40 mm is passed through a sieve with an opening size of 10 mm. The used refractory remaining on the sieve with an opening size of 10 mm is treated as used refractory grains 30 (hereinafter also referred to as refractory grains 30) having a predetermined particle size range.

In the first sieve with an opening size of 40 mm, the used refractory remaining on the sieve is preferably crushed again to further reduce the particle size and then subjected to the above-described particle size adjustment again.

Subsequently, in the gas blowing step, the used refractory grains 30 whose particle size has been adjusted are subjected to gas blowing to remove foreign matter adhering to the refractory. In many cases, the foreign matter adhering to the refractory is mainly blast furnace slag or other types of refractory powder (mainly composed of), and the size of the foreign matter is about 2 mm or less fine powder. . When removing such foreign matter ^, the types of gas suitable for use include air and nitrogen. is desirable, especially 0.05 to 5 Nm ³ /min in order to prevent the used refractories from falling from the belt conveyor. The nozzle size (opening diameter) is 1 to 20 mm, and a plurality of nozzles may be provided. A slit-shaped nozzle with a similar opening area can also be used. In addition, if the foreign matter or refractory is wet, or if the type and size of the foreign matter are adjusted, the flow rate and the size of the nozzle can be adjusted so that the rolling of the refractory grains does not interfere with component analysis and location identification. can be a range.
After that, in the component separation step, the components are separated into a plurality of groups having the same main component based on the results obtained by the component analysis. When the used refractory grains 30 are used blast furnace gutter refractory grains, refractory grains 30a belonging to the group of metal line materials as a group having the same main component (hereinafter referred to as metal line material refractory grains 30a), It is separated into a plurality of groups including refractory grains 30b belonging to the slag line material group (hereinafter referred to as slag line material refractory grains 30b). As described above, there is a clear difference in component composition between the metal line material and the slag line material, and therefore it is possible to select based on the contained components themselves and component ratios. Furthermore, the refractories of the blast furnace gutter usually have slag adhered to them in the course of use, and such impurity-containing refractory grains 30c such as blast furnace slag (hereinafter referred to as impurity refractory grains 30c) are also contained. The selection can be based on the components themselves and the component ratios.
Hereinafter, sorting 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 enables very high-speed measurement, usually several microseconds to several milliseconds per spot, and high work efficiency. Furthermore, laser-induced breakdown spectroscopy has a wide elemental measurement range, including light elements such as O, Na and Mg. Suitable for Furthermore, light elements such as H, Be, Li, and N can also be measured, and substances containing these elements can be analyzed, so used refractories can be accurately determined.

FIG. 3 shows the refractory granules divided into a plurality of groups having the same main component based on the results obtained by performing component analysis on the used refractory granules by laser-induced breakdown spectroscopy. It is a conceptual diagram showing the configuration of a component separation means for separation. Hereinafter, with reference to FIG. 3, the used refractory grains 30 are subjected to component analysis by laser-induced breakdown spectroscopy using component separation means. are separated into a plurality of groups having the same main component.

The component separating means 6 shown in FIG. 13 and drop chutes 14a-14c. Here, the gas blowing device 8b can blow gas at a pressure of 0.05-0.5 MPa, 1-20, preferably 4-12, or suitable for the width of 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 grains on the belt conveyor by 50 to 1000 mm, preferably 100 mm, and the used refractory on the belt conveyor It is characterized by the fact that the air hits all the grains almost evenly, and the foreign matter adhering to the surface can be removed without rolling the refractory grains significantly.

In the component separating means 6, the used refractory grains 30 adjusted to a predetermined grain size range are evenly supplied by the vibrating feeder 7 onto the belt conveyor 8a without being piled up. The conveying position of the used refractory grains 30 supplied onto the belt conveyor 8a is detected by the image camera 9 on the belt conveyor 8a. Based on the conveying position information from the image camera 9 and information on the amount of movement of the belt conveyor 8a tracked from rotation pulse sensor information such as an encoder attached to a drive motor (not shown) of the belt conveyor 8a, Accurately irradiate each of the used refractory grains 30 being transported with the short pulse laser 10, detect the emission spectrum of the high temperature plasma generated from the irradiation point by the spectrometer 11, and based on the detection information, the analysis controller 12 is used to determine whether the refractory grains 30 correspond to any of the metal line material refractory grains 30a, the slag line material refractory grains 30b, or the impurity refractory grains 30c.

