JP2021059469A - Method for processing steel slag - Google Patents
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Abstract
Description
本発明は、鉄鋼スラグの処理方法に関する。 The present invention relates to a method for treating steel slag.
近年、環境負荷低減の観点から、産業廃棄物量の削減が求められている。この産業廃棄物の削減の要請に加えて、天然資源の枯渇等の問題から、鉄鋼スラグを土工用や路盤材として利用されることが注目されている。スラグを土工用や路盤材として利用するためには、環境庁告示第４６号に定められた土壌環境基準を満足する必要がある。この基準では、六価クロムイオン（Ｃｒ６＋）の溶出量（以下、「クロム溶出量」ともいう）を０．０５ｍｇ／Ｌ以下、フッ化物イオン（Ｆ−）の溶出量（以下、「フッ素溶出量」ともいう）を０．８ｍｇ／Ｌ以下とすることが定められている。 In recent years, reduction of the amount of industrial waste has been required from the viewpoint of reducing the environmental load. In addition to this request for reduction of industrial waste, it is attracting attention that steel slag is used for earthwork and roadbed materials due to problems such as depletion of natural resources. In order to use slag for earthwork or as a roadbed material, it is necessary to satisfy the soil environmental standard stipulated in Notification No. 46 of the Environment Agency. According to this standard, the elution amount of hexavalent chromium ion (Cr 6+ ) (hereinafter, also referred to as “chromium elution amount”) is 0.05 mg / L or less, and the elution amount of fluoride ion (F − ) (hereinafter, “fluorine elution amount”). It is stipulated that the amount) should be 0.8 mg / L or less.
クロム元素を含有する鉄鋼スラグからのクロム溶出量を低減する技術として、鉄鋼スラグを冷却することが提案されている（特開２０１６−１９６３８９号公報参照）。フッ素元素を含有する鉄鋼スラグからのフッ素溶出量を低減する技術として、鉄鋼スラグにカルシウムを含有する溶出抑制剤を混合することが提案されている（特開２０１６−４４１０２号公報参照）。 As a technique for reducing the amount of chromium eluted from steel slag containing a chromium element, it has been proposed to cool the steel slag (see Japanese Patent Application Laid-Open No. 2016-196389). As a technique for reducing the amount of fluorine eluted from steel slag containing a fluorine element, it has been proposed to mix a calcium-containing elution inhibitor with the steel slag (see JP-A-2016-44102).
上記特許文献１に示す技術では、フッ素溶出量及びクロム溶出量が上記基準を満たすことができないおそれがある。また、上記特許文献２に示す技術では、溶出抑制剤を製造する必要があり、手間がかかるため、効率的とはいい難い。 In the technique shown in Patent Document 1, there is a possibility that the amount of fluorine elution and the amount of chromium elution cannot meet the above criteria. Further, the technique shown in Patent Document 2 is not efficient because it is necessary to produce an elution inhibitor and it takes time and effort.
本発明はこのような事情に鑑みてなされたものであり、鉄鋼スラグからのフッ素溶出量及びクロム溶出量を、環境庁告示第４６号の基準を満たすよう、しかも効率的に低減することができる鉄鋼スラグの処理方法を提供することを課題とする。 The present invention has been made in view of such circumstances, and the amount of fluorine elution and the amount of chromium elution from steel slag can be efficiently reduced so as to satisfy the criteria of Notification No. 46 of the Environment Agency. An object of the present invention is to provide a method for treating steel slag.
上記課題を解決すべく本発明者らが鋭意研究したところ、フッ素元素及びクロム元素を含有する鉄鋼スラグに関し、溶融状態にある上記鉄鋼スラグを排滓した後の冷却速度を制御し、しかも、製鋼スラグを混合することで、鉄鋼スラグからのクロム溶出量及びフッ素溶出量の双方ともを、環境庁告示第４６号（以下、「環告４６号」ともいう。）の基準を満たし得ることを見出し、本発明を完成させるに至った。 As a result of diligent research by the present inventors to solve the above problems, regarding steel slag containing fluorine element and chromium element, the cooling rate after discharging the molten steel slag is controlled, and moreover, steelmaking is performed. It was found that by mixing slag, both the amount of chromium eluted from the steel slag and the amount of fluorine eluted can meet the criteria of Environmental Agency Notification No. 46 (hereinafter, also referred to as "Environment No. 46"). , The present invention has been completed.
すなわち、上記課題を解決するためになされた発明は、フッ素元素及びクロム元素を含有する鉄鋼スラグの処理方法であって、６００℃以上の上記鉄鋼スラグを８０℃／分以上の冷却速度で冷却する工程と、上記冷却工程で冷却された上記鉄鋼スラグを破砕する工程と、上記冷却工程で冷却された上記鉄鋼スラグを製鋼スラグと混合する工程とを備え、上記混合工程における上記鉄鋼スラグ及び上記製鋼スラグの合計質量に対する上記製鋼スラグの質量の比率が１０質量％以上９０質量％以下である鉄鋼スラグの処理方法である。 That is, the invention made to solve the above problems is a method for treating steel slag containing a fluorine element and a chromium element, in which the steel slag at 600 ° C. or higher is cooled at a cooling rate of 80 ° C./min or higher. A step of crushing the steel slag cooled in the cooling step, a step of mixing the steel slag cooled in the cooling step with the steelmaking slag, and the steelmaking slag and the steelmaking in the mixing step are provided. This is a method for treating steel slag in which the ratio of the mass of the steelmaking slag to the total mass of the slag is 10% by mass or more and 90% by mass or less.
当該鉄鋼スラグの処理方法が、６００℃以上の鉄鋼スラグを８０℃／分以上の冷却速度で冷却する工程を備えることで、鉄鋼スラグからのクロム溶出量を低減することができる。加えて、当該鉄鋼スラグの処理方法が、冷却工程で冷却した鉄鋼スラグを破砕する工程と、冷却工程で冷却した鉄鋼スラグを製鋼スラグと混合する工程とを備えることで、フッ素溶出量も低減することができる。そして、このような冷却工程、破砕工程及び混合工程を備え、製鋼スラグの比率を上記範囲とすることで、クロム溶出量及びフッ素溶出量の双方ともを環告４６号の基準を満たすよう低減することができる。しかも、冷却後の鉄鋼スラグに製鋼スラグを混合するだけで上記溶出量の低減が可能になるため、効率的である。 The method for treating the steel slag includes a step of cooling the steel slag at 600 ° C. or higher at a cooling rate of 80 ° C./min or higher, so that the amount of chromium eluted from the steel slag can be reduced. In addition, the method for treating the steel slag includes a step of crushing the steel slag cooled in the cooling step and a step of mixing the steel slag cooled in the cooling step with the steelmaking slag, thereby reducing the amount of fluorine elution. be able to. By providing such a cooling step, a crushing step and a mixing step and setting the ratio of steelmaking slag within the above range, both the amount of chromium elution and the amount of fluorine elution are reduced so as to satisfy the criteria of Circular No. 46. be able to. Moreover, it is efficient because the elution amount can be reduced only by mixing the steelmaking slag with the cooled steel slag.
