WO2022270516A1 - Method for producing granular solidified slag, and production facility line for same - Google Patents

Abstract

Provided are a method for producing granular solidified slag, whereby slag processing such as heat recovery processing, steam aging processing, and carbonization processing of solidified slag can be efficiently performed, and a production facility line for granular solidified slag. The present invention is characterized by including a mixed solidified material manufacturing step for feeding molten slag S2 and solids S1, M into a mold 1 and causing solidification of the molten slag S2 to progress in a state in which gaps between the solids S1, M are filled by the molten slag S2 in the mold 1 to manufacture a solid/liquid mixed solidified material S, a slag crushing step for crushing the mixed solidified material S into granules to manufacture a mixed crushed material Sg, and a separation step for separating the mixed crushed material Sg in accordance with grain size or material properties into a plurality of mixed crushed material groups to obtain granular solidified slag.

Description

Method for producing granular solidified slag and its production equipment

The present invention relates to a method for producing granular solidified slag and a series of production facilities suitable for this production.

For example, in the iron-making process using the blast furnace method, a large amount of slag is generated as a by-product of steel products. Generally, this slag is commercialized after quality control is performed by water granulation treatment, steam aging treatment, or the like. That is, most of the blast furnace slag is granulated and used as a raw material for cement as granulated blast furnace slag. In addition, steelmaking slag is used for applications such as roadbed materials after promoting hydration expansion of free calcium oxide (f-CaO) by steam aging treatment in advance.

On the other hand, the new value of slag has attracted attention from the viewpoint of reducing carbon dioxide (CO ₂ ) emissions in recent years. For example, molten slag retains heat of about 1.8 GJ/t-slag, and by recovering heat from slag, it is expected to reduce CO ₂ by saving energy. Carbonation of f-CaO in slag is also expected as one of CO ₂ fixation technologies. However, these slag treatment methods are often incompatible with the process for commercializing the slag, and have many problems for practical use.

As a process for recovering heat possessed by molten slag, for example, Patent Document 1 discloses that blast furnace slag is solidified into a plate-like shape using a mold, then the plate-like solidified slag is hot crushed, and then the crushed solidified slag is crushed. A method is described for recovering the heat carried by the slag by charging a slag heat recovery facility. According to this method, an energy-saving effect can be obtained by recovering the heat of the slag, and a dense aggregate having a low water absorption rate and excellent abrasion resistance can be produced as a slag product.

On the other hand, as a process for carbonating f-CaO in slag, for example, in Patent Document ₂ , Ca in slag is extracted by a wet treatment using an acid solution, and then reacted with CO ₂ to be carbonated. are described. Further, in Patent Documents 3 and 4, when water is sprinkled on the solidified high-temperature steelmaking slag to subject the steelmaking slag to steam aging treatment, CO ₂ is supplied to remove the f-CaO contained in the steelmaking slag. is described.

JP 2014-85064 A Japanese Patent Application Laid-Open No. 2005-97072 JP-A-6-158124 JP-A-8-259282

In the method described in Patent Document 1, since the solidified slag produced using the mold is dense and has high strength, it is difficult to hot crush the solidified slag. If the hot crushing of the solidified slag cannot be sufficiently performed, the crushed solidified slag becomes coarser and the total surface area of the slag becomes smaller, so heat cannot be efficiently recovered from the slag.

In the method described in Patent Document 2, a large amount of Ca extraction residue containing SiO ₂ , Al ₂ O ₃ and the like is generated. The extraction residue after wet treatment using an acid solution usually does not become granular, so it cannot be used as a product such as a roadbed material.

Regarding the methods described in Patent Documents 3 and 4, Patent Documents 3 and 4 describe methods for adjusting the size of slag particles while hot for efficient steam aging treatment and carbonation treatment. has not been disclosed in detail. Therefore, for example, when the slag is in the form of a relatively large mass and the total surface area of the slag relative to the mass of the slag is small, the steam aging treatment and the carbonation treatment take time, and the steam aging treatment and the carbonation treatment are performed efficiently. can't do

The present invention has been made in view of the above problems, and its object is to efficiently perform slag treatment such as heat recovery treatment, steam aging treatment, and carbonation treatment on solidified slag. The object of the present invention is to propose a slag production method and a series of production facilities for granular solidified slag.

The present invention for solving the above problems is as follows.
[1] Molten slag and solid matter are supplied into a mold, and solidification of the molten slag proceeds in a state in which gaps between the solid matter are filled with the molten slag in the mold to produce a mixed solidified product. a mixed coagulum making step;
A crushing step of crushing the mixed solidified material into granules to produce a crushed mixed material;
a separation step of separating the mixed crushed material into a plurality of mixed crushed material groups according to particle size or material to obtain granular solidified slag;
A method for producing granular solidified slag, comprising:

[2] The granular solidification according to [1] above, wherein the mixed solidified material preparation step further includes a pushing step of pushing the solid material toward the bottom of the mold after supplying the molten slag and the solid material. A method for producing slag.

[3] further comprising a first slag heat recovery treatment step of subjecting the crushed mixed material of the crushed mixed material group containing granular solidified slag having a relatively low particle size among the plurality of crushed mixed material groups to heat recovery treatment; The method for producing granular solidified slag according to the above [1] or [2].

[4] A steam aging treatment step of supplying steam to the crushed mixed material group of the crushed mixed material group containing granular solidified slag with a relatively low particle size among the plurality of crushed mixed material groups to perform steam aging treatment. The method for producing granular solidified slag according to any one of [1] to [3], further comprising:

[5] A carbonation treatment step of supplying carbon dioxide gas to the crushed mixed material group of the crushed mixed material group containing granular solidified slag having a relatively low particle size among the plurality of crushed mixed material groups to perform carbonation treatment. The method for producing granular solidified slag according to any one of [1] to [4], further comprising

[6] The method for producing granular solidified slag according to [5], wherein the mixed gas of carbon dioxide gas and water vapor is supplied in the carbonation treatment step.

[7] further comprising a second slag heat recovery treatment step of performing a heat recovery treatment on the crushed mixed material group of the crushed mixed material group containing granular solidified slag having a relatively high particle size among the plurality of crushed mixed material groups; The method for producing granular solidified slag according to any one of [1] to [6] above.

[8] Part or all of the crushed mixed material group of the crushed mixed material group containing the granular solidified slag having a relatively high particle size, which has been subjected to heat recovery treatment in the second slag heat recovery step, is subjected to the mixed solidification The method for producing granular solidified slag according to [7] above, further comprising a solid matter recycling step of reusing the solid matter in the object producing step.

[9] The method for producing granular solidified slag according to any one of [1] to [8], wherein the solidified thickness of the mixed coagulum produced in the mixed coagulum producing step is 100 mm or less.

[10] The method for producing granular solidified slag according to any one of [1] to [9], wherein in the mixed solidified material producing step, the solid material is solid slag.

[11] The granular solidified slag according to any one of [1] to [9], wherein in the mixed solidified product producing step, the solid is metal particles having a melting point equal to or higher than the melting point of the molten slag. manufacturing method.

