JP2010119987A - Method of insolubilizing waste casting sand containing fluorine and method of manufacturing roadbed material - Google Patents
Method of insolubilizing waste casting sand containing fluorine and method of manufacturing roadbed material Download PDFInfo
- Publication number
- JP2010119987A JP2010119987A JP2008297979A JP2008297979A JP2010119987A JP 2010119987 A JP2010119987 A JP 2010119987A JP 2008297979 A JP2008297979 A JP 2008297979A JP 2008297979 A JP2008297979 A JP 2008297979A JP 2010119987 A JP2010119987 A JP 2010119987A
- Authority
- JP
- Japan
- Prior art keywords
- fluorine
- curing
- magnesium oxide
- containing fluorine
- waste sand
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
Description
本発明はフッ素を含む鋳物廃砂の不溶化方法及び路盤材の製造方法に関する。詳しくは、鋳物製造工程において排出される鋳物廃砂に含まれるフッ素を不溶化するフッ素を含む鋳物廃砂の不溶化方法、及びフッ素を含む鋳物廃砂を路盤材へ再利用する路盤材の製造方法に係るものである。 The present invention relates to a method for insolubilizing casting waste sand containing fluorine and a method for producing a roadbed material. Specifically, in a method for insolubilizing casting waste sand containing fluorine that insolubilizes fluorine contained in casting waste sand discharged in the casting manufacturing process, and a method for manufacturing roadbed material that reuses casting waste sand containing fluorine as roadbed material. It is related.
自動車産業等の製造現場において鉄の鋳造は必須のものとなっているが、鋳物製造業界で用いられている鋳物砂の廃砂のうち、大規模排出事業所から排出される廃砂（２００ｔ／月）は、大部分がセメント工場等でリサイクルされている。
しかし、中小の鋳物工場においては、排出量が不安定であったり、品質にバラツキがあったりすることから、再資源化率が１０％程度と低い状況にある。
Casting of iron is indispensable at manufacturing sites in the automobile industry, etc., but among the waste sand of foundry sand used in the foundry manufacturing industry, the waste sand discharged from large-scale discharge facilities (200t / Most of them are recycled at cement factories.
However, in small and medium-sized foundries, the amount of recycling is unstable and the quality varies, so the recycling rate is as low as about 10%.
鋳物製造用の鋳型に使用された使用済の砂（鋳物廃砂）は、フッ素やクロム等の有害物質を含む場合が多く、鋳物廃砂を再資源化するには、フッ素化合物等の無害化処理が必要である。
一般的に、鋳物鋳造工程で使用される鋳型や中子の材料には、耐火材料の代表である砂が用いられている。鋳物鋳造工程では、溶解した鉄（銑鉄）を鋳型に流し込み、冷却し、型枠を取り外した後、目的の鉄製品が出来上がる。溶解した銑鉄は通常では粘度が高いので、成型し易くするために粘度調整材として、ほたる石（ＣａＦ２）が銑鉄に添加されることが多い。この場合、鋳型に銑鉄を流し込み、時間をおいて成型する際に、溶解した鉄やＣａ（カルシウム）、Ｆ（フッ素）等の成分が砂の鋳型に溶出し、型枠の鋳物砂の表面に吸着された状態になっている。
Used sand (casting waste sand) used in casting molds often contains harmful substances such as fluorine and chromium. To recycle casting waste sand, detoxify fluorine compounds and the like. Processing is required.
In general, sand, which is a typical refractory material, is used as a material of a mold or a core used in a casting casting process. In the casting process, the melted iron (pig iron) is poured into a mold, cooled, the mold is removed, and the target iron product is completed. Since melted pig iron usually has a high viscosity, fluorite (CaF 2 ) is often added to pig iron as a viscosity modifier to facilitate molding. In this case, molten iron, Ca (calcium), F (fluorine), and other components are eluted into the sand mold when pouring iron into the mold and molding after a long time. It is in an adsorbed state.
また、フッ素は、土壌環境基準の基準値項目となってまだ日が浅く、近年、フロンガスをはじめ多くの生活用品、電化製品等に使用されてきており、ごみ処理場の焼却排ガスにも多く含まれるようになってきている。
また、フッ素の健康面に対する影響としては、適量であれば虫歯予防になるが、量が増えると斑状歯や骨硬化症を発症する。
Fluorine has become a reference value item for soil environmental standards and is still a short day. In recent years, it has been used in many household goods and electrical appliances including chlorofluorocarbons, and is also included in incineration exhaust gas at waste treatment plants. It is becoming
Moreover, as an influence on the health aspect of fluorine, it will be caries prevention if it is an appropriate amount, but if the amount increases, it will cause patchy teeth and osteosclerosis.
フッ素の不溶化方法として、例えば特許文献１には、アルカリ性を呈するフッ素汚染土に、５％の酸化マグネシウムと２．５％以下の塩化マグネシウムを添加して混合する方法が記載されている。
As a method for insolubilizing fluorine, for example,
しかしながら、特許文献１に記載の方法では、酸化マグネシウムの混合効果は、処理前の濃度の１／５程度に減ずるにすぎず、高濃度のフッ素を含んだ鋳物廃砂の環境安全性（０．８ｍｇ／ｌ）を満足することは困難であり、また、酸化マグネシウムの添加量が２質量％を超えると、リサイクル事業として、事業ベースに乗せることが困難な状況となる。
However, in the method described in
また、フッ素を含んだ汚染鋳物廃砂の汚染の程度には大きな幅があるが、溶出試験においては、数十ｍｇ／ｌのフッ素溶出濃度を示すこともたびたびあった。これまで、０〜５ｍｇ／ｌ程度のフッ素溶出濃度の場合は、従来の路盤材製造方法で用いられているセメント処理で環境安全性（環境基準値：０．８ｍｇ／ｌ）試験を満足していた。
しかし、フッ素溶出濃度が５〜１００ｍｇ／ｌの場合は、従来のフッ素不溶化処理技術では環境安全性の点で問題があり、従来は、そのまま安定型の産業廃棄物処理場に排出され、再利用率は１０％程度であった。
In addition, although the degree of contamination of contaminated casting waste sand containing fluorine has a wide range, in the dissolution test, it often showed a fluorine dissolution concentration of several tens mg / l. So far, in the case of fluorine elution concentration of about 0-5 mg / l, the environmental safety (environmental standard value: 0.8 mg / l) test has been satisfied with the cement treatment used in the conventional roadbed material manufacturing method. It was.
However, when the fluorine elution concentration is 5 to 100 mg / l, the conventional fluorine insolubilization treatment technology has a problem in terms of environmental safety. Conventionally, it is discharged directly to a stable industrial waste treatment plant and reused. The rate was about 10%.
