JP2001299129A - Block for forming seaweed bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seaweed bed-forming block which can adhere and overgrow aquatic plants such as seaweed and diatoms in a short period to form an environment suitable for the growth of fishes and shellfishes, even when a cured product using steel-making slag as a raw material is used instead of a concrete product. SOLUTION: This seaweed bed-forming block which is immersed in seawater in a constant area to form a seaweed bed for attracting fishes and shellfishes, characterized by disposing a surface layer comprising a seaweed growth- promoting substance on a cured product obtained by kneading the mixture of granular pre treated slag with blast furnace fine powder with water and then curing the kneaded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seaweed bed forming block, and more particularly, to aquatic plants such as seaweeds and diatoms which grow and proliferate in a short period of time to provide an environment suitable for the growth of seafood. It relates to a seaweed bed forming block.

[0002]

2. Description of the Related Art Slag generated in a steelmaking process has a high basicity (CaO / SiO ₂ ) and contains a large amount of free CaO, so that it easily absorbs moisture and expands. It is not suitable for use as a material and has been difficult to treat. In order to overcome this situation, in recent years, attempts have been made to develop technologies that actively utilize steelmaking slag.

For example, Japanese Patent Application Laid-Open No. Hei 10-152364 discloses that one or two of aggregates containing steelmaking slag, silica-containing materials having latent hydraulic properties, and silica-containing materials having pozzolanic reactivity are at least 50%. Disclosed is a hydrated cured product produced by mixing with a binder that is contained and cured by a hydration reaction. Japanese Patent Application Laid-Open No. Hei 2-233339 discloses a steel slag obtained by crushing and crushing all of a binder, fine aggregate and coarse aggregate, and using a steel slag obtained by mixing a blast furnace slag and a steelmaking slag in the binder. A slag block manufactured using the same is disclosed.

On the other hand, as a block for seaweed bed propagation that replaces natural rocky rocks, tetra pots, plates, fish reef blocks, etc. made of concrete have conventionally been used. However, the surface of these concrete products is simply concrete, and no consideration is given to the action of forming seaweed beds. Therefore, the appearance of blocks capable of improving the surface and increasing the amount of algae attached thereto has been expected.

[0005] Therefore, the present applicant has noticed that such a concrete product is manufactured by the same method as that of the hardened slag. In other words, it was thought that a new use for steelmaking slag would be opened if a hardened product mainly made of steelmaking slag could be used instead of the concrete product during the improvement.

However, when the applicant of the present invention made a trial production of a hardened slag using steelmaking slag as a raw material using the above-described conventional technology, the following problems became apparent.

First, according to the method described in Japanese Patent Application Laid-Open No. 10-152364, when converter slag is used as steelmaking slag, when cured in water at 20 ° C., the cured product collapses and becomes unsatisfactory. was there. Therefore, as a result of investigating this cause in detail, in recent years, the MgO concentration in the converter slag has increased due to dolomite and magnesia clinker added to the slag to protect the refractory lining of the converter. However, when such converter slag having a high MgO concentration is used, free-MgO contained in the converter slag undergoes hydration and expansion by curing in water when it is formed into a cured product, and the cured product to be produced is formed. It was found to collapse.

In order to produce a hardened slag from converter slag by the method described in JP-A-2-233593, it is necessary to pulverize the converter slag.
However, during converter slag, fr
Since the ee-MgO phase is contained, the slag itself is hard and hard to turn into fine powder, and there is a problem that the crushing cost is enormous in crushing the slag to a highly reactive fine powder.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention provides a method for setting aquatic plants such as seaweeds and diatoms in a short period of time even if a hardened product made of steelmaking slag is used instead of a concrete product. It is an object of the present invention to provide a seaweed bed forming block that can be grown and prosperous to provide an environment suitable for the growth of fish and shellfish.

[0010]

SUMMARY OF THE INVENTION The present inventor has studied the above-mentioned problems concerning the production of a hardened body using steelmaking slag as a raw material, and has adopted so-called "hot metal pretreatment slag" as the steelmaking slag. The problem was solved by adjusting the blending amount with other substances. Here, hot metal pretreatment means, in converter steelmaking of hot metal, adding various refining agents in advance to hot metal before performing normal decarburization refining in the converter and performing desiliconization, dephosphorization, and desulfurization processing. And the resulting slag is called hot metal pretreatment slag.

