JP3559905B2 - Environmental purification type inorganic material - Google Patents

Description

【００４０】
（１） 試験体の調製
上記各処方からなる組成物を、練り混ぜ機を用いて３分間練りまぜて、成形型枠に突き詰めて湿気箱中に静置した。２４〜７２時間経過後、成型物を型枠から取り外し、破砕して１０〜２０メッシュの試験体（破砕物）（Ｎｏ．１〜Ｎｏ．９）を調製した。
【００４１】
（２） リン吸着能の測定
上記で調製した試験体（Ｎｏ．１〜Ｎｏ．９）についてリン吸着能を測定した。リン吸着能の測定は、具体的には、各試験体０．２ｇを、塩酸にて約ｐＨ７に調整したリン濃度２６．７ｍＭ−Ｐ Ｎａ_２ＨＰＯ_４水溶液 ２０ｍＬ中にいれて、３０℃にて２４時間横振り振盪（１７０回／分）し、その後該水溶液から試験体を濾別して、濾液中のリン酸イオン濃度をモリブデンブルー法にて定量することによって行った。試験体のリン酸イオン吸着量は、水溶液のリン酸イオンの初期濃度と吸着平衡後の濾液中の残存濃度との差から、試験体１ｇ当たりの吸着量として算出した。結果を図１に示す。
【００４２】
尚、図１中、セメントの重量割合とは、複合金属水酸化物と高炉セメントの総量１００重量部に対する高炉セメントの重量割合を意味する。
【００４３】
実施例２ セメントの種類と強度発現の特性
表２に示す処方からなる環境浄化型無機質材用組成物（Ｎｏ．１０〜Ｎｏ．１２）に骨材２００重量部と水６０重量部を配合して試験体を作成した。具体的には、まず上記混合物を練り混ぜ機を用いて３分間練りまぜて、鋼製の成形型枠に２回にわけて突き硬めながら詰め、５時間以上経過した後、型の上から盛り上げを削り取り、湿気箱中に静置した。２４時間経過後、成形物を型枠から取り外し、水中に完全に浸漬し、さらに２８日間養生を行って試験体（Ｎｏ．１０〜Ｎｏ．１２）を調製した。
【００４４】
【表２】

【００４５】
（１） 強度試験（圧縮強度試験）
上記の試験体（環境浄化型無機質材）Ｎｏ．１０及びＮｏ．１１について、ＪＩＳ Ｒ ５２０１−１９９２の「セメントの物理試験方法」１０．強さ試験の規定に従って、強度（圧縮強度）を測定した。
【００４６】
具体的には曲げ強度試験はＪＩＳ Ｒ ５２０１−１９９２「セメントの物理試験方法」１０．強さの試験に規定されているミハエリス二重てこ型曲げ強さ試験機を用いて、支点間の距離を１００ｍｍとして試験体の中央部に毎秒５ｋｇｆ（４９Ｎ）の割合で載荷し、最大荷重を求めることによって実施した。また、圧縮強度試験はＪＩＳ Ｒ ５２０１「セメントの物理試験方法」１０．強さの試験に規定されている圧縮試験装置を用いて、供試体中央部に（４０±０．１ｍｍ）^２の範囲で、毎秒８０ｋｇｆ（７８５Ｎ）の割合で載荷し、最大荷重を求めることをによって実施した。圧縮強度試験の結果を表３に示す。
【００４７】
【表３】

【００４８】
結果からわかるように、本発明の環境浄化型無機質材Ｎｏ．１０及びＮｏ．１１はいずれも強度においてＪＩＳ Ｒ ５２１１規定の基準と遜色がないか、または該基準を十分に満たすものであった。
【００４９】
（２） リン吸着能の測定
調製した環境浄化型無機質材のうち、Ｎｏ．１１とＮｏ．１２（２８日養生後）をさらに破砕して、破砕状（粒径：１０〜２０メッシュ）とした。調製した破砕状環境浄化型無機質材（Ｎｏ．１１、Ｎｏ．１２）を試験体として、下記の方法に従ってそのリン吸着能を測定した。
【００５０】
＜リン吸着能測定＞
塩酸にて約ｐＨ７に調整した２６．７ｍＭ−Ｐ Ｎａ_２ＨＰＯ_４水溶液２０ｍｌに上記破砕状の無機質材（試験体）を約０．２ｇ添加し、横振り振盪器で振盪する（３０℃、１７０ｒｐｍ×２４ｈ）。振盪後、上澄み液を限外濾過膜（ミリポアー、０．４５μｍ）を用いてろ過し、濾液中のリン酸イオン濃度を分光光度計（波長６６０ｎｍ）により定量する。試験体のリン酸イオン吸着量は、実施例１と同様に水溶液のリン酸イオンの初期濃度と回収した濾液中の残存濃度との差から、試験体１ｇ当たりの吸着量として算出した。結果を表４に示す。なお、その結果から換算した、試験体中に含まれる複合金属水酸化物１ｇあたりのリン酸イオン吸着量（ｍｍｏｌ／ｇ）を併せて示す。
【００５１】
【表４】