本発明は、以上の点に鑑みて創案されたものであり、フッ素溶出濃度を低下させることができるフッ素を含む鋳物廃砂の不溶化方法、並びにこのような不溶化方法を利用した路盤材の製造方法を提供することを目的とする。 The present invention was devised in view of the above points, and is a method for insolubilizing cast waste sand containing fluorine capable of lowering the fluorine elution concentration, and a method for producing a roadbed material using such an insolubilization method. The purpose is to provide.
上記の目的を達成するために、本発明のフッ素を含む鋳物廃砂の不溶化方法は、フッ素を含む鋳物廃砂に酸化マグネシウムを添加する前処理工程と、該前処理工程で得られた混合物を所定の期間で養生する養生工程と、該養生工程で養生された混合物に高炉セメントを添加する後処理工程とを備える。 In order to achieve the above object, the method for insolubilizing waste waste sand containing fluorine according to the present invention comprises a pretreatment step of adding magnesium oxide to a waste waste sand containing fluorine, and a mixture obtained in the pretreatment step. A curing process for curing in a predetermined period, and a post-treatment process for adding blast furnace cement to the mixture cured in the curing process.
ここで、フッ素を含む鋳物廃砂に酸化マグネシウムを添加する前処理工程によって、以下のような反応が生じると考えられる。
ＭｇＯ ＋ Ｈ２Ｏ → Ｍｇ（ＯＨ）２（ブルーサイト）
０．３Ｆ ＋ Ｍｇ（ＯＨ）２ → ＭｇＦ０．３（ＯＨ）１．７
このようにＭｇＯは、水と反応して水酸化マグネシウム［ブルーサイト：Ｍｇ（ＯＨ）２］となる。水酸化マグネシウムは不溶性物質であるが、マグネシウム８面体層状シートより成る立体構造を持っており、その構造の一部にイオン付加が可能なサイトがあり、水酸化マグネシウム生成初期には、ＯＨ−イオンやフッ素イオンと入れ替わることができる。
また、前処理工程で得られた混合物を所定の期間で養生する養生工程によって、不溶化量を上昇させることができる。
また、養生工程で養生された混合物に高炉セメントを添加する後処理工程によって、高炉セメントが少量の硫化物を含み還元効果を示すため、混合物中のクロムが、汚染物質である六価クロムに変化しにくくなり、六価クロムの溶出を抑えることができる。
Here, it is considered that the following reaction occurs in the pretreatment step of adding magnesium oxide to waste casting sand containing fluorine.
MgO + H 2 O → Mg (OH) 2 (Bluesite)
0.3F + Mg (OH) 2 → MgF 0.3 (OH) 1.7
Thus, MgO reacts with water to become magnesium hydroxide [brucite: Mg (OH) 2 ]. While magnesium hydroxide is insoluble material, has a three-dimensional structure consisting of magnesium octahedral layered sheet, there are some possible ion adduct site of the structure, the magnesium hydroxide produced early, OH - ions And can be replaced with fluorine ions.
Moreover, the amount of insolubilization can be raised by the curing process of curing the mixture obtained in the pretreatment process for a predetermined period.
In addition, after the blast furnace cement is added to the mixture cured in the curing process, the blast furnace cement contains a small amount of sulfide and exhibits a reduction effect, so the chromium in the mixture is changed to hexavalent chromium which is a contaminant. The elution of hexavalent chromium can be suppressed.
また、前処理工程におけるブルーサイトとフッ素の反応は、非化学量論的であるが、単なる吸着ではなく、定量的な化学反応であり、その結合は経時的に強固となる性質がある。更にブルーサイトと反応しきれなかったフッ素イオンに対し、高炉セメントのカルシウムが反応し、不溶化を進展させ、更に固化遮蔽効果を発揮していくという複合的な効果により、長期不溶化効果を持続することができる。 Further, the reaction between brucite and fluorine in the pretreatment step is non-stoichiometric, but it is not a simple adsorption but a quantitative chemical reaction, and the bond has a property of becoming stronger with time. Furthermore, the long-term insolubilization effect should be maintained by the combined effect of calcium in the blast furnace cement reacting with fluorine ions that could not react with brucite, causing insolubilization to progress, and further exerting a solidification shielding effect. Can do.
また、本発明のフッ素を含む鋳物廃砂の不溶化方法において、酸化マグネシウムの添加量は、フッ素を含む鋳物廃砂の量の０．２〜５．０質量％であり、酸化マグネシウムが添加される前のフッ素を含む鋳物廃砂の水分率は、１０〜１３％であり、前処理工程においてフッ素を含む鋳物廃砂と酸化マグネシウムを混合撹拌する時間は、１０〜４０分であり、養生工程において養生する期間は、３〜１０日であることが好ましい。 Moreover, in the insolubilization method of the casting waste sand containing fluorine of this invention, the addition amount of magnesium oxide is 0.2-5.0 mass% of the quantity of the casting waste sand containing fluorine, and magnesium oxide is added. The moisture content of the casting waste sand containing fluorine is 10 to 13%, and the time for mixing and stirring the casting waste sand containing fluorine and magnesium oxide in the pretreatment process is 10 to 40 minutes. The curing period is preferably 3 to 10 days.
また、上記の目的を達成するために、本発明の路盤材の製造方法は、フッ素を含む鋳物廃砂に酸化マグネシウムを添加する前処理工程と、該前処理工程で得られた混合物を所定の期間で養生する養生工程と、該養生工程で養生された混合物に、高炉セメントと、骨材と、水とを添加する造粒固化工程とを備える。 In order to achieve the above object, a method for producing a roadbed material according to the present invention includes a pretreatment step of adding magnesium oxide to casting waste sand containing fluorine, and a mixture obtained in the pretreatment step. A curing process for curing for a period, and a granulation solidification process for adding blast furnace cement, aggregate, and water to the mixture cured in the curing process.
また、本発明の路盤材の製造方法において、高炉セメントの添加量は、路盤材全量に対して２〜１０質量％である場合、得られる路盤材の一軸圧縮強度が１０ｋｇｆ／ｃｍ２程度になるので好ましい。 Moreover, in the manufacturing method of the roadbed material of this invention, when the addition amount of a blast furnace cement is 2-10 mass% with respect to the whole roadbed material, the uniaxial compressive strength of the obtained roadbed material will be about 10 kgf / cm < 2 >. Therefore, it is preferable.