[12] Granulated solidified slag according to any one of [1] to [9], wherein in the mixed solidified product producing step, two or more types of solids having different particle sizes or materials are supplied into the mold. manufacturing method.

[13] Any one of the above [1] to [12], further comprising a hot separation step of separating the mixed solidified product by particle size or material between the mixed solidified product preparation step and the crushing step. A method for producing granular solidified slag according to the above item.

[14] Mixed solidified product production equipment having a molten slag supply device for supplying molten slag into the mold and a solid matter supply device for supplying solid matter into the mold;
A crushing facility for crushing the mixed solidified material produced by the mixed solidified material production facility to produce a mixed crushed material, and separating the mixed solidified material into a plurality of mixed crushed material groups according to particle size or material to form granules. and separation equipment for obtaining solidified slag.

[15] Production of granular solidified slag according to the above [14], wherein the mixed solidified material production equipment has a reduction device that presses the solid material into the mold to which the molten slag and solid material are supplied. equipment row.

[16] The train of equipment for producing granular solidified slag according to the above [14] or [15], wherein the mold has a raised portion at the bottom.

[17] The train of equipment for producing granular solidified slag according to any one of [14] to [16], wherein the crushing equipment has a rotating body for crushing the mixed solidified matter.

[18] Said [14] to [14]-[ 17], the production equipment train for granular solidified slag according to any one of the above items.

[19] Said [14], which has a steam supply device downstream of said separation facility for supplying steam to said crushed mixed material of a group of crushed mixed material containing granular solidified slag having a relatively low particle size for steam aging. The equipment train for producing granular solidified slag according to any one of [18].

[20] Downstream of the separation equipment, a carbon dioxide gas supply device for supplying carbon dioxide gas to the crushed mixed material group containing granular solidified slag with a relatively low particle size to perform carbonation treatment. [14] to [19], the production equipment line for granular solidified slag.

[21] Said [14] to [14]-[ 20].

[22] Between the second slag treatment equipment and the solid matter supply device, a conveying path is provided for conveying part or all of the mixed crushed material subjected to the heat recovery treatment to the solid matter supply device. The production equipment line for granular solidified slag according to [21] above.

According to the present invention, slag treatment such as heat recovery treatment, steam aging treatment, and carbonation treatment can be efficiently performed on solidified slag.

It is a figure which shows the relationship between the particle size of granular solidification slag, and a heat recovery rate. FIG. 4 is a diagram showing the relationship between the particle size of granular solidified slag and the fixed amount of carbon dioxide. FIG. 2 is a diagram showing a preferred example of a series of production facilities for granular solidified slag according to the present invention; 4 is a diagram showing a solid-liquid slag mixing solidification facility having a configuration different from that of FIG. 3. FIG. It is a figure which shows the solid-liquid slag mixed solidification installation which has a reduction apparatus. It is a figure which shows the bottom part shape of a casting_mold|template. FIG. 4 is a diagram showing another preferred example of a train of production equipment for granular solidified slag according to the present invention; FIG. 4 is a diagram showing yet another preferred example of a train of production equipment for granular solidified slag according to the present invention; FIG. 5 is a diagram showing yet another preferred example of a train of production equipment for granular solidified slag according to the present invention; FIG. 2 is a diagram showing an example of supplying two types of solids to a mold in a mixed solids production facility according to the present invention; FIG. 4 is a diagram showing another example of supplying two types of solids to a mold in a mixed solids production facility according to the present invention; FIG. 4 is a diagram showing an example of the shape of the bottom of the mold when two types of solids are supplied to the mold in the equipment for producing a mixed solid according to the present invention. FIG. 2 is a diagram showing a preferred example of a train of equipment for producing granular solidified slag that supplies two types of solids to the mold according to the present invention; FIG. 3 shows another preferred example of a production train for granular solidified slag feeding two types of solids to the mold according to the present invention;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the method for producing granular solidified slag according to the present invention, molten slag and solids are supplied into a mold, and the molten slag is solidified and mixed while filling the gaps between the solids in the mold with molten slag. A mixed coagulum production process for producing coagulates, a crushing process for crushing the mixed coagulates into granules to produce mixed crushed materials, and separating the mixed crushed materials into a plurality of mixed crushed material groups according to particle size or material. and a separation step of obtaining granular solidified slag.

The present inventors diligently studied methods for producing granular solidified slag that can efficiently perform slag treatments such as heat recovery treatment, steam aging treatment, and carbonation treatment. As a result, in producing solidified slag, the present inventors supply molten slag and solid slag (solid matter) into a mold to produce solid-liquid mixed solidified slag (mixed solidified matter), It has been found that generating cracks in the solidified region where the molten slag is solidified and/or in the solid slag (solid matter) is extremely effective for convenient subsequent hot crushing.

However, in the solid-liquid mixed solidified slag (mixed solidified material) produced as described above, the occurrence and propagation of cracks are not uniform, so granulation with a single particle size is difficult. Therefore, if granular solidified slag with a large particle size distribution is subjected to slag treatment as it is, the time required to treat coarse-grained slag with a relatively high particle size becomes a constraint in the process, and slag is efficiently treated. cannot be applied, and the processing equipment becomes large.

That is, for example, when heat recovery is performed by filling a slag filling tank with high-temperature granular solidified slag, as is clear from the relationship between the particle size of granular solidified slag and the heat recovery rate shown in FIG. The larger the diameter (that is, the coarser the particles), the smaller the total surface area (that is, the heat transfer area) of the slag, the lower the temperature of the heat recovery gas, and the lower the heat recovery rate. In addition, FIG. 5 m, slag filling amount of 90 t, slag initial temperature of 1100° C., flow rate of heat recovery gas of 50 kNm ³ /h, treatment time of 4 hours, slag heat recovery simulation was performed. At that time, the heat recovery rate was calculated by taking the heat quantity of 100° C. or higher out of the total heat quantity of the heat recovery gas as usable recovered heat.

In addition, as with the heat recovery of the slag, in the slag stabilization treatment such as steam aging treatment and carbonation treatment, the larger the grain size of the granular solidified slag (that is, the coarser the grain), the f - A long time is required for the hydration reaction and carbonation reaction of CaO to proceed. Therefore, when coarse slag with a large particle size and fine slag with a small particle size are mixed in the granular solidified slag, the treatment time is not uniform.

FIG. 2 shows the relationship between the grain size of granular solidified slag and the amount of _CO2 fixed, ie, the amount of slag carbonation. In addition, FIG. 2 shows the amount of CO ₂ fixed when 300 g of steelmaking slag with a particle size of 0 to 60 mm is heated to 120 ° C. and then a CO ₂ -steam mixed gas with a CO ₂ concentration of 25% is passed for 24 hours. ing. The fixed amount of CO ₂ was calculated from a weight change curve obtained by thermogravimetric measurement (TG) of the slag after the CO ₂ -steam mixed gas flowed. As is clear from FIG. 2, the larger the grain size of the granular solidified slag, the smaller the amount of CO ₂ fixed. Therefore, from the viewpoint of quality assurance, in the case of mixed slag in which fine-grained slag and coarse-grained slag are mixed, the processing time for the entire slag is determined by the processing time for the coarse-grained slag, resulting in inefficient processing.

