JP2015160782A - Method of producing artificial stone material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing an artificial stone material by subjecting a kneaded matter of water and a raw material containing steel slag and blast furnace slag fine powder to hydration hardening, and crushing a hydrated solidified body, the method being capable of producing an artificial stone material having a low specific gravity and enhancing a production yield to reduce production costs.SOLUTION: A crushed matter of the hydrated solidified body is sifted into an oversized crushed matter to be used as a product stone material, and an undersized crushed matter to be reused as part of a raw material of the hydrated solidified body. The undersized crushed matter has a smaller specific gravity than steel slag. Therefore, a specific gravidity of an artificial stone material to be produced can be decreased and a product yield can also be improved by blending the undersized crushed matter into the raw material as an alternate material of part or all of the steel slag being an aggregate.

Description

  The present invention relates to a method for producing an artificial stone material by hydrating and hardening a kneaded material of water and raw materials containing steelmaking slag and blast furnace slag fine powder, and crushing the hydrated solidified body.

There is known a hydrated solidified body of steel slag obtained by kneading raw materials mainly composed of powdered steel slag (mainly steelmaking slag) and fine powder of blast furnace slag with water and then hydrating and hardening it (for example, patent documents) 1) This hydrated solidified body can be produced using the same kneading equipment as concrete, and can be used as a roadbed material, civil engineering material, harbor civil engineering material, and other concrete substitutes.
As one of the methods for producing such a steel slag hydrated solid body, a method is known in which a kneaded material and water are placed in a yard and crushed after curing to obtain an artificial stone material (for example, Patent Documents). 2). The irregular shaped artificial stone obtained by this method is particularly suitable for harbor civil engineering materials such as covering stone, root-hardening stone, rubble, backfill material, submerged levee material and the like.

JP 2009-114027 A JP 2012-25658 A

However, the conventional steel slag hydrated solid body and its manufacturing method have the following problems.
First, the slag hydrated solidified body uses steelmaking slag having a high specific gravity as an aggregate, and therefore has a higher specific gravity than ordinary concrete. That is, the specific gravity of general concrete is about 2.3 to 2.5, whereas the specific gravity of steel slag hydrated solid is about 2.5 to 2.7. A high-specific gravity hydrated solid is excellent in wave stability in the sea, and is therefore suitable for harbor civil engineering materials. However, many of the hydrated and solidified bodies used in land areas such as stretched block materials are desirably low specific gravity, and the characteristics of high specific gravity of steel slag hydrated solidified bodies are One of the bottlenecks in use.

  In addition, in the manufacturing process of artificial stone made of steel slag hydrated solidified material, a kneaded mixture of raw material and water is placed on the yard (ground) and cured, and the hydrated and hardened solidified material is crushed and sieved. The particle size is adjusted to make the product stones that are larger than the specified particle size. However, the particle size adjustment generates sieving (fine particles) equivalent to about 10 to 15% of the total, resulting in a decrease in product yield and manufacturing costs. It is a factor of increase.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, hydrate and harden a raw material and water containing steelmaking slag and blast furnace slag fine powder, and then crush the hydrated solidified body. Thus, an object of the present invention is to provide a production method capable of producing an artificial stone material having a low specific gravity and increasing the product yield and reducing the production cost.

As a result of repeated studies to solve the above problems, the inventors of the present invention hydrated and hardened a raw material and water mixture containing steelmaking slag and blast furnace slag fine powder, and crushed this hydrated solidified product. In the manufacturing process of artificial stone material, which obtains the product stone by adjusting the particle size by sieving the crushed material, the idea was to reuse the crushed material under the sieve removed by adjusting the particle size of the crushed material as part of the raw material. . The crushed material under the sieve, which is removed by adjusting the particle size of the hydrated solidified material, contains blast furnace slag fine powder (binding material) as well as steelmaking slag (aggregate), so the specific gravity is smaller than the simple steelmaking slag. Therefore, the specific gravity of the manufactured artificial stone can be reduced by blending this crushed material under the sieve with the raw material as an alternative material for part or all of the steelmaking slag, which is an aggregate, and the crushing Since the crushed material under the sieve removed by adjusting the particle size of the product can be reused, the product yield can be improved and the manufacturing cost can be reduced.
Furthermore, when the crushed material under the sieve as described above is used as an alternative material for a part or all of the steelmaking slag as an aggregate, the strength of the product stone obtained is equal to or higher than the semi-hard stone quality (10 N / mm ² ). On the other hand, since the flowability of the kneaded material is improved and the workability is improved, the paste rate can be reduced, and it has been found that the manufacturing cost can be reduced also from this aspect.