また、本発明の路盤材の製造方法において、骨材の添加量は、路盤材全量に対して１０〜９０質量％である場合、フッ素を含む鋳物廃砂の使用量を減らして、フッ素溶出濃度の低減化を図ることができる。 In addition, in the method for manufacturing a roadbed material according to the present invention, when the amount of aggregate is 10 to 90% by mass with respect to the total amount of the roadbed material, the amount of casting waste sand containing fluorine is reduced, and the fluorine elution concentration Can be reduced.
なお、本発明でいう「鋳物廃砂」には、鋳物製造工程で発生する鋳物型枠をばらして得た鋳物砂、及びその際に発生した鋳物粉塵など砂の粒度に関わりなく鋳物砂やそれから発生した無機廃棄物、若しくは土壌が含まれる。また、フッ素が含まれていれば、例えばＰｂ、Ｃｒ６＋、Ａｓ（ヒ素）、ＣＮ（シアン）、Ｈｇ（水銀）、セレンが、本発明でいう「フッ素を含む鋳物廃砂」にさらに含まれていてもよい。 The “cast waste sand” as used in the present invention refers to foundry sand obtained by separating casting molds generated in the casting production process, and foundry sand and the like regardless of the particle size of sand such as foundry dust generated at that time. Includes generated inorganic waste or soil. Further, if fluorine is contained, for example, Pb, Cr 6+ , As (arsenic), CN (cyan), Hg (mercury), and selenium are further included in the “cast waste sand containing fluorine” in the present invention. It may be.
本発明に係るフッ素を含む鋳物廃砂の不溶化方法によって、フッ素溶出濃度を低下させることができる。
本発明に係る路盤材の製造方法によって、フッ素を含む鋳物廃砂を再利用しても、フッ素溶出濃度が低い路盤材を製造することができる。
The fluorine elution concentration can be lowered by the method for insolubilizing waste waste sand containing fluorine according to the present invention.
By the method for manufacturing a roadbed material according to the present invention, a roadbed material having a low fluorine elution concentration can be manufactured even if casting waste sand containing fluorine is reused.
本発明のフッ素を含む鋳物廃砂の不溶化方法は、フッ素を含む鋳物廃砂に酸化マグネシウムを添加する前処理工程と、前処理工程で得られた混合物を所定の期間で養生する養生工程と、養生工程で養生された混合物に高炉セメントを添加する後処理工程とを備える。
また、本発明の路盤材の製造方法は、フッ素を含む鋳物廃砂に酸化マグネシウムを添加する前処理工程と、前処理工程で得られた混合物を所定の期間で養生する養生工程と、養生工程で養生された混合物に、高炉セメントと、骨材と、水とを添加する造粒固化工程とを備える。
The insolubilization method of fluorine waste casting waste sand of the present invention includes a pretreatment step of adding magnesium oxide to fluorine waste casting sand, a curing step of curing the mixture obtained in the pretreatment step for a predetermined period, A post-treatment step of adding blast furnace cement to the mixture cured in the curing step.
The roadbed material manufacturing method of the present invention includes a pretreatment step of adding magnesium oxide to casting waste sand containing fluorine, a curing step of curing the mixture obtained in the pretreatment step in a predetermined period, and a curing step. The granulated solidification process which adds a blast furnace cement, an aggregate, and water to the mixture cured by this.
本発明の方法によって処理されるフッ素を含む鋳物廃砂は、例えば、フッ素溶出濃度が５〜２０ｍｇ／ｌの鋳物廃砂である。 The casting waste sand containing fluorine treated by the method of the present invention is, for example, casting waste sand having a fluorine elution concentration of 5 to 20 mg / l.
また、酸化マグネシウムの添加量は、フッ素を含む鋳物廃砂の量の０．２〜５．０質量％が好ましく、更に好ましくは０．２〜２．０質量％であり、もっと好ましくは０．５〜１．０質量％であり、より確実な効果及び経済性を考慮した場合、１．０質量％が好ましい。
酸化マグネシウムの添加によって生じる反応は定量的な反応関係であるため、例えば初期フッ素溶出濃度が５０ｍｇ／ｌである鋳物廃砂５０ｇ中のフッ素を全て不溶化するために必要な酸化マグネシウム量は、０．２６５ｇと算出され、これは即ち５０ｍｇ／ｌの鋳物砂の場合、反応理論に基づく酸化マグネシウムの必要量は０．５３質量％であるから、酸化マグネシウムの添加量は、フッ素を含む鋳物廃砂の量の１．０質量％で充分である。
ここで、酸化マグネシウムは、６００〜８００℃で焼成された活性の高い軽質の酸化マグネシウムである。
Further, the addition amount of magnesium oxide is preferably 0.2 to 5.0% by mass, more preferably 0.2 to 2.0% by mass, and more preferably 0.2 to 2.0% by mass of the amount of casting waste sand containing fluorine. It is 5-1.0 mass%, and 1.0 mass% is preferable when the more reliable effect and economical efficiency are considered.
Since the reaction caused by the addition of magnesium oxide has a quantitative reaction relationship, for example, the amount of magnesium oxide required to insolubilize all the fluorine in 50 g of casting waste sand having an initial fluorine elution concentration of 50 mg / l is 0. This is calculated as 265 g, that is, in the case of 50 mg / l of foundry sand, the required amount of magnesium oxide based on the reaction theory is 0.53% by mass, so the amount of magnesium oxide added is the same as that of waste sand containing fluorine. 1.0% by weight of the amount is sufficient.
Here, the magnesium oxide is light and highly active magnesium oxide baked at 600 to 800 ° C.
また、鋳物廃砂と酸化マグネシウムとの反応が進む程度に鋳物廃砂が湿っていればよいが、酸化マグネシウムが添加される前のフッ素を含む鋳物廃砂の水分率［（鋳物廃砂中の水分質量／鋳物廃砂質量）×１００（％）］は、１０〜１３％が好ましい。
また、粉体の高炉セメントを混合する工程においては、各資材の化学反応が進行し易く、かつミキサーにより各資材が均一に混合されることから、鋳物廃砂の水分率を１３〜１８％の範囲に調整することが好ましい。
Further, the casting waste sand may be moistened to such an extent that the reaction between the casting waste sand and magnesium oxide proceeds. However, the moisture content of the fluorine-containing casting waste sand before the magnesium oxide is added [(in the casting
Further, in the step of mixing the powdered blast furnace cement, the chemical reaction of each material is likely to proceed and each material is uniformly mixed by a mixer, so that the water content of the foundry waste sand is 13 to 18%. It is preferable to adjust to the range.