Therefore, the present inventors diligently studied how to efficiently apply slag treatment to granular solidified slag produced by hot crushing solid-liquid mixed solidified slag (mixed solidified material). As a result, the granular solidified slag produced as described above is separated into a plurality of mixed crushed material groups according to the particle size or material, and the granular solidified slag is independently subjected to slag treatment for each mixed crushed material group. The inventors have found that it is extremely effective to create a state in which this is possible, and have completed the present invention.

FIG. 3 shows a preferred example of a production equipment line used in the method for producing granular solidified slag according to the present invention. The row of production facilities for granular solidified slag shown in FIG. A liquid slag mixing equipment 4, a slag crushing equipment 5 for crushing the solid-liquid mixed solidified slag S produced by the solid-liquid slag mixing and solidifying equipment 4 to produce granular solidified slag Sg, A slag classification facility 7 that classifies into a plurality of granular slag groups according to , and a slag heat recovery facility 8 ( A first slag heat recovery facility 8A) and a slag heat recovery facility 8 (second slag heat recovery facility 8B) for recovering the heat of granular solidified slag Si in a group of granular slags with relatively high grain sizes. In this embodiment, "classification" refers to separating the granular solidified slag Sg according to the particle size, and is one form of separation.

In this line of manufacturing equipment, the mold 1 has recesses to accommodate the solid slag S1 and the molten slag S2, and moves horizontally on a line (not shown). First, solid slag S1 is supplied to the mold 1 from the solid slag supply device 2, then molten slag S2 is supplied to the mold 1 from the molten slag supply device 3, and solidification of the molten slag S2 proceeds in the mold 1 to solidify. A liquid-mixed solidified slag S is produced (solidified slag producing step).

As the solid slag S1, as will be described later, the solid slag S1 and the molten slag S2 are supplied to a mold and solidified, and part of the solid-liquid mixed solidified slag S is reused, or manufactured by another manufacturing method. It can be appropriately selected according to the desired slag quality, such as solidified slag.

Instead of the above-described procedure, using another manufacturing equipment train equipped with a solid-liquid slag mixing and solidification equipment 4 shown in FIG. A solid slag S1 may be supplied from the device 2, and the molten slag S2 may be solidified in the mold 1.

3 and 4, the solid slag feeder 2 includes a hopper 2a for receiving the solid slag S1 and cutting out a predetermined amount, and a slag gutter for guiding the solid slag S1 cut out by the hopper 2a into the mold 1. 2b. Similarly, the molten slag supply device 3 includes a tilting ladle 3a that accommodates and tilts the molten slag S2 to supply the molten slag S2, and a slag gutter for pouring the molten slag S2 supplied from the tilting ladle 3a into the mold 1. 3b. Any device is not limited to the illustrated example, and any configuration can be used as long as it can supply a predetermined amount of solid slag S1 and molten slag S2.

By the way, the method using the solid-liquid slag mixing and solidification equipment 4 shown in FIG. 3 is particularly effective when the mold 1 to be used is relatively small. On the other hand, when the mold 1 is relatively large, when the slag flow rate increases when molten slag S2 is supplied, the solid slag S1 charged in advance is swept away by the flow of molten slag S2 and is evenly distributed in the mold 1. It is also assumed that it will not be possible. Therefore, when a large mold 1 is used, the solid-liquid slag mixing and solidification equipment 4 shown in FIG. preferred. Although not shown, a solid slag supply device 2 and a molten slag supply device 3 are arranged so that the solid slag S1 and the molten slag S2 can be simultaneously supplied into the mold 1, and the solid slag S1 and the molten slag S2 are supplied into the mold 1. may be simultaneously supplied to

In any of the above methods, after the solid slag S1 and the molten slag S2 are supplied into the mold 1, the molten slag is filled in the mold 1 with the gaps between the solid slags S1 filled with the molten slag S2. It is essential to allow the solidification of S2 to proceed and introduce cracks in the solidified zone.

That is, the temperature difference is extremely large between the solid slag S1, which is close to room temperature, and the molten slag S2, which is about 1600°C. Therefore, when the molten slag S2 and the solid slag S1 are mixed and solidified, a large thermal stress is generated inside the solidified slag in which the molten slag S2 is solidified, promoting crack generation. Further, the solidified slag thermally shrinks due to cooling, while the solid slag S1 thermally expands due to heating. Therefore, the generation of cracks accompanying the volume change is also promoted. Furthermore, inconsistency of the crystal interface occurs at the boundary between the solidified slag obtained by solidifying the molten slag and the solid slag S1. Therefore, at the boundary between the solidified slag and the solid slag S1, cracks develop more easily than in the solidified slag obtained by solidifying only the molten slag S2. Due to the above synergistic effect, the solid-liquid mixed solidified slag S produced by mixing and solidifying the solid slag S1 and the molten slag S2 is easier to hot crush than the solidified slag obtained by solidifying only the molten slag S2. Therefore, granulation is possible by a simple crushing process.

In order to ensure the above synergistic effect, for example, as shown in FIGS. Advantageously, by placing the molten slag S2 in the layer and allowing the solidification to proceed, the synergistic effect described above is ensured and cracks are introduced during the solidification.

Here, the solid slag S1 supplied into the mold 1 is preferably supplied until the layer thickness is 3/4 or more of the solidified thickness so that the solid-liquid mixed solidified slag S can be easily crushed. . This is because, in the present invention, since cracks occurring near the interface between the solid slag S1 and the solidified slag are used as starting points of destruction in the slag crushing process, the layer thickness of the solid slag S1 is thinner than the layer thickness of the solid-liquid mixed solidified slag S. As a result, there are many regions in which cracks, which are starting points of fracture, do not occur inside the solidified slag, making it difficult to crush the slag.

As for the particle size of the solid slag S1, it is most preferable to supply only one layer of solid slag S1 having a particle size of 3/4 or more of the solidification thickness. It may be supplied in multiple layers. However, if the particle size of the solid slag S1 becomes too small, it becomes difficult for the molten slag S2 to penetrate into the gaps between the solid slag S1, and furthermore, cracks that occur at the boundary between the solidified slag and the solid slag S1 also occur due to solid-liquid mixed solidification. It becomes difficult to progress in the thickness direction of the slag S. Therefore, when the solid slag S1 is supplied in multiple layers, the particle size of the solid slag S1 is adjusted so that the solid slag S1 in the mold 1 has about three layers or less. The solid-liquid ratio between the solid slag S1 and the solidified slag is not particularly limited as long as the solid-liquid mixed solidified slag S can be easily crushed. However, in the case of slag with a large amount of SiO ₂ such as blast furnace slag, for example, if the solid slag S1 is too much for the molten slag S2, the solidified slag is partially vitrified by the rapid cooling action of the solid slag S1 and the mold 1. there is a possibility. Therefore, the cooling rate of the solidified slag and the slag temperature after completion of solidification may be adjusted by suppressing the supply amount of the solid slag S1.