The present invention has been made on the basis of the above ideas and findings, and has the following gist.
[1] A step (A) of kneading a raw material containing steelmaking slag and fine powder of blast furnace slag and water, hydrating and hardening the kneaded product, and a step of crushing the hydrated solidified body obtained in the step (A) (B) and a step (C) of sieving the crushed material of the hydrated solidified body obtained in the step (B), and the crushed material on the sieve in the step (C) is used as a product stone In the method for producing an artificial stone material, a method for producing an artificial stone material, wherein the crushed material (x ₁ ) under the sieve in the step (C) is reused as a part of the raw material in the step (A).
[2] In the production method of [1] above, the crushed material (x ₁ ) under the sieve in step (C) is further sieved to adjust the particle size, and then as part of the raw material in step (A) A method for producing an artificial stone characterized by being reused.

[3] In the production method of [2], in the step of adjusting the particle size of the crushed material (x ₁ ) under the sieve, adjusting the particle size to be equal to or less than the maximum particle size of the steelmaking slag to be blended with the raw material in the step (A). A method for producing artificial stone.
[4] In the production method according to any one of [1] to [3] above, in step (A), as a substitute material for a part or all of the steelmaking slag to be blended with the raw material, crushed material under sieve (x ₁ ) A method for producing an artificial stone material, characterized in that it is blended with a raw material.
[5] In the production method of any one of [1] to [4] above, the crushed material (x ₁ ) under the sieve is adjusted to a moisture content in advance and brought into a surface dry state, and then in step (A). A method for producing an artificial stone characterized by blending with a raw material.
[6] Artificial stone material obtained by hydrating and hardening a kneaded material and water containing steelmaking slag and blast furnace slag fine powder, crushing this hydrated solidified product, and sieving the crushed product of this hydrated solidified product The crushed material (x ₁ ) removed by sieving (however, the crushed material (x ₁ ) is further adjusted in particle size as an alternative material for part or all of the steelmaking slag. )).

  According to the present invention, a raw material containing steelmaking slag and ground granulated blast furnace slag and water are hydrated and hardened, the hydrated solidified product is crushed, and the crushed product is sieved to adjust the particle size to obtain a product stone. In the manufacturing process of the obtained artificial stone, reuse the crushed material under the sieve removed by adjusting the particle size of the crushed material as part of the raw material, specifically, substitute for part or all of the steelmaking slag that is aggregate By blending it into the raw material as a material, an artificial stone material having a low specific gravity can be produced, and the product yield can be increased to reduce the production cost. Also, by reusing the crushed material under the sieve removed by adjusting the particle size of the crushed material as part of the raw material, the fluidity of the kneaded material is improved and the workability is improved, so the paste rate can be reduced. In this respect, the manufacturing cost can be reduced.

When the sieving material (crushed product x ₁ ) of the hydrated solidified product is reused as part of the raw material of the hydrated solidified product, the ratio of the sieving material in the kneaded product and the specific gravity of the kneaded product Graph showing relationship When the sieving material (crushed material x ₁ ) of the hydrated solidified material is reused as a part of the raw material of the hydrated solidified material, the ratio of the sieving material in the kneaded material and the artificial stone material to be produced Graph showing the relationship with strength When the sieving material (crushed material x ₁ ) of the hydrated solidified material is reused as part of the raw material of the hydrated solidified material, the ratio of the sieving material in the kneaded material and the fluidity of the kneaded material ( Graph showing the relationship with the slump value)

A series of manufacturing processes that are the basis of the method of the present invention includes a step (A) in which a raw material containing steelmaking slag and blast furnace slag fine powder and water are kneaded, and the kneaded product is hydrated and cured, and is obtained in this step (A). A step (B) of crushing the obtained hydrated solidified body, and a step (C) of sieving the crushed product of the hydrated solidified body obtained in this step (B). In this step (C) The crushed material on the sieve is used as the product stone.
Such a basic manufacturing process is the same as that of the conventional method, and specific conditions thereof will be described later.