【００５２】
結果からわかるように、試験体Ｎｏ．１１及びＮｏ．１２はいずれも、リン吸着能目標値１．６ｍｍｏｌ／ｇの８割以上を超え、優れたリン吸着能を備えていた。また、この結果から、水硬性無機質材料として高炉セメントを用いることによってより高いリン酸イオン吸着能が得られることがわかる。この理由として、高炉セメントの場合には、試験体中のアルカリ量が少ないため炭酸ガスの吸収量が少なく、複合金属水酸化物の吸着能を高く保っていられることを挙げることができる。
【００５３】
実施例３
下式：
Ｍｇ^２＋ _{０．６６５}Ａｌ^３＋ _{０．３１７}（ＯＨ⁻）_{２．０３３}Ｃｌ⁻ _{０．２３８}（ＣＯ_３ ^２−）_{０．０２３}
で示される複合金属水酸化物に表５に記載する割合（重量比）で水硬性無機質材料（セメント）を配合した環境浄化型無機質材用組成物（Ｎｏ．１３〜１８）を用いて、実施例１に記載の方法に従って破砕物（粒径：１０〜２０メッシュ）を調製した。調製した破砕物（Ｎｏ．１３〜Ｎｏ．１８）を試験体として、下記の方法により耐破砕強度とリン吸着能を測定した。
【００５４】
【表５】

【００５５】
（１） 耐破砕強度の測定
試験体を約０．２ｇ精秤した後、共栓付きの３０ｍｌ容三角フラスコに移し、水２０ｍｌを入れ、横振り振盪機で振盪する（３０℃、１７０ｒｐｍ×２４ｈ）。振盪後、メンブランフィルター（０．８μｍ）を用いて、吸引ろ過し、４０℃で２４時間乾燥する。乾燥後、サンプル重量を測定した後、２０メッシュの篩いで整粒し、２０メッシュ通過品の重量を測定し、２０メッシュの篩いの残留分（重量％）から耐破砕強度を評価する。
【００５６】
（２） リン吸着能の測定
実施例２に記載する方法に従って試験体（Ｎｏ．１３〜Ｎｏ．１８）のリン吸着量を測定した。結果を表６に示す。なお、リン吸着能については、試験体中に含まれる複合金属水酸化物１ｇあたりのリン酸イオン吸着量（ｍｍｏｌ／ｇ）の換算値も併せて示す。
【００５７】
【表６】

