JP4434555B2 - Processing method of granulated blast furnace slag - Google Patents

Description

【００４７】
表１に示すように、比較例１の未処理のスラグでは８０℃の室内規模評価で１ヶ月以内に、常温の実施規模評価でも３ヶ月以内に固結が始まった。１８℃の条件で炭酸水溶液に浸漬した比較例２では、室内規模で２〜３ヶ月の間に固結が始まり、実施規模では６ヶ月から１年で固結が始まった。６０℃の条件で炭酸ガスを吹き込んだ比較例３では、室内規模で２ヶ月から３ヶ月の間に固結が始まり、実施規模では６ヶ月から１年で固結が始まった。これに対して、６０℃の条件で、インバフィルタへ炭酸ガスを吹き込んだ実施例１および篩上および篩下に炭酸ガスを供給した実施例２は、室内規模で６ヶ月、実施規模では２年間固結しなかった。
【００４８】
【発明の効果】
以上説明したように、本発明によれば、十分な水和反応防止効果および固結防止効果を発揮することができる高炉水砕スラグの処理方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の方法の実施状態を説明するための図。
【図２】炭酸水溶液の製造設備の一例を示す概略断面図。
【図３】本発明が実施されるインバフィルタ（ドラム回転脱水機）を示す断面図。
【図４】高炉水砕スラグを搬送するコンベアの乗り継ぎ部で本発明を実施する状態を説明するための図。
【図５】高炉水砕スラグを篩分けする振動篩において本発明を実施する状態を説明するための図。
【符号の説明】
１；高炉水砕スラグ
２，３；ノズル
４；槽
２０；インバフィルタ（ドラム回転脱水機）
２１；回転ドラム
２２；金網
２３；ベーン
２５；ディストリビュータ
２６；クッションボックス
２７；排出コンベア
２８；デフレクタ
３１；炭酸ガス供給配管
３２；ノズル
４１，４２；コンベア
４３；高炉水砕スラグ
４４；ノズル
５２；振動篩
５３；篩目
５５，５７；ノズル
５８，５９；高炉水砕スラグ破砕物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for treating granulated blast furnace slag.
[0002]
[Prior art]
Blast furnace granulated slag is a blast furnace slag produced as a by-product in the ironmaking process, which is rapidly cooled and granulated by injecting pressurized water, and is produced over 20 million tons per year.
Since granulated blast furnace slag has hydraulic properties, it has been finely pulverized and used as a raw material for cement. In recent years, natural sand has been depleted, and from the viewpoint of resource conservation, as a substitute for natural sand, as a material for civil engineering work, as a fine aggregate for concrete, granulated blast furnace slag itself, or by pulverizing the particle size Opportunities for use as adjusted particle size preparations are increasing.
[0003]
By the way, blast furnace granulated slag, whether used as it is or as a granular preparation, is often stored in a piled state or storage tank for a long time because it is awaiting shipment or use. Sometimes transported over a long period of time. The hydraulic property of granulated blast furnace slag is an indispensable property when used as a cement raw material, but if a hydration reaction has already occurred during long-term storage or transportation before use, The performance will deteriorate and the concrete will not be strong enough. Furthermore, when the slag particles are firmly consolidated into a medium and agglomerated, the slag particles can no longer be used as fine aggregates and their bonding strength is high, so they are crushed and sized into the original particles. Is extremely labor intensive.
[0004]
In addition, when blast furnace granulated slag is used as a material for civil engineering work, hydraulic properties work for the purpose of forming a strong ground, but to use it as a sand mat material for surface treatment methods on soft ground Depending on the number of days that have elapsed, the material is consolidated during construction, and it becomes extremely difficult to place a vertical drain material such as a paper drain or a plastic drain through the sand mat material and penetrate it. For civil engineering purposes, it may be used as embankment material, backfill material, backfill material, etc. In this case as well, after construction, a few days to several years later, that part will be dug up and newly buried In some cases, they are buried, planted, or dug up again after several decades. In these cases, consolidation of the granulated slag requires a large force for digging work, and there is also a risk of causing damage to existing objects in piping work or the like. Thus, conventionally, the use of granulated blast furnace slag for this type of application has been limited.