In the present invention method, the crushed x ₁ under sieve in step (C), it is reused as part of the raw material in step (A). Specifically, the crushed x ₁ under sieve and blended in a raw material as a part or all of the alternate materials of steel slag is aggregate. That is, the raw material in some or all of the steel slag to be blended as an aggregate is to replaced by crushed x ₁ under the sieve.
Moreover, crushed x ₁ under sieve in step (C) after adjusting for a further sieving to the particle size, it is preferable to reuse as part of the raw material in step (A). Specifically, sieved crushed x ₁ under the sieve, the undersize is recycled as part of the raw material in step (A) as described above.

The crushed material x ₁ under the sieve (including the crushed material obtained by further adjusting the particle size of the crushed material x ₁ ; the same applies hereinafter) includes steelmaking slag (aggregate) and blast furnace slag fine powder (binding material). Specific gravity is smaller than slag alone. Generally, the proportion of steel slag in the crushed material x ₁ under sieve (aggregate) is about 60 to 70 volume%, the balance being blast furnace slag (binder) and the like. Accordingly, the crushed x ₁ such undersize fraction, by blending the raw material as a part or all of the alternate materials of steel slag is aggregate, it is possible to reduce the specific gravity of the artificial stone to be produced. For this reason, the manufactured artificial stone is suitable for use in land areas.
Moreover, since the generation amount of crushed material x ₁ under the sieve is approximately 10-15% of the total hydrated solid material can reuse the entire amount as a feed to step (A), the order to improve product yield, Manufacturing cost can be reduced.

If the crushed x ₁ under sieve in step (C), further reused as raw material with particle size control, it is preferable to particle size control under maximum particle diameter or less of the steel slag to be blended to the raw material in step (A) . For example, the maximum grain size of steel slag to be blended to the raw material in step (A) is the case of 20 mm, to adjust the particle size of the crushed material _{x 1} under sieve 0-20Mm.
The crushed material x ₁ under the sieve can be added to the raw material as a substitute for all steelmaking slag, which is an aggregate. From the standpoint of stone strength, it should be added to the raw material as a partial substitute for steelmaking slag. Is preferred.

Further, the and the blending ratio crushed x ₁ under sieve with kneaded material, the blending ratio of the crushed material x ₁ under the sieve for steelmaking slag is not particularly limited, the effect of reducing the specific gravity by compounding, such as slump It may be decided in consideration of the influence on fluidity, the influence on quality such as strength, manufacturing cost, etc., but from the viewpoint of the definition of steel slag hydrated solid body described in the manual, the strength of product stone, etc. The ratio in the kneaded product is preferably 70% by volume or less, more preferably 40% by volume or less, and particularly preferably 20% by volume or less.
In step (A), when formulating crushed x ₁ under sieve material, it is preferable that in the-dry state by adjusting the water content beforehand. This crushed x ₁ under the sieve because many water retention capacity, unless you have to-dry state, the slump value is lowered by water absorption during the raw material compounding is because the fluidity of the kneaded product is impaired.
To the water content of the crushed material x ₁ under the sieve was adjusted in advance to-dry state, it may be sprinkled on crushed x ₁ under the sieve.

FIG. 1 shows the relationship between the ratio of the sieving material in the kneaded product and the specific gravity of the kneaded product when the sieving material (crushed material x ₁ under the sieve) is reused as part of the raw material in the step (A). It shows the relationship. The base of this test example is a steelmaking slag with the total amount of aggregate (dephosphorization slag, maximum particle size 25 mm). In contrast to this base, in the present invention example, a sieve is used as a substitute for a part of steelmaking slag. A base material was blended. The total amount of the binder was blast furnace slag fine powder, and appropriate amounts of ordinary Portland cement (alkaline stimulant) and fly ash were blended with the aggregate and the binder. According to FIG. 1, a portion of the steelmaking slag, which is an aggregate, is replaced with a sieving material, and the sieving material ratio is about 16% by volume, so that the specific gravity of the kneaded material is 2.65 to 2.2. Reduced to 50.