[0011] The inventor has conducted intensive studies on supporting a surface layer made of a substance having a seaweed bed forming effect on the surface of the improved cured product, and has embodied the results in the present invention. is there.

That is, the present invention relates to a block for forming a seaweed bed which is immersed in a certain area of seawater and attracts fish and shellfish, and is obtained by kneading a mixture of a granular pre-treated slag and a blast furnace fine powder with water. A seaweed bed forming block, wherein the hardened body is provided with a surface layer made of a substance promoting the growth of algae.

At this time, the substance that promotes the growth of the algae is
One or more selected from iron sulfate, magnesium sulfate, fly ash, red pepper, diatomaceous earth, perlite, talc, zeolite, ground shell, shell fossil, peat, charcoal, activated carbon and carbon fiber Is preferred.

[0014] Further, the present invention provides that the mixture has a particle size of 1.
Hot metal pre-treatment slag of 18mm or less 15-55mas
s%, blast furnace slag fine powder of 5 to 40 mass%, or the mixture is 15 to 55 mass% of hot metal pretreated slag having a particle size of 1.18 mm or less, blast furnace slag fine powder of 3 to 36 mass%, and fly ash. 1.
It is a seaweed bed formation block containing 5 to 30 mass%, and wherein the ratio of the fly ash content to the total content of blast furnace slag and fly ash is 0.1 to 0.75 in terms of mass ratio.

[0015] Further, the present invention provides a blast furnace slag fine powder, fly ash and a ratio of the content of the hot metal pretreated slag to the total content of the hot metal pretreated slag having a particle size of 1.18 mm or less in a mass ratio of 0.2. It is a seaweed bed formation block characterized by becoming a super.

In addition, the mixture may further contain an oxide or hydroxide of an alkali metal and / or an alkaline earth metal,
One or two or more selected from sulfates and chlorides are added in an amount of 0.2 to the total content of blast furnace slag and fly ash.
-20% by mass or adding naphthalenesulfonic acid and / or polycarboxylic acid to the total content of blast furnace slag, fly ash, and hot metal pretreated slag having a particle size of 0.1 mm or less. 0.0 mass%
It is a seaweed bed forming block characterized by being added.

According to the present invention, a substance having an action of forming a seaweed bed can be retained on the surface of the hardened body for a longer period of time than when the hardened body is a concrete product, and a more stable seaweed bed can be secured than before. Become like As a result, it is expected that not only the attracting and growing of fish and shellfish can be performed smoothly, but also a new use of the previously treated molten iron pretreatment slag which has been discarded can be made, which is expected to contribute to the treatment.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the circumstances that led to the invention.

First, in the present invention, the steelmaking slag is particularly
We decided to use hot metal pretreatment slag. The reason
Means that the hot metal pretreatment slag has the characteristics described below.
This is because that. (1) In hot metal pretreatment, do not add MgO to the refining agent
The slag generated originally had a low MgO concentration and C
aO / SiO_TwoIs low. Also, MgO slightly contained
Tond Ca_TwoMgSi_TwoO₇Exist as free-M
There is almost no gO phase. Therefore, conventional converter slag
-Mg generated when using as raw material
Cracking, powdering, deformation, and low strength of the cured product due to hydration expansion of O
There is a possibility that the following problems can be eliminated. (2) Hot metal pretreatment slag is CaO / S
iO_TwoIs low and P_TwoO _FiveSince the concentration is high, free-
CaO concentration is low. Therefore, by free-CaO
Hydration swelling is also low, and the hydration swelling of the free-CaO occurs.
Problems such as cracking, powdering, deformation, and reduced strength of the cured product
May be wiped out. (3) In addition, since there are many fine powders and high reactivity,
Blast furnace slag fine powder or fly ash
It can be an alternative to the menu. (4) As described above, most of the free-MgO phase
Since it does not exist, the slag itself is soft and can be used as converter slag.
It is much easier to grind in comparison. (5) Hot metal pretreatment of fine powder
Slag and blast furnace slag fine powder or fly ash
Easily react with each other, and higher strength of the cured product can be achieved.