また、前処理工程においてフッ素を含む鋳物廃砂と酸化マグネシウムを混合撹拌する時間は、１０〜４０分が好ましく、更に好ましくは２０〜３０分である。この混合撹拌する時間は、酸化マグネシウムが鋳物廃砂とまんべんなく混ざり合うために必要な時間であり、鋳物廃砂の水分率が適切である場合の時間である。
また、高炉セメントを混合する工程では、混合撹拌時間は１〜５分が好ましく、更に好ましくは１〜３分である。
Further, the time for mixing and stirring the casting waste sand containing fluorine and magnesium oxide in the pretreatment step is preferably 10 to 40 minutes, and more preferably 20 to 30 minutes. This mixing and stirring time is a time required for the magnesium oxide to be thoroughly mixed with the casting waste sand, and is a time when the moisture content of the casting waste sand is appropriate.
In the step of mixing blast furnace cement, the mixing and stirring time is preferably 1 to 5 minutes, and more preferably 1 to 3 minutes.
また、養生工程において養生する期間は、３〜１０日が好ましく、更に好ましくは３〜７日であり、最も好ましくは５〜７日である。本発明者らが検討した結果、酸化マグネシウムを添加してから１〜３日間は、フッ素不溶化量が上昇傾向を示し、３日程度で不溶化量がピーク付近に達し、３日以降は変動の少ない漸減傾向の安定期に入るからである。 In addition, the period of curing in the curing process is preferably 3 to 10 days, more preferably 3 to 7 days, and most preferably 5 to 7 days. As a result of investigations by the present inventors, the amount of fluorine insolubilization tends to increase for 1 to 3 days after the addition of magnesium oxide, and the amount of insolubilization reaches the peak in about 3 days, with little fluctuation after 3 days. This is because it enters a stable period of gradual decline.
また、高炉セメントを混合した後の養生期間は、３〜７日が好ましい。
また、路盤材の環境安全性試験は、路盤材の製造終了後、３〜５日経過し、破砕処理したものを試験試料として供するとよい。
Moreover, the curing period after mixing the blast furnace cement is preferably 3 to 7 days.
Moreover, the environmental safety test of a roadbed material is good to use as a test sample what passed 3-5 days after the manufacture of a roadbed material, and was crushed.
図１は、高濃度のフッ素及びクロムを含有する鋳物廃砂を用いた本発明の路盤材の製造方法の流れの一例を示すフロー図である。
先ず、路盤材の骨材として使用するフッ素汚染鋳物廃砂（フッ素を含む鋳物廃砂）のフッ素溶出濃度を測定しておき、他の配合骨材とフッ素汚染鋳物廃砂の配合比を決定するための資料とする（鋳物廃砂の評価）（ステップＳ１）。
FIG. 1 is a flowchart showing an example of a flow of a method for manufacturing a roadbed material according to the present invention using waste casting sand containing high concentrations of fluorine and chromium.
First, the fluorine elution concentration of fluorine-contaminated casting waste sand (casting waste sand containing fluorine) used as the aggregate of roadbed material is measured, and the blending ratio of other blended aggregate and fluorine-contaminated casting waste sand is determined. Material (evaluation of casting waste sand) (step S1).
そして、酸化マグネシウムは、ｐＨ１０程度もしくはｐＨ１０未満の比較的弱いアルカリ性であるフッ素汚染鋳物廃砂（フッ素を含む鋳物廃砂）に添加され、好ましくは１０〜４０分間、更に好ましくは２０〜３０分間混合撹拌されて、鋳物廃砂中のフッ素の一部が不溶化される（前処理工程）（ステップＳ２）。このとき、フッ素汚染鋳物廃砂の水分率は１０〜１３％に調整されており、酸化マグネシウムの添加量は、フッ素汚染鋳物廃砂の量の０．２〜２．０質量％である。
Magnesium oxide is added to fluorine-contaminated casting waste sand (cast waste sand containing fluorine) that is relatively weak alkaline having a pH of about 10 or less than
次に、前処理工程で得られた混合物を３〜１０日間養生した後（養生工程）（ステップＳ３）、養生された混合物に、高炉セメント、砕石骨材及び水を混合し（造粒固化工程）（ステップＳ４）、路盤材を製造する。高炉セメントの添加量は、路盤材全量に対して好ましくは２〜１０質量％、更に好ましくは５〜８質量％であり、砕石骨材の添加量は、路盤材全量に対して好ましくは１０〜９０質量％、更に好ましくは２５〜８３質量％であり、残りが水であるが、水セメント比（Ｗ／Ｃ）を６５％程度に調整することが好ましい。また、造粒固化工程における混合時間は１〜５分が好ましく、更に好ましくは１〜３分である。表１に、路盤材の標準的な配合例を示す。 Next, after curing the mixture obtained in the pretreatment process for 3 to 10 days (curing process) (step S3), the cured mixture is mixed with blast furnace cement, crushed stone aggregate and water (granulation solidification process) (Step S4), a roadbed material is manufactured. The addition amount of blast furnace cement is preferably 2 to 10% by mass, more preferably 5 to 8% by mass, and more preferably 5 to 8% by mass, and the addition amount of crushed aggregate is preferably 10 to 10% with respect to the total amount of roadbed material. Although it is 90 mass%, More preferably, it is 25-83 mass%, and the remainder is water, It is preferable to adjust water cement ratio (W / C) to about 65%. The mixing time in the granulation solidification step is preferably 1 to 5 minutes, more preferably 1 to 3 minutes. Table 1 shows a typical blending example of roadbed materials.
高炉セメントは、少量の硫化物を含み、還元効果を示すため、六価クロムを溶出させるおそれが少なく、固化強度発現の持続性が高いので、造粒固化資材として問題はない。
また、セメントのフッ素不溶化への寄与は、セメントの持つ固化作用に依るところも大きく、その原因解明のため、フッ素汚染鋳物廃砂に酸化マグネシウム及びセメントを混合して水溶液とした水溶液試料を１Ｎ塩酸で滴定を試みた。また、ｐＨ１０以上では高アルカリ域ほど、液中のフッ素イオン濃度は高い。この溶液を１Ｎ塩酸で滴定していくと、ｐＨ１０で溶液中のフッ素イオン濃度は最低となる。さらに滴定し、ｐＨ７前後でフッ素イオン濃度はやや高くなり、ｐＨ５以下では溶液中のフッ素イオンはフッ化水素イオンに変わり、フッ素イオンは低下する。
即ち、セメントの配合量を、路盤材全量の１０％以上に増やすと、混合した鋳物廃砂のアルカリ性が高まり、ＯＨ−イオン過多となり、酸化マグネシウム混合処理された時点で、ブルーサイトに付加していたＦ−イオンがＯＨ−イオンと入れ替わる可能性が高くなり、セメント単独配合の場合ほど効果が発揮できない。
Since blast furnace cement contains a small amount of sulfide and exhibits a reduction effect, there is little risk of elution of hexavalent chromium, and there is no problem as a granulated solidified material because the persistence of solidification strength is high.