FIG. 2 shows the ratio of the sieving material in the kneaded product and the artificial stone material to be produced when the sieving material (crushed material under sieve x ₁ ) is reused as part of the raw material in step (A). The relationship with the strength is shown ("paste ratio 44.5% moisture adjustment" in FIG. 2 is when the water is sprayed and kneaded to the under sieve material that has been dried just before kneading). The base of this test example also uses steel aggregate slag (dephosphorization slag, maximum particle size of 25 mm) as the total amount of aggregate. In contrast to this base, the present invention example uses a sieve as a substitute for part of the steel slag. A base material was blended. The total amount of the binder was blast furnace slag fine powder, and appropriate amounts of ordinary Portland cement (alkaline stimulant) and fly ash were blended with the aggregate and the binder. The strength of the artificial stone was in accordance with the method described in JIS A 1108. According to FIG. 2, when a part of the steelmaking slag as an aggregate is replaced with a sieving material, the strength of the artificial stone decreases as the sieving material ratio increases, but the sieving material ratio is about 16% by volume. Even if it is, it is possible to obtain a strength of quasi-hard stone quality (10 N / mm ² ) or more. Moreover, about 17-20N / mm < ² > is obtained in 4 week intensity | strength.

In the present invention, by reusing the crushed x ₁ under sieves removed the crushed hydrated solidified by particle size control as part of the raw materials improves the flowability of the kneaded product, workability is improves. FIG. 3 shows the ratio of the sieving material in the kneaded product and the fluidity of the kneaded product when the sieving material (crushed material x ₁ under the sieve) is reused as part of the raw material in step (A). It shows the relationship with the slump value). The base of this test example also uses steel aggregate slag (dephosphorization slag, maximum particle size of 25 mm) as the total amount of aggregate. In contrast to this base, the present invention example uses a sieve as a substitute for part of the steel slag. A base material was blended. The total amount of the binder was blast furnace slag fine powder, and appropriate amounts of ordinary Portland cement (alkaline stimulant) and fly ash were blended with the aggregate and the binder. The slump value followed the method described in JIS A 1101. According to FIG. 3, when a part of the steelmaking slag, which is an aggregate, is replaced with a sieving material, the slump value of the kneaded product increases as the sieving material ratio increases, and the fluidity is improved. I understand.
The reason why the fluidity is improved in this way is not necessarily clear, but it is considered that the particle size distribution and the particle shape of the sieving material (crushed material x ₁ under sieving) are affected.

  In the present invention, as shown in FIG. 3, the fluidity of the kneaded product is improved, so that the paste rate can be reduced, and as a result, the manufacturing cost (material cost) can be reduced. Furthermore, in this invention, the effect of reducing manufacturing cost is acquired by the improvement of the yield of the artificial stone material by reuse of a sieving material. As a result, the manufacturing cost can be reduced by up to about 15% compared to the conventional method as disclosed in Patent Document 2.

In the present invention, the basic method for obtaining a stone product (artificial stone) may be the same as the conventional method. For example, a kneaded mixture of raw material and water is placed flat in a wide area in the yard, and the hydrated and solidified product after hydration and curing is crushed using a heavy machine such as a concrete breaker, and if necessary, further a jaw crusher, etc. And crush this crushed material into a product stone. The sieving can be performed using grizzly or the like. On the other hand, crushed x ₁ under sieve after particle size adjustment by further sieving if necessary, be reused as a raw material of the hydrated solid material as described earlier. The crushed materials x ₁ under the sieve sieving can be carried out using a stationary screen.

  In addition, as a method of placing the kneaded material in the yard, for example, as shown in Patent Document 2, a method of providing a plurality of parallel ridges in the yard and placing the kneaded material in a groove between these ridges, A method may be employed in which a ridge is provided in the yard, a mold plate parallel to the ridge is disposed, and a kneaded material is placed in a groove between the ridge and the mold plate. There is no particular restriction on the yard where this manufacturing method is carried out, and it may be a normal outdoor ground on which ridges can be formed. Moreover, in this manufacturing method, in order to form a plurality of parallel fences in the yard, the ground may be embanked or the ground may be dug up so as to form a groove.

As for the raw material containing steelmaking slag and blast furnace slag fine powder used in the present invention, steelmaking slag becomes an aggregate and blast furnace slag fine powder becomes a binder.
There are no special restrictions on the type of steelmaking slag. Steelmaking slag includes converter decarburization slag, hot metal pretreatment slag (for example, dephosphorization slag, desiliconization slag), electric furnace slag, secondary refining slag, ingot slag, etc. It may be used. Among the steelmaking slags, the hot metal pretreatment slag is particularly preferable because not only the air aging is completed quickly because there is little free-CaO, but also cracking due to hydration expansion is difficult to occur because there is little free-MgO phase.

