JP2014024728A - Method for producing solid body including magnesia-based binding material and paper sludge ash as main material, and the solid body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a solid body which can be made to contain a larger amount of PS ash by using a magnesia-based binding material, which has compression strength required as a building material, and which includes the magnesia-based binding material and the paper sludge ash as main materials, and to provide the solid body.SOLUTION: In producing a solid body by mixing a magnesia-based binding material and paper sludge ash, magnesium oxide, magnesium sulfate, and magnesium chloride are measured so as to obtain a predetermined ratio as a binding material, and the binding material and the paper sludge ash with an amount of 0.7 to 1.5 times the total mass of the binding material are mixed with each other, and are solidified with water.

Description

  The present invention relates to a method for producing a solid body mainly composed of a magnesia-based binder and paper sludge ash, and the solid body.

  In a papermaking factory, a large amount of paper sludge, which is a papermaking sludge made up of fine fibers that could not be made into paper, fillers such as talc and kaolin, and foreign matters mixed in waste paper, is discharged in a large amount. Paper sludge, which is industrial waste, is incinerated to reduce the amount. Paper sludge ash (hereinafter also referred to as PS ash) is changed to ash by incineration.

  PS ash is an industrial waste that is disposed of in landfills, so that large-scale recycling has been developed in various fields, mainly in the construction or construction field, so that landfill disposal is not necessary. .

  The chemical component of PS ash is composed of silicon dioxide, aluminum trioxide, ferric oxide, etc., and its chemical component and configuration are close to ordinary cement.

  On the other hand, PS ash generally elutes fluorine and its compounds (hereinafter also referred to as fluorine) that greatly exceed environmental standards. The amount of elution of fluorine or the like is defined as a limit value of 0.8 mg / L or less according to environmental standards.

  Furthermore, in the structural field of construction or construction, chloride ions are strictly regulated to prevent rusting of steel materials such as reinforcing bars, but PS ash contains chloride ions in amounts that greatly exceed this regulation value. Yes.

  Since PS ash has almost the same chemical composition and composition as ordinary cement, it must be recycled on a large scale for the production of solids such as auxiliary materials for cement or coarse aggregates mixed with cement in the construction or construction field. Can be expected. However, in practice, there are many limitations due to the presence of fluorine and the like and chloride ions. A solid product made of PS ash itself or cement cannot be commercialized as a general product unless the elution amount of fluorine and the like is 0.8 mg / L or less. This is also true for the case of chloride ions. When PS ash is used for structural concrete containing steel materials that do not like rust, the concrete has an elution amount of fluorine or the like of 0.8 mg / L or less, and there are also chloride ions contained in the concrete. Unless it is less than the value (for example, 0.3 kg / 1m3 in the case of chloride amount), it cannot be commercialized as a general product.

From the above, when commercializing a solid body consisting of paper sludge ash and binder, which is industrial waste, with mechanical properties (specific gravity, strength), the performance required for the solid body is either It becomes.
(A) The physical properties and the elution amount of fluorine and the like are 0.8 mg / L or less.
(B) Mechanical properties, elution amount of fluorine or the like is 0.8 mg / L or less, and chloride ions are also below the regulation value.
(C) Mechanical properties and chloride ions are below regulation values.
(D) Only mechanical properties.

  Among these, (c) and (d) cannot be commercialized if the elution amount of fluorine or the like is unknown, no matter how excellent the mechanical properties are. (B) can be applied to any case where the mechanical properties are related to the structural yield strength. (A) can be applied to building materials such as finishing parts not related to structural strength.

  When PS ash is used unconditionally, that is, in the case of (b), it is necessary to consider a technique that simultaneously solves the problems of fluorine and the like and chloride ions (for example, Patent Document 1 described later). In this case, however, large-scale equipment and facilities are required. On the other hand, when trying to apply PS ash to building materials such as parts for finishing that are not related to structural strength, as in (a), the technology to solve the problem of fluorine and chloride ions at the same time is actually It ’s not good or reasonable. It is only necessary to establish a technique for suppressing elution of fluorine and the like.

  Based on the above, for solids consisting of paper sludge ash, which is industrial waste, and a binder, the specific gravity is as low as class 2 concrete or less according to the classification of concrete, and the compressive strength is high. The inventors have invented satisfying at least one of a solid body having a compressive strength or a solid body having an elution amount of fluorine or the like required for commercialization not more than the environmental standard.

  An example of the prior art when PS ash is recycled is as follows.

  As a representative example of recycled PS ash, its use as a cement raw material is known. Patent Document 2 to be described later includes PS ash containing about 10 to 60% by weight of SiO2 in solid content, about 10 to 50% by weight of Ai2O3 in solid content, and about 3 to 50% by weight of CaO in solid content. A cement composition is disclosed which is blended with cement so as to be 30% or less by weight. According to the examples, when the ratio of PS ash / cement weight is changed from 1/9 to 3/7, the compression strength tends to decrease as the ratio increases. In particular, in the case of PS ash / cement weight ratio = 1/9 and 3/7, the compressive strength of the latter is only about 0.33 times that of the former at the age of 28 days. That is, in the case of ordinary Portland cement or the like, it is shown that a large amount of PS ash cannot be added because of a significant decrease in compressive strength.

  Moreover, as an example of the artificial aggregate using PS ash, in Patent Document 3 to be described later, water and / or hot water, quicklime and cement are added to PS ash and mixed at 60 to 95 ° C. for 5 to 10 minutes. A granulation step for forming into granules is performed, and then the granulated product is precured, and then steam curing is performed at 40 to 250 ° C. for 3 to 24 hours, preferably at 180 ° C. for 5 hours in a curing chamber such as a thermostat or autoclave. Thus, a method for producing a solidified body is disclosed. In this patent it is shown that the production of artificial aggregates with PS ash and cement as main materials requires considerable equipment.

Patent No. 4901911 JP 7-69694 A JP 2005-313032 A Patent No. 4065402

Edited by Yoshio Kasai: Overview of concrete, pp. 54-55, 1998.8.6, Technical Shoin

  As seen in Patent Document 2, in cement compositions such as Portland cement, if PS ash is blended with cement in an amount exceeding 30% by weight, the required compressive strength cannot be obtained, and as a building material It turns out that it cannot be used.

  Moreover, in the manufacturing method of the solidified body in patent document 3, since a granulation machine construction is required in a granulation process, and also heating is required in a granulation process and a steam training process, for example in the outdoors without such equipment. Cannot be implemented. Moreover, since a granulation process is required, it cannot be formed into an arbitrary shape such as a plate or a column.

  On the other hand, the inventor has intensively studied a method for containment of elution of fluorine and the like with respect to PS ash. When magnesium oxide and magnesium sulfate are added to PS ash and water-cured, the amount of fluorine and the like eluted from the solid is as follows. The knowledge that it can reduce considerably is obtained.

  The inventor has further developed this knowledge and has come up with a powder obtained by mixing and stirring magnesium chloride in addition to magnesium oxide and magnesium sulfate. Here, since these three materials are all magnesium, the powder obtained by mixing and stirring is referred to as a magnesia-based binder. This magnesia-based binder can remarkably suppress elution of fluorine and the like, and a solid body using PS ash, which is industrial waste, can be commercialized. Moreover, it was also obtained from the experimental results that this binder is a binder having a binding strength higher than that of blast furnace cement and Portland cement, and can contain a larger amount of PS ash.