In addition, the contribution of cement to insolubilization of fluorine is largely due to the solidification action of cement. To clarify the cause, an aqueous solution sample prepared by mixing magnesium oxide and cement with waste sand from fluorine-contaminated casting was used as an aqueous solution. Attempted titration with Further, at a pH of 10 or higher, the higher the alkali region, the higher the fluorine ion concentration in the liquid. When this solution is titrated with 1N hydrochloric acid, the fluorine ion concentration in the solution becomes the lowest at
In other words, if the amount of cement is increased to 10% or more of the total amount of roadbed material, the alkalinity of the mixed casting waste sand increases, OH - ion is excessive, and added to brucite when magnesium oxide is mixed. In addition, there is a high possibility that F − ions are replaced with OH − ions, and the effect cannot be exhibited as much as in the case of blending cement alone.
また、フッ素汚染鋳物廃砂の初期フッ素溶出濃度が２０ｍｇ／ｌの濃度以下では、酸化マグネシウム等を配合することにより、そのまま環境基準（０．８ｍｇ／ｌ）以下の路盤材を製造することが可能であるが、初期フッ素溶出濃度が２０ｍｇ／ｌ超１００ｍｇ／ｌ以下の場合、フッ素汚染鋳物廃砂に対して他の細砂、低フッ素濃度のフッ素汚染鋳物廃砂及び粗骨材等を任意に配合し、配合比を調整することによって希釈効果が生じ、最終製造品の路盤材のフッ素溶出濃度を環境基準値以下とすることが可能である。
例えば、骨材混合割合で、鋳物砂の混合量を最も減らした場合の一例として、フッ素汚染鋳物廃砂：細砂：粗骨材の比を、０．６：２．４：１．０とすれば、初期フッ素溶出濃度１００ｍｇ／ｌのフッ素汚染鋳物廃砂を用いても、環境基準値以下の路盤材を製造できる。
In addition, when the initial fluorine elution concentration of fluorine-contaminated casting waste sand is 20 mg / l or less, it is possible to produce roadbed materials with environmental standards (0.8 mg / l) or less as they are by adding magnesium oxide or the like. However, when the initial fluorine elution concentration is more than 20 mg / l and 100 mg / l or less, other fine sand, fluorine-contaminated casting waste sand with low fluorine concentration, coarse aggregate, etc. are arbitrarily added to the fluorine-contaminated casting waste sand. By blending and adjusting the blending ratio, a diluting effect is produced, and the fluorine elution concentration of the roadbed material of the final manufactured product can be made the environmental standard value or less.
For example, as an example of the case where the mixing amount of foundry sand is reduced most at the aggregate mixing ratio, the ratio of fluorine-contaminated casting waste sand: fine sand: coarse aggregate is 0.6: 2.4: 1.0 By doing so, it is possible to produce a roadbed material having an environmental standard value or less even if fluorine-contaminated casting waste sand having an initial fluorine elution concentration of 100 mg / l is used.
また、造粒固化工程の後、好ましくは３〜１０日間、更に好ましくは３〜５日間養生して（養生工程）（ステップＳ５）、酸化マグネシウムと高炉セメントの複合的効果を発揮せしめる。養生の後、得られた路盤材について強度試験、ＣＢＲ試験及び有害物質溶出試験を行ない（環境安全性試験）（ステップＳ６）、試験後、破砕処理を行なって粒度を調整し（破砕処理工程）（ステップＳ７）、製品として出荷する（ステップＳ８）。
上記の工程により、鋳物廃砂中のフッ素は、各不溶化資材の効果が最大に発揮された状態で不溶化される。
なお、鋳物廃砂を用いた従来の路盤材の製造方法は、図３に示すように、酸化マグネシウム添加による前処理工程とその後の養生工程が実施されていなかった。
Further, after the granulation solidification step, curing is preferably performed for 3 to 10 days, more preferably 3 to 5 days (curing step) (step S5), and the combined effect of magnesium oxide and blast furnace cement is exhibited. After curing, strength test, CBR test and toxic substance elution test are performed on the obtained roadbed material (environmental safety test) (step S6), and after the test, the particle size is adjusted by crushing treatment (crushing treatment process) (Step S7), shipped as a product (Step S8).
Through the above steps, the fluorine in the casting waste sand is insolubilized in a state where the effect of each insolubilizing material is maximized.
In addition, as shown in FIG. 3, the conventional roadbed material manufacturing method using waste casting sand has not been subjected to a pretreatment step by adding magnesium oxide and a subsequent curing step.
また、フッ素汚染鋳物廃砂の初期フッ素溶出濃度確認と不溶化処理後のフッ素溶出濃度の測定に際しては、蒸留比色法（ランタンアリザリンコンプレクソン法）でなく、測定が簡便且つ迅速で製造現場での測定が可能なイオン電極法を用いることが推奨される。 In addition, when checking the initial fluorine elution concentration of fluorine-contaminated casting waste sand and measuring the fluorine elution concentration after insolubilization treatment, it is not a distillation colorimetric method (lanthanum alizarin complexone method). It is recommended to use an ion electrode method that allows measurement.
（実施例１）
フッ素汚染鋳物廃砂中のフッ素に対する酸化マグネシウムの不溶化率［不溶化材混合前のフッ素溶出濃度（ｍｇ／ｌ）／不溶化材混合後のフッ素溶出濃度（ｍｇ／ｌ）］について調べるために、フッ素溶出量の高い（３０〜６０ｍｇ／ｌ）フッ素汚染鋳物廃砂に、段階的に酸化マグネシウムを配合して、フッ素溶出量を測定した。また、フッ素汚染鋳物廃砂中のフッ素に対する高炉セメントの不溶化率についても、同様に調べた。結果を表２に示す。
Example 1
In order to investigate the insolubilization ratio of magnesium oxide to fluorine in fluorine-contaminated casting waste sand [fluorine elution concentration before mixing insolubilizing material (mg / l) / fluorine elution concentration after mixing insolubilizing material (mg / l)] Magnesium oxide was blended in stages with high-contaminated (30-60 mg / l) fluorine-contaminated casting waste sand, and the fluorine elution amount was measured. Further, the insolubilization rate of the blast furnace cement with respect to fluorine in the fluorine-contaminated casting waste sand was similarly examined. The results are shown in Table 2.