【００５８】
結果からわかるように、水硬性無機質材料として早強セメントを用いることによって、調製された破砕物（試験体Ｎｏ．１３〜１６）はリン吸着能目標値１．６ｍｍｏｌ／ｇの約７．５割以上のリン吸着能を備え、また耐破砕強度目標値である９５重量％（残留分）を十分に超えることが可能であった。
【００５９】
実施例４
（１）試験体の調製
下式：
Ｍｇ^２＋ _{０．６６５}Ａｌ^３＋ _{０．３１７}（ＯＨ⁻）_{２．０３３}Ｃｌ⁻ _{０．２３８}（ＣＯ_３ ^２−）_{０．０２３}
で示される複合金属水酸化物１００重量部に対して、ポルトランドセメント１００重量部に対して微粉砕高炉スラグ（比表面積６０００ｇ／ｍ^２）を１００重量部配合して環境浄化型無機質材用組成物を調製した。この環境浄化型無機質材用組成物に、骨材３７５重量部、水４６重量部を配合し混合した後、φ１０×１０の大きさに充填率約７５％で充填し、１４日間水中養生を行って試験体を調製した。
【００６０】
（２） リン吸着能の測定
上記で調製した試験体についてリン吸着能を測定した。リン吸着能の測定は、具体的には、試験体を、塩酸にて約ｐＨ７に調整したリン濃度２６．７ｍＭ−Ｐ Ｎａ_２ＨＰＯ_４水溶液中にいれて、４８時間静置した。所定の時間経過後、該水溶液から試験体を濾別して濾液中のリン酸イオン濃度をモリブデンブルー法にて定量した。また、同時にｐＨメーターを用いて該溶液のｐＨを測定し、リン吸着能に対するｐＨの影響を調べた。
【００６１】
結果を図２に示す。図２からわかるように、溶液のｐＨの上昇に伴って水溶液中のリン濃度が低下しており、このことからｐＨが高くなってもリン酸イオンの放出は認められず、リン吸着能が維持されていることが明らかになった。従って、本発明の無機質材はセメントやコンクリート調製物などの高ｐＨ環境下でもリン吸着能を発揮し、また一旦吸着したリン酸イオンは、セメントやコンクリート調製物などの高ｐＨ環境下で最放出しないことが判明した。
【００６２】
【発明の効果】
本発明によれば、本来有害物質を含まずまた再生容易な低環境負荷材料である無機質材にリン酸イオン吸着能を付与することによって、所望のリン酸イオン吸着能を発揮する環境浄化型の無機質材を提供することができる。本発明の環境浄化型無機質材は各種用途に応じた強度を備えているため、当該無機質材によれば従来より使用されている公知用途に環境浄化という有用な機能を付加することができる。
【００６３】
さらには、本発明の無機質材は、高ｐＨ条件下でも吸着したリン酸イオンを放出しないため、リン吸着後の環境浄化型無機質材は再生骨材等の土木・建築用資材として再資源化利用することが可能である。
【図面の簡単な説明】
【図１】セメント含有量とリン吸着量との関係を示す図である（実施例１）。
【図２】ｐＨとリン吸着能との関係を示す図である（実施例５）。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inorganic material having an ability to adsorb phosphate ions in a solution as an environmental purification ability.
[0002]
[Prior art]
Regarding the eutrophication of lakes and marshes, removal of phosphorus and nitrogen as nutrient sources of algae, micro-organisms and the like has become a major problem. In recent years, revetment works for rivers and the like have been switched to natural construction methods, and interest in environmental purification has been increasing.
[0003]
In order to solve such problems as eutrophication of lakes and marshes, it is necessary to remove phosphorus and nitrogen which cause the problem.
[0004]
Current measures include a method of spreading reed fields in lakes and marshes, etc., and in many cases, a purification method using living organisms. Specifically, as a method of removing nitrogen from lake water, there is a method of finally diffusing into the air as nitrogen gas etc. by the action of microorganisms, but phosphorus does not gasify like nitrogen It is necessary to remove the organisms that have accumulated phosphorus.
[0005]
On the other hand, in revetment works using natural construction methods, how to grow plants as quickly as possible remains an issue. Furthermore, when phosphorus is adsorbed and removed by the adsorbent, the adsorbent itself that has adsorbed phosphorus becomes waste and the method of treating it remains a problem.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide an inorganic material which itself has an environmental purification function by imparting a phosphate ion-adsorbing ability to a hydraulic inorganic material such as cement. More specifically, the present invention covers both inorganic materials that are constructed on site (wet construction products) and those that are pre-molded and manufactured in a factory (dry construction products), and are used in accordance with various applications. It is an object of the present invention to provide an inorganic material having high strength and phosphate ion adsorption ability.
[0007]
Further, another object of the present invention is to provide an inorganic material which hardly contains harmful substances and organic substances and is easy to recycle. More specifically, the present invention is an environment-purifying inorganic material having a low environmental load composed of inorganic materials and having a phosphate ion-adsorbing ability, and after phosphorus adsorption, is used as a material for civil engineering and construction such as recycled aggregate. Another object of the present invention is to provide an inorganic material that can be reused as a substrate for supplying phosphorus to plants.
[0008]
[Means for Solving the Problems]
The present inventors have been conducting diligent studies day and night with the aim of achieving the above-mentioned object, and provided a desired phosphate ion-adsorbing ability by combining a hydraulic inorganic material such as cement, a composite metal hydroxide and a filler. It was found that an environmentally purified inorganic material could be prepared. Furthermore, the present inventors can appropriately adjust the type of the hydraulic inorganic material and the amounts of the composite metal hydroxide and the filler to be blended with the material to obtain a desired phosphate ion adsorption while having strength corresponding to various applications. It has been found that an inorganic material having a function can be prepared, and thereby, it is possible to impart an environmental purification function of phosphate ion adsorption ability to a conventionally used inorganic material of a known use, and by providing such a new function, It was confirmed that the use of inorganic materials, which do not contain harmful substances and are easily recyclable and low in environmental load, can be further expanded. Furthermore, the present inventors have found that the above-mentioned inorganic material does not decrease its phosphate ion-adsorbing ability even under high pH conditions, so that it can be prepared as a cement or concrete preparation. It was confirmed that it could be used as a material.
[0009]
The present invention has been completed based on such findings.
[0010]
That is, the present invention is an environmental purification type inorganic material listed below:
Item 1. An environment-purifying inorganic material containing a composite metal hydroxide, a hydraulic inorganic material and a filler.
Item 2. Item 2. The environment-purifying inorganic material according to Item 1, wherein the hydraulic inorganic material is cement.
Item 3. Item 3. The environment-purifying inorganic material according to Item 1 or 2, comprising 2 to 900 parts by weight of the hydraulic inorganic material and 2 to 9000 parts by weight of the filler with respect to 100 parts by weight of the composite metal hydroxide.
Item 4. Item 4. The environment-purifying inorganic material according to any one of Items 1 to 3, wherein phosphorus is adsorbed.
[0011]
The environment-purifying inorganic material of the present invention only needs to include at least a composite metal hydroxide, a hydraulic inorganic material and a filler, and the form thereof is not particularly limited. For example, a powder containing the above three components, a paste prepared by further adding water thereto, and a dried or solidified pellet formed into a pellet or other desired shape are all included. Is done. Further, the molded product may be either one that is constructed on site (wet construction product) or one that is manufactured in advance in a factory or the like (dry construction product).
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The composite metal hydroxide used in the present invention has the chemical composition formula (1)
M_1-x ²⁺M_x ³⁺(OH⁻)_{2 + xy}(A_n ⁻)_{y / n}      (1)
[Where M²⁺Is Mg²⁺, Ni²⁺, Zn²⁺, Fe²⁺, Ca²⁺And Cu²⁺At least one divalent metal ion selected from the group consisting of³⁺Is Al³⁺And Fe³⁺At least one trivalent metal ion selected from the group consisting of^n-Represents an n-valent anion. Further, x is a positive number satisfying 0.1 ≦ x ≦ 0.5, y is a positive number satisfying 0.1 ≦ y ≦ 0.5, and n is 1 or 2. ]
Is represented by
[0013]
Where M²⁺As the divalent metal ion represented by²⁺, Ni²⁺, Zn²⁺, Fe²⁺, Ca²⁺, Cu²⁺Etc., but preferably Mg²⁺, Ca²⁺It is. M³⁺As the trivalent metal ion represented by³⁺, Fe³⁺But preferably Al³⁺It is.
[0014]
A^n-Represents an n-valent anion (n = 1 or 2). That is, A^n-Is composed of only a monovalent or divalent anion, or contains both a monovalent anion and a divalent anion. However, the divalent anion is preferably smaller in molar ratio than the monovalent anion. Examples of the monovalent anion include OH⁻, Cl⁻, NO₂ ⁻, NO₃ ⁻, F⁻, Br⁻, HCO₃ ⁻Etc. can be exemplified. Preferably Cl⁻It is. As the divalent anion, for example, SO₄ ^2-, CO₃ ^2-, SO₃ ^2-Etc., but preferably CO 2₃ ^2-It is.
[0015]
x is usually 0.1 ≦ x ≦ 0.5, preferably 0.2 ≦ x ≦ 0.4, and more preferably 0.2 ≦ x ≦ 0.35.
[0016]
y is usually 0.1 ≦ y ≦ 0.5, preferably 0.2 ≦ y ≦ 0.4, more preferably 0.2 ≦ y ≦ 0.35.
[0017]