  In addition, the manufacturing method of hydraulically combining PS ash and magnesia-based binder is completely different from the manufacturing method of the solidified body in the previous Patent Document 3, and is manufactured with a high-speed stirrer such as a turbo mixer, which is extremely easy. It is.

  The present invention is based on the knowledge obtained from the preliminary experimental results as described above. By using a magnesia-based binder, a larger amount of PS ash can be contained, and The solid body has a required compressive strength as a building material, and produces a solid body mainly composed of a magnesia-based binder and paper sludge ash capable of suppressing elution of fluorine and the like from the solid body. Methods and solids thereof are provided.

  A magnesia-based bond composed of magnesium oxide as the main raw material, and a material obtained by adding one or both of magnesium chloride and magnesium sulfate (referred to here as a magnesia-based binder as described above) Materials have been proposed. The solid body obtained by water-curing this binder has a low impact on the environment in production, while it has high bonding properties and has excellent properties not found in Portland cement, which is a general cement, in that it provides a high hardness and a dense painted surface. Have. However, on the other hand, the composition ratio of magnesium oxide, magnesium chloride and magnesium sulfate as raw materials, the amount of water for water curing and the mixing / stirring method, etc. show numerous deformations such as expansion and cracking, so magnesia-based binders It is very difficult to produce a solid body. As a result of earnestly examining the possibility of producing a solid body by adding this magnesia-based binder to PS ash and water-curing, the present inventor determined the composition of the magnesia-based binder, its ratio and the amount of water. By adjusting, it is possible to produce a solid body having a required compressive strength as a building material even if a larger amount of PS ash is contained, and requirements for commercializing recycled PS ash The present invention was completed upon obtaining the knowledge that “elution of fluorine or the like” can be suppressed.

That is, (1) the method for producing a solid body mainly composed of a magnesia-based binder and PS ash according to the present invention is a method for producing a solid body by mixing a magnesia-based binder and PS ash. As the binder, magnesium oxide, magnesium sulfate and magnesium chloride are weighed so as to have a predetermined ratio, and this binder and PS ash not less than 0.7 times and not more than 1.5 times the total mass of the binder. These are mixed and water-cured to satisfy at least one of the following (i) and (ii).
(I) The solid body has a specific gravity of 1.70 or less and a compressive strength of 10 N / mm 2 or more.
(Ii) The elution amount of fluorine and the compound thereof in the solid body is less than 0.8 mg / L.

  In the method for producing a solid body mainly composed of a magnesia-based binder and PS ash according to the present invention, when a solid body is produced by mixing a magnesia-based binder and paper sludge ash, the binder is used. As above, magnesium oxide, magnesium sulfate, and magnesium chloride are weighed to a predetermined ratio. As a result of the study by the present inventors, three types of raw materials of magnesium oxide, magnesium sulfate and magnesium chloride were used, and by mixing them at a predetermined ratio, the binder was cracked or solidified by water curing. A solid body with high compressive strength can be obtained without causing expansion or other deformation.

  When such a magnesia-based binder is used, even if PS ash that is 0.7 times or more and 1.5 times or less the total mass of the binder is mixed, the solid obtained by water curing these is 10N. Compressive strength of about / mm2 to about 80 N / mm2. That is, according to the method of the present invention, as seen in Patent Document 2, approximately 2 to 5 times as much PS ash can be mixed as compared with a solid material of cement and PS ash such as conventional Portland cement, Therefore, PS ash can be processed with high efficiency, while a wide range of compressive strength from low compressive strength to ultra-high compressive strength can be provided as a building material.

  The solid body has a specific gravity of 1.4 or more and 1.70 or less, which is very light compared to concrete using Portland cement or blast furnace cement. Can be achieved.

  Moreover, although the mixing ratio of PS ash is high, the elution amount of fluorine and the like from such a solid body is less than 0.8 mg / L, and the solid body satisfies environmental standards such as fluorine. Commercialization is possible.

  Further, (2) in the method for producing a solid body mainly composed of magnesia-based binder and paper sludge ash according to the present invention, the ratio of magnesium oxide, magnesium sulfate and magnesium chloride is the total mass of the binder. In contrast, magnesium oxide is 50% or less, magnesium sulfate is 2.5% or more and less than 40%, and magnesium chloride is more than 10% and 2.5% or less.

  In the method for producing a solid body mainly composed of magnesia-based binder and paper sludge ash according to the present invention, the proportions of magnesium oxide, magnesium sulfate and magnesium chloride constituting the magnesia-based binder are as follows. Like that. That is, magnesium oxide is 50% or less, magnesium sulfate is 2.5% or more and less than 40%, and magnesium chloride is more than 10% and 2.5% or less with respect to the total mass of the binder. This allows a solid body with high compressive strength to be reliably produced without incurring cracks or expansion or other deformations.

  (3) In the method for producing a solid body mainly composed of a magnesia-based binder and PS ash according to the present invention, when the above (ii) is satisfied, the amount of elution of fluorine and its compound is 0 in the binder. It is characterized by replacing with blast furnace cement within a range satisfying less than 8 mg / L.

  In the method for producing a solid body mainly composed of the magnesia-based binder of the present invention and PS ash, when the above (ii) is satisfied, that is, the elution amount of fluorine or the like of the solid body is 0.8 mg / When satisfying that it is less than L, the binder is replaced with blast furnace cement within a range in which the elution amount of fluorine or the like satisfies less than 0.8 mg / L.

  Even when the binder is replaced with blast furnace cement so that the mass ratio is 90%, the concentration of fluorine or the like eluted from the solid body can be suppressed to less than 0.8 mg / L. Therefore, a part of the magnesia-based binder can be replaced with blast furnace cement within such a range. Blast furnace cement has a considerably lower price per unit mass than magnesia-based binders, and by replacing some of the magnesia-based binders with blast furnace cement, the production cost of solid bodies can be significantly reduced.

  (4) The method for producing a solid body mainly composed of a magnesia-based binder and PS ash according to the present invention includes an appropriate amount of sodium silicate or acrylic resin to increase the compressive strength before water curing. It is characterized by mixing.

  In the method for producing a solid body mainly composed of the magnesia-based binder of the present invention and paper sludge ash, an appropriate amount of sodium silicate or acrylic resin is mixed before the above-described water curing. The compressive strength of the solid obtained by mixing sodium silicate or acrylic resin is higher than the compressive strength of the solid obtained without mixing it. Therefore, an appropriate amount of sodium silicate or acrylic resin is mixed in the mixture of the binder and PS ash according to the compressive strength required for the design. Thereby, a solid body having a required compressive strength can be obtained without changing the mixing ratio of the binder and PS ash.