4 to 6 are diagrams showing examples of emission spectra of metal line material refractory grains, slag line material refractory grains, and impurity refractory grains detected by a spectrometer. Here, comparing the composition of the metal line material and the slag line material 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. . Furthermore, 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-described knowledge (Table 1), it is found that the refractory grains 30 are the metal line material refractory grains 30a or the slag line material refractory grains 30b. It is possible to determine whether it corresponds to either. For example, in the example of the emission spectrum of the metal line material refractory grains shown in FIG. 4, there is a peak in Al and the spectrum of Mg can be confirmed, so it contains Al ₂ O ₃ as a main component and also contains MgO. It is determined that it is the metal line material refractory grains 30a. On the other hand, in the example of the emission spectrum of the slag line material refractory grains shown in FIG. 5, since there is no Mg spectrum, it is determined that the slag line material refractory grains 30b are mainly composed of SiC. Furthermore, in the example of the emission spectrum of the impurity refractory grains shown in FIG. 6, since there is a Ca peak, it can be determined to be the impurity refractory grains 30c such as blast furnace slag.

The used refractory grains 30 determined by the analysis controller 12 to be metal line material refractory grains 30a, slag line material refractory grains 30b, or impurity refractory grains 30c are dropped using an air jet 13. It is separated by controlled position to the chutes 14a-14c. The metal line material refractory grains 30a are separated into the drop chute 14a, the slag line material refractory grains 30b are separated into the drop chute 14b, and the impurity refractory grains 30c are separated into the drop chute 14c. Although the air jet 13 is used in the illustrated example, paddles can also be used to control the position of the drop chutes 14a to 14c.
The used refractory grains 30 whose particle size has been adjusted in this manner are subjected to component analysis, and based on the results obtained, the refractory grains 30 are classified into metal line material refractory grains 30a and slag line material refractory grains 30a. It can separate into either grains 30b or impure refractory grains 30c.

In addition, in the component separation step in the present invention, it is preferable to separate the refractory grains containing bare metal iron from the refractory grains 30 using a magnetic force before or after the component analysis. In general, refractory materials for blast furnace troughs are designed so that slag and molten iron are less likely to adhere to them. In the reuse of refractory materials, refractory particles to which slag containing such bare metal iron is attached are separated from the refractory particles by using the magnetism of the bare metal iron contained in the slag and using a magnetic force. is preferred. Using a magnetic force includes, for example, using a magnetic force separator having a magnetic field with a magnetic flux density of 0.1T to 1T. A preferable magnetic flux density is 0.3T to 0.6T. A drum type or a belt suspension type can be used for this magnetic separator. Preferably, by using a drum-type magnetic separation means, it is possible to prevent slag from being left out more effectively.
In this way, by separating the refractory grains containing base iron from the refractory grains using a magnetic force, it is possible to reduce the risk of slag being mixed into the valuables.

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

That is, subsequently, in the present embodiment, the refractory grains 30 belonging to at least one of the plurality of groups are pulverized into refractory powder (pulverization step). More specifically, among the refractory grains 30 separated into the metal line material refractory grains 30a and the slag line material refractory grains 30b by the above component separation step, the refractory grains belonging to the slag line material refractory grains 30b The material is further pulverized 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 slag line material refractory grains 30b are further finely pulverized into powder, Al ₂ O ₃ is the main component. A mixed powder of an Al ₂ O ₃ -based powder and a SiC-based powder containing SiC as a main component can be used.