In the compound of the general formula (1) of the present invention, the divalent metal ion M²⁺And trivalent metal ion M³⁺Is a value measured by a titration method. In addition, n-valent anion A^n-Is a value measured by a titration method when it is a carbonate ion, Cl⁻If it is an ion, the value measured by an ion meter equipped with a chloride ion selective electrode, carbonate ion and Cl⁻NO excluding ions₂ ⁻, NO₃ ⁻, F⁻, Br⁻, HCO₃ ⁻Monovalent anions and SO₄ ^2-, SO₃ ^2-In the case of a divalent anion such as, for example, a value measured by ion chromatography. The value of “y” for the divalent anion is represented by the number of moles measured by the above method as A^2-Is the value expressed as Hydroxide ion OH⁻Is M²⁺, M³⁺And A^n-Is a value obtained by calculation from the electrical neutral condition based on the measured value of.
[0018]
In the composite metal hydroxide, (A^n-NO) as a monovalent anion₂ ⁻, NO₃ ⁻Halogen ions except (Cl⁻, F⁻, Br⁻) And hydroxide ion OH⁻Can also be used. In this case, since not only the adsorption of the phosphorus component but also the adsorption of the nitrogen component can be carried out, it is useful for removing the phosphorus component and the nitrogen component which are often contained in eutrophic lakes and drains. In this case, due to environmental problems, in particular, Cl⁻Is preferred.
[0019]
These composite metal hydroxides may be used singly, or two or more composite metal hydroxides prepared by combining the above ions may be arbitrarily mixed and used.
[0020]
The above-mentioned composite metal hydroxide can be generally prepared by reacting a divalent metal salt and a trivalent metal salt as raw materials in an alkaline environment. A method for producing such a composite metal hydroxide is known and can be prepared, for example, according to the description of Langmuir, 9, 1418-1422 (1993). In addition, these composite metal hydroxides are commercially available, and such composite metal hydroxides can be used simply.
[0021]
The shape of the composite metal hydroxide used in the present invention is not particularly limited, but usually includes powder and particles. Examples of the size include a powder having an average particle diameter of 10 μm or less (by a laser diffraction measurement method) and a particle having an average particle diameter of about 10 to 200 μm, but are not limited thereto. Absent.
[0022]
In the present invention, the hydraulic inorganic material broadly includes a material having a so-called water-hardening property (a hydraulic component) which itself reacts with water to condense or harden, and specifically includes cement, water, and the like. Examples thereof include hard coal, hydraulic pozzolan, silica, and gypsum (calcium sulfate). These can be used alone or in combination of two or more. Preferred are cement and gypsum, and more preferred is cement.
[0023]
The cement is not particularly limited as long as it is a hydraulic cement, and various kinds of silicate calcareous cement (for example, ordinary Portland cement, early-strength Portland cement, moderately heated Portland cement, sulfate-resistant Portland cement or white Portland cement, etc.) Portland cement; mixed cement such as blast furnace cement, silica cement or fly ash cement), calcareous aluminate cement, calcareous aluminate silicate cement, phosphate cement and the like are widely included. Preferred are calcareous silicate cement, calcareous aluminate cement and calcareous aluminate silicate, more preferably early-strength Portland cement and blast furnace cement. According to JIS R 5211, blast furnace cement has a slag amount of more than 5% and less than 30%, Class A, a slag amount of more than 30% and less than 60%, and a slag amount of more than 60% and less than 70%. Of the C species are included, and it does not matter whether the species is C or not. Preferably, it is a type B blast furnace cement.
[0024]
The gypsum may have hydration-hardening properties by itself or may be hydrate-hardening properties when used in combination with an auxiliary agent such as a coagulant or a setting accelerator. Water gypsum (α, β) and type II anhydrous gypsum can be mentioned. As the coagulant or coagulation accelerator used here, those having an action of assisting or enhancing the hydration hardening of calcium sulfate, which is a component of gypsum, can be widely mentioned, for example, potassium sulfate, alum, Examples include fine powder of gypsum dihydrate and organic acids such as oxalic acid.
[0025]
In the present invention, as the filler, aggregate commonly used in the field of cement and concrete can be widely used. For example, natural aggregates such as silica sand, cold water sand, river sand, etc .; colored aggregates such as ceramic pieces and glass grains; lightweight aggregates such as perlite, vermiculite and shirasu spheres; And artificial aggregates such as wood. However, the present invention is not limited thereto, and an aggregate equivalent having the same function as the aggregate can be used. These aggregates may be used alone or in any combination of two or more.
[0026]
The compounding ratio of the composite metal hydroxide, the hydraulic inorganic material and the filler varies depending on the type of the inorganic material to be prepared and its use and cannot be specified unconditionally.For example, the hydraulic inorganic material is a composite metal water. It can be appropriately selected from the range of 2 to 900 parts by weight, preferably 5 to 600 parts by weight, more preferably 5 to 400 parts by weight based on 100 parts by weight of the oxide. It can be appropriately selected from the range of 2 to 9000 parts by weight, preferably 3 to 8000 parts by weight, more preferably 3 to 6000 parts by weight, based on 100 parts by weight of the product.
[0027]
More specifically, for example, when the inorganic material of the present invention is a molded product manufactured in advance in a factory or the like, the ratio of the hydraulic inorganic material to be blended with respect to 100 parts by weight of the composite metal hydroxide is 2 to 2. 100 parts by weight, preferably from 5 to 100 parts by weight, more preferably from 5 to 50 parts by weight, and the amount of the filler compounded with respect to 100 parts by weight of the mixture of the composite metal hydroxide and the hydraulic inorganic material. The ratio may be in the range of 20 to 900 parts by weight, preferably 30 to 800 parts by weight, more preferably 30 to 600 parts by weight. By using the composite metal hydroxide, the hydraulic inorganic material and the filler at such a ratio, it is possible to prepare an inorganic material exhibiting a strong phosphate ion-adsorbing ability with a small amount while having appropriate strength. Such an inorganic material can be used for applications requiring higher phosphate ion adsorbability than strength, such as a filter material for adsorbing and removing phosphate ions (granular, plate-like or And the like). When the phosphorus adsorption capacity is emphasized as in the case of the above-mentioned filter material, the environmental purification type inorganic material of the present invention is prepared by using a hydraulic inorganic material which expresses strength early, such as early-strength Portland cement. Is preferred.
[0028]