[0005]
Such a hydration reaction and a caking phenomenon are particularly noticeable in summer when the temperature is high, and are considered to proceed by the following mechanism. First, the hydration reaction of granulated blast furnace slag begins with the elution of calcium from the glass and the pH increase, and components such as silicon and aluminum are eluted by this alkali stimulation. When the concentration of components such as calcium, silicon, and aluminum in the liquid phase near the blast furnace granulated slag particles rises to the precipitation conditions for various hydrated products due to the eluted components, hydrate formation begins, and ettringite (3CaO · Al₂O₃・ 3CaSO₄・ 32H₂O) and hydrates such as calcium silicate hydrate (C—S—H) are generated, and the layer thickness is gradually increased, leading to consolidation of particles. In addition, this hydrate formation reaction occurs not only in the liquid phase but also inside the particles near the surface of the granulated blast furnace slag.
[0006]
Several methods have been proposed in the past to prevent hydration and consolidation of granulated blast furnace slag or its particle size preparation. For example, Japanese Examined Patent Publication No. 58-35944 discloses an anti-caking agent containing an aliphatic oxycarboxylic acid, an aliphatic oxycarboxylate or a mixture of two or more thereof as an important component. Japanese Patent Application Laid-Open No. 54-71793 discloses an anti-caking method in which an aqueous acid solution is sprayed on granulated blast furnace slag to neutralize active calcium once.
[0007]
Further, carbon dioxide contained in water in which carbon dioxide gas is brought into contact with CaO in the granulated blast furnace slag, or carbon dioxide gas is bubbled into CaO in the granulated blast furnace slag.₂CO₃) And the like, and the slightly soluble CaCO on the surface of the slag particles₃In this method, a method of suppressing elution reaction of calcium and the like from blast furnace granulated slag and suppressing hydration reaction and thus caking is shown.
[0008]
Specifically, Japanese Patent Laid-Open Nos. 54-112304, 54-127895, 54-131504, and 55-162454 disclose blast furnace granulated slag or blast furnace water. A method in which carbon dioxide gas in a gas phase is brought into contact with lightly crushed slag is shown.
[0009]
Japanese Patent Application Laid-Open No. 10-95644 discloses a caking prevention method in which blast furnace granulated slag is immersed in a carbonic acid aqueous solution in which carbon dioxide gas is dissolved.
[0010]
However, among these prior arts, in the method using the anti-caking agent disclosed in Japanese Patent Publication No. 58-35944, the anti-caking agent elutes from the surface of the granulated blast furnace slag if it rains during the piled state. Does not exhibit sufficient anti-caking function. In addition, when used as a civil engineering material under the condition of being immersed in water or seawater, the anti-caking agent flows out into the water or seawater as well, so that the caking cannot be sufficiently prevented.
[0011]
In addition, in the method of spraying an acid aqueous solution disclosed in JP-A-54-71793, when used as a cement raw material or a concrete aggregate, residual acid ions adversely affect the properties of the concrete. There must be.
[0012]
Furthermore, in the case of a method in which carbon dioxide gas in a gas phase is brought into contact with blast furnace granulated slag as disclosed in JP-A-54-112304, carbon dioxide gas is uniformly applied to granular granulated slag filled in a hopper or a piled state. It is difficult to spread, and there are cases where sufficient hydration reaction suppression effect and consolidation suppression effect cannot be obtained at locations where gas does not spread.
[0013]
On the other hand, in the case of the method of immersing cooled blast furnace granulated slag in an aqueous carbonate solution in JP-A-10-95644, macroscopically, carbon dioxide can be uniformly supplied to the blast furnace granulated slag. If the granulated slag is agglomerated, the aqueous solution of carbonate may not be supplied to all of the filled blast furnace granulated slag particles when viewed microscopically. Also in this case, there may be a case where a sufficient hydration reaction inhibitory effect and a caking inhibitory effect cannot be obtained at locations where the aqueous carbonate solution does not spread.