In the method described in Patent Document 1 described above, the heat load on the mold increases as the solidified thickness increases, but when the equipment according to the present invention is used, the heat load on the mold 1 is reduced by the amount of heat transferred to the solid slag S1. Therefore, it is also suitable from the viewpoint of reducing the heat load on the mold 1 .

In the present invention, the term "crack" refers to the quenching effect of the solid slag S1, the thermal contraction and It is a local crack that occurs due to thermal stress occurring in the vicinity of the interface between the solidified region of the molten slag S2 and the solid slag S1 due to the difference in thermal expansion. This crack develops in a form of relieving the thermal stress inside the solidified slag, and mainly in the solidified region of the gap between the solid slugs S1, and has a length of about 5 to 20 mm in a form that bridges the solid slugs S1. However, since this thermal stress also acts on the solid slug S1 side, cracks may occur on the solid slug S1 side. In any case, it is essential to form crack initiation points by introducing cracks in the solidified zone and/or solid slag S1.

If cracks are introduced into the solidified region of the molten slag S2 as described above, the solid-liquid mixed solidified slag S solidified after the solid slag S1 and the molten slag S2 are mixed can be easily granulated in the subsequent slag crushing equipment 5. Can be crushed. That is, the solid-liquid mixed solidified slag S obtained by mixing and solidifying the solid-liquid slag according to the above is easier to break than the conventional solidified slag solidified by supplying only the molten slag, so it can be granulated by simple crushing. is.

As shown in FIG. 5, especially in the procedure using the solid-liquid slag mixing and solidification equipment 4 of FIG. Pushing S1 toward the bottom of the mold 1 (pushing step) is advantageous in the following points. That is, when the molten slag S2 is solidified in the mold 1, since the temperature of the molten slag S2 is extremely high, the surface of the molten slag S2 is rapidly cooled by the atmosphere to form a solidified layer. There is no problem if the supply of the solid slag S1 is completed before the solidified layer is formed on the surface of the molten slag S2 supplied to the mold 1, but the solidified layer is formed prior to the supply of the solid slag S1. Otherwise, it becomes difficult to charge the solid slug S1 into the mold 1 only by the weight of the solid slug S1. Therefore, as shown in FIG. 5, a reduction device 6 is provided on the downstream side of the solid slag supply device 2, and after supplying molten slag S2 into the mold 1, solid slag S1 is supplied into the mold 1. Then, the solid slag S1 is pushed down toward the bottom of the mold 1 by the reduction device 6, so that the solid slag S1 is reliably charged into the molten slag S2 layer in the mold 1. As the solidified layer on the surface of the molten slag S2 grows, it becomes difficult to push the solid slag S1. Therefore, the reduction device 6 is preferably arranged close to the solid slag supply device 2 so that the reduction device 6 can reduce the solid slag S1 at a relatively early stage before the solidified layer grows.

As the screw-down device 6, a screw-down device that moves up and down with only one vertical axis, and a multi-axis type screw-down device that goes up and down while moving or swinging according to the horizontal movement of the mold 1 can be applied, but the invention is not limited to this. .

Furthermore, the mold 1, as shown in FIG. 6, has a plurality of protuberances 1a on its bottom, which is advantageous in the following points. That is, by supporting the solid slag S1 with the plurality of protrusions 1a on the bottom of the mold 1, it is possible to prevent the solid slag S1 from being swept away by the slag flow when the molten slag S2 is supplied. In addition, since the raised portion 1a itself also has the effect of locally reducing the solidified thickness t in the depth direction of the mold 1, it acts effectively when the solid-liquid mixed solidified slag S is crushed. If the protruding portion 1a has even a small portion protruding from the bottom of the mold 1, it will exhibit the above-described effects. . Therefore, it is preferable that the raised portion 1a has a height capable of supporting the solid slugs S1 and has a relatively gentle raised portion shape so that the solid slugs S1 are distributed at regular intervals.

Next, after the mold 1 is turned over to separate the solid-liquid mixed solidified slag S from the mold 1, the solid-liquid mixed solidified slag S produced as described above is crushed by the slag crushing equipment 5 to produce granular solidified slag Sg. (slag crushing step). As described above, since the solid-liquid mixed solidified slag S is easier to crush than the solidified slag obtained by solidifying only the molten slag S2, the solid-liquid mixed solidified slag S can be granulated by simple crushing. As a slag crushing equipment 5 for crushing the solid-liquid mixed solidified slag S from the mold 1 and then crushing it into granules, solid-liquid mixed solidification is performed by applying an impact force due to collision to the solid-liquid mixed solidified slag S as shown in FIG. Although the rotating body 5a for crushing the slag S can be used, it is not limited to this.

Subsequently, the granular solidified slag Sg produced as described above is classified into a plurality of granular slag groups according to the particle size by the slag classification equipment 7 (slag classification step). As described above, the solid-liquid mixed solidified slag S is difficult to granulate with a single particle size because the locations where cracks are generated and propagated are not uniform. Therefore, if granular solidified slag with a large particle size distribution is subjected to slag treatment as it is, the time required to treat coarse-grained slag with a relatively high particle size becomes a constraint in the process, and slag is efficiently treated. cannot be applied, and the quality of the obtained product slag is not stable. Moreover, there is also a problem that the equipment becomes large-sized.

Therefore, in the method of the present invention, the granular solidified slag Sg produced by crushing the solid-liquid mixed solidified slag S is classified into a plurality of granular slag groups according to the particle size. As a result, it is possible to perform slag treatment on granular solidified slag Sg with a certain degree of particle size, and granular solidified slag that can efficiently perform slag treatments such as heat recovery treatment, steam aging treatment, and carbonation treatment. Sg can be produced.

A sieve can be used most conveniently as the slag classifying equipment 7 . In addition, when classifying at a high temperature immediately after crushing, it is necessary to have a heat-resistant structure such as a water-cooled lattice mesh, so as the slag classifying equipment 7, for example, a dry classifying equipment using an air jet method can be used. . Alternatively, it is also possible to use a classification facility based on a cut gate system that uses a gate that allows only slag smaller than a predetermined size to pass through in the conveying direction. As described above, the slag classifier 7 can be appropriately selected according to the treatment temperature and treatment amount.

The particle size when classifying the granular solidified slag Sg can be arbitrarily set according to the target particle size of the slag product. For example, when the granular solidified slag produced by the method according to the present invention is used as a roadbed material slag, the granular solidified slag (fine slag) Ss of the granular slag group having a relatively low particle size obtained after the slag classification step is The particle size distribution is set so that it falls within the particle size standard for roadbed material slag. Since the particle size of the slag may change in the slag heat recovery process and the carbonation treatment process, which will be described later, the particle size of the granular solidified slag in the slag classification process is appropriately adjusted according to the particle size of the final target slag product.