上記破砕工程で破砕された上記鉄鋼スラグの最大粒径の上限としては、４０ｍｍが好ましく、上記混合工程で混合された上記製鋼スラグの最大粒径の上限としては、４０ｍｍが好ましい。 The upper limit of the maximum particle size of the steel slag crushed in the crushing step is preferably 40 mm, and the upper limit of the maximum particle size of the steelmaking slag mixed in the mixing step is preferably 40 mm.
上記鉄鋼スラグの最大粒径及び上記製鋼スラグの最大粒径が上記範囲であることで、上記鉄鋼スラグ及び上記製鋼スラグの全体の表面積が大きくなるため、より確実にフッ素溶出量及びクロム溶出量を低減することができる。 When the maximum particle size of the steel slag and the maximum particle size of the steelmaking slag are within the above ranges, the total surface area of the steel slag and the steelmaking slag becomes large, so that the amount of fluorine elution and the amount of chromium elution can be more reliably determined. Can be reduced.
上記冷却工程では、上記鉄鋼スラグを水冷することが好ましい。このように、上記冷却として上記鉄鋼スラグを水冷することで、より確実に上記冷却速度を８０℃／分以上にすることができるため、より確実にフッ素溶出量及びクロム溶出量を低減することができる。 In the cooling step, it is preferable to cool the steel slag with water. In this way, by cooling the steel slag with water as the cooling, the cooling rate can be more reliably set to 80 ° C./min or more, so that the amount of fluorine elution and the amount of chromium elution can be reduced more reliably. it can.
上記冷却工程では、上記鉄鋼スラグを水に浸漬することが好ましい。このように、上記冷却として上記鉄鋼スラグを水に浸漬することで、より確実に上記冷却速度を８０℃／分以上にすることができるため、より確実にフッ素溶出量及びクロム溶出量を低減することができる。 In the cooling step, it is preferable to immerse the steel slag in water. In this way, by immersing the steel slag in water as the cooling, the cooling rate can be more reliably set to 80 ° C./min or more, so that the amount of fluorine elution and the amount of chromium elution can be reduced more reliably. be able to.
ここで、「フッ素元素」には０価のフッ素元素（フッ素元素単体）の形態、フッ素元素と他の元素との化合物（フッ素元素化合物）の形態が含まれる。「クロム元素」には０価のクロム元素の形態、クロム元素と他の元素との化合物（クロム元素化合物）の形態が含まれる。「最大粒径」とは、ＪＩＳ Ａ５０１５（２０１８）「道路用鉄鋼スラグ」におけるＪＩＳ Ａ１１０２（２０１４）「骨材のふるい分け試験方法」に準拠して得られた粒径分布の累積ふるい下質量百分率が百となる最小の粒径を意味する。上記「累積ふるい下質量百分率が百となる最小の粒径」とは、測定に用いた試料が全て通過するふるいのうち、最も目開き（粒径）が小さいふるいの粒径を意味する。 Here, the "fluorine element" includes a form of a zero-valent fluorine element (elemental substance of fluorine element) and a form of a compound of a fluorine element and another element (fluorine element compound). The "chromium element" includes a form of a zero-valent chromium element and a form of a compound of a chromium element and another element (chromium element compound). The "maximum particle size" is the cumulative under-sieving mass percentage of the particle size distribution obtained in accordance with JIS A1102 (2014) "Aggregate sieving test method" in JIS A5015 (2018) "Road steel slag". It means the smallest particle size of 100. The above-mentioned "minimum particle size at which the cumulative mass percentage under the sieve is 100" means the particle size of the sieve having the smallest opening (particle size) among the sieves through which all the samples used for the measurement pass.
以上説明したように、本発明の鉄鋼スラグの処理方法を用いることで、鉄鋼スラグからのフッ素溶出量及びクロム溶出量を、環告４６号の基準を満たすよう、しかも効率的に低減することができる。 As described above, by using the method for treating steel slag of the present invention, it is possible to efficiently reduce the amount of fluorine elution and the amount of chromium elution from the steel slag so as to satisfy the criteria of Notification No. 46. it can.
以下、本発明の鉄鋼スラグの処理方法の実施形態について詳説する。なお、本明細書では、任意の事項について記載された複数の上限値のうちの１つと複数の下限値のうちの１つとを適宜組み合わせることができる。このように組み合わせることで、組み合わされた上限値と下限値との間の数値範囲が上記任意の事項の好適な数値範囲として本明細書中に記載されているものとする。ここで、上記した上限値と下限値との間の数値範囲は上限値から下限値までの数値範囲、及び下限値から上限値までの数値範囲を含む。 Hereinafter, embodiments of the method for treating steel slag of the present invention will be described in detail. In this specification, one of the plurality of upper limit values described for any matter and one of the plurality of lower limit values can be appropriately combined. By combining in this way, it is assumed that the numerical range between the combined upper limit value and the lower limit value is described in the present specification as a suitable numerical range of any of the above items. Here, the numerical range between the upper limit value and the lower limit value described above includes a numerical range from the upper limit value to the lower limit value and a numerical range from the lower limit value to the upper limit value.
当該鉄鋼スラグの処理方法は、フッ素元素及びクロム元素を含有する鉄鋼スラグの処理方法であって、６００℃以上の上記鉄鋼スラグを８０℃／分以上の冷却速度で冷却する工程と、上記冷却工程で冷却された鉄鋼スラグを破砕する工程と、上記冷却工程で冷却された鉄鋼スラグを製鋼スラグと混合する工程とを備え、上記混合工程における上記鉄鋼スラグ及び上記製鋼スラグの合計質量に対する上記製鋼スラグの質量の比率が１０質量％以上９０質量％以下である。 The steel slag treatment method is a method for treating steel slag containing a fluorine element and a chromium element, and is a step of cooling the steel slag at 600 ° C. or higher at a cooling rate of 80 ° C./min or higher, and a cooling step. A step of crushing the steel slag cooled in the above step and a step of mixing the steel slag cooled in the cooling step with the steelmaking slag are provided, and the steelmaking slag with respect to the total mass of the steelmaking slag and the steelmaking slag in the mixing step is provided. The mass ratio of is 10% by mass or more and 90% by mass or less.
［鉄鋼スラグ］
上記鉄鋼スラグは、フッ素元素及びクロム元素を含有する。鉄鋼スラグとしては、高炉スラグといった製銑の過程で生じる製銑スラグであってフッ素元素及びクロム元素を含有するもの、転炉スラグ又は電気炉スラグといった製鋼の過程で生じる製鋼スラグであってフッ素元素及びクロム元素を含有するもの等が挙げられる。上記鉄鋼スラグにおいて、フッ素元素は、通常、フッ化カルシウム（ＣａＦ２）といった塩（化合物）の形態で存在しているが、その存在形態は特に限定されない。上記鉄鋼スラグにおいて、クロム元素は、通常、ＭｇＣｒ２Ｏ４等の等の塩（化合物）の形態で存在しているが、その存在形態は特に限定されない。
[Steel slag]
The steel slag contains a fluorine element and a chromium element. Steel slags include iron-making slags such as blast furnace slags that are produced in the process of ironmaking and that contain fluorine elements and chromium elements, and steelmaking slags that are produced in the process of steelmaking such as converter slags or electric furnace slags and have fluorine elements. And those containing a chromium element and the like. In the above steel slag, the fluorine element usually exists in the form of a salt (compound) such as calcium fluoride (CaF 2), but the present form is not particularly limited. In the steel slag, the chromium element usually exists in the form of a salt (compound) such as MgCr 2 O 4, but the present form is not particularly limited.