[0014]
[Problems to be solved by the invention]
This invention is made | formed in view of this situation, Comprising: It aims at providing the processing method of the granulated blast furnace slag which can exhibit sufficient hydration reaction prevention effect and caking prevention effect.
[0016]
[Means for Solving the Problems]
  To solve the above problem,First of the present invention1In view of the above, when the blast furnace granulated slag is being dehydrated by the drum rotary dehydrator in the blast furnace granulated slag manufacturing process, the blast furnace granulated slag is brought into contact with a substance containing at least one of carbon dioxide and carbonic acid aqueous solution. A method for treating granulated blast furnace slag is provided.
[0017]
  First of the present invention2From this point of view, when blast furnace granulated slag is transported to the belt conveyor or dropped from the belt conveyor,, By blowing a gas containing carbon dioxide, or spraying a carbonic acid aqueous solution with a gas, or spraying a substance containing a carbonic acid aqueous solution,A method for treating granulated blast furnace slag, comprising contacting a substance containing at least one of carbon dioxide and an aqueous carbonate solution.
[0018]
First of the present invention3From the viewpoint of blast furnace granulated slag, when containing blast furnace granulated slag on the sieve or blast furnace granulated slag falling under the sieve, a gas containing carbon dioxide is sprayed or an aqueous solution of carbon dioxide is used as the gas. A method for treating ground granulated blast furnace slag, characterized by contacting a substance containing at least one of carbon dioxide gas and an aqueous carbonate solution by spraying or spraying a substance containing an aqueous carbonate solution, is provided.
[0019]
In a state where blast furnace granulated slag is filled in a container or in a piled state, even if a substance containing at least one of carbon dioxide gas and aqueous carbonic acid solution is supplied, carbonized up to the internal blast furnace granulated slag particles due to the presence of agglomerated parts. There is a possibility that a substance containing at least one of gas and aqueous carbonic acid solution may not reach sufficiently, but when blast furnace granulated slag is dispersed as in the present invention, carbon dioxide gas and aqueous carbonic acid solution are uniformly distributed throughout the blast furnace granulated slag. Thus, carbonate ions are supplied to individual blast furnace granulated slag particles, and a calcium carbonate film can be uniformly formed on the surface of each blast furnace granulated slag particle. Accordingly, a sufficient hydration reaction suppressing effect and anti-caking effect can be obtained.
[0020]
First viewpointIn this drum rotation dehydrator, the blast furnace granulated slag in the drum is dispersed by the rotation of the drum,2When the blast furnace granulated slag is dropped onto or from the belt conveyor accompanying the transportation of the blast furnace granulated slag, the blast furnace granulated slag particles are dispersed in a dispersed state.3The ground granulated blast furnace slag on the sieve or the ground granulated blast furnace slag falling below the sieve is also in a dispersed state, and in that state, a substance containing at least one of carbon dioxide and aqueous carbonate solution is supplied. As a result, carbonate ions are uniformly supplied to the entire blast furnace granulated slag, and a calcium carbonate film can be uniformly formed on the entire surface of the granulated blast furnace slag particles, and a sufficient hydration reaction suppressing effect and An anti-caking effect can be obtained.
[0021]
In any of the above aspects, it is preferable that the temperature of the granulated blast furnace slag with which the substance containing at least one of the carbon dioxide gas and the carbonic acid aqueous solution is contacted is 20 ° C. or higher. Moreover, the blast furnace granulated slag can be used as it is, as a granulated preparation with a further adjusted particle size, or by mixing them.