However, when a hardened material was trial-produced with the hot metal pretreated slag, the effect alone was insufficient for the strength and cracking of the hardened material. Then, when using the hot metal pretreatment slag, the inventor found that a portion having a particle size of 1.18 mm or less was 15 to 55 ma.
s%. In other words, the inventor investigated in detail what parts of the hot metal pretreatment slag contributed greatly to the hardening reaction, and as a result, those having a particle size of 1.18 mm or less had particularly high reactivity. It was found that the strength of the obtained cured product was high, and the occurrence of cracks was significantly reduced. Therefore,
In the present invention, the particle diameter of 1.1 contained in the hot metal pre-treatment slag
The content of those having a size of 8 mm or less is particularly limited among all the formulations (also referred to as mixtures) except for water. In addition, this does not prevent that the hot metal pretreatment slag having a larger particle size is contained in the mixed hot metal pretreatment slag. Hot metal pretreated slag with a large particle size simply means that it was difficult to pulverize during the pulverization process, and itself has a certain level of strength. This is because there can be a high contribution as a binder.

In the present invention, such a particle size of 1.1
While limiting the amount of the hot metal pre-treatment slag of 8 mm or less, the SiO ₂ -containing substance reacting with the slag was also blended in an appropriate amount. Such SiO ₂ -containing substances are preferably those having latent hydraulic properties or pozzolanic reactivity, and specifically, blast furnace slag fine powder alone or a mixture of blast furnace slag fine powder and fly ash is preferable. This fly ash is a substance having latent hydraulic property or pozzolanic reactivity like the blast furnace fine powder, and is generated by burning coal. In addition, fly ash itself is extremely fine powder, and when used as a substitute for blast furnace slag fine powder, reactivity with hot metal pre-treatment slag is further improved, suppressing the occurrence of cracks in the hardened body and curing for a long time. It is possible to improve the strength later. When the blast furnace slag fine powder is used alone, its proper content is 5 to 40.
mass%. The reasons for limiting the contents of the hot metal pretreatment slag and the blast furnace slag fine powder as described above in the present invention are as follows.

When the content of the hot metal pre-treated slag having a particle size of 1.18 mm or less is less than 15 mass% or the content of the blast furnace slag fine powder exceeds 40 mass%,
This is because the supply of alkali metal (or alkaline earth metal) ions that relatively cures SiO ₂ tends to be insufficient, and the strength of the obtained cured product decreases. Further, the content of the hot metal pre-treated slag having a particle size of 1.18 mm or less is 55%.
If the content of the blast furnace slag fine powder exceeds 5 mass% or less than 5 mass%, the amount of SiO ₂ for fixing components such as CaO having a hydration swelling property in the hot metal pretreatment slag tends to be insufficient. This is because the cured product expands and powders in the process of curing in water, and the strength of the cured product is significantly reduced.

Furthermore, in the present invention, when a mixture of blast furnace slag fine powder and fly ash is used as the SiO ₂ -containing substance having latent hydraulic properties, the appropriate content of the mixture is 1.18 mm in particle diameter. The content of the following hot metal pretreatment slag is 15 to 55 mass%, the content of blast furnace slag fine powder is 3 to 36 mass%, and the content of fly ash is 1.5 to 30 mass%. And, in particular,
The ratio of the fly ash content to the total content of the blast furnace slag fine powder and the fly ash is 0.1 to 0.
It must be 75. The reason for this limitation is as follows.

First, the reason for limiting the content of the hot metal pre-treated slag having a particle size of 1.18 mm or less is the same as that already described, and will not be described. Blast furnace slag fine powder is 3-36 mass
The reason for setting the percentage is that if it is less than 3 mass%, a cured product of high strength cannot be obtained, and if it exceeds 36 mass%, no further increase in strength can be expected, and it is uneconomical. Fly ash has a remarkable effect when its content is 1.5 mass% or more and the ratio of fly ash content to the total content of blast furnace slag fine powder and fly ash is 0.1 or more by mass ratio. It is. However, fly ash tends to be inferior in hardening at room temperature to blast furnace slag fine powder, and the content of fly ash exceeds 30 mass%, or fly ash content based on the total content of blast furnace slag fine powder and fly ash. When the ratio of the amounts exceeds 0.75 by mass, the curing of the cured product as a whole is delayed, which is not preferable. Therefore, the fly ash content is 1.5 to 30 mass%, and the ratio of the fly ash content to the total content of the blast furnace slag fine powder and the fly ash is 0.1 to 0.7 in mass ratio.
5 is assumed.

In addition, in the present invention, blast furnace slag fine powder,
More preferably, the ratio of the content of the hot metal pretreated slag to the total content of the fly ash and the hot metal pretreated slag having a particle size of 1.18 mm or less is more than 0.2 in terms of mass ratio. In this way, the amount of alkali metal (or alkaline earth metal) ions supplied from the hot metal pretreatment slag and the reactivity of the reactive S in the SiO ₂ -containing substance having latent hydraulic properties
This is because the quantitative balance of iO ₂ becomes more appropriate and the effect of preventing the cured product from cracking increases.