［冷却工程］
冷却工程では、６００℃以上の上記鉄鋼スラグを８０℃／分以上の冷却速度で冷却する。鉄鋼スラグは炉内で通常１５５０℃以上の温度にて溶融状態で生成し、この溶融状態で炉内から排滓される。排滓された鉄鋼スラグを放置すると、排滓直後は比較的大きな冷却速度で冷却されるが、その後、冷却速度が小さくなる。冷却速度が小さくなると、冷却後の鉄鋼スラグからのクロム溶出量が大きくなる。そこで、冷却工程では、上記排滓後、６００℃以上の鉄鋼スラグを、８０℃／分以上の冷却速度で強制的に冷却する。
[Cooling process]
In the cooling step, the steel slag at 600 ° C. or higher is cooled at a cooling rate of 80 ° C./min or higher. Steel slag is usually produced in a molten state at a temperature of 1550 ° C. or higher in a furnace, and is discharged from the furnace in this molten state. If the discharged steel slag is left unattended, it is cooled at a relatively large cooling rate immediately after the slag is discharged, but then the cooling rate becomes low. As the cooling rate decreases, the amount of chromium eluted from the steel slag after cooling increases. Therefore, in the cooling step, after the slag is discharged, the steel slag at 600 ° C. or higher is forcibly cooled at a cooling rate of 80 ° C./min or higher.
冷却を行う際（直前）の鉄鋼スラグの温度は、６００℃以上であれば特に限定されない。冷却を行う際の鉄鋼スラグの温度の下限としては、例えば１３００℃が好ましい。鉄鋼スラグの温度が１３００℃に満たないと、鉄鋼スラグに含有されるクロム元素が六価のクロム元素に酸化され難くなるため、本１３００℃未満の温度から冷却を行っても十分な六価クロム溶出量の低減効果を得られないおそれがある。しかし、このように下限を１３００℃とする温度規定を行うことで、当該処理方法の優位性が向上する。一方、上記冷却を行う際の鉄鋼スラグの温度の上限としては、例えば１６００℃が好ましい。鉄鋼スラグの温度が１６００℃を超えると、熱エネルギーが無駄になるおそれがある。 The temperature of the steel slag at the time of cooling (immediately before) is not particularly limited as long as it is 600 ° C. or higher. As the lower limit of the temperature of the steel slag during cooling, for example, 1300 ° C. is preferable. If the temperature of the steel slag is less than 1300 ° C, the chromium element contained in the steel slag is less likely to be oxidized to the hexavalent chromium element. Therefore, even if cooling is performed from a temperature lower than 1300 ° C, sufficient hexavalent chromium is obtained. The effect of reducing the elution amount may not be obtained. However, by defining the temperature with the lower limit set to 1300 ° C. in this way, the superiority of the treatment method is improved. On the other hand, as the upper limit of the temperature of the steel slag when performing the above cooling, for example, 1600 ° C. is preferable. If the temperature of the steel slag exceeds 1600 ° C, thermal energy may be wasted.
さらに詳述すれば、８０℃／分以上の冷却速度での冷却は、鉄鋼スラグの温度が冷却を行う際（直前）の温度から６００℃になるまで行うことが好ましい。上記した冷却を行う際の鉄鋼スラグの温度を考慮すれば、鉄鋼スラグの温度が１３００℃から６００℃になるまでの間は少なくとも８０℃／分以上の冷却速度で冷却を行うことが好ましく、鉄鋼スラグの温度が１６００℃から６００℃になるまでの間は少なくとも８０℃／分以上の冷却速度で冷却を行うことがより好ましい。 More specifically, cooling at a cooling rate of 80 ° C./min or higher is preferably performed until the temperature of the steel slag becomes 600 ° C. from the temperature at which the steel slag is cooled (immediately before). Considering the temperature of the steel slag when performing the above-mentioned cooling, it is preferable to perform cooling at a cooling rate of at least 80 ° C./min or more from 1300 ° C. to 600 ° C., and the steel steel. It is more preferable to cool at a cooling rate of at least 80 ° C./min or more from 1600 ° C. to 600 ° C. for the slag temperature.
冷却速度の下限としては、８０℃／分であり、１００℃／分がより好ましい。上記冷却速度が上記範囲に満たないと、鉄鋼スラグからのフッ素溶出量及びクロム溶出量、特にクロム溶出量を十分に低減し難いおそれがある。一方、上記冷却速度の上限としては、特に限定されないが、７００℃／分が好ましく、５００℃／分がより好ましい。上記冷却速度が上記範囲を超えると、冷却速度の増大に比して鉄鋼スラグからのフッ素溶出量及びクロム溶出量の低減効果、特にクロム溶出量の低減効果が小さく、冷却に要するエネルギーが無駄になるおそれがある。 The lower limit of the cooling rate is 80 ° C./min, more preferably 100 ° C./min. If the cooling rate is less than the above range, it may be difficult to sufficiently reduce the amount of fluorine elution and the amount of chromium elution from the steel slag, particularly the amount of chromium elution. On the other hand, the upper limit of the cooling rate is not particularly limited, but is preferably 700 ° C./min, more preferably 500 ° C./min. When the cooling rate exceeds the above range, the effect of reducing the amount of fluorine elution and the amount of chromium elution from the steel slag, particularly the effect of reducing the amount of chromium elution, is small compared to the increase in the cooling rate, and the energy required for cooling is wasted. There is a risk of becoming.
上記冷却速度は、サーモグラフィを用いて経時的に鉄鋼スラグの温度を測定することや、ＪＩＳ Ｃ １６０２（２０１５）に記載のＲ熱電対と、データロガーとを用いて測定することによって得ることができる。 The cooling rate can be obtained by measuring the temperature of the steel slag over time using thermography, or by measuring using the R thermocouple described in JIS C 1602 (2015) and a data logger. ..
冷却を実施する手段としては、鉄鋼スラグを強制的に冷却することが可能であれば、特に限定されない。冷却を実施する手段としては、例えば水冷が挙げられる。水冷を用いることで、より確実に８０℃／分以上の冷却速度で鉄鋼スラグを冷却することができる。水冷としては、水を用いた冷却であれば、特に限定されない。水冷としては、例えば鉄鋼スラグに対して水を散布すること、鉄鋼スラグを水に浸漬すること等が挙げられる。このうち、水冷としては、鉄鋼スラグを水に浸漬することが好ましい。鉄鋼スラグを水に浸漬することで、より確実に鉄鋼スラグを８０℃／分以上の冷却速度で水冷することが可能となる。鉄鋼スラグの水への浸漬は、例えば排滓後のスラグを、水を収容した容器内に投入することによって行うことができる。この際、鉄鋼スラグを部分的に水に浸漬しても、鉄鋼スラグの全体を水に浸漬してもよいが、このうち、鉄鋼スラグ全体を水に浸漬することが好ましい。 The means for performing cooling is not particularly limited as long as it is possible to forcibly cool the steel slag. Examples of the means for performing cooling include water cooling. By using water cooling, the steel slag can be more reliably cooled at a cooling rate of 80 ° C./min or more. The water cooling is not particularly limited as long as it is cooling using water. Examples of water cooling include spraying water on steel slag, immersing steel slag in water, and the like. Of these, for water cooling, it is preferable to immerse the steel slag in water. By immersing the steel slag in water, the steel slag can be more reliably water-cooled at a cooling rate of 80 ° C./min or more. Immersion of steel slag in water can be performed, for example, by putting the slag after slag into a container containing water. At this time, the steel slag may be partially immersed in water or the entire steel slag may be immersed in water. Of these, it is preferable to immerse the entire steel slag in water.