In addition, when preparing an inorganic material requiring strength, such as a cement preparation (wet construction product, dry construction product) such as concrete or mortar, it is preferable to use a relatively large amount of hydraulic inorganic material. For example, in the case of concrete, in order to obtain the same strength as that of a conventional concrete preparation, the proportion of the hydraulic inorganic material (cement) to be mixed with 100 parts by weight of the composite metal hydroxide is preferably 50 to 900 parts by weight, preferably. Is 100 to 400 parts by weight, more preferably 200 to 400 parts by weight, and 100 to 900 parts by weight of a filler to be mixed with 100 parts by weight of the mixture of the composite metal hydroxide and the hydraulic inorganic material. The range may be exemplified by parts by weight, preferably 150 to 500 parts by weight, more preferably 200 to 400 parts by weight. In the case of mortar, in order to obtain the same strength as a conventional mortar preparation, 40 to 900 parts by weight of a hydraulic inorganic material (cement) to be mixed with 100 parts by weight of a composite metal hydroxide, Preferably, the content is in the range of 100 to 700 parts by weight, more preferably 300 to 600 parts by weight, and the proportion of the filler to be added to 100 parts by weight of the mixture of the composite metal hydroxide and the hydraulic inorganic material is 20 to 100 parts by weight. A range of 500 parts by weight, preferably 30 to 300 parts by weight, more preferably 30 to 200 parts by weight can be exemplified. By using the composite metal hydroxide, hydraulic inorganic material and filler at such a ratio, phosphate ion adsorption capacity, which is an environmental purification function, is newly added while maintaining the strength required for conventional concrete and mortar preparations. An environmental purification type inorganic material can be prepared. The above concrete and mortar preparations include, for example, wet construction products such as ready-mixed concrete and premixed mortar used for retaining walls of seawalls, environmentally-friendly river products (large blocks, etc.), and fish reef products (general Fish and algae reefs), water and sewage products (manhole reinforced concrete pipes, etc.), civil engineering building blocks, agricultural water products, agricultural drainage products, road gutters (JIS and JIS outer gutters, etc.), retaining wall products, Includes dry construction products such as box culvert products, storage tanks, fire prevention water tanks, landscape products (such as interlocking blocks), products for greening and planting (such as products using porous concrete), and filter media used for filter beds in purification facilities. You.
[0029]
As the hydraulic inorganic material used for the concrete or mortar preparation, a material having excellent long-term strength such as blast furnace cement is preferable.
[0030]
In addition, the environment-purifying inorganic material of the present invention can be prepared by blending an admixture, an admixture or a polymer admixture generally used in the art, if necessary.
[0031]
Here, as the admixture, admixtures commonly used in cement can be widely used, and specific examples include fly ash, silica fume, pozzolan, blast furnace slag, siliceous fine powder, and mineral powder. it can.
[0032]
Examples of the admixture include an AE agent, a water reducing agent, an AE water reducing agent, a water reducing accelerator, a water reducing retarder, an accelerator, a retarder, a quick-setting agent, a waterproofing agent, a foaming agent, a foaming agent, a water retaining agent, an adhesive, Waterproofing agents can be exemplified. These admixtures can be arbitrarily used without limitation as long as they are included in the above-mentioned category. For example, as the AE agent, an anionic, nonionic, cationic or zwitterionic AE agent can be arbitrarily used, but a nonionic AE agent is preferred. As the water reducing agent, a lignin sulfonate type, a higher polyhydric alcohol sulfonate type, an oxyorganic acid, an alkyl allyl sulfonate, a polyoxyethylene alkyl ether or a polyol complex water reducing agent may optionally be used. But preferably a polyol complex.
[0033]
The polymer admixture may be compounded in a powder form or in a liquid form. Here, specific examples of the polymer admixture include an aqueous polymer dispersion and a water-soluble polymer. Specifically, rubber latex, acrylic emulsion, acrylic styrene emulsion, ethylene vinyl acetate emulsion, styrene butadiene rubber latex, epoxy resin emulsion, mixed latex, mixed emulsion, polyvinyl alcohol, polyacrylate, melamine and the like can be exemplified.
[0034]
The environment-purifying inorganic material of the present invention may be prepared as a powder by simply mixing the above-mentioned composite metal hydroxide, hydraulic inorganic material and filler, and, if necessary, the above-mentioned optional components. May be further mixed with water to prepare a paste, or the hydrate may be dried and solidified to form a desired shape.
[0035]
The thus obtained environment-purifying inorganic material of the present invention, for example, when prepared using cement as a hydraulic inorganic material, includes cement mortar, concrete, and various other cement preparations containing cement as components (fresh concrete, Premixed mortar, dry-processed product, wet-processed product).
[0036]
The environment-purifying inorganic material of the present invention, as described above, adsorbs phosphorus based on its phosphate ion adsorption ability, and after phosphorus adsorption, under specific conditions based on the ion exchange capacity of the composite metal hydroxide. Since phosphorus can be released, it can be used as a source of phosphorus. Such phosphorus is useful as a nutrient source for plants. In addition, since the adsorption capacity of phosphorus is not affected by the level of pH, it can be recycled and used as civil engineering and building materials such as recycled aggregate.
[0037]
The present invention includes the following embodiments:
(1) An environment-purifying inorganic material containing a composite metal hydroxide, a hydraulic inorganic material, and a filler.
(2) The environment-purifying inorganic material according to (1), wherein the hydraulic inorganic material is cement.
(3) The environmental purification according to (1) or (2), wherein the content of the hydraulic inorganic material is 2 to 900 parts by weight and the filler is 2 to 9000 parts by weight based on 100 parts by weight of the composite metal hydroxide. Type inorganic material.
(4) The environmental purification according to (1) or (2), wherein the amount of the hydraulic inorganic material is 2 to 100 parts by weight and the amount of the filler is 20 to 900 parts by weight based on 100 parts by weight of the composite metal hydroxide. Type inorganic material.
(5) The environment-purifying inorganic material according to (4), wherein the hydraulic inorganic material is an early-strength Portland cement.
(6) The environment-purifying inorganic material according to (3), (4) or (5), which is a molded product having a predetermined shape.
(7) The environment-purifying inorganic material according to (6), which is used as a filtering material.
(8) The environmental purification according to (1) or (2), wherein the amount of the hydraulic inorganic material is 50 to 900 parts by weight and the amount of the filler is 100 to 900 parts by weight based on 100 parts by weight of the composite metal hydroxide. Type inorganic material.
(9) The environmental purification according to (1) or (2), wherein the hydraulic inorganic material is contained in a proportion of 40 to 900 parts by weight and a filler is contained in a proportion of 20 to 500 parts by weight based on 100 parts by weight of the composite metal hydroxide. Type inorganic material.
(10) The environment-purifying inorganic material according to (8) or (9), wherein the hydraulic inorganic material is blast furnace cement.
(11) The environment-purifying inorganic material according to any one of (8) to (10), which is used as ready-mixed concrete or premix mortar.
(12) The environment-purifying inorganic material according to any one of (1) to (11) above, which adsorbs phosphorus.
(13) The environment-purifying inorganic material according to (12), which is used as a phosphorus supply source.
(14) The environment-purifying inorganic material according to (12), which is used as a civil engineering or building material such as recycled aggregate.
(15) A mortar or concrete prepared using the environment-purifying inorganic material according to (12) as a material.
[0038]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Experimental Examples and Examples, but the present invention is not limited to the Examples.
Example 1  Relationship between cement content and phosphorus adsorption
The following formula:
Mg²⁺ _0.665Al³⁺ _0.317(OH⁻)_2.033Cl⁻ _0.238(CO₃ ^2-)_0.023
, A finely ground blast furnace slag (specific surface area: 6000 g / m2) with respect to 100 parts by weight of Portland cement.²) Was blended at a ratio (weight ratio) shown in Table 1 to prepare blast furnace cements prepared by blending 100 parts by weight), to prepare compositions for environmental purification type inorganic material to be tested (No. 1 to No. 9). Specifically, test specimens were prepared according to the following preparation method.
[0039]
[Table 1]