表２から判るように、フッ素汚染鋳物廃砂の量に対する酸化マグネシウムの配合量が０．１〜５．０質量％の範囲では、配合量と不溶化率は直線的関係があり、例えば、１質量％配合の場合、フッ素の溶出濃度は約１／６になり、２質量％配合の場合、フッ素の溶出濃度は約１／１２になった。
一方、フッ素汚染鋳物廃砂中のフッ素に対する、高炉セメントの配合量と不溶化効果についても直線的関係があり、例えばフッ素汚染鋳物廃砂の量に対して高炉セメント８．４質量％配合の場合、フッ素の溶出濃度は約１／１２となることが明らかとなった。
As can be seen from Table 2, when the compounding amount of magnesium oxide with respect to the amount of fluorine-contaminated casting waste sand is in the range of 0.1 to 5.0% by mass, the compounding amount and the insolubilization rate have a linear relationship. In the case of% blending, the elution concentration of fluorine was about 1/6, and in the case of 2% by mass blending, the elution concentration of fluorine was about 1/12.
On the other hand, there is a linear relationship between the blending amount of blast furnace cement and the insolubilization effect with respect to fluorine in fluorine contaminated casting waste sand. For example, when 8.4% by mass of blast furnace cement is blended with respect to the amount of fluorine contaminated casting waste sand, It became clear that the elution concentration of fluorine was about 1/12.
（実施例２）
次に、酸化マグネシウムの配合量（フッ素汚染鋳物廃砂の量の１．０質量％）を一定とし、フッ素汚染鋳物廃砂に酸化マグネシウムを添加した後の養生日数を変えて、養生日数と不溶化率の関係を調べた。なお、高炉セメントも添加した場合の高炉セメントの養生日数は３日とした。結果を表３に示す。
(Example 2)
Next, the compounding amount of magnesium oxide (1.0% by mass of the amount of fluorine-contaminated casting waste sand) is kept constant, and the curing days after adding magnesium oxide to the fluorine-contaminated casting waste sand are changed to insolubilize the curing days. The relationship between rates was examined. In addition, the aging time of the blast furnace cement when adding blast furnace cement was 3 days. The results are shown in Table 3.
表３に示すように、例えば、フッ素の初期溶出濃度が３１．８ｍｇ／ｌのフッ素汚染鋳物廃砂に対して、フッ素汚染鋳物廃砂の量の１質量％の酸化マグネシウムを配合し、６日間養生した後、混合物全量の８．４質量％の高炉セメントを配合し、さらに３日間養生した結果、フッ素溶出濃度は１．３ｍｇ／ｌとなり、フッ素の初期溶出濃度の約１／２５になることが判った。
この結果は、酸化マグネシウムと高炉セメントを連続して混合した場合に比べて約２倍のフッ素不溶化率であると共に、従来の高炉セメントのみの不溶化率に比べて約３倍のフッ素不溶化率であった。
As shown in Table 3, for example, 1 mass% magnesium oxide of the amount of fluorine-contaminated casting waste sand is added to fluorine-contaminated casting waste sand having an initial elution concentration of fluorine of 31.8 mg / l for 6 days. After curing, 8.4 mass% of blast furnace cement of the total amount of the mixture was blended and further cured for 3 days. As a result, the fluorine elution concentration was 1.3 mg / l, which was about 1/25 of the initial elution concentration of fluorine. I understood.
As a result, the fluorine insolubilization rate was about twice that of the case where magnesium oxide and blast furnace cement were continuously mixed, and the fluorine insolubilization rate was about 3 times that of the conventional blast furnace cement alone. It was.
（実施例３）
フッ素汚染鋳物廃砂と、他の骨材である細砂の配合比調整による希釈効果を調べるために、酸化マグネシウムの配合量（フッ素汚染鋳物廃砂の量の１．０質量％）と、酸化マグネシウム配合後の養生期間（７日間）と、高炉セメントの配合量（混合物全量の８．４質量％）と、高炉セメント配合後の養生期間（５日間）を一定とし、鋳物廃砂と細砂の配合比を変えて、フッ素溶出量の変化を調べた。
(Example 3)
In order to examine the dilution effect by adjusting the mixing ratio of fluorine-contaminated casting waste sand and fine sand, which is another aggregate, the amount of magnesium oxide (1.0% by mass of the amount of fluorine-contaminated casting waste sand) and oxidation Casting waste sand and fine sand with a constant curing period after magnesium blending (7 days), blending quantity of blast furnace cement (8.4% by mass of the total mixture) and curing period after blending blast furnace cement (5 days) The change in the fluorine elution amount was examined by changing the blending ratio.
表４から判るように、路盤材の製造においては、更に、鋳物廃砂とその他の骨材の配合比調整による希釈効果を考慮することができ、初期のフッ素溶出濃度が５〜１００ｍｇ／ｌであるフッ素汚染鋳物廃砂を骨材として用いて路盤材を製造しても、環境基準値（０．８ｍｇ／ｌ）を満足する路盤材を製造できることが判った。下記の式は、最終製品である路盤材のフッ素溶出濃度の計算式である。
路盤材製品のフッ素溶出濃度（ｍｇ／ｌ）＝初期フッ素溶出濃度（ｍｇ／ｌ）÷２５×フッ素汚染鋳物廃砂質量（ｋｇ）÷鋳物砂を含む細骨材質量（ｋｇ）
As can be seen from Table 4, in the production of the roadbed material, the dilution effect by adjusting the mixing ratio of the casting waste sand and other aggregates can be taken into account, and the initial fluorine elution concentration is 5 to 100 mg / l. It has been found that even when a roadbed material is produced using certain fluorine-contaminated casting waste sand as an aggregate, a roadbed material that satisfies the environmental standard value (0.8 mg / l) can be produced. The following formula is a formula for calculating the fluorine elution concentration of the roadbed material that is the final product.
Fluorine elution concentration of roadbed materials (mg / l) = Initial fluorine elution concentration (mg / l) ÷ 25 x Fluorine-contaminated casting waste sand mass (kg) ÷ Fine aggregate mass including casting sand (kg)
（現場実証試験）
また、酸化マグネシウムと高炉セメントの複合効果について室内実験で表３及び表４に示す結果が得られたが、更に、路盤材製造現場のポットミキサー（０．１ｍ３）を用いて、現場で実用化規模の約１／７の規模で、実証試験を実施した。
即ち、（１）フッ素汚染鋳物廃砂の量に対して１．０質量％の酸化マグネシウムを添加した場合と、（２）フッ素汚染鋳物廃砂の量に対して２．０質量％の酸化マグネシウムを添加した場合と、（３）フッ素汚染鋳物廃砂の量に対して１．０質量％の酸化マグネシウム、及び高炉セメントを添加した場合と、（４）フッ素汚染鋳物廃砂の量に対して２．０質量％の酸化マグネシウム、及び高炉セメントを添加した場合について、酸化マグネシウム添加後の養生期間を変えて、フッ素不溶化率を調べた。結果を図２に示す。
(Field verification test)
Moreover, although the result shown in Table 3 and Table 4 was obtained in the laboratory experiment about the combined effect of magnesium oxide and blast furnace cement, it was further put into practical use on the spot using a pot mixer (0.1 m 3 ) at the roadbed material manufacturing site. Demonstration tests were conducted on a scale about 1/7 of the scale.