According to the present invention, the above composition
It is intended to improve the strength of the produced cured product and significantly reduce the occurrence of cracks. In addition, the mixture further contains an alkali metal and / or alkaline earth metal oxide, hydroxide,
One or more selected from sulfates and chlorides are added in an amount of 0.2 to 20% by mass based on the total content of the blast furnace slag fine powder and fly ash, or naphthalenesulfonic acid and / or Carboxylic acid is used in an amount of 0.1 to 2.% based on the total content of blast furnace slag fine powder, fly ash, and hot metal pretreated slag having a particle size of 0.1 mm or less.
0 mass% may be added.

Curing of the cured product by adding at least 0.2 mass% of one or more selected from oxides, hydroxides, sulfates and chlorides of alkali metals and / or alkaline earth metals Is promoted, and the time required for curing can be reduced. However, 2.
Even if added in excess of 0 mass%, the effect is saturated, so the upper limit is 20 mass%.

The addition of naphthalene sulfonic acid and / or polycarboxylic acid improves the kneading properties when the mixture is kneaded with water. Therefore, the amount of water required for kneading can be reduced, and as a result, a cured product having higher strength can be obtained. At that time, the effect is poor when the addition amount is less than 0.1 mass% with respect to the total content of the blast furnace slag fine powder and fly ash, and the effect is poor.
Even if it is added in excess of s%, the effect is saturated.
Limited to ~ 2.0 mass%.

The above is the description of the hardened body using steelmaking slag adopted in place of concrete. In the present invention, the surface of the hardened body is provided with a substance that promotes the growth of algae. Substances that promote the growth of algae here include
Investigation and research of substances present in seagrass beds, from iron sulfate, magnesium sulfate, fly ash, bengara, diatomaceous earth, perlite, talc, zeolite, crushed shells, shell fossils, peat, charcoal, activated carbon, carbon fiber, etc. I decided to adopt. The use of at least one of these substances is more effective than the case where they are not used. Therefore, in the present invention, one or more of these substances are used simultaneously.

The thickness of the surface layer is not particularly limited. This is because the thickness required to cover the block differs depending on the size of the material forming the surface layer. The surface layer does not need to cover the entire surface of the block, and may be a partial coating according to the use, laying down, loading, and the like. For the method of forming this surface layer,
The present invention is not particularly limited. This is because various methods can be used. However, specifically, the following two methods can be adopted. One of them is a method of spraying, applying, or impregnating the surface of a manufactured cured product in a liquid state. The other one is pre-treatment slag, blast furnace slag fine powder,
And / or a mixture for a surface layer prepared by adding an appropriate amount of the substance to a mixture such as fly ash, and then pouring the mixture to a predetermined thickness into a frame for the production of a cured product, and then subjecting the mixture to the original curing The mixture for body production is poured and cured simultaneously with the body. Further, instead of preparing such a special mixture, it is also possible to simply lay these substances on a mold and then pour the mixture of the hardened material raw materials.

An important point of the present invention is that the characteristics of the surface layer are improved by using the hardened body of the slag pretreated with hot metal as compared with the case of using concrete. That is, the action of forming a seaweed bed was further improved, and the retention time of the action could be extended. Although the reason for this is not clear at present, it is expected that the amount and the elution rate of the eluted substances are different from those of concrete.

[0032]

EXAMPLES (Example 1) First, a slag hardened product was trial-produced using the hot metal pretreatment slag (three types of desiliconization, desulfurization, and dephosphorization slag) shown in Table 1 as main raw materials. Pulverized molten iron pre-treated slag of Table 1 having a particle size of 0.
Blast furnace slag fine powder pulverized to 1 mm or less, and / or fly ash (particle diameter 0.1 mm or less), and further Ca
(OH) ₂ was kneaded with water, and the mixture was poured into a previously prepared mold, which was cured in water at 20 ° C. to produce a cured product.

[0033]

[Table 1]

The content and ratio of each raw material in the mixture, the amount of kneading water added, the strength of the cured product after curing for 28 days, and the test piece (10 cmφ × 20 cm) immersed in 24 liters of artificial seawater for 500 hours Table 2 and Table 3 show the pH values of the seawater in Table 2. For comparison, a hardened concrete using conventional Portland cement as a main raw material was manufactured, and the same measured values as above are shown in Table 4. Judging on the basis of Table 4, the slag hardened products shown in Table 3 are all equal to or rather superior to the hardened concrete products in terms of strength and cracks and can withstand use in seawater. Obviously.