[0040]
(1) Preparation of test specimen
The composition composed of each of the above formulations was kneaded for 3 minutes using a kneading machine, pressed into a mold, and allowed to stand in a moisture box. After a lapse of 24 to 72 hours, the molded product was removed from the mold and crushed to prepare 10 to 20 mesh test pieces (crushed products) (No. 1 to No. 9).
[0041]
(2) Measurement of phosphorus adsorption capacity
The test pieces (No. 1 to No. 9) prepared as described above were measured for phosphorus adsorption ability. Specifically, the phosphorus adsorption capacity was measured by measuring 0.2 g of each specimen to about pH 7 with hydrochloric acid at a phosphorus concentration of 26.7 mM-P Na.₂HPO₄Place in 20 mL of an aqueous solution, shake horizontally (170 times / minute) at 30 ° C. for 24 hours, and then filter the specimen from the aqueous solution, and determine the phosphate ion concentration in the filtrate by a molybdenum blue method. Made by. The phosphate ion adsorption amount of the test specimen was calculated as the adsorption amount per 1 g of the test specimen from the difference between the initial concentration of the phosphate ion in the aqueous solution and the residual concentration in the filtrate after the adsorption equilibrium. The results are shown in FIG.
[0042]
In FIG. 1, the weight ratio of the cement means the weight ratio of the blast furnace cement to the total amount of the composite metal hydroxide and the blast furnace cement of 100 parts by weight.
[0043]
Example 2      Types of cement and characteristics of strength development
Specimens were prepared by blending 200 parts by weight of aggregate and 60 parts by weight of water with the composition for environmental purification type inorganic material (No. 10 to No. 12) having the formulation shown in Table 2. Specifically, first, the above mixture is kneaded with a kneading machine for 3 minutes, packed in a steel forming mold twice while being pressed and hardened, and after elapse of 5 hours or more, is raised from the mold. Was scraped off and left in a moisture box. After a lapse of 24 hours, the molded product was removed from the mold, completely immersed in water, and further cured for 28 days to prepare test specimens (No. 10 to No. 12).
[0044]
[Table 2]