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

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

The refractory powder pulverized in this manner is sorted into magnetic powder and non-magnetic powder using a magnetic force (magnetic sorting step). Here, since Al ₂ O ₃ is derived from natural ore, it contains a trace amount of Fe, whereas SiC does not exist in nature and is produced artificially, so it does not contain any Fe. have Thus, in order to sense a trace amount of Fe contained in Al ₂ O ₃ , it is necessary to perform magnetic separation using a sufficient magnetic force. As a result of investigation by the inventors, it is preferable to use a magnetic force 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 this magnetic force selection means, for example, a magnetic force selection means designed so that a large number of poles of 1 T or more are locally arranged by devising a magnetic circuit may be used. The form 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 magnetic media, or the like.

Al ₂ O ₃ -based powder, which contains a small amount of Fe and is tinged with magnetism, and non-magnetic SiC-based powder, which does not contain Fe, can be separated from the slag line material powder using the above-mentioned magnetic force sorting means. can. Thus, SiC can be recovered with higher purity by performing magnetic separation after component separation.

The pulverizing process and the magnetic sorting process described above may be applied to refractory grains belonging to the group of metal line materials. Among the refractory grains 30 separated into the metal line material group and the slag line material group by the above component separation step, the refractory grains belonging to the metal line material refractory grains 30a are further pulverized into refractory powder ( hereinafter referred to as metal line material powder). The metal line material contains Al ₂ O ₃ and SiC, and when the metal line material refractory grains 30a are pulverized, Al _{2 O 3 -based powder containing Al 2 O 3 as} the main component and SiC as the main component Metal line material powder is obtained, which is a mixed powder with _SiC - _based powder of can.

In this way, valuables can be sorted out from used refractories with high accuracy. It was 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 method of the present invention, that is, laser-induced breakdown spectroscopy, enables the separation of the metal line material and the slag line material. At that time, by blowing a gas onto the refractory, even the used refractory that is in a wet state and has foreign matter adhering to the surface can be sorted out with high accuracy without adding a process such as drying.

(Used refractory sorting equipment)
Next, an apparatus for sorting out valuables from used refractories according to the present invention will be described. A used refractory sorting apparatus (hereinafter referred to as a refractory sorting apparatus) according to the present invention includes crushing means for crushing used refractory, and the used refractory crushed by the crushing means is separated into a predetermined particle size range. Based on the results obtained by performing particle size adjustment means for adjusting the particle size, means for removing foreign matter adhering to the refractory by gas blowing against the used refractory grains whose particle size has been adjusted, and component analysis, a component separating means for separating the refractory grains into a plurality of groups 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 means that can crush the used refractory to be processed into an appropriate size can be used. can use things. For example, heavy machines such as jaw crushers and bucket crushers can be used.

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

Moreover, 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 the used refractory can be adjusted to a predetermined particle size range. Particle size control means that can be used include sieves. For example, when the particle size range of the used refractory is 10 mm or more and 40 mm or less, it is first passed through a sieve with an opening size of 40 mm. After that, the used refractory that has passed through a sieve with an opening size of 40 mm is passed through a sieve with an opening size of 10 mm. The used refractory remaining on the sieve with an opening size of 10 mm is treated as used refractory grains 30 having a predetermined particle size range.