That is, (1) when 1.0% by mass of magnesium oxide is added to the amount of fluorine-contaminated casting waste sand, and (2) 2.0% by mass of magnesium oxide with respect to the amount of fluorine-contaminated casting waste sand And (3) 1.0% by mass of magnesium oxide and blast furnace cement with respect to the amount of fluorine-contaminated casting waste sand, and (4) with respect to the amount of fluorine-contaminated casting waste sand. About the case where 2.0 mass% magnesium oxide and a blast furnace cement were added, the curing period after magnesium oxide addition was changed, and the fluorine insolubilization rate was investigated. The results are shown in FIG.
図２から判るように、酸化マグネシウムと高炉セメントの複合効果は、酸化マグネシウム養生期間が６日間の場合に２５倍の不溶化率を示した。これは室内実験結果とほぼ同様の結果であり、現場でも、良好な結果が得られることを確認した。 As can be seen from FIG. 2, the combined effect of magnesium oxide and blast furnace cement showed a 25-fold insolubilization rate when the magnesium oxide curing period was 6 days. This was almost the same result as the laboratory test result, and it was confirmed that good results could be obtained even in the field.
なお、酸化マグネシウムよりも先に高炉セメントをフッ素汚染鋳物廃砂に添加することも考えられるが、高炉セメントを先に添加すると、水分をかなり高くするので固化がすぐに始まる。そして、高炉セメントを添加した後、時間をおいて酸化マグネシウムを添加すると、すでに固化が進行しており、フッ素がセメント固化材に閉じ込められた形になっており、酸化マグネシウムとの反応が阻害される。また、将来、路盤材の劣化が進んだときに、閉じ込められていたフッ素の再溶出が危惧される。
また、路盤材製造の場合、高炉セメントの添加によって製品としての強度を発現させているが、酸化マグネシウムを後で添加すると、強度品質が確保できない可能性もある。
It is conceivable to add blast furnace cement to the fluorine-contaminated casting waste sand prior to magnesium oxide. However, if blast furnace cement is added first, the water content becomes considerably high and solidification starts immediately. And after adding blast furnace cement, when magnesium oxide is added after a while, solidification has already progressed and fluorine is confined in the cement solidifying material, and the reaction with magnesium oxide is hindered. The Moreover, when the roadbed material deteriorates in the future, the trapped fluorine may be re-eluted.
Further, in the manufacture of roadbed materials, strength as a product is expressed by adding blast furnace cement, but if magnesium oxide is added later, strength quality may not be ensured.
以上説明したように、本発明は、フッ素汚染鋳物廃砂に酸化マグネシウムを添加した後、所定の期間養生させ、養生した後に高炉セメントを添加することによって、フッ素溶出濃度を大きく低下させることができ、フッ素汚染鋳物廃砂を骨材として利用しても、環境基準値を満たす路盤材を製造することができる。 As described above, the present invention can greatly reduce the fluorine elution concentration by adding magnesium oxide to fluorine-contaminated casting waste sand, curing it for a predetermined period, and adding blast furnace cement after curing. Even if fluorine-contaminated casting waste sand is used as an aggregate, a roadbed material that satisfies the environmental standard value can be manufactured.
また、本発明により、産業廃棄物として廃棄処分されていた高いフッ素溶出濃度のフッ素汚染鋳物廃砂を路盤材製造用骨材として再利用することができ、産廃処理費用よりも安価に路盤材を製造することができる。これにより、産廃処理場の負担軽減や、フッ素汚染鋳物廃砂を骨材として利用できるので路盤材製造に必要な骨材（砂や砕石等）資源を削減でき、資源の循環に貢献することができる。 In addition, according to the present invention, fluorine-contaminated casting waste sand having a high fluorine elution concentration, which has been disposed of as industrial waste, can be reused as aggregate for manufacturing roadbed materials, and roadbed materials can be used at a lower cost than industrial waste processing costs. Can be manufactured. As a result, the burden on industrial waste treatment plants can be reduced, and fluorine-contaminated casting waste sand can be used as aggregates, reducing aggregate resources (sand, crushed stones, etc.) required for roadbed manufacturing, and contributing to resource circulation. it can.
Claims (5)
該前処理工程で得られた混合物を所定の期間で養生する養生工程と、
該養生工程で養生された混合物に高炉セメントを添加する後処理工程とを備える
フッ素を含む鋳物廃砂の不溶化方法。 A pretreatment step of adding magnesium oxide to waste casting sand containing fluorine;
A curing step of curing the mixture obtained in the pretreatment step in a predetermined period;
And a post-treatment step of adding blast furnace cement to the mixture cured in the curing step. A method for insolubilizing casting waste sand containing fluorine.
前記酸化マグネシウムが添加される前のフッ素を含む鋳物廃砂の水分率は、１０〜１３％であり、
前記前処理工程において前記フッ素を含む鋳物廃砂と前記酸化マグネシウムを混合撹拌する時間は、１０〜４０分であり、
前記養生工程において養生する期間は、３〜１０日である
請求項１に記載のフッ素を含む鋳物廃砂の不溶化方法。 The amount of magnesium oxide added is 0.2 to 5.0 mass% of the amount of casting waste sand containing fluorine,
The moisture content of the casting waste sand containing fluorine before the magnesium oxide is added is 10 to 13%,
The time for mixing and stirring the casting waste sand containing fluorine and the magnesium oxide in the pretreatment step is 10 to 40 minutes,
The period for curing in the curing process is 3 to 10 days. The method for insolubilizing casting waste sand containing fluorine according to claim 1.
該前処理工程で得られた混合物を所定の期間で養生する養生工程と、
該養生工程で養生された混合物に、高炉セメントと、骨材と、水とを添加する造粒固化工程とを備える
路盤材の製造方法。 A pretreatment step of adding magnesium oxide to waste casting sand containing fluorine;
A curing step of curing the mixture obtained in the pretreatment step in a predetermined period;
A method for producing a roadbed material comprising a granulation solidification step of adding a blast furnace cement, an aggregate, and water to the mixture cured in the curing step.
請求項４に記載の路盤材の製造方法。 The method for producing a roadbed material according to claim 4, wherein the amount of the blast furnace cement added is 2 to 10% by mass with respect to the total amount of the roadbed material.