(5) A solid body mainly composed of a magnesia-based binder and PS ash according to the present invention is a solid body obtained by mixing a magnesia-based binder and PS ash and water curing them. The binder has a predetermined proportion of magnesium oxide, magnesium sulfate, and magnesium chloride, and contains 0.7 to 1.5 times PS ash of the total mass of the binder. It satisfies at least one of (i) and (ii).
(I) The solid body has a specific gravity of 1.70 or less and a compressive strength of 10 N / mm 2 or more.
(Ii) The elution amount of fluorine and the compound thereof in the solid body is less than 0.8 mg / L.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, it is a solid body obtained by mixing the magnesia-based binder and PS ash and water curing them. The binder has a predetermined proportion of magnesium oxide, magnesium sulfate, and magnesium chloride, and contains 0.7 to 1.5 times the paper sludge ash of the total mass of the binder, Since at least one of (i) and (ii) is satisfied, as before, high compression strength without causing cracks, expansion or other deformations in the solid body obtained by water-curing the binder. The solid body can be obtained.

  In such a binder, even if PS ash having a total mass of 0.7 to 1.5 times the total mass of the binder is mixed, the solid obtained by water curing these is about 10 N / mm 2. It has a compressive strength of about ~ 80 N / mm2. In other words, as seen in Patent Document 2, approximately 2 to 5 times as much PS ash can be mixed as compared with conventional solids of cement such as Portland cement and PS ash, so paper sludge ash is highly efficient. On the other hand, the building material can have a wide range of compressive strength from low compressive strength to ultra-high compressive strength.

  Moreover, since the specific gravity of the solid body is 1.4 or more and 1.70 or less, which is very light compared to Portland cement and blast furnace cement, the weight of the structure using this can be reduced.

  Further, the elution amount of fluorine and the like from such a solid body is less than 0.8 mg / L, and the solid body satisfies the environmental standard such as fluorine even though the mixing ratio of PS ash is high.

  (6) The solid body mainly composed of the magnesia-based binder according to the present invention and PS ash has a ratio of magnesium oxide, magnesium sulfate and magnesium chloride such that magnesium oxide is based on the total mass of the binder. 50% or less, magnesium sulfate is 2.5% or more and less than 40%, and magnesium chloride is more than 10% and 2.5% or less.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, the proportion of magnesium oxide, magnesium sulfate and magnesium chloride is 50% of magnesium oxide with respect to the total mass of the binder. Since magnesium sulfate is not less than 2.5% and less than 40% and magnesium chloride is more than 10% and not more than 2.5%, a solid body with high compressive strength is cracked or chipped as before. It can be manufactured reliably without being invited.

  (7) When the solid body mainly composed of the magnesia-based binder and PS ash according to the present invention satisfies the above (ii), the amount of elution of fluorine and its compound is 0.8 mg / It is characterized by being replaced with blast furnace cement within a range satisfying less than L.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, when the above (ii) is satisfied in the above (5) or (6), that is, the solid body such as fluorine. When the elution amount is less than 0.8 mg / L, the binder is replaced with blast furnace cement within a range where the elution amount of fluorine or the like satisfies less than 0.8 mg / L. As a result, even when the binder is replaced with blast furnace cement so that the mass ratio becomes 90%, the amount of elution of fluorine and the like eluted from the solid body is suppressed to less than 0.8 mg / L. can do. Therefore, a part of the binder can be replaced with blast furnace cement within such a range. Blast furnace cement has a considerably lower price per unit mass than magnesia-based binders, and by replacing some of the magnesia-based binders with blast furnace cement, the production cost of solid bodies can be significantly reduced.

  (8) The solid body mainly composed of the magnesia-based binder according to the present invention and PS ash is mixed with an appropriate amount of sodium silicate or acrylic resin in order to increase the compressive strength before water curing. It is characterized by being.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, an appropriate amount of sodium silicate or acrylic resin is mixed before the water curing to increase the compressive strength. It is configured. As a result, a solid body having a required compressive strength can be obtained without changing the mixing ratio of the binder and the paper sludge ash.

  (9) A solid body mainly composed of a magnesia-based binder and PS ash according to the present invention is characterized in that the outer shape is formed into a spherical shape, a columnar shape, a cylindrical shape, or a plate shape.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, the outer shape of the solid body is formed into a spherical shape, a columnar shape, a cylindrical shape, or a plate shape. It is possible to select a solid body having an optimum outer shape. As a result, a more effective application state can be achieved.

  (10) A solid body mainly composed of a magnesia-based binder according to the present invention and PS ash is mixed with an appropriate microbial agent before water curing, or an appropriate microorganism is added to the surface of the solid body. It is characterized by adhering an agent.

  In the solid body mainly composed of the magnesia-based binder of the present invention and PS ash, an appropriate microbial agent is provided inside and / or on the surface thereof. Any microorganism can be used as long as it has an environmental purification effect, but bacteria belonging to the genus Bacillus are preferred. Moreover, what mixed suitably the bacteria which belong to Bacillus genus and other bacteria, such as lactic acid bacteria and yeast, is also applicable. Although the mixing amount of the microbial agent may be appropriate, for example, it can be mixed so as to be about 0.1% by mass to 1.0% by mass of the solid body. In any case, in order to increase the number of bacteria reliably after construction, it is preferable to mix a culture medium according to the microorganism to be used. If such solids are installed in aquatic zones such as rivers and ponds that are contaminated with organic matter, etc., pollution indices such as ammonia nitrogen and COD (Chemical Oxygen Demand) due to the action of the contained PS ash The value decreases. Furthermore, in addition to the value of the contamination index being further reduced by the action of the contained microorganisms, the value of nitrite nitrogen is also reduced.

  Conventionally, in order to clean the aquatic zone, a solid material having a larger internal void obtained by adding the above-mentioned microbial agent to lightweight aggregate or pumice and water-curing it with cement such as Portland cement has been used. (For example, Patent Document 4 described above). However, it has been found in the prior patent documents and non-patent documents that the aquifer contaminated with solid bodies mainly composed of magnesia-based binder and PS ash can be purified. Was not. Solid bodies mainly composed of magnesia-based binder and PS ash are obtained by adding the above-mentioned microbial agent to lightweight aggregate or pumice, and then water-curing this with cement such as Portland cement. Experiments have found that significantly more contaminated aquaspheres can be cleaned than solids with a large.

  (11) A method for producing a solid according to the present invention comprises mixing a magnesia-based binder with the solid described in (9) or (10), or combining a magnesia-based binder, paper sludge ash, and (9) Alternatively, the solid material described in (10) is mixed and then water-cured.

  In the method for producing a solid body according to the present invention, the magnesia-based binder and the solid body described in (9) or (10) are mixed and then water-cured. Alternatively, the magnesia-based binder, the paper sludge ash, and the solid body described in (9) or (10) are mixed and then water-cured. At this time, the solid body described in (9) or (10) functions as an artificial aggregate. By using such an artificial aggregate, the weight can be further reduced.

  (12) The method for producing a solid according to the present invention is characterized in that, in the above (11), an appropriate pH adjusting agent and / or an appropriate microbial agent is mixed before water curing.

  In the method for producing a solid body of the present invention, an appropriate pH adjusting agent and / or an appropriate microbial agent is mixed before water curing. As the pH adjuster, an acid agent or an alkaline agent can be used. Depending on the purpose of applying the solid body, the corresponding pH adjuster is selected and mixed in an appropriate amount. Moreover, it replaces with a pH adjuster or a microbial agent is mixed with a pH adjuster. Thereby, for example, water purification can be performed. On the other hand, when the microbial agent is mixed with the pH adjuster, the growth environment of the microorganisms contained in the microbial agent can be adjusted.