Furthermore, foreign matter attached to the surface of the used refractory granules 30 whose grain size has been adjusted affects the accuracy of component analysis, such as those found in wet refractories. component analysis. Foreign matter is removed to the extent that 50% or more of the surface of the used refractory grains is exposed, and subjected to component analysis. In removing the foreign matter from the surface of the used refractory grains, a test run is carried out in advance, and a suitable gas flow rate and nozzle arrangement can be set by observing the removal state of the foreign matter. In the test run, the used refractory grains from which foreign matter has been removed are placed in a wet state, and blast furnace slag powder is sprinkled on them. For the used refractory granules that were actually subjected to trial operation, the gas flow rate and nozzle arrangement were set so that the surface of the used refractory granules was exposed to 50% or more, and the gas was blown under these conditions, the results is assumed to have been achieved. A component separation means for separating into a plurality of groups having the same principal component based on the results obtained by performing component analysis will be described. The component separating means is not particularly limited, either, and any means can be used. When the used refractory grains 30 are used blast furnace refractory grains, refractory grains 30a belonging to the group of metal line materials (hereinafter referred to as metal line material refractory grains 30a) and slag are included as groups having the same main component. The refractory grains 30b belonging to the line material group (hereinafter referred to as slag line material refractory grains 30b) are separated into a plurality of groups. As described above, there is a clear difference in component composition between the metal line material and the slag line material, and therefore it is possible to select based on the contained components themselves and component ratios. Furthermore, the refractories of the blast furnace gutter usually have slag adhered to them in the course of use, and such impurity-containing refractory grains 30c such as blast furnace slag (hereinafter referred to as impurity refractory grains 30c) are also contained. The selection can be based on the components themselves and the component ratios.

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

Furthermore, the component separating means preferably includes a magnetic separator because the refractory grains containing base metal iron are separated from the refractory grains using magnetic force. More specifically, in the reuse of the refractory, the refractory grains of slag containing such base metal iron are extracted from the refractory grains 30 by using the magnetism of the base metal iron contained in the slag. Separation using is preferred. For example, a magnetic separator having a magnetic field with a flux density of 0.1T to 1T may be used. A preferable magnetic flux density is 0.3T to 0.6T. A drum type or a belt suspension type can be used for this magnetic separator. Preferably, by using a drum-type magnetic separation means, it is possible to prevent slag from being left out more effectively.
In this way, by separating the refractory grains containing base iron from the refractory grains using a magnetic force, it is possible to reduce the risk of slag being mixed into the valuables.

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

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

As the above-described magnetic force selection means, for example, a magnetic force selection means designed to locally arrange a large number of poles of 1 T or more by devising a magnetic circuit may be used. The form 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 magnetic media, or the like.

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

In this way, valuables can be sorted out from used refractories with high accuracy.

EXAMPLES The present invention will be specifically described below according to examples. However, the present invention is not limited by the following examples, and can be modified as appropriate within the scope of the gist of the present invention, all of which are included in the technical scope of the present invention. .

[Example 1]
The used blast furnace gutter refractories were sorted according to the flow chart shown in FIG.
That is, first, the used refractories including the metal line material and the slag line material were crushed by a jaw crusher. Next, the crushed used refractories are passed through a sieve with an opening size of 40 mm, the used refractories that have passed through the sieve are collected, and the used refractories that have passed through the sieve are collected and passed through a sieve with an opening size of 5 mm. By recovering, used refractory grains having a grain size adjusted to a grain size of 5 mm or more and 40 mm or less were obtained.

After that, gas was blown to the used refractory particles whose particle size was adjusted to 5 mm or more and 40 mm or less, and component separation was performed. That is, the used refractory granules were evenly supplied on the belt conveyor without being piled up by a vibrating feeder, and gas was blown to the used refractory supplied on the belt conveyor to remove adhering foreign matter. Later, the transport position of the used refractory on the belt conveyor was detected with an image camera. Here, the gas to be blown has a supply pipe pressure of 0.3 MPa. Although the supply pipe pressure can be higher than 0.3 MPa, it is necessary to spray all the used refractories moving on the belt conveyor, so if the width of the belt conveyor exceeds 100 mm, It is preferable to spray from a plurality of blowing nozzles or slit-like nozzles elongated in the width direction of the belt conveyor. In addition, the flow rate should be controlled so that the used refractory does not continue to roll to the position of the visual field of the image camera due to the gas blowing, which reduces the accuracy of grasping the position from the image, or does not fall off the belt conveyor. It was adjusted. Based on the conveying position information of the used refractory by this image camera and information on the amount of movement of the belt conveyor tracked from rotation pulse sensor information such as an encoder attached to the drive motor of the belt conveyor, Accurately irradiate each of the used refractory grains 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 detected information to determine the refractory It was determined whether the grains corresponded to metal line material refractory grains, slag line material refractory grains, or impurity refractory grains.