[0045]
(1) Strength test (compression strength test)
The test piece (environmental purification type inorganic material) No. 10 and No. Regarding No. 11, JIS R 5201-1992 “Physical test method of cement” The strength (compression strength) was measured according to the rules of the strength test.
[0046]
Specifically, the bending strength test is described in JIS R 5201-1992 “Physical test method for cement”. Using the Michaelis double lever type bending strength tester specified in the strength test, the distance between the fulcrums was set to 100 mm, and the sample was loaded at the center of the test specimen at a rate of 5 kgf (49 N) per second. Performed by asking. The compressive strength test was conducted according to JIS R 5201 “Physical test method for cement”. Using a compression tester specified in the strength test, place (40 ± 0.1 mm)²In the range of 80 kgf (785 N) per second, and the maximum load was determined. Table 3 shows the results of the compression strength test.
[0047]
[Table 3]

[0048]
As can be seen from the results, the environment-purifying inorganic material No. of the present invention. 10 and No. No. 11 was inferior to the standard of JIS R 5211 in strength or sufficiently satisfied the standard.
[0049]
(2) Measurement of phosphorus adsorption capacity
Among the prepared environment-purifying inorganic materials, No. 11 and No. 12 (after curing for 28 days) was further crushed to a crushed shape (particle size: 10 to 20 mesh). Using the prepared crushed environment-purifying inorganic materials (No. 11 and No. 12) as test specimens, the phosphorus adsorption ability was measured according to the following method.
[0050]
<Phosphorus adsorption ability measurement>
26.7 mM-P Na adjusted to about pH 7 with hydrochloric acid₂HPO₄About 0.2 g of the above crushed inorganic material (test body) is added to 20 ml of the aqueous solution, and shaken with a horizontal shaker (30 ° C., 170 rpm × 24 h). After shaking, the supernatant is filtered using an ultrafiltration membrane (Millipore, 0.45 μm), and the phosphate ion concentration in the filtrate is quantified using a spectrophotometer (wavelength 660 nm). The phosphate ion adsorption amount of the test specimen was calculated as the adsorption amount per 1 g of the test specimen from the difference between the initial concentration of the phosphate ion in the aqueous solution and the residual concentration in the recovered filtrate as in Example 1. Table 4 shows the results. In addition, the phosphate ion adsorption amount (mmol / g) per 1 g of the composite metal hydroxide contained in the test sample, which is converted from the result, is also shown.
[0051]
[Table 4]