[0022]
In the present invention, the substance containing at least one of carbon dioxide and an aqueous solution of carbonic acid may be only carbon dioxide or only an aqueous solution of carbonic acid, these may contain other substances, and both It may be a mixture. Therefore, a droplet of a fine carbonic acid aqueous solution (spray droplet) formed by supplying a gas such as air to a carbonic acid aqueous solution, or a droplet of a fine carbonic acid aqueous solution (sprayed liquid) formed by supplying a carbon dioxide gas to a carbonic acid aqueous solution Naturally, droplets are also included in the above substances.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention will be described in detail below.
  In the present invention, a step of dispersing blast furnace granulated slag, and a substance containing at least one of carbon dioxide and carbonic acid aqueous solution in the dispersed blast furnace granulated slagMake contactProcess.
[0024]
The method for dispersing the granulated blast furnace slag is not limited, and the granulated blast furnace slag is preferably dispersed almost in the form of particles. Special equipment for dispersing blast furnace granulated slag may be provided, but it is preferable to use a process capable of dispersing blast furnace granulated slag in existing equipment such as blast furnace granulated slag manufacturing equipment. For example, when mixing, stirring, sieving, and transporting blast furnace granulated slag, since the blast furnace granulated slag can be in a dispersed state, any of these processes can be implemented as a dispersing process. In order to disperse the blast furnace granulated slag during transportation, it is possible to use, for example, the case where the blast furnace granulated slag is dropped when the conveyor is connected.
[0025]
As a method of bringing a substance containing at least one of carbon dioxide and aqueous carbonate solution into contact with dispersed granulated blast furnace slagThe figureAs shown in 1 (a), carbon dioxide gas or a gas containing carbon dioxide gas is sprayed from a nozzle 2 to a blast furnace granulated slag 1 dispersed in a particulate form by an appropriate means, or a carbonic acid aqueous solution is used as carbon dioxide gas or It sprays with other gas, such as air, and these are made to contact blast furnace granulated slag 1, or as shown in FIG.1 (b), it was provided above the blast furnace granulated slag 1 of the dispersed state. Spray carbonic acid solution from nozzle 3Method is adopted.
[0026]
In such a state where the granulated blast furnace slag is dispersed, by contacting a substance containing at least one of carbon dioxide gas and aqueous carbonic acid solution in the form as described above, carbon dioxide gas and aqueous carbonic acid solution are easily distributed uniformly throughout, Carbonate ions are supplied to each blast furnace granulated slag particle, and a calcium carbonate film can be uniformly formed on the surface of each blast furnace granulated slag particle, thereby obtaining a sufficient hydration suppression effect and anti-caking effect. be able to.
[0027]
In addition, although the blast furnace granulated slag may be processed as it is, the blast furnace granulated slag whose particle size has been adjusted by pulverization may be processed.
[0028]
In the present invention, either carbon dioxide gas or carbonic acid aqueous solution is used as described above, and the carbonic acid aqueous solution can be easily produced by dissolving carbon dioxide gas in water as follows.
[0029]
Carbon dioxide gas is easily soluble in water, and its solubility is CO₂Proportional to concentration and gas pressure. CO at 25 ° C atmospheric pressure₂The saturation solubility of 100% gas is 0.037 N (0.16 g / 100 g water). Dissolution of carbon dioxide gas is represented by the following formula (1), and the form after dissolution is carbonic acid (H₂CO₃), Bicarbonate ion (HCO₃ ⁻), Carbonate ion (CO₃ ^2-Carbonic acid ions are stable in the acidic region, hydrogen carbonate ions in the neutral region, and carbonate ions in the alkaline region, and their abundances change depending on the pH.
CO₂+ H₂O → H₂CO₃→ H⁺+ HCO₃ ⁻→ 2H⁺+ CO₃ ^2-...... (1)
[0030]
FIG. 2 is a schematic cross-sectional view showing an example of a facility for producing an aqueous carbonate solution.