4 to 6 are diagrams showing emission spectra of metal line material refractory grains, slag line material refractory grains, and impurity refractory grains detected by a spectrometer. In the emission spectrum of the refractory grains shown in FIG. 4, there is a peak for Al and a spectrum for Mg can be confirmed, so it can be said that the metal line material contains Al ₂ O ₃ as a main component and also contains MgO. judgment is obtained. On the other hand, in the example of the emission spectrum of the refractory grains shown in FIG. 5, since there is no Mg spectrum, it can be determined that the slag line material contains SiC as the main component. Furthermore, since the emission spectrum shown in FIG. 6 has a Ca peak, it can be determined that it is an impurity-containing refractory such as blast furnace slag.

Refractory granules belonging to the group of metal line material and the group of slag line material determined by the analysis controller were separated by controlling the position of the drop chute using an air jet. As a result, the purities of both the metal line material and the slag line material were 95% by mass.
Table 2 shows a comparison of the separation accuracy with the conventional method. In the method using fluorescent X-rays, the presence of the Mg spectrum could not be detected, and the slag line material and the metal line material could not be discriminated, making separation difficult. Since laser-induced breakdown spectroscopy has a wide elemental range including light elements, it has become possible to separate refractories containing these elements by composition. Among these light elements, C and O, in addition to Mg, are particularly useful for determining the used refractory.
In addition, when foreign matter such as wet refractories adheres to the surface, it affects the accuracy of component analysis. , it became possible to improve the separation accuracy.

The above purity is calculated by the following formula for each dropping chute that collects the metal line material and the slag line material.
(Formula 1)
Purity of metal line material (% by mass) = mass of metal line material / (mass of metal line material + mass of slag line material + mass of impurities such as blast furnace slag)
(Formula 2)
Purity of slag line material (% by 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, refractory grains belonging to the group of slag line material, separated by component separation after gas blowing (invention example), were pulverized with a hammer mill to a particle size of 2 mm or less to obtain a slag line. The material powder was sorted into magnetic Al ₂ O ₃ powder and non-magnetic SiC powder by magnetic force sorting means having a 1.1 T rare earth permanent magnet. The purities of the Al ₂ O ₃ -based powder and the SiC-based powder obtained by this magnetic separation were 25% by mass for the Al ₂ O ₃ -based powder and 92% by mass for the SiC-based powder. rice field. In this way, by sorting out the metal line material and the slag line material, and further sorting out the Al ₂ O ₃ -based powder and the SiC-based powder, it was possible to recover valuable resources.

[Example 3]
In Example 1, refractory grains belonging to the group of metal line materials, which were separated by component separation after gas blowing (invention example), were pulverized with a hammer mill to a particle size of 2 mm or less to obtain metal lines. The material powder was sorted into magnetic Al ₂ O ₃ powder and non-magnetic SiC powder by magnetic force sorting means having a 1.1 T rare earth permanent magnet. The purities of the Al ₂ O ₃ -based powder and the SiC-based powder obtained by this magnetic separation were 95% by mass for the Al ₂ O ₃ -based powder and 90% by mass for the SiC-based powder. rice field. In this way, by sorting out the metal line material and the slag line material, and further sorting out the Al ₂ O ₃ -based powder and the SiC-based powder, it was possible to recover valuable resources.