水冷に用いる水としては、水道水や工業用水等が挙げられる。なお、浸漬等の水冷に用いた水は、水冷後に除去してもよいし、水冷後もそのまま後段の工程で使用し続けてもよい。 Examples of water used for water cooling include tap water and industrial water. The water used for water cooling such as immersion may be removed after water cooling, or may be continued to be used in the subsequent step as it is after water cooling.
［破砕工程］
破砕工程では、上記冷却工程で冷却された鉄鋼スラグを破砕する。鉄鋼スラグの破砕には、従来公知の破砕装置を用いることができる。破砕後の鉄鋼スラグの最大粒径の上限としては、４０ｍｍが好ましい。上記最大粒径の上限が上記範囲を超えると、鉄鋼スラグの全体の表面積が小さ過ぎるため、製鋼スラグとの全体の接触面積が小さくなり、フッ素溶出量及びクロム溶出量を低減すること、特にフッ素溶出量を低減することが困難になるおそれがある。一方、上記最大粒径の下限としては、１０ｍｍが好ましく、２０ｍｍがより好ましい。上記最大粒径の下限が上記範囲に満たないと、鉄鋼スラグが小さくなり過ぎ、取り扱い性が低下するおそれがある。また、鉄鋼スラグの粒径に比してフッ素溶出量及びクロム溶出量の低減効果、特にフッ素溶出量の低減効果が小さく、破砕に要するエネルギーが無駄になるおそれがある。
[Crushing process]
In the crushing step, the steel slag cooled in the cooling step is crushed. A conventionally known crushing device can be used for crushing the steel slag. The upper limit of the maximum particle size of the crushed steel slag is preferably 40 mm. When the upper limit of the maximum particle size exceeds the above range, the total surface area of the steel slag is too small, so that the total contact area with the steelmaking slag becomes small, and the amount of fluorine elution and the amount of chromium elution are reduced, particularly fluorine. It may be difficult to reduce the amount of elution. On the other hand, as the lower limit of the maximum particle size, 10 mm is preferable, and 20 mm is more preferable. If the lower limit of the maximum particle size does not reach the above range, the steel slag may become too small and the handleability may be deteriorated. Further, the effect of reducing the amount of fluorine elution and the amount of chromium elution, particularly the effect of reducing the amount of fluorine elution is small compared to the particle size of steel slag, and the energy required for crushing may be wasted.
破砕工程は、製鋼スラグを混合する前に行っても、製鋼スラグと混合した後に行ってもよい。破砕工程を製鋼スラグとの混合後に行う場合、別途破砕した製鋼スラグと上記冷却後の鉄鋼スラグとを混合し、製鋼スラグと共に鉄鋼スラグを破砕しても、破砕する前の製鋼スラグを上記冷却後の鉄鋼スラグとを混合し、製鋼スラグと共に鉄鋼スラグを破砕してもよい。 The crushing step may be performed before mixing the steelmaking slag or after mixing with the steelmaking slag. When the crushing step is performed after mixing with the steelmaking slag, even if the separately crushed steelmaking slag and the cooled steel slag are mixed and the steel slag is crushed together with the steelmaking slag, the steelmaking slag before crushing is after cooling. The steel slag may be mixed with the steel slag of the above and crushed together with the steel slag.
［混合工程］
混合工程では、上記冷却工程で冷却された上記鉄鋼スラグを製鋼スラグと混合する。この混合工程では、上記の通り、上記破砕工程で破砕した鉄鋼スラグと、別途破砕した製鋼スラグとを混合してもよく、上記冷却後の鉄鋼スラグと破砕前の製鋼スラグとを混合してもよい。後者の場合、上記冷却後の鉄鋼スラグと破砕前の製鋼スラグとを混合した後、上記破砕工程を行なえばよい。すなわち、上記破砕工程及び上記混合工程は、上記冷却工程の後で行われればよく、その順序は限定されない。
[Mixing process]
In the mixing step, the steel slag cooled in the cooling step is mixed with the steelmaking slag. In this mixing step, as described above, the steel slag crushed in the crushing step and the steelmaking slag crushed separately may be mixed, or the steel slag after cooling and the steelmaking slag before crushing may be mixed. Good. In the latter case, the crushing step may be performed after mixing the cooled steel slag and the steelmaking slag before crushing. That is, the crushing step and the mixing step may be performed after the cooling step, and the order thereof is not limited.
上記混合工程における上記鉄鋼スラグ及び上記製鋼スラグの合計質量に対する上記製鋼スラグの質量の比率の下限としては、１０質量％であり、２０質量％が好ましく、３０質量％がより好ましい。上記比率の下限が上記範囲に満たないと、フッ素溶出量及びクロム溶出量、特にフッ素溶出量を十分に低減することができないおそれがある。一方、上記比率の上限としては、９０質量％であり、８０質量％がより好ましく、７０質量％がさらに好ましく、６０質量％が特に好ましい。上記比率の上限が上記範囲を超えると、上記比率の増大に比してフッ素溶出量及びクロム溶出量の低減効果、特にフッ素溶出量の低減効果が小さく、製鋼スラグが無駄になるおそれがある。 The lower limit of the ratio of the mass of the steelmaking slag to the total mass of the steelmaking slag and the steelmaking slag in the mixing step is 10% by mass, preferably 20% by mass, and more preferably 30% by mass. If the lower limit of the above ratio does not fall within the above range, the amount of fluorine elution and the amount of chromium elution, particularly the amount of fluorine elution may not be sufficiently reduced. On the other hand, the upper limit of the above ratio is 90% by mass, more preferably 80% by mass, further preferably 70% by mass, and particularly preferably 60% by mass. When the upper limit of the above ratio exceeds the above range, the effect of reducing the amount of fluorine elution and the amount of chromium elution, particularly the effect of reducing the amount of fluorine elution, is smaller than the increase of the above ratio, and steelmaking slag may be wasted.
混合後の製鋼スラグの最大粒径の上限としては、４０ｍｍが好ましい。上記最大粒径の上限が上記範囲を超えると、製鋼スラグの全体の表面積が小さ過ぎるため、鉄鋼スラグとの全体の接触面積が小さくなり、フッ素溶出量及びクロム溶出量を低減すること、特にフッ素溶出量を低減することが困難になるおそれがある。一方、上記最大粒径の下限としては、１０ｍｍが好ましく、２０ｍｍがより好ましい。上記最大粒径の下限が上記範囲に満たないと、製鋼スラグが小さくなり過ぎて取り扱い性が低下するおそれがある。また、製鋼スラグの粒径に比してフッ素溶出量及びクロム溶出量、特にフッ素溶出量の低減効果が小さく、製鋼スラグの破砕に要するエネルギーが無駄になるおそれがある。 The upper limit of the maximum particle size of the steelmaking slag after mixing is preferably 40 mm. When the upper limit of the maximum particle size exceeds the above range, the total surface area of the steelmaking slag is too small, so that the total contact area with the steel slag becomes small, and the amount of fluorine elution and the amount of chromium elution are reduced, particularly fluorine. It may be difficult to reduce the amount of elution. On the other hand, as the lower limit of the maximum particle size, 10 mm is preferable, and 20 mm is more preferable. If the lower limit of the maximum particle size does not reach the above range, the steelmaking slag may become too small and the handleability may be deteriorated. Further, the effect of reducing the amount of fluorine elution and the amount of chromium elution, particularly the amount of fluorine elution, is smaller than the particle size of the steelmaking slag, and the energy required for crushing the steelmaking slag may be wasted.