The classification of the granular solidified slag Sg is not limited to the classification into two granular slag groups as shown in FIG. 3, and can be classified into three or more granular slag groups.

Next, by the slag heat recovery equipment 8 (first slag heat recovery equipment 8A), among the plurality of granular slag groups classified as described above, granular slag with a relatively low particle size (for example, a particle size of less than 10 mm) A heat recovery treatment is applied to the granular solidified slag Ss of the group (first slag heat recovery treatment step). Since the solid-liquid mixed solidified slag S solidified in the solid-liquid slag mixed solidification equipment 4 can be easily crushed even when hot, high-temperature granular solidified slag Sg can be produced by hot crushing. After the produced granular solidified slag Sg is classified into a plurality of granular slag groups according to the particle size by the slag classifying equipment 7, the granular solidified slag Ss of the granular slag group with a relatively low particle size that can be used as product slag is classified as a first slag. It is charged into the heat recovery facility 8A and filled in the slag filling tank 8a. Then, a cooling gas 8b such as air is supplied into the slag filling tank 8a to recover the inherent heat of the granular solidified slag Ss. The obtained heat-recovery gas 8c is supplied to, for example, each process in the steelworks, and effective utilization of the heat potential of the molten slag S2 (that is, the potential heat of the granular solidified slag Ss) is achieved. After heat recovery, the granular solidified slag Ss is discharged from the first slag heat recovery facility 8A, and then shipped as product slag as a roadbed material or aggregate.

As the first slag heat recovery equipment 8A, a vertical packed tank system such as a coke dry quenching system (CDQ) or a rotary It is possible to appropriately design and use such as a floor system.

In the method of the present invention, the particle size of the granular solidified slag Ss charged into the first slag heat recovery equipment 8A is made relatively small by classification. Therefore, the heat can be efficiently recovered in a short period of time compared to the case where the slag is not uniform in particle size and contains slag with a relatively large particle size.

Further, in the conventional method described in Patent Document 1, when the molten slag is solidified in the mold, most of the heat (and latent heat of solidification) of the molten slag is taken away by the mold or dissipated into the atmosphere. lose. On the other hand, in the method of the present invention, part of the heat stored in the molten slag S2 is transferred to the solid slag S1 and stored therein. Therefore, the amount of heat recovered by the first slag heat recovery facility 8A is greater than the amount of heat recovered in the conventional method described in Patent Document 1.

On the other hand, among the classified multiple granular slag groups, the granular solidified slag Si of the granular slag group with a relatively high grain size (for example, a grain size of 10 mm or more) is used as product slag such as roadbed materials and aggregates. It is not possible. However, the granular solidified slag Si, which has a relatively large grain size, is also at a high temperature like the granular solidified slag Ss, which has a relatively small grain size. Therefore, as shown in FIG. 3, a second slag heat recovery facility 8B is provided separately from the first slag heat recovery facility 8A, and high-temperature granular solidified slag Si is charged into the second slag heat recovery facility 8B. It is preferable that the cooling gas 8b is supplied into the slag-filled tank 8a by filling the slag-filled tank 8a with the cooling gas. As a result, the heat of the granular solidified slag Si can be recovered in the same manner as the granular solidified slag Ss (second slag heat recovery step). It takes longer time to recover heat from the granular solidified slag Si than from the granular solidified slag Ss having a relatively low particle size.

Between the second slag heat recovery equipment 8B and the solid slag supply device 2, a transport path 12 for transporting the granular solidified slag Si after heat recovery to the solid slag supply device 2 of the solid-liquid slag mixing and solidification equipment 4 is provided, and part or all of the granular solidified slag Si subjected to heat recovery treatment is preferably reused as solid slag S1 (slag recycling step). As shown in Figures 1 and 2, coarse slag is inefficient in both heat recovery and slag stabilization processes such as _CO2 fixation. On the other hand, for the solid slag S1 supplied to the mold 1 in the solid-liquid slag mixing and solidification equipment 4, it is more effective to use slag with a relatively large grain size in order to improve the crushability of the solidified slag. Therefore, it is preferable to reuse part or all of the granular solidified slag Si subjected to the heat recovery treatment as the solid slag S1.

If the grain size of the reusable granular solidified slag Si is too small with respect to the slag solidification thickness of the solid-liquid mixed solidified slag S produced in the solid-liquid slag mixing and solidification equipment 4, the molten slag S2 will flow into the gaps between the particles of the solid slag S1. The molten slag S2 solidifies before it permeates, making uniform solid-liquid mixed solidification difficult. Therefore, it is necessary to increase the particle gap to such an extent that the molten slag S2 can penetrate into the solid slag S1 gap. Therefore, it is preferable that the particle size of the reusable granular solidified slag Si is 10 mm or more. On the other hand, when the particle size of the granular solidified slag Si is larger than the slag solidification thickness of the solid-liquid mixed solidified slag S produced in the solid-liquid slag mixing and solidification equipment 4, the particle size of the solid slag S1 is larger than the solidification thickness of the molten slag S2. As a treatment, the produced solid-liquid mixed solidified slag S is similarly subjected to hot crushing, and the uncrushed coarse-grained slag having a relatively large grain size is reused. Coarse-grained slag undergoes repeated heat history due to solid-liquid slag mixed solidification and repeated hot crushing, and is gradually refined into fine-grained slag with a relatively small grain size, so it can be reused permanently. It is finally commercialized as fine-grained slag.

Regarding the second slag heat recovery equipment 8B, as with the first slag heat recovery equipment 8A, depending on the transportation method and supply pitch of the granular solidified slag Si, a vertical type such as a coke dry quenching equipment (CDQ) A packed tank system, a rotating bed system such as a sintering cooler, or the like can be appropriately designed and used.

As described above, in the method for producing granular solidified slag using the production equipment line shown in FIG. Depending on the particle size of the solidified slag Sg, different slag heat recovery equipment 8 performs slag treatment. With such a configuration, for example, the granular solidified slag Ss of the granular slag group with a relatively low grain size is treated for a short time, while the granular solidified slag Si of the granular slag group with a relatively high grain size is treated for a short time. can perform independent processing, such as performing long-running processing.

As described above, the first slag heat recovery equipment 8A for granular solidified slag Ss with a relatively low grain size and the second slag heat recovery equipment 8B for granular solidified slag Si with a relatively high grain size are used for slag filling. If the height of the tank 8a is the same, the temperature of the heat recovery gas 8c will be lower for the granular solidified slag Si, which has a smaller total slag surface area per unit volume. Therefore, for example, the height of the slag filling tank 8a of the second slag heat recovery facility 8B for granular solidified slag Si is higher than the slag filling tank 8a of the first slag heat recovery facility 8A for granular solidified slag Ss. It is also possible to increase the temperature of the heat recovery gas 8c by designing the heat recovery gas 8c to increase the chances of contact with the granular solidified slag Si during gas flow.