In addition, the steelmaking slag may be one that has been subjected to natural aging or steam aging in advance, or one that has been subjected to various treatments such as carbonation treatment.
Moreover, it is preferable to use the blast furnace slag fine powder which becomes a binder of the hydrated solidified material in conformity with JIS-A-6206 (1997).
In addition to the crushed material under sieve x ₁ according to the present invention, the raw material may further contain at least one selected from powdered granulated blast furnace granulated slag, fly ash, alkaline stimulant, etc., if necessary. Can do.

The granulated blast furnace granulated slag is basically blended as a part of the aggregate, but has a weak hydraulic property. It solidifies upon stimulation and contributes to strength.
The fly ash acts as a pozzolanic substance, helps improve the strength at long-term ages, reduces the alkalinity of the hydrated solidified body as a whole, and reduces the amount of alkaline substance eluted when the hydrated solidified body is immersed in water. There is also a function to reduce.
As the alkali stimulating material, for example, Ca-based materials such as slaked lime and cement can be used. The ground granulated blast furnace slag has latent hydraulic properties, and curing is accelerated by alkali stimulation. For this reason, high intensity | strength can be obtained more stably by adding an alkali stimulating material.

In a conventional general steel slag hydrated solid body, the aggregate is composed of 50 to 100% by mass of steelmaking slag, and the main binder is composed of blast furnace slag fine powder. One or more selected from blast furnace granulated slag, fly ash, alkali stimulating material, and the like are blended. If based on such steel slag hydrated solidified body, in the present invention, crushed x ₁ under the sieve is to be formulated as part or all of the alternate materials for the steelmaking slag.
The blending ratio of the crushed material x ₁ under the sieve is determined from various viewpoints as described earlier, as a general material mixing ratio, for example, steel slag: 0 to 55 volume%, crushed under the sieve Product x ₁ : 15 to 70% by volume, blast furnace slag fine powder: about 3 to 25% by volume, and other components (one or more types of granulated blast furnace slag, fly ash, alkali stimulant, etc.) as appropriate Add.

The artificial stone produced by the production method described above hydrates and hardens a kneaded mixture of raw materials and water containing steelmaking slag and blast furnace slag fine powder, crushes this hydrated solidified product, and crushes this hydrated solidified product. Artificial stone material obtained by sieving a material, and as a substitute material for part or all of the steelmaking slag, crushed material x ₁ removed by sieving (however, the crushed material x ₁ was further adjusted in particle size) Including the case where it is a thing).
As already described, this artificial stone material has a lower specific gravity than a conventional steel slag hydrated solid body and can be manufactured at a low cost because of a high product yield.

Claims (6)

A step (A) of kneading a raw material containing steelmaking slag and fine powder of blast furnace slag and water, hydrating and hardening the kneaded product, and a step (B) of crushing the hydrated solidified body obtained in the step (A) And a step (C) of sieving the crushed material of the hydrated solidified body obtained in the step (B), and the artificial stone material having the crushed material on the sieve in the step (C) as a product stone material In the manufacturing method,
A method for producing an artificial stone, wherein the crushed material (x ₁ ) under the sieve in the step (C) is reused as a part of the raw material in the step (A). The crushed material (x ₁ ) under the sieve in the step (C) is further sieved to adjust the particle size, and then reused as a part of the raw material in the step (A). The manufacturing method of the described artificial stone material. 3. The artificial stone material according to claim 2, wherein in the step of adjusting the particle size of the crushed material (x ₁ ) under the sieve, the particle size is adjusted to be equal to or less than the maximum particle size of the steelmaking slag mixed in the raw material in the step (A). Production method. In step (A), as part or all of the alternate materials of steel slag to be blended to the raw material, crushed under sieve (x ₁₎ to any one of claims 1 to 3, characterized in that incorporated into the raw material The manufacturing method of the described artificial stone material. The crushed material (x ₁ ) under the sieve is mixed with the raw material in the step (A) after the moisture content is adjusted in advance and brought into a surface dry state. Manufacturing method for artificial stone. An artificial stone material obtained by hydrating and hardening a kneaded material and water containing steelmaking slag and blast furnace slag fine powder, crushing the hydrated solidified product, and sieving the hydrated solidified product. ,
As a substitute material for a part or all of the steelmaking slag, the crushed material (x ₁ ) removed by the sieving (including the case where the particle size of the crushed material (x ₁ ) is further adjusted) is included. An artificial stone characterized by that.

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