なお、上記の通り、上記破砕工程後に破砕後の鉄鋼スラグと製鋼スラグとを混合する場合、混合後の製鋼スラグの粒径は、混合前の製鋼スラグの粒径に相当する。一方、破砕工程前に鉄鋼スラグと製鋼スラグとを混合する場合、製鋼スラグが予め別途破砕されていても破砕されていなくても、混合後に上記破砕工程を行うことで、製鋼スラグが破砕される。よって、混合工程後、破砕工程を行う場合には、製鋼スラグの粒径は、上記破砕工程後の製鋼スラグの粒径に相当する。 As described above, when the steel slag after crushing and the steelmaking slag are mixed after the crushing step, the particle size of the steelmaking slag after mixing corresponds to the particle size of the steelmaking slag before mixing. On the other hand, when the steel slag and the steelmaking slag are mixed before the crushing step, the steelmaking slag is crushed by performing the above crushing step after the mixing regardless of whether the steelmaking slag is separately crushed or not crushed in advance. .. Therefore, when the crushing step is performed after the mixing step, the particle size of the steelmaking slag corresponds to the particle size of the steelmaking slag after the crushing step.
製鋼スラグとしては、転炉スラグ又は電気炉スラグといった製鋼の過程で生じる製鋼スラグ等が挙げられる。ここで、製鋼スラグは、通常、酸化カルシウム（塩）成分としてカルシウム元素を含有しており、この製鋼スラグが水と接触すると、製鋼スラグ中のカルシウム元素分がカルシウムイオンとして溶出する。一方、鉄鋼スラグがフッ素元素を含有していると、鉄鋼スラグが水と接触すると、フッ化物イオンが溶出する。よって、製鋼スラグとフッ素元素を含有する鉄鋼スラグとの混合物が水と接触すると、製鋼スラグに由来するカルシムイオンと鉄鋼スラグに由来するフッ化物イオンとが溶出し、これらによって水に難溶性のフッ化カルシウムが生成する。このフッ化カルシウムの生成により、フッ素溶出量を低減することができる。 Examples of the steelmaking slag include steelmaking slag generated in the process of steelmaking such as converter slag or electric furnace slag. Here, the steelmaking slag usually contains a calcium element as a calcium oxide (salt) component, and when the steelmaking slag comes into contact with water, the calcium element component in the steelmaking slag is eluted as calcium ions. On the other hand, when the steel slag contains a fluorine element, when the steel slag comes into contact with water, fluoride ions are eluted. Therefore, when a mixture of steelmaking slag and steel slag containing a fluorine element comes into contact with water, calcium ions derived from steelmaking slag and fluoride ions derived from steelmaking slag are eluted, which are sparingly soluble in water. Calcium fluoride is produced. By producing this calcium fluoride, the amount of fluorine eluted can be reduced.
製鋼スラグ中のカルシウム元素の含有量は、鉄鋼スラグ中のフッ素元素の含有量等に応じて適宜設定されればよい。例えば製鋼スラグ中のカルシウム元素の含有量の下限としては、製鋼スラグのみを水に接触させたときのカルシウムイオンの溶出量が６００ｍｇ／Ｌ以上となるような含有量であると好ましい。上記下限がこの含有量に満たないと、フッ素溶出量を十分に低減することが困難になるおそれがある。一方、製鋼スラグ中のカルシウム元素の含有量の上限としては、製鋼スラグのみを水に接触させたときのカルシウムイオンの溶出量が１０００ｍｇ／Ｌ以下、好ましくは９００ｍｇ／Ｌ以下となるような含有量であると好ましい。上記上限がこの含有量を超えると、カルシウム元素の含有量に比してフッ素溶出量の低減効果が小さく、カルシウム元素の含有量が無駄に増大するおそれがある。 The content of the calcium element in the steelmaking slag may be appropriately set according to the content of the fluorine element in the steelmaking slag and the like. For example, the lower limit of the content of the calcium element in the steelmaking slag is preferably such that the amount of calcium ions eluted when only the steelmaking slag is brought into contact with water is 600 mg / L or more. If the above lower limit does not reach this content, it may be difficult to sufficiently reduce the amount of fluorine eluted. On the other hand, the upper limit of the content of calcium element in the steelmaking slag is such that the amount of calcium ions eluted when only the steelmaking slag is brought into contact with water is 1000 mg / L or less, preferably 900 mg / L or less. Is preferable. If the above upper limit exceeds this content, the effect of reducing the amount of fluorine elution is small as compared with the content of calcium element, and the content of calcium element may be unnecessarily increased.
このような点を考慮すると、製鋼スラグ中のカルシウム元素の含有量の上限としては、酸化カルシウム（ＣａＯ）換算で、１０質量％が好ましく、２０質量％がより好ましく、３０質量％がさらに好ましい。一方、製鋼スラグ中のカルシウム元素の含有量の上限としては、酸化カルシウム（ＣａＯ）換算で、６０質量％が好ましく、５０質量％がより好ましい。 Considering these points, the upper limit of the content of the calcium element in the steelmaking slag is preferably 10% by mass, more preferably 20% by mass, and even more preferably 30% by mass in terms of calcium oxide (CaO). On the other hand, the upper limit of the content of the calcium element in the steelmaking slag is preferably 60% by mass, more preferably 50% by mass in terms of calcium oxide (CaO).
鉄鋼スラグ以外の成分からの無駄なフッ素溶出量及びクロム溶出量の溶出を抑制するという点では、製鋼スラグ中のフッ素元素及びクロム元素の含有量が小さい程好ましい。この点では、例えば製鋼スラグ中のフッ素元素の含有量の上限としては、０．２質量％が好ましい。また、例えば製鋼スラグ中のクロム元素の含有量の上限としては、三酸化二クロム（Ｃｒ２Ｏ３）換算で１．０質量％が好ましい。 The smaller the content of the fluorine element and the chromium element in the steelmaking slag is, the more preferable it is in terms of suppressing the elution of the unnecessary fluorine elution amount and the chromium elution amount from the components other than the steel slag. In this respect, for example, the upper limit of the content of the fluorine element in the steelmaking slag is preferably 0.2% by mass. Further, for example, the upper limit of the content of the chromium element in the steelmaking slag is preferably 1.0% by mass in terms of dichromium trioxide (Cr 2 O 3).