In FIG. 3, the granular solidified slag Ss of the group of granular slag having a relatively low particle size was subjected to heat recovery treatment, but steam was supplied as in the slag manufacturing facility line shown in FIG. A steam supply device 9 for performing steam aging treatment is provided, and the granular solidified slag Ss can be subjected to steam aging treatment (steam aging treatment step). That is, the classified high-temperature granular solidified slag Ss is charged into the slag stabilization treatment equipment 10 and steam is supplied from the steam supply device 9 into the slag stabilization treatment equipment 10 . Since the granular solidified slag Ss has a relatively large total surface area, the penetration efficiency of steam into the slag is high, and efficient steam aging treatment is possible. Therefore, steam is supplied to the granular solidified slag Ss of the granular slag group with relatively low particle size classified by the slag classifier 7, and the steam aging treatment is performed with the following formula (1) as the main reaction. The product slag obtained in this way has undergone an expansion reaction by steam aging treatment, and can be shipped as a roadbed material or aggregate.
CaO + _H2O → Ca(OH) ₂ (1)

Further, as in the slag manufacturing facility line shown in FIG. 8, a carbon dioxide gas supply device 11 for supplying carbon dioxide gas to perform carbonation treatment is provided, and the granular solidified slag Ss can be subjected to carbonation treatment. . That is, the classified high-temperature granular solidified slag Ss is charged into the slag stabilization treatment facility 10, and carbon dioxide gas is supplied from the carbon dioxide supply device 11 into the slag stabilization treatment facility 10. FIG. Since the granular solidified slag Ss has a relatively large total surface area, the efficiency of carbon dioxide gas permeation into the slag is high as in the case of water vapor, enabling efficient carbonation. Therefore, carbon dioxide gas is supplied to the granular solidified slag Ss of the group of granular slags with relatively small particle sizes classified by the slag classifier 7, and the carbonation treatment is performed with the following formula (2) as the main reaction. The product slag obtained in this way has undergone an expansion reaction by carbonation, and can be shipped as a roadbed material or aggregate.
CaO+ _CO2 → _CaCO3 (2)

One or both of the steam supply device 9 shown in FIG. 7 and the carbon dioxide gas supply device 11 shown in FIG. 8 can be incorporated into the first slag heat recovery facility 8A shown in FIG. That is, the high temperature granular solidified slag Ss is charged into the first slag heat recovery equipment 8A at a high temperature of about 1000°C. Here, regarding the steam aging treatment and carbonation treatment of slag, according to equilibrium theory, the hydration expansion of f-CaO in steam aging treatment is 580 ° C. or less, and the carbonation of f-CaO in carbonation treatment is at 898 ° C. or less. proceed. Therefore, it is advantageous to perform heat recovery prior to steam aging or carbonation and switch to steam aging and/or carbonation after the slag temperature has sufficiently decreased. It is preferable to switch these treatment methods within the same slag filling tank 8a (see FIG. 3). It is preferred to incorporate one or both of Although such equipment is not particularly illustrated, in FIG. 3, the supply of the cooling gas 8b can be selected from among air, water vapor and carbon dioxide by means of a switching valve or the like. In this configuration, it is possible, for example, to switch from air supply for heat recovery to steam supply for steam aging according to the progress of slag heat recovery.

The slag temperature in the slag filling tank 8a is determined using the shape and temperature of the filled slag, the temperature of the heat recovery gas during heat recovery, etc., as described above, ISIJ International, Vol. 55 (2015), No. 10, pp. 2258-2265. Alternatively, a method of estimating the temperature of the granular solidified slag Ss from the temperature of the inner wall by installing a thermocouple on the inner wall of the slag filling tank 8a that is in direct contact with the slag is also possible.

Further, one or both of the steam supply device 9 shown in FIG. 7 and the carbon dioxide gas supply device 11 shown in FIG. 8 can be provided downstream of the first slag heat recovery facility 8A shown in FIG. That is, in the manufacturing equipment line shown in FIG. 3, the granular solidified slag Ss in the slag filling tank 8a of the first slag heat recovery equipment 8A has a temperature distribution in the flow direction of the cooling gas 8b. The temperature in the slag filling tank 8a does not become uniform except for the case where the heat is recovered by heating. For example, for the slag-filled tank 8a in which high-temperature granular solidified slag Ss of about 1000° C. immediately after charging and low-temperature granular solidified slag Ss of about 100° C. or lower after completion of heat recovery are mixed, the first slag When performing the steam aging treatment and the carbonation treatment in the heat recovery facility 8A, both treatment effects can be non-uniform. Therefore, one or both of the steam supply device 9 and the carbon dioxide gas supply device 11 are provided downstream of the first slag heat recovery facility 8A independently of the first slag heat recovery facility 8A. Then, after cooling the granular solidified slag Ss to a predetermined temperature in the first slag heat recovery equipment 8A, the granular solidified slag Ss after heat recovery is discharged, and this discharged slag is treated as the slag stabilization shown in FIG. 7 or FIG. It is charged into the chemical treatment facility 10 . Thereby, the effect of the steam aging treatment and/or the carbonation treatment by the steam supply device 9 and the carbon dioxide gas supply device 11 can be made uniform.

It is also possible to install all of the above-described first slag heat recovery equipment 8A, steam supply device 9, and carbon dioxide gas supply device 11. For example, as shown in FIG. 9, it is possible to form a manufacturing equipment line in which a first slag heat recovery equipment 8A, a steam supply device 9 and a carbon dioxide gas supply device 11 are arranged in order on the outlet side of the slag classification equipment 7. is. According to this line of production equipment, it is of course possible to have the effects of the first slag heat recovery equipment 8A, the steam supply device 9 and the carbon dioxide gas supply device 11 described above.

The present invention has been described above, but as a result of further studies by the present inventors, the following findings have been obtained. That is, in the above explanation, the solid slag S1 and the molten slag S2 are supplied into the mold 1 to produce the solid-liquid mixed solidified slag S. It was found that even when metal particles or the like having As described above, what is supplied to the mold 1 together with the molten slag S2 is not limited to the solid slag S1, and may be a solid material including solid slag and metal particles having a melting point higher than the melting point of the molten slag S2. By supplying the molten slag S2 into the mold 1 together with such solids, the mixed solidified material S can be produced (mixed solidified material producing step).

Then, the produced mixed solidified material S is crushed into granules to produce mixed crushed material Sg (crushing step), and the mixed crushed material Sg is separated into a plurality of mixed crushed material groups according to the particle size or material to form granular solidified slag. Ss and Si can be obtained (separation step).

When supplying the solid matter into the mold 1 together with the molten slag S2, the solid slag supply device 2 is used as the solid matter supply device 2 for supplying the solid matter in the manufacturing equipment line for granular solidified slag shown in FIG. The slag mixing and solidification facility 4 is assumed to be a mixed solidification production facility 2 having a solid matter supply device 2 and a molten slag supply device 3 . Further, the slag crushing equipment 5 is used as the crushing equipment 5 for crushing the mixed solidified material S to produce the crushed mixed material Sg. Further, the slag classifying equipment 7 is a separation equipment 7 for obtaining granular solidified slag by separating the mixed crushed material Sg into a plurality of mixed crushed material groups according to the particle size or material.