[0052]
As can be seen from the results, the test pieces No. 11 and No. Each of the samples No. 12 had an excellent phosphorus adsorption ability exceeding 80% or more of the target value of the phosphorus adsorption ability of 1.6 mmol / g. In addition, it can be seen from the results that a higher phosphate ion adsorption ability can be obtained by using blast furnace cement as the hydraulic inorganic material. This is because, in the case of blast furnace cement, the amount of carbon dioxide gas absorbed is small because the amount of alkali in the specimen is small, and the ability to adsorb composite metal hydroxide can be kept high.
[0053]
Example 3
The following formula:
Mg²⁺ _0.665Al³⁺ _0.317(OH⁻)_2.033Cl⁻ _0.238(CO₃ ^2-)_0.023
Using a composition (No. 13 to 18) for an environmental purification type inorganic material in which a hydraulic inorganic material (cement) is blended with a composite metal hydroxide represented by the following formula (weight ratio) in the ratio (weight ratio) shown in Table 5. A crushed product (particle size: 10 to 20 mesh) was prepared according to the method described in Example 1. Using the prepared crushed materials (No. 13 to No. 18) as test specimens, crushing strength and phosphorus adsorption ability were measured by the following methods.
[0054]
[Table 5]

[0055]
(1) Measurement of crushing strength
After precisely weighing about 0.2 g of the test body, it is transferred to a 30 ml Erlenmeyer flask equipped with a stopper and filled with 20 ml of water, and shaken with a horizontal shaker (30 ° C., 170 rpm × 24 h). After shaking, suction filtration is performed using a membrane filter (0.8 μm), and drying is performed at 40 ° C. for 24 hours. After drying, the weight of the sample is measured, sized with a 20-mesh sieve, the weight of the product passing through the 20-mesh is measured, and the crushing strength is evaluated from the residue (% by weight) of the 20-mesh sieve.
[0056]
(2) Measurement of phosphorus adsorption capacity
According to the method described in Example 2, the phosphorus adsorption amount of the test specimens (No. 13 to No. 18) was measured. Table 6 shows the results. In addition, about the phosphorus adsorption ability, the conversion value of the phosphate ion adsorption amount (mmol / g) per 1 g of the composite metal hydroxide contained in the specimen is also shown.
[0057]
[Table 6]

[0058]
As can be seen from the results, the crushed material (specimens Nos. 13 to 16) prepared by using the early-strength cement as the hydraulic inorganic material was about 7.5% of the target value of the phosphorus adsorption capacity of 1.6 mmol / g. It was possible to provide the above-mentioned phosphorus adsorption ability, and to sufficiently exceed the crushing strength target value of 95% by weight (residual content).
[0059]
Example 4
(1) Preparation of test specimen
The following formula:
Mg²⁺ _0.665Al³⁺ _0.317(OH⁻)_2.033Cl⁻ _0.238(CO₃ ^2-)_0.023
And 100 parts by weight of Portland cement with respect to 100 parts by weight of the composite metal hydroxide represented by²) Was blended in an amount of 100 parts by weight to prepare a composition for an environmental purification type inorganic material. After mixing and mixing 375 parts by weight of aggregate and 46 parts by weight of water with this composition for environmental purification type inorganic material, the mixture was filled into a size of φ10 × 10 at a filling rate of about 75%, and cured in water for 14 days. To prepare a test body.
[0060]
(2) Measurement of phosphorus adsorption capacity
The phosphorus adsorption capacity of the test specimen prepared above was measured. Specifically, the phosphorus adsorption capacity was measured by adjusting the phosphorus concentration of a test sample to about pH 7 with hydrochloric acid at 26.7 mM-P Na.₂HPO₄It was placed in an aqueous solution and allowed to stand for 48 hours. After a predetermined time had elapsed, the test specimen was separated from the aqueous solution by filtration, and the phosphate ion concentration in the filtrate was determined by the molybdenum blue method. At the same time, the pH of the solution was measured using a pH meter, and the influence of the pH on the phosphorus adsorption ability was examined.
[0061]
FIG. 2 shows the results. As can be seen from FIG. 2, the concentration of phosphorus in the aqueous solution decreased with the increase in the pH of the solution. Therefore, even when the pH was increased, phosphate ions were not released, and the phosphorus adsorption ability was maintained. It became clear that it was. Therefore, the inorganic material of the present invention exhibits a phosphorus adsorption ability even in a high pH environment such as cement and concrete preparations, and phosphate ions once adsorbed are most released under a high pH environment such as cement and concrete preparations. Turned out not to be.
[0062]
【The invention's effect】
According to the present invention, an environment-purifying type exhibiting a desired phosphate ion-adsorbing ability by imparting a phosphate ion-adsorbing ability to an inorganic material which is originally a low-environmental load material that does not contain harmful substances and is easily regenerated. An inorganic material can be provided. Since the environment-purifying inorganic material of the present invention has strength corresponding to various uses, the inorganic material can add a useful function of environmental purification to conventionally used applications.
[0063]
Furthermore, since the inorganic material of the present invention does not release adsorbed phosphate ions even under high pH conditions, the environment-purifying inorganic material after phosphorus adsorption is recycled as civil engineering and building materials such as recycled aggregate. It is possible to do.
[Brief description of the drawings]
FIG. 1 is a view showing a relationship between a cement content and a phosphorus adsorption amount (Example 1).
FIG. 2 is a view showing the relationship between pH and phosphorus adsorption ability (Example 5).

Claims (3)

An environment-purifying inorganic material containing a composite metal hydroxide, a hydraulic inorganic material and a filler , wherein the composite metal hydroxide has a chemical composition formula (1)
M _1-x ²⁺ M _x ³⁺ (OH ⁻ ) _{2 + xy} (A ⁿ⁻ ) _{y / n} (1)
[ ^Wherein , M ²⁺ represents at least one divalent metal ion selected from the group consisting of Mg ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Ca ²⁺ and Cu ²⁺ ; ³⁺ represents at least one trivalent metal ion selected from the group consisting of Al ³⁺ and Fe ^3+, a ^n-is an anion of n valence. Further, x is a positive number satisfying 0.1 ≦ x ≦ 0.5, y is a positive number satisfying 0.1 ≦ y ≦ 0.5, and n is 1 or 2. ]
The hydraulic inorganic material is a blast furnace cement, which is an environmental purification inorganic material . 2. The environment-purifying inorganic material according to claim 1 , comprising 2 to 900 parts by weight of the hydraulic inorganic material and 2 to 9000 parts by weight of the filler based on 100 parts by weight of the composite metal hydroxide. 3. The environment-purifying inorganic material according to any one of claims 1 to 2 , wherein phosphorus is adsorbed.

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