＜鉄鋼スラグからのフッ素溶出量及びクロム溶出量の低下の確認＞
上記冷却工程、混合工程及び破砕工程によって得られた鉄鋼スラグと製鋼スラグとの混合物について、後述する実施例の「溶出試験」にて示すように、環告４６号に基づいて溶出試験を行う。この溶出試験を行うことで、フッ素溶出量及びクロム溶出量を測定することができる。そして、これらの溶出量が環告４６号の土壌環境基準、具体的にはフッ素溶出量が０．８ｍｇ／Ｌ以下、クロム溶出量が０．０５ｍｇ／Ｌ以下であることを確認すればよい。
<Confirmation of decrease in fluorine elution amount and chromium elution amount from steel slag>
A mixture of steel slag and steelmaking slag obtained by the above cooling step, mixing step and crushing step is subjected to an elution test based on Notification No. 46 as shown in the "dissolution test" of Examples described later. By performing this elution test, the amount of fluorine elution and the amount of chromium elution can be measured. Then, it may be confirmed that these elution amounts are based on the soil environmental standard of Circular No. 46, specifically, the fluorine elution amount is 0.8 mg / L or less and the chromium elution amount is 0.05 mg / L or less.
＜利点＞
当該鉄鋼スラグの処理方法を用いることで、鉄鋼スラグからのフッ素溶出量及びクロム溶出量を、環告４６号の基準を満たすよう、しかも効率的に低減することができる。
<Advantage>
By using the method for treating steel slag, the amount of fluorine elution and the amount of chromium elution from the steel slag can be efficiently reduced so as to satisfy the criteria of Notification No. 46.
［その他の実施形態］
なお、本発明は、上記実施形態に限定されるものではない。例えば、上記実施形態では冷却工程で鉄鋼スラグの温度が６００℃になるまで８０℃／分以上の冷却速度で冷却する場合について説明したが、当該鉄鋼スラグの処理方法では、６００℃未満の温度まで８０℃／分以上の冷却速度で冷却を行ってもよい。
[Other Embodiments]
The present invention is not limited to the above embodiment. For example, in the above embodiment, the case where the steel slag is cooled at a cooling rate of 80 ° C./min or more until the temperature of the steel slag reaches 600 ° C. in the cooling step has been described. Cooling may be performed at a cooling rate of 80 ° C./min or higher.
以下、実施例によって本発明をさらに詳細に説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
処理対象物である鉄鋼スラグ（「Ａ」成分）として、下記表１に示す組成を有する鉄鋼スラグを用いた。製鋼スラグ（「Ｂ」成分）として、下記表２に示す組成を有する製鋼スラグを用いた。また、「Ａ」成分を処理（加熱、冷却、破砕及び混合）する前に、その「Ａ」成分中の組成を、以下の方法で測定した。この「Ａ」成分からのフッ素溶出量及びクロム溶出量を、下記の溶出試験によって測定した。この「Ａ」成分及び「Ｂ」成分の最大粒径を、下記の方法で測定した。 As the steel slag (“A” component) to be treated, steel slag having the composition shown in Table 1 below was used. As the steelmaking slag (component "B"), a steelmaking slag having the composition shown in Table 2 below was used. Further, before treating (heating, cooling, crushing and mixing) the "A" component, the composition in the "A" component was measured by the following method. The amount of fluorine elution and the amount of chromium elution from the "A" component were measured by the following elution test. The maximum particle size of the "A" component and the "B" component was measured by the following method.
「Ｂ」成分についても、「Ａ」成分と混合する前に、その「Ｂ」成分中の組成、「Ｂ」成分からのフッ素溶出量及びクロム溶出量、及びこの「Ｂ」成分の最大粒径を、上記「Ａ」成分と同様にして測定した。 As for the "B" component, the composition in the "B" component, the amount of fluorine eluted from the "B" component and the amount of chromium eluted, and the maximum particle size of the "B" component before being mixed with the "A" component. Was measured in the same manner as the above-mentioned "A" component.
（試料中に含有される組成成分の測定方法）
試料に含まれる組成成分の含有量を下記のように測定した。すなわち、酸化カルシウム（ＣａＯ）の含有量は、ＪＩＳ Ｍ８２２１（１９９７）「鉄鉱石−カルシウム定量方法」によって測定した。酸化ケイ素（ＳｉＯ２）の含有量、酸化アルミニウム（Ａｌ２Ｏ３）の含有量及び酸化マグネシウム（ＭｇＯ）の含有量は、ＪＩＳ Ｍ８２０６（２０１４）「鉄鉱石−ＩＣＰ発行分光分析方法」によって測定した。三酸化二クロム（Ｃｒ２Ｏ３）の含有量は、ＪＩＳ Ｍ８２０６（２０１４）「鉄鉱石−ＩＣＰ発行分光分析方法」のうち、「３ 用語及び定義」〜「５ 要旨」、「７ 装置」〜「１４．１ 最終結果の計算」を引用して測定した。ただし、この規格のうち、「６ 試薬」については、この項目に記載された原液及び標準液に代えて、市販のクロム標準液（１０００ｐｐｍ）を使用することで、この項目を引用した。また、「１４．２ 酸化物含有率の算出」については、この項目に記載された換算係数に代えて、クロム（Ｃｒ）から三酸化二クロム（Ｃｒ２Ｏ３）への換算係数として１．４６１５を用いることで、この項目を引用した。
(Measuring method of composition components contained in the sample)
The content of the composition component contained in the sample was measured as follows. That is, the content of calcium oxide (CaO) was measured by JIS M8221 (1997) "Iron ore-calcium quantification method". The content of silicon oxide (SiO 2 ), the content of aluminum oxide (Al 2 O 3 ), and the content of magnesium oxide (MgO) were measured by JIS M8206 (2014) "Iron ore-ICP-issued spectroscopic analysis method". .. The content of dichromium trichloride (Cr 2 O 3 ) is described in "3 Terms and Definitions" to "5 Abstracts" and "7 Instruments" in JIS M8206 (2014) "Iron Ore-ICP Issued Spectroscopic Analysis Method". The measurement was carried out by citing "14.1 Calculation of final result". However, for "6 reagents" in this standard, this item was cited by using a commercially available chromium standard solution (1000 ppm) instead of the stock solution and standard solution described in this item. Regarding "14.2 Calculation of Oxide Content", instead of the conversion coefficient described in this item, the conversion coefficient from chromium (Cr) to dichromium trioxide (Cr 2 O 3 ) is 1. This item was cited by using 4615.