  (13) In the method for producing a solid body according to the present invention, in (11) or (12), when the elution amount of fluorine and its compound in the solid body is less than 0.8 mg / L, a magnesia-based binder is used. It is characterized in that it is replaced with blast furnace cement within a range in which the elution amount of fluorine and its compound is less than 0.8 mg / L.

  In the method for producing a solid body of the present invention, when the elution amount of fluorine or the like of the solid body is less than 0.8 mg / L, the elution amount of fluorine or the like is reduced to 0.8 mg / L for the magnesia-based binder. Replace with blast furnace cement within the range satisfying less than L. As before, even when the magnesia-based binder is replaced with a blast furnace cement so that the mass ratio is 90%, the concentration of fluorine or the like eluted from the solid is suppressed to less than 0.8 mg / L. be able to. Therefore, a part of the magnesia-based binder can be replaced with blast furnace cement within such a range. Blast furnace cement has a considerably lower price per unit mass than magnesia-based binders, and by replacing some of the magnesia-based binders with blast furnace cement, the production cost of solid bodies can be significantly reduced.

(14) In the method for producing a solid body according to the present invention, in any one of (11) to (13),
The outer shape is spherical, columnar, cylindrical or plate-shaped, or the cross-section is shaped to be T-shaped, L-shaped or U-shaped.

  In the method for producing a solid body of the present invention, the solid body has a spherical shape, a columnar shape, a cylindrical shape, a plate shape, or a cross-sectional shape that is T-shaped, L-shaped, or U-shaped. Accordingly, a solid body having an optimal shape can be obtained. Thereby, a more effective construction state can be achieved.

It is a flowchart which shows the procedure which manufactures the solid body which concerns on this invention. It is a flowchart which shows the procedure which manufactures the solid body which concerns on this invention. It is a flowchart which shows the procedure which manufactures the PS ash containing solid body which concerns on 3rd Embodiment. It is a flowchart which shows the procedure which manufactures the PS ash containing solid body which concerns on 3rd Embodiment.

(First embodiment)
FIG.1 and FIG.2 is a flowchart which shows the procedure which manufactures the solid body based on this invention.
As shown in FIG. 1, magnesium oxide, magnesium sulfate, and magnesium chloride, which are raw materials for the magnesia-based binder, are weighed and introduced into the mixer (steps S1 and S2). Here, as a magnesium oxide, the highly active thing which baked magnesium hydroxide or magnesium carbonate at the temperature of about 600 degreeC can be used. In addition, although an omni mixer can be used as a mixer, you may use the turbo mixer which can stir more rapidly.

  By the way, when only magnesium oxide and magnesium chloride are used as the raw material of the magnesia-based binder, the solid body obtained by mixing water with the raw material and hydraulically hardening is likely to be warped and expanded due to high hygroscopicity. In addition, the water resistance and durability are low, and there is a risk of corroding steel materials such as rebar incorporated by acidification. On the other hand, when only magnesium oxide and magnesium sulfate are used as a raw material for the binder, expansion or cracking occurs in a solid body obtained by mixing water with the raw material and hardening it.

  On the other hand, when magnesium oxide, magnesium sulfate and magnesium chloride are used as the raw material for the binder, the solid material is warped and expanded as described above by mixing these three raw materials at a predetermined ratio as will be described later. In addition to being excellent in water resistance and durability without causing cracks, it can be easily adjusted to a pH near neutrality, and is extremely high compared to cement paste obtained by water-hardening Portland cement and blast furnace cement. A solid body having a compressive strength can be obtained.

  Here, the mixing ratio of the three raw materials of magnesium oxide, magnesium sulfate and magnesium chloride is 50% or less of magnesium oxide and 2.5% of magnesium sulfate with respect to the total mass of the raw materials constituting the magnesia-based binder. More than 40% and magnesium chloride is preferably more than 10% and 2.5% or less. More preferable mixing ratio is 50% of magnesium oxide, 2.5 to 40% of magnesium sulfate, and more than 10% of magnesium chloride with respect to the total mass of raw materials constituting the magnesia-based binder. 2.5% or less. Thereby, a solid body having a high compressive strength can be reliably produced without causing cracks or chips.

  Next, PS ash is weighed and put into a mixer, and the magnesia-based binder and PS ash described above are mixed well (steps S3 to S5). The amount of PS ash mixed is preferably 0.7 times or more and 1.5 times or less the total mass of the above-described binder. Here, in the case of structural concrete among building materials, the compressive strength of concrete using ordinary cement is about 24 N / mm2, and the compressive strength of concrete using high strength cement is about 30 N / mm2, The compressive strength of concrete using ultra high strength cement is about 80 N / mm 2. In general, in the case of cement mortar or concrete used as a building material, the strength may be about 10 N / mm 2.

  In the present invention, as described above, the amount of PS ash mixed is 0.7 times or more of the total mass of the binder. When the mixing amount of PS ash is less than 0.7 times the total mass of the binder, while the processing rate of PS ash is low, the compressive strength of the solid body becomes larger than the compressive strength of the ultra high strength cement, A solid body having a high compressive strength is unnecessarily formed, which is not practical. On the other hand, when the mixing amount of PS ash is 0.7 times or more of the total mass of the binder, it is possible to obtain a solid body having a practical compressive strength according to the construction situation, and the total mass of the binder. PS ash can be processed at a rate equal to or higher than that, and the processing efficiency of PS ash is remarkably high.

  Moreover, the more preferable mixing amount of PS ash is 1.0 times or more of the total mass of the binder. When the mixing amount of PS ash is 1.0 times or more of the total mass of the binder, in addition to further improving the processing efficiency of PS ash, solids with an unnecessarily high compressive strength regardless of the mixing ratio of water Since it is avoided that a body is formed, it is more practical.

  On the other hand, when the mixing amount of PS ash is 1.5 times or more of the total mass of the magnesia-based binder, the solid body is less than 10 N / mm 2 necessary for the strength of the structure, so the structure of the building It cannot be used generally as a substitute for concrete. On the other hand, in the present invention, as described above, the mixing amount of PS ash is 1.5 times or less of the total mass of the binder, so the strength of the solid body is for structural use of buildings. Since it is avoided that the concrete strength falls below 10 N / mm 2, it can be appropriately used as a substitute for structural concrete for buildings.

  In this embodiment, the magnesia-based binder is introduced into the mixer before the PS ash. However, the present invention is not limited to this, and PS ash may be introduced into the mixer before the magnesia-based binder.

  Next, an appropriate amount of water is charged into the mixer (step S6), and the magnesia-based binder, PS ash, and water are sufficiently stirred and kneaded (step S7). Here, the amount of water to be added is, for example, a ratio of (mass of water) / (total mass of the binder) of 0.24 or more and 0.33 or less so that the slump flow is about 130 mm to 140 mm. It is good to set as follows.

  When the kneading of the magnesia-based binder, PS ash and water is completed, the kneaded product is poured into a pre-made mold (step S8), and the kneaded product is water-cured and trained (step S9). Thus, a PS ash-containing solid body is obtained (step S10).