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

(Example 2) Next, an underwater immersion test of the seaweed bed forming block according to the present invention was performed. This test block had a size of 25 cm in length, 40 cm in width, and 5 cm in height, and was manufactured by the following three methods including formation of a surface layer.

A) The hardened slag obtained by the method of Example 1 was immersed in a 10 mass% aqueous solution of an algal growth promoting substance for 1 hour and then dried.

B) Preliminarily mixed powder of pretreated slag having a maximum particle size of 5 mm or less, blast furnace slag fine powder, fly ash and slaked lime was mixed with 10 ma of an algal growth promoting substance.
A mixture for surface layer was prepared by mixing s% and kneading with water.
Then, the slag cured body produced by the method of Example 1 was applied to the surface with a brush to a desired thickness, and then cured.

C) Immediately before producing a cured product by the method of Example 1, an algal growth promoting material is laid on a mold at a constant thickness.
The original mixture was poured over it and cured.

A similar block was manufactured using the above-mentioned hardened concrete using Portland cement as a main raw material.

Then, these blocks were actually immersed in the sea at a depth of 5 m for about 6 months, and the adhesion amount of seaweed (wet weight) was examined. The results are collectively shown in Table 5. From Table 5, it is clear that all the algal bed forming blocks according to the present invention exhibit higher algal adhesion than concrete blocks.

[0044]

[Table 5]

[0045]

As described above, according to the present invention, even if a hardened product made of steelmaking slag is used instead of a concrete product, aquatic plants such as seaweeds and diatoms can be established in a short time, It has become possible to prosper and create an environment suitable for the growth of seafood. Thus, the present invention provides for resource reuse,
It greatly contributes to the improvement of the environment.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fumio Kogiku 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside the Technical Research Institute of Kawasaki Steel Co., Ltd. (72) Makiko Nakagawa 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture (72) Inventor Masato Kumagai 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term (reference) 2B003 AA01 BB03 DD04 EE04 2B026 AA02 AB05 AC01 AF04

Claims (7)

[Claims] 1. A block for forming a seaweed bed which is immersed in the sea and attracts fish and shellfish, wherein the cured product is obtained by kneading and mixing a mixture of powdery and granular hot metal pre-treated slag and blast furnace slag with water. A seaweed bed forming block comprising a surface layer made of a substance that promotes the growth of algae. 2. The substance which promotes the growth of algae is iron sulfate, magnesium sulfate, fly ash, red bengal, diatomaceous earth, perlite, talc, zeolite, ground shell, shell fossil, peat, charcoal, activated carbon, and the like. 2. One or more kinds selected from carbon fibers.
The described seaweed bed forming block. 3. The mixture according to claim 1, wherein the mixture contains 15 to 55 mass% of hot metal pretreated slag having a particle size of 1.18 mm or less and 5 to 40 mass% of blast furnace slag fine powder. An algal bed forming block according to any of the above. 4. The mixture contains 15 to 55 mass% of hot metal pre-treated slag having a particle size of 1.18 mm or less, 3 to 36 mass% of blast furnace slag fine powder, and 1.5 to 30 mass% of fly ash. The seaweed bed forming block according to any one of claims 1 to 2, wherein a ratio of a fly ash content to a total content of the slag and the fly ash is 0.1 to 0.75 by mass ratio. 5. The mass ratio of the hot metal pretreatment slag content to the total content of the blast furnace slag fine powder, fly ash and hot metal pretreatment slag having a particle size of 1.18 mm or less is more than 0.2. The seaweed bed forming block according to claim 4, characterized in that: 6. A blast furnace slag and a fly ash containing one or more kinds selected from oxides, hydroxides, sulfates and chlorides of alkali metals and / or alkaline earth metals. The seaweed bed forming block according to any one of claims 3 to 5, wherein 0.2 to 20 mass% is added to the seaweed bed. 7. Naphthalene sulfonic acid and / or polycarboxylic acid may be added to the blast furnace slag, fly ash and hot metal pretreated slag having a particle size of 0.1 mm or less in a total content of 0.1 to 2.0 mass%. %. The algal bed forming block according to any one of claims 3 to 6, wherein the algal bed forming block is added.