（溶出試験）
試験液として、ＪＩＳ Ｋ ０５５７（１９９８）のＡ３又はＡ４の水（以下、「純水」という）を用いた。各試料を、環境省の土壌環境基準である環境庁告示第４６号の（イ）に準拠して、０．５ｍｍ以上５ｍｍ以下の目のふるいを通過させた後、純水と混合した。具体的には、上記各試料と純水とを質量体積比（｛（試料の質量）／（純水の体積）｝×１００）が１０％となる割合で、かつ、全体の体積が５００ｍＬ以上となるように混合した。得られた混合液（混合物）を常温（おおよそ２０℃、具体的には５℃以上３５℃以下）、常圧（おおよそ１０１．３ｋＰａ（１気圧）、具体的には８６ｋＰａ以上１０６ｋＰａ以下）、振とう回数：２００回／分、振とう幅：４ｃｍ以上５ｃｍ以下、振とう時間：６時間の条件で振とうした。この振とうによって、試料からフッ化物イオン及び六価クロムイオンを水に溶出させた（溶出操作）。この振とう後、混合液を静置し、その後、遠心加速度：３０００Ｇ、時間：２０分の条件で遠心分離操作を行った。遠心分離操作の後、上澄み（試料液）を孔径１μｍのメンブランフィルターでろ過し、溶出液を得た。得られた溶出液中のフッ素溶出量を、ＪＩＳ Ｋ０１０２（２０１６）の３４．１「工場排水試験方法：ふっ素化合物：ランタン−アリザリンコンプレキソン吸光光度法」によって測定した。溶出液中のクロム溶出量を、ＪＩＳ Ｋ０１０２（２０１６）の６５．２．１「工場排水試験方法：クロム（ＶＩ）：ジフェニルカルバジド吸光光度法」及びＪＩＳ Ｋ０１０２（２０１６）の６５．２．４「工場排水試験方法：クロム（ＶＩ）：ＩＣＰ発光分析法」に定める方法に準拠して測定した。
(Dissolution test)
As the test solution, JIS K 0557 (1998) A3 or A4 water (hereinafter referred to as "pure water") was used. Each sample was passed through an eye sieve of 0.5 mm or more and 5 mm or less in accordance with (a) of Notification No. 46 of the Environment Agency, which is a soil environmental standard of the Ministry of the Environment, and then mixed with pure water. Specifically, the mass-volume ratio ({(mass of sample) / (volume of pure water)} × 100) between each of the above samples and pure water is 10%, and the total volume is 500 mL or more. It was mixed so as to be. The obtained mixed solution (mixture) is shaken at room temperature (approximately 20 ° C., specifically 5 ° C. or higher and 35 ° C. or lower), normal pressure (approximately 101.3 kPa (1 atm), specifically 86 kPa or higher and 106 kPa or lower). The mixture was shaken under the conditions of the number of times of shaking: 200 times / minute, the shaking width: 4 cm or more and 5 cm or less, and the shaking time: 6 hours. By this shaking, fluoride ions and hexavalent chromium ions were eluted from the sample into water (eluting operation). After this shaking, the mixed solution was allowed to stand, and then the centrifugation operation was performed under the conditions of centrifugal acceleration: 3000 G and time: 20 minutes. After the centrifugation operation, the supernatant (sample solution) was filtered through a membrane filter having a pore size of 1 μm to obtain an eluate. The amount of fluorine eluted in the obtained eluate was measured by JIS K0102 (2016) 34.1 “Factory waste test method: fluorine compound: lanthanum-alizarin complexone absorptiometry”. The amount of chromium eluted in the eluent was determined by JIS K0102 (2016) 65.2.1 “Factory waste test method: Chromium (VI): diphenylcarbazide absorptiometry” and JIS K0102 (2016) 65.2.4. The measurement was performed in accordance with the method specified in "Factory wastewater test method: Chromium (VI): ICP emission spectrometry".
（最大粒径）
ＪＩＳ Ａ５０１５（２０１８）「道路用鉄鋼スラグ」におけるＪＩＳ Ａ１１０２（２０１４）「骨材のふるい分け試験方法」に準拠して各試料の粒径分布を得た。得られた粒径分布の累積ふるい下質量百分率が百となる最小の粒径を、各試料の最大粒径とした。上記「累積ふるい下質量百分率が百となる最小の粒径」とは、試料が全て通過するふるいのうち、最も目開き（粒径）が小さいふるいの粒径である。
(Maximum particle size)
The particle size distribution of each sample was obtained in accordance with JIS A1102 (2014) "Aggregate sieving test method" in JIS A5015 (2018) "Road steel slag". The minimum particle size at which the cumulative mass percentage under the sieve of the obtained particle size distribution was 100 was defined as the maximum particle size of each sample. The above-mentioned "minimum particle size at which the cumulative mass percentage under the sieve is 100" is the particle size of the sieve having the smallest opening (particle size) among the sieves through which all the samples pass.
［試験例１］
上記「Ａ」成分を電気炉で１６００℃に加熱し、加熱炉から「Ａ」成分を排滓した直後の１６００℃の「Ａ」成分を６００℃になるまで、表３に示す冷却速度となるようそれぞれ冷却した後、破砕した。このときの冷却速度と、破砕後の「Ａ」成分からのクロム溶出量との関係を調べた。クロム溶出量は、上記溶出試験によって測定した。結果を表３に示す。
[Test Example 1]
The cooling rate shown in Table 3 is obtained until the "A" component at 1600 ° C. is heated to 1600 ° C. in an electric furnace and the "A" component at 1600 ° C. immediately after the "A" component is discharged from the heating furnace reaches 600 ° C. After cooling each, it was crushed. The relationship between the cooling rate at this time and the amount of chromium eluted from the "A" component after crushing was investigated. The amount of chromium eluted was measured by the above dissolution test. The results are shown in Table 3.
表３に示す結果に基づいて、冷却速度をｘ軸、クロム溶出量をｙ軸とするグラフにて実験例１〜実験例５のデータをプロットし、近似曲線を作成すると、この近似曲線は式ｙ＝７．９４６８ｘ−１．１５３で表され、相関係数はＲ２＝０．９９５８となる。この近似曲線式によると、冷却速度が８０℃／分以上ではクロム溶出量が０．０５ｍｇ／Ｌ以下となる。このように、６００℃以上の鉄鋼スラグを８０℃／分以上の冷却速度で冷却することで、クロム溶出量を、環告４６号の土壌環境基準を満たす程度まで低減できることが分かった。 Based on the results shown in Table 3, plot the data of Experimental Examples 1 to 5 on a graph with the cooling rate on the x-axis and the amount of chromium elution on the y-axis, and create an approximate curve. It is represented by y = 7.9468 x −1.153 , and the correlation coefficient is R 2 = 0.9958. According to this approximate curve formula, the chromium elution amount is 0.05 mg / L or less when the cooling rate is 80 ° C./min or more. As described above, it was found that by cooling the steel slag at 600 ° C. or higher at a cooling rate of 80 ° C./min or higher, the amount of chromium elution can be reduced to the extent that the soil environmental standard of Circular No. 46 is satisfied.
［試験例２］
上記「Ａ」成分を電気炉で１６００℃に加熱し、加熱炉から「Ａ」成分を排滓した後の１６００℃の「Ａ」成分を６００℃になるまで、水に浸漬することで８０℃／分の冷却速度で冷却した後、破砕した。破砕した「Ａ」成分と、上記「Ｂ」成分とを、表４に示す配合でそれぞれ混合し、混合物を試料として上記溶出試験によってフッ素溶出量及びカルシウムイオン溶出量を測定した。結果を表４に示す。
[Test Example 2]
The above "A" component is heated to 1600 ° C. in an electric furnace, and after the "A" component is discharged from the heating furnace, the "A" component at 1600 ° C. is immersed in water until it reaches 600 ° C. to reach 80 ° C. After cooling at a cooling rate of / min, it was crushed. The crushed "A" component and the above "B" component were mixed in the formulations shown in Table 4, and the amount of fluorine elution and the amount of calcium ion elution were measured by the above elution test using the mixture as a sample. The results are shown in Table 4.