  In the PS ash-containing solid body thus obtained, PS ash is contained at 0.7 to 1.5 times the total mass of the binder, and as a result, as much as possible. A large amount of PS ash will be processed. Further, the specific gravity of the PS ash-containing solid body is about 1.4 to 1.70, which is very light compared to Portland cement and blast furnace cement. Furthermore, as will be described later, the elution amount of fluorine and the like from the PS ash-containing solid is less than 0.8 mg / L, which satisfies the environmental standards. On the other hand, since the compressive strength of the PS ash-containing solid body is more than 10 N / mm 2 and about 80 N / mm 2 or less, it has a practical compressive strength that can be used as a building material.

  It is also possible to produce an artificial aggregate by pouring the kneaded material into a mold having a plurality of recesses corresponding to the aggregate such as gravel, performing water hardening and training, and then releasing the mold. it can. At that time, the artificial aggregate may have various shapes such as a spherical shape, a columnar shape, a cylindrical shape, or a plate shape.

  Further, after the artificial aggregate is put into the mixer in step 5 and the magnesia-based binder is further added and mixed, or after the magnesia-based binder and PS ash are added and mixed, the step You may make it obtain the solid body containing this artificial aggregate or the solid body containing this artificial bone and PS ash by performing operation from S6 to step S10.

  Alternatively, the pH of the solid body may be adjusted to a required pH by adding an appropriate amount of an appropriate pH adjusting agent before or at the same time as the addition of water in Step S6.

  In the solid body containing the artificial aggregate thus obtained, or the solid body containing the artificial aggregate and PS ash, the outer shape is spherical, columnar, cylindrical, or plate depending on the formwork described above. It can be formed into various shapes such as a rectangular shape, a rectangular shape, a T shape, an L shape, or a U shape. Therefore, when a solid body containing artificial aggregate or a solid body containing artificial aggregate and PS ash is applied as a building material, when applied as an artificial aggregate, it is applied as a structure other than a building. In some cases, it is formed into a shape according to the application status. Thereby, the required purpose according to the application situation can be achieved.

(Second Embodiment)
Next, the PS ash-containing solid body according to the second embodiment of the present invention will be described.
In the production process of the present PS ash-containing solid, the PS ash-containing solid in the first embodiment described above, except for further mixing sodium silicate or / and acrylic resin following the PS ash mixing process. It is the same as each manufacturing process.

  The compressive strength of the PS ash-containing solid obtained by mixing sodium silicate and / or acrylic resin is higher than the compressive strength of the PS ash-containing solid obtained without mixing sodium silicate and acrylic resin. Therefore, an appropriate amount of sodium silicate or / and acrylic resin is mixed in the mixture of magnesia-based binder and PS ash according to the compressive strength required for design. Thereby, a solid body having a required compressive strength can be obtained without changing the mixing ratio of the magnesia-based binder and the PS ash.

  Various compressive strengths are required in the design of the solid body, but in order to cope with all of them, the mixing ratio of the three raw materials constituting the magnesia-based binder and the mixing ratio of PS ash are variously changed. However, as described above, when sodium silicate or / and acrylic resin are mixed, the three kinds of constituents constituting the binder are measured. Since a solid body having a required compressive strength can be obtained without changing the mixing ratio of the raw materials and the mixing ratio of PS ash, the troublesome work required for the preliminary test can be reduced as much as possible.

  The relationship between the amount of sodium silicate and / or acrylic resin added and the compressive strength of the solid body is determined in advance. For example, the compressive strength of a solid body in which PS ash equivalent to the total mass of the binder is mixed, and the compressive strength of a solid body in which 0.3% by mass of sodium silicate is mixed with the total mass of the binder In comparison, the latter compressive strength is approximately 22% higher than the former compressive strength. By performing the same test with different mixing ratios of sodium silicate, the relationship between the mixing amount of sodium silicate and the amount of increase in compressive strength can be determined in advance, and the result is used to achieve the required compressive strength. The amount of sodium silicate mixed can be determined.

  In addition, for example, sodium silicate manufactured by Fuji Chemical Co., Ltd. can be used as the sodium silicate, and nonene R066 manufactured by Maruhishi Oil Chemical Co., Ltd. can be used as the acrylic resin. Needless to say, sodium silicate and acrylic resin are not limited to these products.

(Third embodiment)
Next, the PS ash-containing solid body according to the third embodiment of the present invention will be described.
3 and 4 are flowcharts showing a procedure for producing the PS ash-containing solid body according to the third embodiment, in which a microbial agent is further mixed.

  In the same manner as in Steps S1 to S4 described in the first embodiment, magnesium oxide, magnesium sulfate, and magnesium chloride, which are the raw materials of the binder, are metered into the mixer, PS ash is metered, and the mixer is charged. (Steps S21 to S24).

  Next, a microbial agent mainly composed of microorganisms having an environmental purification effect is weighed and put into the mixer, and these magnesia-based binder, PS ash and microbial agent are mixed well (steps S25 to S27). Furthermore, aggregates such as sand, pebbles and gravel may be mixed. It is because the solid body which has many space | gap inside can be manufactured by adjusting the mixing rate of a binder and PS ash, and an aggregate.

  Here, as the microbial agent, for example, BB bacteria (manufactured by Big Bio Inc.) can be used. This microbial agent contains cells of Bacillus subtilis, Bacillus thuringiensis and Bacillus sphaericus and their culture media. In addition, as the microbial agent, a mixture of a plurality of types of microorganisms may be used, or a single type of microorganism may be used. As the microorganism, those belonging to the genus Bacillus are preferable. Moreover, what mixed suitably the thing which belongs to the genus Bacillus, and other bacteria, such as lactic acid bacteria and yeast, is also applicable. In any case, in order to increase the number of bacteria reliably after construction, it is preferable to mix a culture medium according to the microorganism to be used.

  Although the mixing amount of the microbial agent may be appropriate, for example, it can be mixed so as to be about 0.1% by mass to 1.0% by mass of the solid body.

  Next, an appropriate amount of water is charged into the mixer as before (step S28), and the magnesia-based binder, PS ash, microbial agent and water are sufficiently stirred and kneaded (step S29). When the kneading is completed, the kneaded product is poured into a pre-made mold (step S30), the kneaded product is water-cured and trained (step S31), and then the PS ash-containing solid body is removed by mold release. Obtain (step S32).

  When such PS ash-containing solids are installed in aquatic zones such as rivers and ponds contaminated with organic substances, ammonia nitrogen and COD (Chemical Oxygen Demand), etc. are produced by the action of the contained PS ash. The value of the pollution index decreases. Furthermore, in addition to the value of the contamination index being further reduced by the action of the contained microorganisms, the value of nitrite nitrogen is also reduced.

  Conventionally, in order to clean the aquatic zone, a solid material having a larger internal void obtained by adding the above-mentioned microbial agent to lightweight aggregate or pumice and water-curing it with cement such as Portland cement has been used. (For example, Patent Document 4). However, it has been found in the prior patent documents and non-patent documents that the aquifer contaminated with solid bodies mainly composed of magnesia-based binder and PS ash can be purified. Was not. Solid bodies mainly composed of magnesia-based binder and PS ash are obtained by adding the above-mentioned microbial agent to lightweight aggregate or pumice, and then water-curing this with cement such as Portland cement. Experiments have found that significantly more contaminated aquaspheres can be cleaned than solids with a large.