This manufacturing facility includes a tower 11 capable of storing water therein, a water supply mechanism 12 for supplying water from the lower part of the tower 11, a gas distributor 13 for blowing carbon dioxide into the water in the tower 11, and a gas distributor 13, a carbon dioxide supply mechanism 14 for supplying carbon dioxide gas, a water intake pipe 15 for taking out a carbonic acid aqueous solution from the top of the tower 11, a duct 16 provided so as to cover the top of the tower 11, and exhaust from the duct 16. And an introduction pipe 18 that guides the exhaust from the exhaust 17 to the gas inlet side of the gas distributor 13.
[0031]
When the carbonated water solution is produced with this production facility, water is supplied continuously from the water supply mechanism 12 into the tower 11 or after a predetermined amount of water is supplied from the water supply mechanism 12 into the tower 11. After the water supply mechanism 12 is stopped, the carbon dioxide gas or the gas containing carbon dioxide supplied from the carbon dioxide supply mechanism 14 is continuously blown into the water in the tower 11 from the gas disperser 13 and dispersed as a group of bubbles. The carbon dioxide gas is absorbed in the water in the tower 11 to obtain a carbonic acid aqueous solution. In this case, if the pressurized gas is supplied from the carbon dioxide supply mechanism 14, the pressurized gas can be dissolved in the water in the tower 11. The obtained aqueous carbonate solution is taken out from the intake pipe 15 and supplied to the granulated blast furnace slag. Further, excess carbon dioxide gas or the like blown from the gas distributor 13 is exhausted from the duct 16 through the exhaust unit 17. At this time, the exhausted gas can be discharged out of the system as it is, but it can also be circulated and reused in the gas distributor 13 via the introduction pipe 18. Further, it is possible to use exhaust gas as the gas containing carbon dioxide gas blown from the gas disperser 13, and by combining this with the reuse of the exhaust gas from the top of the tower 11, an aqueous carbonate solution can be produced at a very low cost. can do.
[0032]
Instead of blowing carbon dioxide gas or a gas containing carbon dioxide gas into the water in this way, carbon dioxide water or a gas containing carbon dioxide gas is supplied into the container and water is sprayed into the container. Can be manufactured. Also in this case, carbon dioxide or a gas containing carbon dioxide can be dissolved in water in a pressurized state.
[0033]
Next, a specific example in which the present invention is implemented in a blast furnace granulated slag production facility or a blast furnace granulated slag particle size adjusted product production facility will be described.
In the manufacture of granulated blast furnace slag, when water is supplied to the slag discharged from the blast furnace and granulated, the granulated blast furnace slag becomes a slurry, and this granulated slag slurry is dewatered by an inba filter that is a drum rotary dehydrator. However, since the granulated blast furnace slag is in a dispersed state at this time, the present invention is carried out by bringing a substance containing at least one of carbon dioxide and aqueous carbonate solution into contact with the granulated blast furnace slag in the invar filter. be able to.
[0034]
This will be specifically described below. 3A and 3B are diagrams illustrating the structure of the invar filter, in which FIG. 3A is a side sectional view and FIG. 3B is a sectional view taken along line AA in FIG. The invar filter 20 has a rotating drum 21 that can be rotated by a motor (not shown), and the outer peripheral portion of the rotating drum 21 is composed of a double metal mesh 22 for filtration and reinforcement. Inside the wire mesh 22, a large number of vanes (scraping wire mesh) 23 are attached along the circumference. A distributor 25 is inserted along the longitudinal direction of the rotary drum 21 from the introduction portion 24 into the rotary drum 21. A cushion box 26 is provided below the distributor 25, and the slurry distributed by the distributor 25 is uniformly supplied to the vane 23 of the rotating rotary drum 21 through the cushion box 26. Above the distributor 25, a discharge conveyor 27 is provided horizontally along the longitudinal direction of the rotary drum 21, and above the discharge conveyor 27, the blast furnace granulated slag that has been scraped up and dewatered is guided to the discharge conveyor. A deflector (guide plate) 28 is provided. The deflector 28 is supported by a support beam 29. An annular carbon dioxide supply pipe 31 is provided horizontally above the discharge conveyor 27, and a plurality of nozzles 32 are provided above the carbon dioxide supply pipe 31. Carbon dioxide gas is supplied from the nozzle 32 to the blast furnace granulated slag 33 that is falling from the upper vane 23 to the discharge conveyor 27.