表４に示すように、６００℃以上の鉄鋼スラグを８０℃／分の冷却速度で冷却した鉄鋼スラグに製鋼スラグを混合し、この混合の際、鉄鋼スラグと製鋼スラグの鉄鋼スラグ及び製鋼スラグの合計質量に対して製鋼スラグを１０質量％以上９０質量％以下とすることで、フッ素溶出量を環告４６号の土壌環境基準を満たす程度まで低減できることが分かった。 As shown in Table 4, steelmaking slag is mixed with steelmaking slag obtained by cooling steelmaking slag at 600 ° C. or higher at a cooling rate of 80 ° C./min. It was found that by setting the steelmaking slag to 10% by mass or more and 90% by mass or less with respect to the total mass, the amount of fluorine elution can be reduced to the extent that the soil environmental standard of Circular No. 46 is satisfied.
上記表３及び表４の結果、６００℃以上の鉄鋼スラグを８０℃／分以上の冷却速度で冷却した鉄鋼スラグに製鋼スラグを混合し、この混合の際、鉄鋼スラグと製鋼スラグの鉄鋼スラグ及び製鋼スラグの合計質量に対して製鋼スラグを１０質量％以上９０質量％以下とすることで、フッ素溶出量及びクロム溶出量をそれぞれ環告４６号の土壌環境基準を満たす程度まで低減できることが分かった。 As a result of Tables 3 and 4 above, steel slag was mixed with steel slag obtained by cooling steel slag at 600 ° C or higher at a cooling rate of 80 ° C / min or higher. It was found that by setting the steelmaking slag to 10% by mass or more and 90% by mass or less with respect to the total mass of the steelmaking slag, the fluorine elution amount and the chromium elution amount can be reduced to the extent that each of them meets the soil environment standard of Circular No. 46. ..
以上説明したように、本発明の鉄鋼スラグの処理方法を用いることで、鉄鋼スラグからのフッ素溶出量及びクロム溶出量を、環告４６号の基準を満たすよう、しかも効率的に低減することができる。従って、本発明の鉄鋼スラグの処理方法は、フッ素及びクロム元素を含有する鉄鋼スラグを、陸上埋立、海域埋立といった埋立等に有効に利用することが可能となる。 As described above, by using the method for treating steel slag of the present invention, it is possible to efficiently reduce the amount of fluorine elution and the amount of chromium elution from the steel slag so as to satisfy the criteria of Notification No. 46. it can. Therefore, the method for treating steel slag of the present invention makes it possible to effectively use steel slag containing fluorine and chromium elements for land reclamation, land reclamation, and the like.
Claims (4)
６００℃以上の上記鉄鋼スラグを８０℃／分以上の冷却速度で冷却する工程と、
上記冷却工程で冷却された鉄鋼スラグを破砕する工程と、
上記冷却工程で冷却された鉄鋼スラグを製鋼スラグと混合する工程と
を備え、
上記混合工程における上記鉄鋼スラグ及び上記製鋼スラグの合計質量に対する上記製鋼スラグの質量の比率が１０質量％以上９０質量％以下である鉄鋼スラグの処理方法。 A method for treating steel slag containing elemental fluorine and elemental chromium.
A process of cooling the above steel slag at 600 ° C or higher at a cooling rate of 80 ° C / min or higher, and
The process of crushing the steel slag cooled in the above cooling process and
It is provided with a process of mixing the steel slag cooled in the above cooling process with the steelmaking slag.
A method for treating steel slag in which the ratio of the mass of the steel slag to the total mass of the steel slag and the steel slag in the mixing step is 10% by mass or more and 90% by mass or less.
上記混合工程で混合された製鋼スラグの最大粒径が４０ｍｍ以下である請求項１に記載の鉄鋼スラグの処理方法。 The maximum particle size of the steel slag crushed in the above crushing step is 40 mm or less.
The method for treating steel slag according to claim 1, wherein the maximum particle size of the steelmaking slag mixed in the mixing step is 40 mm or less.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002053905A (en) * | 2000-08-03 | 2002-02-19 | Kawasaki Steel Corp | Method of suppressing elution of fluorine from slag |
| JP2009114011A (en) * | 2007-11-05 | 2009-05-28 | Taiheiyo Cement Corp | Cement additive and cement composition |
| JP2014065627A (en) * | 2012-09-25 | 2014-04-17 | Nippon Steel & Sumitomo Metal | Processing method of civil engineering construction material using iron steel slag |
| JP2015189602A (en) * | 2014-03-27 | 2015-11-02 | Ｊｆｅスチール株式会社 | Method of modifying steel slag and steel slag |
| JP2015202479A (en) * | 2014-04-16 | 2015-11-16 | 株式会社神戸製鋼所 | Method for suppressing elution of fluorine and/or hexavalent chromium |
| JP2016044102A (en) * | 2014-08-22 | 2016-04-04 | 株式会社神戸製鋼所 | Method for suppressing elution of fluorine from steel by-product |
| JP2016182572A (en) * | 2015-03-26 | 2016-10-20 | 株式会社神戸製鋼所 | Elution inhibition method for fluorine and hexavalent chromium, manufacturing method of civil engineering and harbor material, manufacturing method of underground burying material, civil engineering and harbor material, and underground burying material |
| JP2016196389A (en) * | 2015-04-06 | 2016-11-24 | 株式会社神戸製鋼所 | Method for suppressing hexavalent chromium elution from slag |
| JP2016209847A (en) * | 2015-05-13 | 2016-12-15 | 株式会社神戸製鋼所 | Elution suppression method of fluorine, production method of material for civil engineering and port, production method of underground burying material, material for civil engineering and port and underground burying material |
-
2019
- 2019-10-04 JP JP2019184035A patent/JP2021059469A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002053905A (en) * | 2000-08-03 | 2002-02-19 | Kawasaki Steel Corp | Method of suppressing elution of fluorine from slag |
| JP2009114011A (en) * | 2007-11-05 | 2009-05-28 | Taiheiyo Cement Corp | Cement additive and cement composition |
| JP2014065627A (en) * | 2012-09-25 | 2014-04-17 | Nippon Steel & Sumitomo Metal | Processing method of civil engineering construction material using iron steel slag |
| JP2015189602A (en) * | 2014-03-27 | 2015-11-02 | Ｊｆｅスチール株式会社 | Method of modifying steel slag and steel slag |
| JP2015202479A (en) * | 2014-04-16 | 2015-11-16 | 株式会社神戸製鋼所 | Method for suppressing elution of fluorine and/or hexavalent chromium |
| JP2016044102A (en) * | 2014-08-22 | 2016-04-04 | 株式会社神戸製鋼所 | Method for suppressing elution of fluorine from steel by-product |
| JP2016182572A (en) * | 2015-03-26 | 2016-10-20 | 株式会社神戸製鋼所 | Elution inhibition method for fluorine and hexavalent chromium, manufacturing method of civil engineering and harbor material, manufacturing method of underground burying material, civil engineering and harbor material, and underground burying material |
| JP2016196389A (en) * | 2015-04-06 | 2016-11-24 | 株式会社神戸製鋼所 | Method for suppressing hexavalent chromium elution from slag |
| JP2016209847A (en) * | 2015-05-13 | 2016-12-15 | 株式会社神戸製鋼所 | Elution suppression method of fluorine, production method of material for civil engineering and port, production method of underground burying material, material for civil engineering and port and underground burying material |
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