  Note that the PS ash-containing solid body can be formed into various shapes such as a spherical shape, a columnar shape, a plate shape, or a rectangular shape, T shape, L shape, U shape, etc., depending on the application location. . In addition, by designing the above-described molds in various ways, it may be formed into a shape having a large surface area such as a cylindrical shape or a net shape. Thereby, the contaminated aquatic sphere can be cleaned more efficiently.

  Further, an artificial aggregate is obtained from the PS ash-containing solid mixed with the microbial agent as described above, and the artificial aggregate is put into a mixer and mixed, or a magnesia-based binder and PS ash are added. After mixing, the operations from step S6 to step S10 may be performed to obtain a solid body containing the artificial aggregate or a solid body containing the artificial aggregate and PS ash. .

  In addition, by adding an appropriate amount of an appropriate pH adjusting agent before or at the same time as the addition of water in step S28, the pH of the solid body is adjusted according to the growth environment of the microorganism contained in the microbial agent. You may make it adjust to pH.

  In the present embodiment, the case where the microbial agent is mixed with the magnesia-based binder and PS ash has been described. However, the present invention is not limited to this, and the above-described steps S25 and S26 are skipped to form a solid body. Then, a microbial agent may be attached to the surface of the solid body. In order to attach the microbial agent to the surface of the solid body, for example, the microbial agent is dissolved with a small amount of water, and the obtained solution is applied or sprayed on the surface of the solid body. Moreover, you may immerse a solid body in the said solution.

Next, the results of comparative tests and the like will be described.
Example 1
The result of examining the composition of the magnesia-based binder will be described.
Using only magnesium oxide and magnesium sulfate as raw materials for the magnesia-based binder, the state of the solid bodies obtained by varying the mixing ratios of both was observed. Further, magnesium oxide, magnesium sulfate and magnesium chloride were used as raw materials for the magnesia-based binder, and the state of the solid bodies obtained by varying the mixing ratios of these was observed. In the latter case, solid bodies were formed and observed in the case where PS ash was added and in the case where PS ash was not added. The mixing ratio of each solid body is shown in Table 1, and the result of observing the state of each solid body is shown in Table 2.

  Note that, as described in Non-Patent Document 1 described above, when only magnesium oxide and magnesium chloride are used as a raw material for the binder, water resistance and durability are low, and rebars incorporated by acidification are used. Excluded from consideration because there is a risk of corroding steel.

  The raw material for the magnesia-based binder is magnesium oxide (product name AM-2), magnesium sulfate (product name MG-3K), magnesium chloride (product name crystallin for industry) (all manufactured by Ako Kasei Co., Ltd.). It was.

  As shown in Table 1, Comparative Examples 1-12 show each mixing ratio when only magnesium oxide and magnesium sulfate are used as raw materials for the magnesia-based binder, and Comparative Examples 13-15 are The mixing ratios when magnesium oxide, magnesium sulfate and magnesium chloride are used as raw materials for the magnesia-based binder are shown. Moreover, the raw material composition of the binder and the mixing ratio thereof are the same as those of Example 1 of the present invention.

  As is clear from Comparative Examples 1 to 12 in Table 2, when only magnesium oxide and magnesium sulfate are used as raw materials for the magnesia-based binder, the mixing ratio of magnesium oxide is 0.4 to 0.67 by mass ratio. In the range, cracks, expansion or deformation were observed in the obtained solid body in any case. Moreover, the crack or deformation of the solid body occurred regardless of the presence or absence of PS ash. As a result, when only magnesium oxide and magnesium sulfate are used as raw materials for the magnesia-based binder, the solid body is cracked or deformed regardless of the mixing ratio of magnesium oxide and magnesium sulfate and the mixing ratio of PS ash. It turns out that etc. arise.

  Further, as is clear from Comparative Examples 2, 3, 4, and 13 in Table 2, when the mixing ratio of magnesium oxide is 0.6, only magnesium oxide and magnesium sulfate are used as raw materials for the magnesia-based binder. Even when magnesium oxide, magnesium sulfate, and magnesium chloride were used as raw materials for the magnesia-based binder, cracking or deformation occurred in the solid. Accordingly, the mixing ratio of magnesium oxide is preferably 0.5, that is, 50% or less. Further, considering the following results, a more preferable mixing ratio of magnesium oxide is 50%.

  On the other hand, as is clear from Comparative Examples 14 and 15 in Table 2, even when magnesium oxide, magnesium sulfate and magnesium chloride were used as the raw materials for the binder, the mixing ratio of magnesium chloride to magnesium sulfate was in mass ratio. In the case of a relatively small amount of 0.25, cracks or deformations were observed in the solid regardless of the presence or absence of PS ash. Therefore, the mixing ratio of magnesium chloride needs to exceed 10% of the total mass of magnesium oxide, magnesium sulfate and magnesium chloride. Similarly, the mixing ratio of magnesium sulfate needs to be less than 40% of the total mass of magnesium oxide, magnesium sulfate and magnesium chloride.

  On the other hand, in the solid body of Invention Example 1, no cracks or deformations were observed. Also, no cracks or deformations were observed in the solid body of Target Example 1.

  From these results and the experience of the present inventors, the mixing ratio of magnesium sulfate is 2.5% or more of the total mass of magnesium oxide, magnesium sulfate and magnesium chloride, and the mixing ratio of magnesium chloride is magnesium oxide, sulfuric acid. It is preferably 2.5% or less of the total mass of magnesium and magnesium chloride.

  From the above, the ratio of mixing three raw materials of magnesium oxide, magnesium sulfate and magnesium chloride is 50% or less of magnesium oxide and 2.5% or more and less than 40% of magnesium sulfate with respect to the total mass of the binder. Magnesium chloride is preferably more than 10% and 2.5% or less. A more preferable mixing ratio is 50% magnesium oxide, 2.5% or more and less than 40% magnesium sulfate, and magnesium chloride is more than 10% with respect to the total mass of the magnesia-based binder. 50% or less.

(Example 2)
Next, the result of examining the mixing ratio of PS ash will be described.
The results of measuring the compressive strength and specific gravity of each solid body obtained by mixing PS ash with different ratios in the binder constituting the present invention example 1 shown in Example 1 and hydraulically nurturing it are as follows. Table 3 shows. In addition, each binder is comprised by the same mixture ratio, and the characteristic of the binder used as a reference | standard is described as the target example 2 which is not mixing PS ash. The compressive strength was measured according to a test method defined in JIS 1108.

  As is clear from Table 3, when the mixing ratio of PS ash is 1.5 times the total mass of the binder, the compression strength of the obtained solid body exceeded 10 N / mm2, but the mixing ratio of PS ash Is 2.0 times or more of the total mass of the binder, the compression strength of the obtained solid was less than 10 N / mm 2. As described above, in general, in the case of cement mortar or concrete when used as a building material, the strength should be about 10 N / mm2, so the upper limit for mixing PS ash is about 1.5 times the total mass of the binder. It turns out that it is.