[0035]
In the invar filter 20 configured as described above, the blast furnace granulated slag slurry is uniformly supplied to the vane 23 of the rotating rotary drum 21 through the distributor 25 and the cushion box 26 while rotating the rotary drum 21. Is done. While the supplied slurry is scraped up by the vane 23, the water therein is discharged through the wire mesh 22 and dehydrated. The dewatered blast furnace granulated slag 33 is dropped near the top, and the blast furnace granulated slag 33 in the middle of dropping is guided by the deflector 28 and placed on the discharge conveyor 27 and discharged from the inva filter 20.
[0036]
Since the ground granulated blast furnace slag at this time is in a dispersed state, carbon dioxide gas is supplied to the dispersed grounded blast furnace slag from a plurality of nozzles 32 provided above the discharge conveyor 27. Spreads throughout the blast furnace granulated slag, dissolves in the water around each blast furnace granulated slag particle and is supplied with carbonate ions, forming a uniform calcium carbonate film on the surface of each granulated blast furnace slag particle. Sufficient hydration reaction inhibiting effect and anti-caking effect can be obtained.
[0037]
Moreover, the blast furnace granulated slag discharged from the invar filter by the discharge conveyor 27 is supplied to the product tank through several conveyors. Since the granulated blast furnace slag is in a dispersed state when the granulated blast furnace slag is dropped into the tank, a substance containing at least one of carbon dioxide and an aqueous carbonate solution may be brought into contact with the granulated blast furnace slag. For example, as shown in FIG. 4, when dropping the blast furnace granulated slag 43 from the conveyor 41 to the conveyor 42, the blast furnace granulated slag 43 is in a dispersed state. For example, if the carbonated aqueous solution is brought into contact with the granulated blast furnace slag by spraying the carbonated aqueous solution, the carbonated aqueous solution spreads over the entire granulated blast furnace slag, and carbonate ions are supplied to the individual granulated blast furnace slag particles. A calcium carbonate film can be uniformly formed on the surface of the crushed slag particles, and a sufficient hydration reaction inhibiting effect and anti-caking effect can be obtained.
[0038]
A facility for producing granulated blast furnace slag fine aggregates from granulated blast furnace slag is equipped with a vibrating sieve that sifts crushed blast furnace granulated slag. Since both the blast furnace granulated slag crushed material and the blast furnace granulated slag crushed material falling through the vibrating sieve are in a dispersed state, the blast furnace granulated slag crushed material contains at least one of carbon dioxide and carbonic acid aqueous solution. You may make it contact a substance. For example, as shown in FIG. 5, a vibrating sieve 52 is provided below the conveyor 51, a carbon dioxide gas supply pipe 54 having a plurality of nozzles 55 is provided above the vibrating sieve 52, and the conveyor 51 is connected to the sieve mesh 53. Carbon dioxide can be blown from the nozzle 55 against the blast furnace granulated slag crushed material 58 that has fallen. Further, for example, carbon dioxide gas can be sprayed from the nozzle 57 while the blast furnace granulated slag crushed material 59 that has passed through the sieve mesh 53 falls on the conveyor 56. In addition, the blast furnace granulated slag crushed material that has not passed through the sieve mesh 53 is discharged from the discharge port 52a provided on the side wall of the vibrating sieve 52 and returned to the crushing apparatus. Moreover, the blast furnace granulated slag crushed material 59 that has passed through the sieve mesh 53 is conveyed to the product tank by the conveyor 56 as a product.