1 blast furnace gutter 2 steel shell 3 refractory 4 metal line material 5 slag line material 6 component separation means 7 vibration feeder 8a belt conveyor 8b gas spraying device for removing powder adhering to refractories 9 image camera 10 short pulse laser 11 spectrometer 12 Analysis controller 13 Air jet 14 Drop chute 30 Refractory grain 30a Metal line material refractory grain 30b Slag line material refractory grain 30c Impurity refractory grain

Claims (14)

A method for sorting used refractories,
A crushing step of crushing the used refractory;
A particle size adjustment step of adjusting the used refractory crushed by the crushing step to a predetermined particle size range;
A step of blowing a gas onto the used refractory particles whose particle size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory grains are classified as having the same main component. A component separation step of separating into a plurality of groups as a certain group;
A method for sorting used refractories, comprising: The used refractory is a used blast furnace gutter refractory,
The plurality of groups includes 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. A method for sorting used refractories,
A crushing step of crushing the used refractory;
A particle size adjustment step of adjusting the used refractory crushed by the crushing step to a predetermined particle size range;
A step of blowing a gas onto the used refractory particles whose particle size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using laser-induced breakdown spectroscopy, the used refractory grains are classified as having the same main component. A component separation step of separating into a plurality of groups as a certain group;
a pulverizing step of pulverizing refractory grains belonging to at least one of the plurality of groups into refractory powder;
A method for sorting used refractories, comprising a magnetic force sorting step of sorting the refractory powder into magnetic powder and non-magnetic powder using a magnetic force. The used refractory is a used blast furnace gutter refractory,
The plurality of groups includes 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 pulverizing step pulverizes the refractory grains belonging to the slag line material group into slag line material powder,
In the magnetic separation step, the slag line material powder is separated into Al ₂ O ₃ -based powder and SiC-based 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 includes 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 pulverizing step pulverizes the refractory grains belonging to the metal line material group into metal line material powder,
The magnetic force sorting step uses a magnetic force to sort the metal line material powder into Al ₂ O ₃ -based powder and SiC-based powder.
The method for sorting used refractories according to claim 3 or 4. The used refractory sorting method 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 includes separating refractory grains containing base metal iron from the refractory grains using a magnetic force before or after the component analysis.
The method for sorting used refractories according to any one of claims 1 to 6. A sorting device for used refractories,
Crushing means for crushing the used refractory;
a particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range;
means for blowing gas onto the grains of the used refractory whose grain size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing component analysis on the used refractory grains from which the foreign matter has been removed using a laser-induced breakdown spectrometer, the used refractory grains are determined to have the same main component. A component separating means for separating into a plurality of groups as a group;
A device for sorting used refractories, characterized by comprising: The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 apparatus according to claim 8. A sorting device for used refractories,
Crushing means for crushing the used refractory;
a particle size adjusting means for adjusting the used refractory crushed by the crushing means to a predetermined particle size range;
means for blowing gas onto the grains of the used refractory whose grain size has been adjusted to remove foreign matter from the surface of the refractory;
Based on the results obtained by performing a laser-induced breakdown spectroscopy component analysis on the used refractory grains from which the foreign matter has been removed, the used refractory grains are classified into groups having the same main component A component separation means for separating into a plurality of groups as
pulverizing means for pulverizing refractory grains belonging to at least one of the plurality of groups into refractory powder;
Magnetic force sorting means for sorting the refractory powder into magnetic powder and non-magnetic powder using magnetic force;
A device for sorting used refractories, characterized by comprising: The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 pulverizing means pulverizes the refractory grains belonging to the slag line material group into slag line material powder,
The magnetic force sorting means sorts the slag line material powder into Al ₂ O ₃ -based powder and SiC-based powder using magnetic force.
The used refractory sorting apparatus according to claim 10. The crushing means crushes the used blast furnace gutter refractories,
The component separating means separates the refractory grains 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 pulverizing means pulverizes the refractory grains belonging to the metal line material group into metal line material powder,
The magnetic force sorting means sorts the metal line material powder into Al ₂ O ₃ -based powder and SiC-based powder using magnetic force.
The used refractory sorting apparatus according to claim 10 or 11. The used refractory sorting apparatus according to any one of claims 10 to 12, wherein said magnetic force sorting means has a magnet with a magnetic flux density of 0.6 T or more. The component separating means is further capable of separating refractory grains containing base metal iron from the refractory grains using a magnetic force.
The apparatus for sorting used refractories according to any one of claims 8 to 13.

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