  Next, PS ash is weighed and put into a mixer, and the magnesia-based binder and PS ash described above are mixed well (steps S3 to S5). The amount of PS ash mixed is preferably 0.7 times or more and 1.5 times or less the total mass of the above-described binder. Here, in the case of structural concrete among building materials, the compressive strength of concrete using ordinary cement is about 24 N / mm2, and the compressive strength of concrete using high strength cement is about 30 N / mm2, The compressive strength of concrete using ultra high strength cement is about 80 N / mm 2. In general, in the case of cement mortar or concrete used as a building material, the strength may be about 10 N / mm 2.

  On the other hand, when the mixing ratio of PS ash was 0.7 times the total mass of the binder, the obtained solid had a compressive strength of 80.3 N / mm 2. As described above, among the building materials, in the case of structural concrete, the compressive strength of concrete using ordinary cement is about 24 N / mm2, and the compressive strength of concrete using high strength cement is about 30 N / mm2, The compressive strength of concrete using ultra high strength cement is about 80 N / mm 2. When the mixing amount of PS ash is less than 0.7 times the total mass of the magnesia-based binder, the processing rate of PS ash is low, while the compressive strength of the solid body becomes larger than the compressive strength of the ultra high strength cement. As a result, a solid body having a high compressive strength is formed unnecessarily, which is not practical. Therefore, it can be seen that the lower limit for mixing PS ash is about 0.7 times the total mass of the binder. As a result, it is possible to obtain a solid body having a practical compressive strength according to the construction situation, and to treat PS ash at a rate equal to or higher than the total mass of the magnesia-based binder, with high efficiency. PS ash can be treated.

  A more preferable amount of PS ash mixed is 1.0 times or more of the total mass of the magnesia-based binder. When the mixing amount of PS ash is 1.0 times or more of the total mass of the binder, in addition to further improving the processing efficiency of PS ash, as shown in Table 3, it is related to the mixing ratio of water. Therefore, it is more practical because it is avoided that a solid body having a high compressive strength is formed unnecessarily.

  On the other hand, as can be seen from Table 3, by mixing PS ash, a solid body having a low specific gravity can be obtained, so that the structure in which the PS ash-containing solid body is constructed can be reduced in weight.

(Example 3)
Next, the result of mixing sodium silicate will be described.
The results of comparing the characteristics of the PS ash-containing solid shown in Example 4 of Example 2 and the PS ash-containing solid obtained by mixing sodium silicate with the solid are shown in Table 4 below. The sodium silicate used was manufactured by Fuji Chemical Co., Ltd.

  As is clear from Table 4, the compression strength of the PS ash-containing solid body when 7% by mass of sodium silicate of the magnesia-based binder was mixed into the mixture of the binder and PS ash was 74.1 N / Compared to the compressive strength of 60.9 N / mm 2 of the solid body containing PS ash that was mm 2 and not mixed with sodium silicate, it was about 22% higher.

  As described above, the compressive strength of the PS ash-containing solid body can be increased without changing the mixing ratio of the binder and the PS ash, so that the PS ash-containing solid body having the compressive strength corresponding to the design strength is complicated. It can be formed without the need for labor.

  In addition, even if it exists in an acrylic resin from the experience of this inventor, the knowledge that the compressive strength of PS ash containing solid body can be raised like such a sodium silicate has been acquired.

Example 4
Next, the results of the fluorine elution test performed on the PS ash-containing solid according to the present invention will be described.

  The binder shown in Example 2 of Example 2 and PS ash were weighed to a mass ratio of 1: 9 and mixed together, and water was added to this mixture so that the ratio of both was 66:34. The solids were obtained by kneading them and water-curing them to obtain solids, and the concentration of fluorine eluted from the solids was measured when the age was 1, 3, and 7. The results are shown in Table 5.

  In addition, the elution test for fluorine from solids is based on the “Measurement Method for Soil Elution Survey stipulated by the Minister of the Environment” 6th, Ministry of the Environment Notification 18) ”. In addition, the dissolution test was commissioned to Dojin Glocal Co., Ltd., a research organization designated by the soil pollution control law.

  As is clear from Table 5, the elution amount of fluorine is from 0.5 to 1 mg / L from the 1st day, which is less than the environmental standard value of 0.8 mg / L, and 0 to 3 days and 7th. .37 mg / L and lower concentration.

  Thus, even when the binder and PS ash are mixed so that the mass ratio is 1: 9, the elution amount of fluorine is kept below the environmental standard value. When PS ash is mixed at a mass ratio of 1: 0.7 to 1.5, the elution amount of fluorine is naturally less than the environmental standard value.

  By the way, it can be seen from the above results that if the binding material is mixed at 10% by mass with respect to PS ash, the elution amount of fluorine can be made less than the environmental standard value. Therefore, this binder and blast furnace cement are mixed so that the mass ratio is about 1: 9, that is, approximately 90% of this binder is replaced with blast furnace cement, and PS ash is added to the mass ratio of 0.7 to Even if it is a solid body obtained by water curing after mixing so as to be 1.5, the elution amount of fluorine can be made less than the environmental standard value. Therefore, a case where approximately 90% of the binder is replaced with blast furnace cement can be included in the present invention.

(Example 5)
Next, the result of examining the PS ash-containing solid mixed with the microbial agent will be described.
PS ash-containing solids mixed with different amounts of microbial agents are molded and water-cured into ring-shaped blocks, respectively, and these blocks are individually installed in each water layer in which artificial sewage is stored, Artificial sewage COD, ammonia concentration, and nitrite nitrogen concentration in each water layer were measured over time to obtain Invention Examples 7 and 8. In addition, what was measured similarly about the artificial sewage of the aquarium in which the block is not installed is set as the target example 3, and the artificial in the aquarium in which the block obtained in the same manner as before from the PS ash-containing solid body not mixed with the microbial agent is installed. What was similarly measured about sewage was set as Comparative Example 18. The results are shown in Table 7 below. In Table 7, N.I. D shows that it was below the detection limit value.

  The compositions of the PS ash-containing solid bodies of Invention Examples 7 and 8 and the PS ash-containing solid body of Comparative Example 18 are shown in Table 6 below. Moreover, the composition of the artificial sewage mentioned above is as follows. That is, CaCl2: 7.5 mg / L, MgSO4 · 7H2O: 7.5 mg / L, NaCl: 12.5 mg / L, NaHCO3: 500 mg / L, KH2PO4: 35 mg / L, NH4Cl3: 191 mg / L, KCl: 25 mg / L L, glucose: 150 mg / L, peptone (Wako Pure Chemical Industries, Ltd.): 50 mg / L, yeast extract (Kanto Chemical Co., Ltd.): 50 mg / L, gravy extract (Wako Pure Chemical Industries, Ltd.): 50 mg / L And the pH is 9.66. Further, BB bacteria (manufactured by Big Bio Co., Ltd.) were used as the above-mentioned microbial agent.