When metal particles having a melting point equal to or higher than the melting point of the molten slag S2 are used as the solid matter, it is possible to efficiently remove heat from the molten slag S2 by utilizing the high thermal conductivity of the metal. In addition, the separation of the molten slag S2 from the solidified slag is improved, and the crushing process of the mixed solidified product can be simplified. The melting point of the metal particles M is preferably higher than the melting point of the molten slag S2. When metal particles M are used as the solid matter, particles of a ferromagnetic material such as iron, which can be separated by magnetic separation in a downstream step, are more preferable.

If the mixed solidified material S is too thick, the load on the crushing equipment 5 in the crushing process will increase, and the mixed solidified material S that remains uncrushed may increase. On the other hand, if the mixed solidified material S is too thin, the particle size of the crushed mixed material Sg after crushing becomes too small, and there is a possibility that it cannot be used as steel slag for roads. Therefore, the solidified thickness t of the mixed solidified material S is preferably 30 mm or more and 100 mm or less. In particular, in the case of using equipment that can easily control the solidified thickness, the solidified thickness t of the mixed solidified material S is more preferably 30 mm or more and 50 mm or less.

In addition, the solid matter S1 may be two or more kinds of solid matter having different particle sizes or materials. For example, both solid slag S1 and metal particles M may be used as solids. As shown in FIG. 10, this can be done by configuring the solid matter feeder 2 with a solid slag feeder 2A that feeds solid slugs S1 and a metal particle feeder 2B that feeds metal particles M. The metal particle supply device 2B includes a hopper that stores the metal particles M and supplies a predetermined amount, and a gutter for guiding the metal particles M supplied from the hopper into the mold 1 .

When both the solid slag S1 and the metal particles M are used as the solid matter, as shown in FIG. 11, the metal particles M can be placed on the solid slag S1 having a small size. As a result, even if the metal particles M are iron balls that tend to roll easily, they can be stably dispersed and held within the mold 1 . In addition, by laying the solid slag S1 with a small size on the bottom surface of the mold 1, the heat load on the mold 1 can be reduced, the vitrification of the solid slag S1 can be suppressed, and the crushability of the mixed solidified material S by the metal particles M can be improved. Multiple effects can be obtained.

When two or more kinds of solids having different particle sizes or materials are used as the solids to be supplied to the mold 1, for example, as shown in FIG. 1a may be provided at the bottom of the mold 1; By making the shape of the bottom portion such a shape, it is possible not only to facilitate the dispersion and retention of the solids, but also to provide a portion with a small solidified thickness and a portion with a large solidified thickness in the mixed solidified product S to be produced. . As a result, it becomes possible to adjust the particle size distribution of the finally produced granular solidified slag. In addition, by arranging metal particles M such as iron balls with high thermal conductivity at the ends of the mold 1 with a large solidified thickness, it is possible to improve the balance of the solidification speed of the molten slag S2. In addition, a configuration may be adopted in which a plurality of protrusions 1a are provided on the bottom of the mold 1 to hold a plurality of metal particles M in a dispersed manner.

FIG. 13 shows a preferred example of a production equipment train used in the method for producing granular solidified slag in which two types of solids are supplied to the mold according to the present invention. In the production equipment line shown in FIG. 13, two types of solids, solid slag S1 and iron balls as metal particles M, are used as solids. It is composed of a supply device 2A and a metal particle supply device 2B that supplies metal particles M. As shown in FIG.

In the mixed solidified material production process in the mixed solidified material production apparatus 4, for example, the viscosity of the molten slag S2 is high, and the mixed solidified material S cannot be controlled to a predetermined solidification thickness, and a coarse mixed solidified material S is formed. If the molten slag S2 is supplied with bare metal mixed therein, supplying the mixed solidified material S as it is to the crushing equipment 5 may lead to damage to the equipment. Therefore, as shown in FIG. 13, a hot separation device 7 (7A) is provided between the mixed solidified material production equipment 4 and the crushing equipment 5, and the mixed solidified material S is separated by grain size or material while hot. It is more desirable to provide a hot separation step for separation. For example, a movable chute or the like can be used as the hot separation equipment 7A.

In the hot separation process, for example, by using a laser displacement meter, a metal detector, image processing, etc., the transport timing of the coarse mixed solidified material S and the base metal is detected, and the mold 1 is reversed to drop the mixed solidified material S. This can be done by moving the separating equipment 7A, such as a movable chute, which is provided directly below the position where the separation is carried out, in accordance with the falling timing of the coarse mixed solidified material S and the base metal.

In the slag manufacturing equipment line shown in FIG. 8, high-temperature granular solidified slag Ss is charged into the slag stabilization treatment equipment 10, and carbon dioxide gas is supplied from the carbon dioxide supply device 11 into the slag stabilization treatment equipment 10. However, as shown in FIG. 13, the slag heat recovery equipment 8A and 8B in FIG. 8 can be used not only for heat recovery but also for steam aging and carbonation. It may be configured as a possible slag treatment facility 8A, 8B. Further, when the granular solidified slag Ss is subjected to the carbonation treatment, the granular solidified slag Ss is charged into the first slag heat recovery equipment 8A and filled in the filling layer 8a, and the water vapor supply device 9 and the carbon dioxide gas are supplied. A mixed gas of carbon dioxide gas and water vapor may be supplied to the granular solidified slag Sg by the device 11 .

By mixing water vapor into carbon dioxide gas, the calcium on the surface of the granular solidified slag Sg is ionized, the reactivity between the granular solidified slag Sg and the carbon dioxide gas and water vapor is improved, and calcium is produced by the reaction between the water vapor and the carbon dioxide gas. The hydrate serves as an intermediate, which reduces the activation energy during the carbonation reaction and improves the reaction rate of carbonation. When using a mixed gas of carbon dioxide gas and water vapor, the concentration of water vapor is 1 to 80% by volume, more preferably 1 to 60% by volume, where the sum of the concentration of carbon dioxide gas and water vapor is 100% by volume. %.

In the manufacturing equipment line shown in FIG. 13, the mixed condensate S produced by the mixed condensate producing apparatus 4 contains iron balls. Therefore, the crushing equipment 5 is preferably of a ball mill type, and as the iron balls for crushing the mixed condensate S, the iron balls contained in the mixed condensate S can be used as they are. When using the ball mill type crushing equipment 5 , iron balls may be additionally charged into the crushing equipment 5 . The mixed crushed material Sg discharged from the crushing equipment 5 is separated into a plurality of mixed crushed material groups according to the particle size or material. In FIG. 13, iron balls are separated together with solidified slag Si having a relatively large grain size. The separated iron balls and the solidified slag Si having a relatively large grain size are subjected to heat recovery by the slag processing equipment 8B, and then to grain size adjustment and separation by grain size or material by the grain size adjustment equipment and the cold separation equipment. , can be reused as solids.