[0039]
In this case, both the ground granulated blast furnace slag 58 on the sieve 53 and the ground granulated blast furnace slag 59 that are falling after passing through the sieve 53 are in a dispersed state. When carbon dioxide gas is brought into contact, carbon dioxide gas spreads throughout the blast furnace granulated slag, and carbon dioxide gas is supplied to the individual blast furnace granulated slag particles, so that the surface of each blast furnace granulated slag particle is uniformly coated with calcium carbonate. Can be formed, and a sufficient hydration reaction suppressing effect and anti-caking effect can be obtained. The blowing of the carbon dioxide gas from the nozzle 55 and the nozzle 57 may be performed both, or one of them may be performed.
[0040]
In the above specific examples, examples of spraying carbon dioxide gas have been shown. However, as a matter of course, spraying of an aqueous carbonate solution, spraying of an aqueous carbonate solution with a gas such as carbon dioxide gas, immersion in an aqueous carbonate solution, etc. Any of the embodiments in which a substance containing at least one of carbon dioxide gas and an aqueous carbonic acid solution is contacted may be adopted.
[0041]
In the present invention, from the viewpoint of reactivity, it is preferable that the temperature of the granulated blast furnace slag with which the substance containing at least one of carbon dioxide and carbonic acid aqueous solution is contacted is 20 ° C. or higher. Even if the blast furnace granulated slag in contact with a substance containing at least one of carbon dioxide and an aqueous carbonic acid solution is allowed to stand in summer, it can be kept at 20 ° C. or higher, but in winter it is difficult to secure 20 ° C. or higher. Therefore, it is preferable to heat the granulated blast furnace slag in contact with a substance containing at least one of carbon dioxide and an aqueous carbonate solution by an appropriate heating means. The granulated blast furnace slag immediately after production is 60 ° C. or higher, which is preferable from the viewpoint of reactivity. Since the carbonation reaction proceeds at higher temperatures and the solubility of carbonate ions decreases at higher temperatures, the higher the temperature of the mixture of the aqueous carbonate solution and blast furnace granulated slag, the greater the carbon dioxide supply effect. However, since the solubility of carbonate ions is significantly reduced at 90 ° C., the upper limit is practically about 80 ° C.
[0042]
【Example】
Examples of the present invention will be described below.
Example 1
In the process of supplying the blast furnace granulated slag slurry to the invar filter shown in FIG. 3 at a feed rate of 150 t / h in terms of dryness and dehydrating the carbon dioxide gas with a concentration of 20%, 500 Nm³The carbon dioxide gas was brought into contact with the blast furnace granulated slag by being fed into the invar filter at a feed rate of / h. The temperature of the granulated blast furnace slag at that time was 60 ° C.
[0043]
(Example 2)
In the process of supplying blast furnace granulated slag crushed material at a feed rate of 150 t / h to the vibrating sieve for sieving the crushed material of blast furnace slag shown in FIG. 500 Nm with 20% carbon dioxide gas from the nozzle (nozzle 57 in FIG. 5)³Carbon dioxide gas was brought into contact with the ground granulated blast furnace slag in a dispersed state on the sieve and the ground granulated blast furnace slag falling under the sieve in a dispersed state. The temperature of the granulated blast furnace slag at that time was 60 ° C.
[0044]
(Comparative Examples 1, 2, 3)
Completely untreated blast furnace granulated slag was set as Comparative Example 1, and an aqueous carbonate solution of 100 m.³And blast furnace granulated slag 100 t were charged and the blast furnace granulated slag was immersed in an aqueous carbonate solution and the temperature was set to 18 ° C. as Comparative Example 2. When charging granulated blast furnace slag, 500 Nm of carbon dioxide gas³Comparative Example 3 was prepared by supplying the blast furnace granulated slag storage tank at a supply rate of / h and setting the temperature of the blast furnace granulated slag to 60 ° C.