  As can be seen from Table 7, in the target example 3 with only artificial sewage, the COD and ammonia concentrations were higher than the original, and were 120 mg / L or more and 10 mg / L or more, respectively. When these values were measured over time, the COD value started to decrease slightly after about two weeks, but was 80 mg / L even after about one month. The value of ammonia concentration was 10 mg / L even after 20 to 24 days. On the other hand, the value of nitrite nitrogen began to be measured after 1 day and was 0.2 mg / L after about 2 to 3 weeks, and was 0.5 mg / L or more after about 4 weeks.

  On the other hand, in the case of the comparative example 18 using the PS ash-containing solid not mixed with the microbial agent, the COD and ammonia concentrations were earlier and much lower than the target example 3, but the trend of nitrite nitrogen was the target. It was almost the same as Example 3.

  On the other hand, in the present invention examples 7 and 8 using the PS ash-containing solid mixed with the microbial agent, the trend of COD was almost the same as the target example 3, but the ammonia concentration was The amount was decreased more rapidly than Comparative Example 18. Furthermore, nitrite nitrogen could also be suppressed below the detection limit in about 3 weeks in Example 8 of the present invention.

(Example 6)
Next, the result of adjusting the pH of the PS ash-containing solid according to the present invention will be described.
Sodium bisulfate (pH = 0.9) (manufactured by Ako Kasei Co., Ltd.) was added to the PS ash-containing solid shown in Example 4 of the present invention in Example 2 at 1% by mass of the PS ash-containing solid, The results of measuring the pH are shown in Table 8 below. The pH was measured as follows. That is, a solid material having an age of about one week was finely pulverized, and the obtained powder was put into 10 times by mass water and stirred sufficiently, and then the pH of the supernatant was measured with a pH meter. .

  The result of measuring the pH of the PS ash-containing solid to which sodium bisulfate was not added was taken as the target example 4, and the pH of the PS ash and magnesia-based binder used for the PS ash-containing solid was measured. The results are shown as Reference Examples 1 and 2. Note that the pH of the PS ash-containing solid was measured in the same manner as before, and the PS ash and the binder were powders. Therefore, the powders were poured into 10 times the mass of water and stirred sufficiently, The pH of the supernatant was measured with a pH meter.

  As is clear from Reference Examples 1 and 2 in Table 8, the pH of the PS ash used for the PS ash-containing solid was 11.40, and the pH of the binder was 9.62. The pH of the PS ash-containing solid obtained by mixing these was 10.11 as shown in Target Example 4, indicating weak alkalinity. On the other hand, as shown in Example 9 of the present invention, the pH of the PS ash-containing solid body to which sodium bisulfate was added was adjusted to 8.3 and neutral.

  Thus, in the PS ash-containing solid according to the present invention, the pH can be easily adjusted. Therefore, when the microbial agent as described in Example 5 is mixed, the pH of the PS ash-containing solid body can be adjusted according to the optimum pH of the microorganism contained in the microbial agent. Thereby, the growth of the microorganism can be promoted and the purification action can be improved.

  In the case of a PS ash-containing solid body to which no microbial agent is mixed or adhered, the pH may be adjusted to a strong alkalinity of 11 or more by mixing a strong alkaline pH adjusting agent.

S1 Step S1
S2 Step S2
S3 Step S3

Claims (14)

When mixing a magnesia-based binder and paper sludge ash to produce a solid,
As the binder, magnesium oxide, magnesium sulfate, and magnesium chloride are weighed so as to have a predetermined ratio, and this binder and paper sludge ash that is 0.7 times to 1.5 times the total mass of the binder, Are mixed with water, and these are water-cured to satisfy at least one of the following (i) and (ii): solids mainly composed of magnesia-based binder and paper sludge ash Body manufacturing method.
(I) The solid body has a specific gravity of 1.70 or less and a compressive strength of 10 N / mm 2 or more.
(Ii) The elution amount of fluorine and the compound thereof in the solid body is less than 0.8 mg / L.   The ratio of magnesium oxide, magnesium sulfate and magnesium chloride is 50% or less for magnesium oxide, 2.5 to 40% for magnesium sulfate, and more than 10% for magnesium chloride with respect to the total mass of the binder. The manufacturing method of the solid body which uses the magnesia type | system | group coupling material and paper sludge ash of Claim 1 made into 2.5 or less as a main material.   3. The magnesia-based binder and paper according to claim 1 or 2, wherein when satisfying (ii), the binder is replaced with blast furnace cement within a range where the elution amount of fluorine and its compound is less than 0.8 mg / L. A method for producing a solid body mainly composed of sludge ash.   The magnesia-based binder and paper sludge ash according to any one of claims 1 to 3, wherein an appropriate amount of sodium silicate or acrylic resin is mixed in order to increase compressive strength before water curing. Method for producing a solid. A solid body formed by mixing magnesia-based binder and paper sludge ash, and water-curing them.
The binder has a predetermined proportion of magnesium oxide, magnesium sulfate, and magnesium chloride, and contains 0.7 to 1.5 times as much paper sludge ash as the total mass of the binder. A solid body mainly composed of a magnesia-based binder and paper sludge ash characterized by satisfying at least one of (i) and (ii).
(I) The solid body has a specific gravity of 1.70 or less and a compressive strength of 10 N / mm 2 or more.
(Ii) The elution amount of fluorine and the compound thereof in the solid body is less than 0.8 mg / L.   The ratio of magnesium oxide, magnesium sulfate and magnesium chloride is 50% or less of magnesium oxide, 2.5% or more and less than 40% of magnesium sulfate, and 10% of magnesium chloride with respect to the total mass of the binder. A solid body mainly composed of the magnesia-based binder according to claim 5 and paper sludge ash.   The magnesia-based binder according to claim 5 or 6, wherein when satisfying the above (ii), the binder is replaced with blast furnace cement within a range in which the elution amount of fluorine and a compound thereof is less than 0.8 mg / L. And a solid body consisting mainly of paper sludge ash.   The magnesia-based binder according to any one of claims 5 to 7 and paper sludge ash mainly mixed with an appropriate amount of sodium silicate or acrylic resin to increase the compressive strength before water curing. Solid material.   A solid body mainly composed of a magnesia-based binder and paper sludge ash according to any one of claims 5 to 8, wherein the outer shape is formed into a spherical shape, a columnar shape, a cylindrical shape, or a plate shape.   The magnesia-based binder and paper sludge according to any one of claims 5 to 9, wherein an appropriate microbial agent is mixed before water curing, or an appropriate microbial agent is attached to the surface of the solid body. Solid body mainly made of ash.   The magnesia-based binder and the solid body described in claim 9 or 10 are mixed, or the magnesia-based binder, paper sludge ash and the solid body described in claim 9 or 10 are mixed, and then A method for producing a solid body, characterized by water curing.   The method for producing a solid body according to claim 11, wherein an appropriate pH adjusting agent and / or an appropriate microbial agent is mixed before water curing.   If the elution amount of solid fluorine and its compound is less than 0.8 mg / L, replace the magnesia-based binder with blast furnace cement within the range where the elution amount of fluorine and its compound is less than 0.8 mg / L. The manufacturing method of the solid body of Claim 11 or 12. The manufacturing method of the solid body in any one of Claim 11 to 13 shape | molded so that an external shape may be spherical shape, columnar shape, cylinder shape, plate shape, or a cross section may become T shape, L shape, or U shape.

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