FIG. 14 shows another example of a production equipment train used in the method for producing granular solidified slag in which two types of solids are supplied to the mold according to the present invention. In the row of manufacturing equipment shown in FIG. 14, iron balls having a relatively small size are used as the metal particles M, and when the mesh of the separation equipment 7 (7B) is large, the iron balls have a relatively large particle size It is supplied to the slag processing facility 8A together with small solidified slag Ss. After performing heat recovery together with the granular solidified slag Ss, the iron balls are finally separated and removed from the product slag by a magnetic separation process, and reused as the solid material supplied by the solid material supply device 2 .

According to the present invention, slag treatment such as heat recovery treatment, steam aging treatment, and carbonation treatment can be efficiently performed on solidified slag, so it is useful in the steel industry.

1 mold 2 solid slag feeder (solid feeder)
2A Solid slag feeder 2B Metal particle feeder 2a Hoppers 2b, 3b Slag gutter 3 Molten slag feeder 3a Tilting pan 4 Solid-liquid slag mixed solidification equipment (mixed solidified material producing device)
5 Slag crushing equipment (crushing equipment)
5a Rotating body 6 Reduction device 7 Slag classification equipment (separation equipment)
8, 8A, 8B Slag heat recovery equipment (slag treatment equipment)
8a Slag filling tank (filling bed)
8b Cooling gas 8c Heat recovery gas 9 Water vapor supply device 10 Slag stabilization equipment 11 Carbon dioxide gas supply device 12 Conveyance path S1 Solid slag S2 Molten slag S Solid-liquid mixed solidified slag (mixed solidified material)
Sg Granular solidified slag Si Granular solidified slag with a relatively high grain size Ss Granular solidified slag with a relatively low grain size t Solidified thickness

Claims (22)

1. Mixed solidification in which molten slag and solids are supplied into a mold, and solidification of the molten slag proceeds in a state in which gaps between the solids in the mold are filled with the molten slag to produce a mixed solidified product. a manufacturing process;
   A crushing step of crushing the mixed solidified material into granules to produce a crushed mixed material;
   a separation step of separating the mixed crushed material into a plurality of mixed crushed material groups according to particle size or material to obtain granular solidified slag;
   A method for producing granular solidified slag, comprising:
2. 2. The method for producing granular solidified slag according to claim 1, wherein the mixed solidified material producing step further includes a pushing step of pushing the solid material toward the bottom of the mold after supplying the molten slag and the solid material. .
3. Further comprising a first slag heat recovery treatment step of subjecting the crushed mixed material of the crushed mixed material group containing granular solidified slag having a relatively low particle size among the plurality of crushed mixed material groups to heat recovery treatment. Item 3. A method for producing granular solidified slag according to Item 1 or 2.
4. A steam aging treatment step of supplying steam to the crushed mixed material group of the crushed mixed material group containing granular solidified slag having a relatively low particle size among the plurality of crushed mixed material groups to perform steam aging treatment. A method for producing granular solidified slag according to any one of claims 1 to 3.
5. Further comprising a carbonation treatment step of supplying carbon dioxide gas to the crushed mixed material group of the crushed mixed material group containing granular solidified slag having a relatively low particle size to carry out carbonation treatment among the plurality of crushed mixed material groups. , The method for producing granular solidified slag according to any one of claims 1 to 4.
6. The method for producing granular solidified slag according to claim 5, wherein the mixed gas of carbon dioxide gas and water vapor is supplied in the carbonation treatment step.
7. Further comprising a second slag heat recovery treatment step of performing a heat recovery process on the crushed mixed material of the crushed mixed material group containing granular solidified slag having a relatively high particle size among the plurality of crushed mixed material groups. Item 7. A method for producing granular solidified slag according to any one of Items 1 to 6.
8. Part or all of the crushed mixed material of the crushed mixed material group containing the granular solidified slag having a relatively high particle size, which has been heat-recovered in the second slag heat recovery process, is added to the mixed solidified material producing process. 8. The method for producing granular solidified slag according to claim 7, further comprising a solid matter recycling step of reusing the solid matter in.
9. The method for producing granular solidified slag according to any one of claims 1 to 8, wherein the solidified thickness of the mixed solidified material produced in the mixed solidified material production step is 100 mm or less.
10. The method for producing granular solidified slag according to any one of claims 1 to 9, wherein in the mixed solidified material producing step, the solid material is solid slag.
11. The method for producing granular solidified slag according to any one of claims 1 to 9, wherein in the mixed solidified material producing step, the solid material is metal particles having a melting point equal to or higher than the melting point of the molten slag.
12. The method for producing granular solidified slag according to any one of claims 1 to 9, wherein in the mixed solidified material producing step, two or more types of solid materials having different particle sizes or materials are supplied into the mold.
13. Granular solidification according to any one of claims 1 to 12, further comprising a hot separation step of separating the mixed coagulum by particle size or material between the mixed coagulum preparation step and the crushing step. A method for producing slag.
14. A mixed solidified product production facility having a molten slag supply device for supplying molten slag into the mold and a solid substance supply device for supplying solid substances into the mold;
    A crushing facility for crushing the mixed solidified material produced by the mixed solidified material production facility to produce a mixed crushed material, and separating the mixed solidified material into a plurality of mixed crushed material groups according to particle size or material to form granules. and separation equipment for obtaining solidified slag.
15. 15. The train of equipment for producing granular solidified slag according to claim 14, wherein the mixed solidified material production equipment has a reduction device that presses the solid material into the mold supplied with the molten slag and solid material.
16. The train of equipment for producing granular solidified slag according to claim 14 or 15, wherein the mold has a raised portion at the bottom.
17. The train of equipment for producing granular solidified slag according to any one of claims 14 to 16, wherein the crushing equipment has a rotating body for crushing the mixed solidified matter.
18. Any one of claims 14 to 17, comprising a first slag treatment facility downstream of the separation facility for recovering the heat of the mixed and crushed mixed material group containing granular solidified slag with a relatively low particle size. A train of equipment for producing granular solidified slag according to the above paragraph.
19. Any one of claims 14 to 18, comprising a steam supply device downstream of the separation equipment for performing steam aging by supplying steam to the crushed mixed material group of the crushed mixed material group containing granular solidified slag having a relatively low particle size. or a row of production facilities for granular solidified slag according to any one of the above items.
20. Claim 14-, comprising a carbon dioxide gas supply device downstream of the separation equipment for supplying carbon dioxide gas to the crushed mixed material of the crushed mixed material group containing granular solidified slag having a relatively low particle size to perform carbonation treatment. 20. A production facility train for granular solidified slag according to any one of 19.
21. Any one of claims 14 to 20, comprising a second slag treatment facility downstream of the separation facility for recovering the heat of the mixed crushed material of the mixed crushed material group containing granular solidified slag with a relatively high particle size. A production facility train for granular solidified slag as described.
22. Between the second slag treatment equipment and the solids supply device, a transport path is provided for transporting part or all of the crushed mixed material subjected to the heat recovery treatment to the solids supply device. Item 22. Equipment train for producing granular solidified slag according to item 21.
    

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