[0045]
Examples 1, 2 and Comparative Examples 2 and 3 treated as described above and untreated Comparative Example 1 were filled in a container having an inner diameter of 100 mm and a height of 127 mm (internal volume of 1 liter). Were immersed in a constant temperature water bath, and the solidified state after curing for a predetermined period was observed (indoor scale evaluation). Moreover, about 100 t of each processing slag was inserted into a groove having a depth of 1.5 m, a width of 4 m, and a length of 10 m, and water was applied to observe the solidified state (scale evaluation). These results are shown in Table 1.
[0046]
[Table 1]

[0047]
As shown in Table 1, in the untreated slag of Comparative Example 1, consolidation started within one month in the indoor scale evaluation at 80 ° C., and within three months in the practical scale evaluation at room temperature. In Comparative Example 2 immersed in an aqueous carbonate solution at 18 ° C., consolidation started in 2 to 3 months on an indoor scale, and consolidation started in 6 months to 1 year on an implementation scale. In Comparative Example 3 in which carbon dioxide gas was blown at 60 ° C., consolidation started from 2 months to 3 months on the indoor scale, and consolidation started from 6 months to 1 year on the implementation scale. On the other hand, Example 1 in which carbon dioxide gas was blown into the Inba filter under the condition of 60 ° C. and Example 2 in which carbon dioxide gas was supplied onto the sieve and below the sieve were 6 months on the indoor scale and 2 years on the implementation scale. It did not consolidate.
[0048]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a method for treating granulated blast furnace slag capable of exhibiting a sufficient hydration reaction preventing effect and a caking preventing effect.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an implementation state of a method of the present invention.
FIG. 2 is a schematic cross-sectional view showing an example of a facility for producing an aqueous carbonate solution.
FIG. 3 is a cross-sectional view showing an invar filter (drum rotary dehydrator) in which the present invention is implemented.
FIG. 4 is a diagram for explaining a state in which the present invention is implemented at a transfer section of a conveyor that conveys blast furnace granulated slag.
FIG. 5 is a diagram for explaining a state in which the present invention is implemented in a vibrating sieve for sieving blast furnace granulated slag.
[Explanation of symbols]
1: Blast furnace granulated slag
2, 3; Nozzle
4; tank
20: Inva filter (drum rotary dehydrator)
21; rotating drum
22; Wire mesh
23: Vane
25; Distributor
26; Cushion box
27: Discharge conveyor
28; Deflector
31; Carbon dioxide supply piping
32; Nozzle
41, 42; conveyor
43; Blast Furnace Granulated Slag
44; Nozzle
52; Vibrating sieve
53; sieve mesh
55, 57; Nozzle
58, 59; blast furnace granulated slag crushed material

Claims (5)

  When dewatering the blast furnace granulated slag with a drum rotary dehydrator in the blast furnace granulated slag manufacturing process, the blast furnace granulated slag is brought into contact with a substance containing at least one of carbon dioxide gas and aqueous carbonic acid solution. To process granulated blast furnace slag.   A substance containing carbon dioxide gas is sprayed or sprayed with a carbonic acid aqueous solution on the blast furnace water granulated slag, or a substance containing a carbonic acid aqueous solution is sprayed onto the blast furnace granulated slag when the blast furnace granulated slag is dropped onto or from the belt conveyor. A method for treating granulated blast furnace slag, characterized by bringing a substance containing at least one of carbon dioxide and an aqueous carbonate solution into contact with each other by spraying.   When sifting granulated blast furnace slag, the blast furnace granulated slag on the sieve or the ground granulated blast furnace slag falling below the sieve is brought into contact with a substance containing at least one of carbon dioxide and aqueous carbonate solution. To process granulated blast furnace slag. The blast furnace water according to any one of claims 1 to 3 , wherein the temperature of the granulated blast furnace slag in contact with the substance containing at least one of the carbon dioxide gas and the carbonic acid aqueous solution is 20 ° C or higher. Processing method of crushed slag. The water-granulated blast furnace slag, any one of claims 1 to 4, characterized in that use a water-granulated blast furnace slag generated in the iron making process as granularity preparations prepared as and / or the particle size The processing method of granulated blast furnace slag as described in 2.

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