請求項３または請求項４に記載の路盤材の製造方法。 The method for manufacturing a roadbed material according to claim 3 or 4, wherein an amount of the aggregate added is 10 to 90 mass% with respect to a total amount of the roadbed material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008297979A JP4990870B2 (en) | 2008-11-21 | 2008-11-21 | Method for insolubilizing casting waste sand containing fluorine and method for producing roadbed material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008297979A JP4990870B2 (en) | 2008-11-21 | 2008-11-21 | Method for insolubilizing casting waste sand containing fluorine and method for producing roadbed material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2010119987A true JP2010119987A (en) | 2010-06-03 |
| JP4990870B2 JP4990870B2 (en) | 2012-08-01 |
Family
ID=42321801
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008297979A Expired - Fee Related JP4990870B2 (en) | 2008-11-21 | 2008-11-21 | Method for insolubilizing casting waste sand containing fluorine and method for producing roadbed material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4990870B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110144783A (en) * | 2019-04-26 | 2019-08-20 | 福建省昊立建设工程有限公司 | A kind of roadbed construction method |
| CN111041916A (en) * | 2019-12-30 | 2020-04-21 | 中交水利水电建设有限公司 | Roadbed construction method by solidifying earthwork |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002047607A (en) * | 2000-08-01 | 2002-02-15 | Wahei Nishimura | Execution work method of upper layer roadbed and upper layer roadbed material and storage method of sludge |
| JP2004105944A (en) * | 2002-07-25 | 2004-04-08 | Toshio Kitahara | Stabilizing material for heavy metals, method of stabilizing heavy metals and method of treating substance containing heavy metals |
| JP2004283795A (en) * | 2003-03-25 | 2004-10-14 | Taiheiyo Cement Corp | Solidification/insolubilization treatment method for contaminated soil |
| JP2004292285A (en) * | 2003-03-28 | 2004-10-21 | Taiheiyo Cement Corp | Concrete |
| JP2005324083A (en) * | 2004-05-12 | 2005-11-24 | Hitachi Constr Mach Co Ltd | Polluted soil treatment method and polluted soil treatment system |
| JP2007331976A (en) * | 2006-06-15 | 2007-12-27 | Taiheiyo Cement Corp | Cement admixture and cement composition |
-
2008
- 2008-11-21 JP JP2008297979A patent/JP4990870B2/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002047607A (en) * | 2000-08-01 | 2002-02-15 | Wahei Nishimura | Execution work method of upper layer roadbed and upper layer roadbed material and storage method of sludge |
| JP2004105944A (en) * | 2002-07-25 | 2004-04-08 | Toshio Kitahara | Stabilizing material for heavy metals, method of stabilizing heavy metals and method of treating substance containing heavy metals |
| JP2004283795A (en) * | 2003-03-25 | 2004-10-14 | Taiheiyo Cement Corp | Solidification/insolubilization treatment method for contaminated soil |
| JP2004292285A (en) * | 2003-03-28 | 2004-10-21 | Taiheiyo Cement Corp | Concrete |
| JP2005324083A (en) * | 2004-05-12 | 2005-11-24 | Hitachi Constr Mach Co Ltd | Polluted soil treatment method and polluted soil treatment system |
| JP2007331976A (en) * | 2006-06-15 | 2007-12-27 | Taiheiyo Cement Corp | Cement admixture and cement composition |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110144783A (en) * | 2019-04-26 | 2019-08-20 | 福建省昊立建设工程有限公司 | A kind of roadbed construction method |
| CN110144783B (en) * | 2019-04-26 | 2020-04-28 | 福建省昊立建设工程有限公司 | Roadbed construction method |
| CN111041916A (en) * | 2019-12-30 | 2020-04-21 | 中交水利水电建设有限公司 | Roadbed construction method by solidifying earthwork |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4990870B2 (en) | 2012-08-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5599061B2 (en) | Neutral solidifying material additive, neutral solidifying material and method for suppressing elution of heavy metals | |
| CN103834410A (en) | Heavy metal immobilizing agent and method for immobilization and stabilization of soil heavy metals by using heavy metal immobilizing agent | |
| JP5963177B2 (en) | Method for treating solid heavy metal contaminated material and method for producing cement solidified material | |
| Qiao et al. | Use of flue gas desulphurisation (FGD) waste and rejected fly ash in waste stabilization/solidification systems | |
| JP5092203B2 (en) | Method for suppressing elution of fluorine and heavy metals from waste | |
| JP4990870B2 (en) | Method for insolubilizing casting waste sand containing fluorine and method for producing roadbed material | |
| JP2007222694A (en) | Cement based treatment material for heavy metal-contaminated soil and solidification/insolubilization treatment method using it | |
| JP6942392B1 (en) | A method for manufacturing recycled ash and a system for manufacturing recycled ash | |
| CN105130346A (en) | Safety treatment method for fluorine-containing solid waste | |
| JPH108029A (en) | Stabilizer for heavy metal, stabilizing treatment of heavy metal, use of substance containing heavy metal and device for stabilizing treatment of heavy metal | |
| KR20110113329A (en) | Manufacturing method of antibacterial and deodorizing agent using ferro-nickel slag | |
| CN112495984B (en) | Hazardous waste solidification/stabilization comprehensive treatment method | |
| JP3213054B2 (en) | Treatment method for incinerated ash containing heavy metals | |
| JP5610568B2 (en) | Method for producing hydrated hardened body using fine aggregate made of steel slag | |
| JPS6215274B2 (en) | ||
| JP3766833B2 (en) | PC grout admixture | |
| JP6525238B2 (en) | Heavy metal insoluble material | |
| JP2010138053A (en) | Method of reducing fluorine elution from steel making slag product | |
| JP5830862B2 (en) | Method for producing hydraulic material and method for selecting concrete crushed material | |
| CN105148447B (en) | A kind of method of the mechanical activation removing toxic substances waste acid slag of cadmium containing arsenic | |
| JP4827580B2 (en) | Hydrated hardened body with reinforcing bars with excellent neutralization resistance and salt damage resistance | |
| WO2018120051A1 (en) | Waste incineration fly ash stabilizing agent and preparation method therefor | |
| EP4197983A1 (en) | Method of manufacturing inorganic binder by reduction furnace slag and cured solid manufactured by the method | |
| TW201200492A (en) | Method of making concrete compositions | |
| Parisis | Utilisation of Glass for the Production of Inorganic Polymeric Materials for Construction Industry |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20110802 |
|
| A871 | Explanation of circumstances concerning accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A871 Effective date: 20110802 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20120116 |
|
| A975 | Report on accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A971005 Effective date: 20120116 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120124 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120322 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120417 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120502 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150511 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |