JP2013028520A - Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag - Google Patents

Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag Download PDF

Info

Publication number
JP2013028520A
JP2013028520A JP2012090736A JP2012090736A JP2013028520A JP 2013028520 A JP2013028520 A JP 2013028520A JP 2012090736 A JP2012090736 A JP 2012090736A JP 2012090736 A JP2012090736 A JP 2012090736A JP 2013028520 A JP2013028520 A JP 2013028520A
Authority
JP
Japan
Prior art keywords
slag
sulfur
hot metal
aqueous solution
metal desulfurization
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.)
Pending
Application number
JP2012090736A
Other languages
Japanese (ja)
Inventor
Keiji Watanabe
圭児 渡辺
Katsunori Takahashi
克則 高橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Priority to JP2012090736A priority Critical patent/JP2013028520A/en
Publication of JP2013028520A publication Critical patent/JP2013028520A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies

Landscapes

  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Furnace Details (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Processing Of Solid Wastes (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

PROBLEM TO BE SOLVED: To extract sulfur from sulfur-containing slag in a short time without carrying out high temperature treatment, to separate and remove sulfur from hot metal desulfurization slag, and to recycle the slag thereof.SOLUTION: At least one kind of slag selected from hot metal desulfurization slag and air-cooled blast furnace slag is immersed in an aqueous solution of pH 13.0 or more, whereby the sulfur content in the slag is dissolved in the aqueous solution and extracted. Hot metal desulfurization slag from which sulfur has been extracted by this extraction method is used as a desulfurization flux in hot metal pretreatment or as a raw material for sintering.

Description

本発明は、硫黄含有スラグから硫黄分を抽出する方法と、この方法によって硫黄分を抽出された溶銑脱硫スラグのリサイクル方法に関する。   The present invention relates to a method for extracting sulfur from sulfur-containing slag and a method for recycling hot metal desulfurization slag from which sulfur has been extracted by this method.

高炉溶銑中には鋼の品質に悪影響を及ぼす硫黄（Ｓ）が０．０２〜０．０５mass％程度含まれているが、転炉工程は不純物の酸化除去を目的としているために、一部気化脱硫するものを除いて転炉工程での溶鋼の脱硫は見込めない。そこで、要求される品質に応じて、高炉と転炉工程間での溶銑脱硫や転炉工程後の溶鋼脱硫が行われている。脱硫剤としては、Ｃａ化合物（ＣａＯ，ＣａＣ２等）が使用されることが多く、これらは溶銑中のＳと反応して脱硫スラグとして排出される。 The blast furnace hot metal contains about 0.02 to 0.05 mass% of sulfur (S), which adversely affects the quality of steel, but the converter process is intended to remove impurities, so it is partially vaporized. Except for what is desulfurized, desulfurization of molten steel in the converter process is not expected. Therefore, hot metal desulfurization between the blast furnace and the converter process and molten steel desulfurization after the converter process are performed according to the required quality. As the desulfurizing agent, Ca compounds (CaO, CaC 2 etc.) are often used, and these react with S in the hot metal and are discharged as desulfurized slag.

転炉などの乾式精錬工程で生成するスラグは、メタル分を除去した後、肥料、路盤材、土工材などに再利用されている。しかしながら、脱硫スラグは硫黄分が高い上に、ＣａＯ分が高く粉化しやすいことから、路盤材や土工材等の用途には使用できず、ごく限られた用途にしか使用できない。
一方、高炉で生成するスラグには、吹製水により急冷した水砕スラグと、ドライピット等で比較的ゆっくりと冷却した徐冷スラグがある。このうち高炉水砕スラグはセメント原料やコンクリート骨材などに利用され、高炉徐冷スラグは主に路盤材に利用されている。高炉スラグ中には１mass％程度のＳが含有され、高炉徐冷スラグについては、それが原因で黄水が発生する場合があるため、数ヶ月程度のエージング期間を経て十分に酸化させた後、出荷されている。 Slag produced in dry refining processes such as converters is reused for fertilizers, roadbed materials, earthwork materials, etc. after removing the metal. However, since desulfurization slag has a high sulfur content and a high CaO content and is easily pulverized, it cannot be used for applications such as roadbed materials and earthwork materials, and can be used only for limited applications.
On the other hand, the slag generated in the blast furnace includes a granulated slag rapidly cooled by blown water and a slowly cooled slag cooled relatively slowly by a dry pit or the like. Of these, granulated blast furnace slag is used for cement raw materials and concrete aggregates, and blast furnace slow-cooled slag is mainly used for roadbed materials. The blast furnace slag contains about 1 mass% of S, and the blast furnace slow-cooled slag may generate yellow water due to this, so after being sufficiently oxidized after an aging period of about several months, It has been shipped.

従来、スラグから硫黄を除去するための方法として、スラグをＣＯ２雰囲気下で９００℃以上に加熱する方法（特許文献１）、還元スラグに水蒸気を接触させて加水分解により硫黄を低減させる方法（特許文献２）、水蒸気を１５〜５０vol％含む７０℃以上の気体を流速０．０３〜３０ｍ／minで吹き付ける方法（特許文献３）、還元剤を添加して加熱減圧して気化脱硫する方法（特許文献４）、脱硫滓に水や空気を吹き込んでＨ２Ｓあるいは燃焼ガスとして除去する方法（特許文献５〜７）などが提案されている。 Conventionally, as a method for removing sulfur from slag, a method of heating slag to 900 ° C. or more under a CO 2 atmosphere (Patent Document 1), a method of bringing sulfur into contact with reduced slag and reducing sulfur by hydrolysis ( Patent Document 2), a method of spraying a gas of 70 ° C. or more containing 15 to 50 vol% of water vapor at a flow rate of 0.03 to 30 m / min (Patent Document 3), a method of adding a reducing agent and heating and depressurizing to vaporize and desulfurize ( Patent Document 4), a method (Patent Documents 5 to 7) in which water or air is blown into a desulfurization slag and removed as H 2 S or combustion gas has been proposed.

特開２００８−３０８７５４号公報JP 2008-308754 A 特開２００８−１６３３９１号公報JP 2008-163391 A 特許３１９３８６９号公報Japanese Patent No. 3193869 特許２５２０５８７号公報Japanese Patent No. 2520587 特開昭５５−９７４０８号公報JP-A-55-97408 特開昭５４−８４８８９号公報JP-A-54-84889 特開昭５３−９０１９３号公報JP-A-53-90193

しかし、特許文献１、３、４の方法では、スラグを９００〜１０００℃以上に加熱する必要があり、処理コストが高くなる。また、特許文献５〜７の方法では、高温の脱硫滓に同様の処理をすることにより、短時間処理を可能にしているものの、すでに冷却してしまったスラグには適用できない。一方、１００℃程度で低温処理する特許文献２の方法は、処理に数日程度要するため、処理効率が低いという問題がある。   However, in the methods of Patent Documents 1, 3, and 4, it is necessary to heat the slag to 900 to 1000 ° C. or higher, which increases the processing cost. In addition, the methods of Patent Documents 5 to 7 are not applicable to slag that has already been cooled, although the same treatment can be performed on high-temperature desulfurization soot for a short time. On the other hand, the method of Patent Document 2 in which the low temperature treatment is performed at about 100 ° C. has a problem that the treatment efficiency is low because the treatment requires several days.

したがって本発明の目的は、硫黄含有スラグから硫黄分を短時間で且つ高温処理することなく抽出することができる方法を提供することにある。また、本発明の他の目的は、その方法で硫黄分が分離除去された溶銑脱硫スラグをリサイクルする方法を提供することにある。   Accordingly, an object of the present invention is to provide a method capable of extracting a sulfur content from a sulfur-containing slag in a short time and without being subjected to a high temperature treatment. Another object of the present invention is to provide a method for recycling hot metal desulfurization slag from which sulfur content has been separated and removed by the method.

本発明者らは、上記課題を解決すべく検討を重ねた結果、（i）元々溶銑脱硫スラグはｐＨ１２程度、高炉徐冷スラグはｐＨ１１程度の高アルカリであるが、これをより高ｐＨの水溶液に浸漬すると硫黄分が優先的に溶解し、硫黄を効率的に抽出できること、（ii）一方、溶銑脱硫スラグの場合、ＣａＯなどの塩基性酸化物については、スラグからの溶解が抑えられるため、硫黄抽出処理後のスラグは、硫黄分が少なく且つＣａＯを十分に含有する材料としてリサイクル利用が可能であること、を見出した。
本発明は、このような知見に基づきなされたもので、以下を要旨とするものである。 As a result of repeated studies to solve the above-mentioned problems, the inventors of the present invention (i) Originally, the hot metal desulfurization slag is a high alkali having a pH of about 12, and the blast furnace slow-cooled slag is a high alkali having a pH of about 11. (Ii) On the other hand, in the case of hot metal desulfurization slag, for basic oxides such as CaO, dissolution from the slag can be suppressed. It has been found that the slag after the sulfur extraction treatment can be recycled as a material having a low sulfur content and sufficiently containing CaO.
The present invention has been made on the basis of such knowledge and has the following gist.

［1］溶銑脱硫スラグ、高炉徐冷スラグの中から選ばれる１種以上のスラグをｐＨ１３．０以上の水溶液中に浸漬し、水溶液にスラグ中の硫黄分を溶解させ、硫黄分を抽出することを特徴とする硫黄含有スラグからの硫黄の抽出方法。
［2］上記［1］の抽出方法において、水溶液がｐＨ調整剤として水酸化ナトリウム、水酸化カリウムの中から選ばれる１種又は２種を含むことを特徴とする硫黄含有スラグからの硫黄の抽出方法。
［3］上記［1］又は［2］の抽出方法により硫黄が抽出された溶銑脱硫スラグを、溶銑予備処理における脱硫フラックスとして用いることを特徴とする溶銑脱硫スラグのリサイクル方法。
［4］上記［1］又は［2］の抽出方法により硫黄が抽出された溶銑脱硫スラグを、焼結原料として用いることを特徴とする溶銑脱硫スラグのリサイクル方法。 [1] One or more slags selected from hot metal desulfurization slag and blast furnace slow-cooled slag are immersed in an aqueous solution having a pH of 13.0 or more, and the sulfur content in the slag is dissolved in the aqueous solution to extract the sulfur content. A method for extracting sulfur from sulfur-containing slag characterized by the above.
[2] Extraction of sulfur from sulfur-containing slag, wherein the aqueous solution contains one or two kinds selected from sodium hydroxide and potassium hydroxide as a pH adjusting agent in the extraction method of [1] above Method.
[3] A method for recycling hot metal desulfurization slag, wherein the hot metal desulfurization slag from which sulfur has been extracted by the extraction method of [1] or [2] is used as a desulfurization flux in hot metal pretreatment.
[4] A method for recycling hot metal desulfurization slag, wherein the hot metal desulfurization slag from which sulfur is extracted by the extraction method of [1] or [2] is used as a sintering raw material.

本発明の抽出方法によれば、溶銑脱硫スラグや高炉徐冷スラグから硫黄分を短時間で且つ高温処理することなく抽出することができる。
また、本発明の溶銑脱硫スラグのリサイクル方法によれば、硫黄分が分離除去された溶銑脱硫スラグを有効にリサイクル利用することができる。 According to the extraction method of the present invention, sulfur can be extracted from hot metal desulfurization slag or blast furnace slow-cooled slag in a short time without being subjected to high-temperature treatment.
Moreover, according to the hot metal desulfurization slag recycling method of the present invention, the hot metal desulfurization slag from which the sulfur content has been separated and removed can be effectively recycled.

ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際に水溶液に溶出したＳの濃度を、水溶液のＮａＯＨ濃度との関係で示したグラフThe graph which showed the density | concentration of S eluted to aqueous solution when hot metal desulfurization slag was immersed in the aqueous solution which added NaOH (pH adjuster) in relation to the NaOH concentration of aqueous solution. ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際に水溶液に溶出したＳｉの濃度を、水溶液のＮａＯＨ濃度との関係で示したグラフThe graph which showed the density | concentration of Si eluted to aqueous solution when hot metal desulfurization slag was immersed in the aqueous solution which added NaOH (pH adjuster) in relation to the NaOH concentration of aqueous solution. ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際に水溶液に溶出したＡｌの濃度を、水溶液のＮａＯＨ濃度との関係で示したグラフThe graph which showed the density | concentration of Al eluted to aqueous solution when the hot metal desulfurization slag was immersed in the aqueous solution which added NaOH (pH adjuster) in relation to the NaOH concentration of aqueous solution. ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際に水溶液に溶出したＣａの濃度を、水溶液のＮａＯＨ濃度との関係で示したグラフThe graph which showed the density | concentration of Ca eluted to aqueous solution when the hot metal desulfurization slag was immersed in the aqueous solution which added NaOH (pH adjuster) in relation to the NaOH concentration of aqueous solution. ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際に水溶液に溶出したＭｇの濃度を、水溶液のＮａＯＨ濃度との関係で示したグラフThe graph which showed the density | concentration of Mg eluted to aqueous solution when hot metal desulfurization slag was immersed in the aqueous solution which added NaOH (pH adjuster) in relation to the NaOH concentration of aqueous solution. 水溶液のＮａＯＨ濃度とｐＨとの関係を示したグラフGraph showing the relationship between NaOH concentration and pH of aqueous solution 図１〜図５の結果などに基づき、スラグ中の各成分（元素）の水溶液中への抽出率と水溶液ｐＨとの関係を示したグラフA graph showing the relationship between the extraction rate of each component (element) in the slag into the aqueous solution and the aqueous solution pH based on the results of FIGS.

溶銑脱硫スラグは、鉄鋼製造プロセスの溶銑予備処理工程で発生するスラグであり、一般的な組成は、Ｓが１〜３mass％であり、ＣａＯとＳｉＯ２を主成分とし、またはさらにＡｌ２Ｏ３およびＭｇＯを含有する。また、高炉徐冷スラグの一般的な組成は、Ｓが０．５〜１．４mass％であり、ＣａＯとＳｉＯ２を主成分とし、またはさらにＡｌ２Ｏ３およびＭｇＯを含有する。
本発明による硫黄含有スラグからの硫黄の抽出方法は、溶銑脱硫スラグ、高炉徐冷スラグの中から選ばれる１種以上のスラグをｐＨ１３．０以上の水溶液中に浸漬し、水溶液にスラグ中の硫黄分を溶解させ、硫黄分を抽出するものである。 Hot metal desulfurization slag is slag generated in the hot metal pretreatment step of the steel manufacturing process, and the general composition is that S is 1 to 3 mass%, CaO and SiO 2 are the main components, or Al 2 O 3. And MgO. Further, general composition of slowly cooled blast furnace slag, S is 0.5～1.4Mass%, mainly composed of CaO and SiO 2, or further contains Al 2 O 3 and MgO.
In the method for extracting sulfur from sulfur-containing slag according to the present invention, one or more slags selected from hot metal desulfurization slag and blast furnace slow cooling slag are immersed in an aqueous solution having a pH of 13.0 or more, and the sulfur in the slag is immersed in the aqueous solution. The component is dissolved and the sulfur component is extracted.

さきに述べたように溶銑脱硫スラグや高炉徐冷スラグは元々ｐＨ１１〜１２程度の高アルカリであるが、このようなスラグを、よりｐＨが高いｐＨ１３．０以上（好ましくはｐＨ１４．０以上、より好ましくはｐＨ１４．５以上）の水溶液に浸漬すると硫黄分が優先的に溶解し、硫黄を効率的に抽出することができる。
すなわち、このような高ｐＨ領域では、溶銑脱硫スラグに含まれる成分のうち、硫黄酸化物の溶解量が非常に多くなる一方で、ＣａＯやＭｇＯ等の塩基性酸化物の溶解量が少なくなる。また、中性酸化物（Ａｌ２Ｏ３等）や酸性酸化物（ＳｉＯ２等）の溶解は増加するが、後述する図７に示されるように量的にはそれほど多くない。したがって、実質的に硫黄分のみを選択的に溶解させ、水溶液に抽出することができ、必要であれば硫黄分の回収を行うことができる。一方、ＣａＯ、ＭｇＯ、ＳｉＯ２等の大部分は溶解することなくスラグに留まるため、硫黄分を抽出処理後のスラグは、例えば、脱硫フラックスや焼結原料としてリサイクル利用することができる。また、高炉徐冷スラグについても、上記と同様に硫黄を効率的に抽出することができ、且つ他の酸化物の溶解（抽出）は少なくすることが可能である。このように硫黄の効率的な抽出を行えることにより、従来、数ヶ月を要していたエージング期間を大幅に短縮することができる。 As mentioned above, hot metal desulfurization slag and blast furnace slow-cooled slag are originally highly alkaline with a pH of about 11 to 12, but such slag has a higher pH of 13.0 or more (preferably a pH of 14.0 or more, more When immersed in an aqueous solution (preferably pH 14.5 or higher), the sulfur content is preferentially dissolved and sulfur can be extracted efficiently.
That is, in such a high pH region, among the components contained in the hot metal desulfurization slag, the amount of dissolved sulfur oxides becomes very large, while the amount of dissolved basic oxides such as CaO and MgO decreases. Moreover, although dissolution of neutral oxides (Al 2 O 3 etc.) and acidic oxides (SiO 2 etc.) increases, it is not so much quantitatively as shown in FIG. Therefore, substantially only the sulfur content can be selectively dissolved and extracted into an aqueous solution, and if necessary, the sulfur content can be recovered. On the other hand, since most of CaO, MgO, SiO 2 and the like remain in the slag without being dissolved, the slag after extracting the sulfur component can be recycled, for example, as a desulfurization flux or a sintering raw material. Also, blast furnace slag slag can be extracted efficiently in the same manner as described above, and the dissolution (extraction) of other oxides can be reduced. As a result of the efficient extraction of sulfur in this way, the aging period, which conventionally required several months, can be greatly shortened.

これに対して、例えば、酸を添加して低ｐＨにした水溶液に溶銑脱硫スラグや高炉徐冷スラグを浸漬した場合には、ＣａＯ、ＭｇＯ、ＳｉＯ２も同時に溶解するため、硫黄分のみの選択的な抽出ができない。また、溶銑脱硫スラグについては、処理後のスラグ（残渣）を脱硫フラックスや焼結原料としてリサイクル利用することもできない。
水溶液をｐＨ１３．０以上にするために添加されるｐＨ調整剤としては、水酸化ナトリウムや水酸化カリウムが挙げられ、これらの１種又は２種を用いることができる。 On the other hand, for example, when hot metal desulfurization slag or blast furnace slow-cooled slag is immersed in an aqueous solution that has been made to have a low pH by adding an acid, CaO, MgO, and SiO 2 are simultaneously dissolved, so only the sulfur content is selected. Extraction is impossible. Moreover, about hot metal desulfurization slag, the processed slag (residue) cannot be recycled as a desulfurization flux or a sintering raw material.
Sodium hydroxide and potassium hydroxide are mentioned as a pH adjuster added in order to make aqueous solution pH13.0 or more, These 1 type or 2 types can be used.

ｐＨ調整剤の添加量は、調整するｐＨ値によって決められるが、通常、水酸化ナトリウムを用いる場合には１規定以上とする。
溶銑脱硫スラグは粉状である場合が多いので、粒度調整しなくても充分な溶解特性が得られるものであり、水溶液に浸漬する溶銑脱硫スラグの粒度は特に制限はないが、最大粒度を２ｍｍ以下とすることが好ましい。７５μｍ以下がさらに好ましい。 The addition amount of the pH adjusting agent is determined by the pH value to be adjusted, but is usually 1 N or more when sodium hydroxide is used.
Since the hot metal desulfurization slag is often in the form of powder, sufficient dissolution characteristics can be obtained without adjusting the particle size, and the particle size of the hot metal desulfurization slag immersed in the aqueous solution is not particularly limited, but the maximum particle size is 2 mm. The following is preferable. More preferably, it is 75 μm or less.

溶銑脱硫スラグを上記水溶液に浸漬する際の浸漬時間は、１時間以上が好ましい。また、水溶液の温度は０〜１００℃で充分な溶解特性が得られる。
水溶液中での浸漬処理は、スラグを容器（カラム）に充填して水溶液中Ｓ濃度が所定濃度となるまで水溶液を循環する方式、スラグを水溶液に入れた槽で水溶液を循環または撹拌する方式などにより実施できる。
一方、高炉徐冷スラグの場合、通常、最大粒径２５〜４０ｍｍとする粒度で路盤材に適用されるため、その粒度のスラグを水溶液に入れた槽で水溶液を循環または撹拌する方式などにより実施できる。 The immersion time when the hot metal desulfurization slag is immersed in the aqueous solution is preferably 1 hour or more. Moreover, sufficient dissolution characteristics are obtained when the temperature of the aqueous solution is 0 to 100 ° C.
Immersion treatment in an aqueous solution is a method in which slag is filled in a container (column) and the aqueous solution is circulated until the S concentration in the aqueous solution reaches a predetermined concentration, a method in which the aqueous solution is circulated or stirred in a tank in which the slag is placed in the aqueous solution, etc. Can be implemented.
On the other hand, in the case of blast furnace chilled slag, it is usually applied to roadbed materials with a maximum particle size of 25 to 40 mm. Therefore, it is carried out by circulating or stirring the aqueous solution in a tank containing the slag of that particle size in the aqueous solution. it can.

図１〜図５は、ＮａＯＨ（ｐＨ調整剤）を添加した水溶液に溶銑脱硫スラグを浸漬した際のスラグ成分（元素）の溶解量を、水溶液のＮａＯＨ濃度との関係で示したものである。溶銑脱硫スラグとしては、スラグ中のＳがエージング期間とともに変化する可能性があるため、脱硫処理直後からの期間が５日間、３週間、１年間という３種類のスラグを用いた。この試験では、ポリエチレン製の広口ビン（８ｃｍφ）に最大粒度７５μｍのスラグ２０ｇと水溶液２００ｍｌを入れ、撹拌翼（６ｃｍ）を用いて撹拌（撹拌速度：２００ｒｐｍ）し、６時間の溶出処理を行った。
なお、ＮａＯＨを添加した水溶液であって、溶銑脱硫スラグ（図７では溶銑脱硫スラグと高炉徐冷スラグ）を浸漬し、スラグ成分（元素）が溶解されている状態の水溶液を、図１〜７では溶出液と表記した。 1 to 5 show the amount of slag components (elements) dissolved in an aqueous solution to which NaOH (pH adjusting agent) is added in relation to the NaOH concentration of the aqueous solution. As the hot metal desulfurization slag, since there is a possibility that S in the slag changes with the aging period, three types of slag having a period immediately after the desulfurization treatment of 5 days, 3 weeks, and 1 year were used. In this test, 20 g of slag having a maximum particle size of 75 μm and 200 ml of an aqueous solution were placed in a polyethylene wide-mouthed bottle (8 cmφ), stirred using a stirring blade (6 cm) (stirring speed: 200 rpm), and subjected to an elution treatment for 6 hours. .
In addition, it is the aqueous solution which added NaOH, Comprising: Hot metal desulfurization slag (FIG. 7 hot metal desulfurization slag and blast furnace slow cooling slag) is immersed, and the aqueous solution in the state in which the slag component (element) is melt | dissolved is shown in FIGS. In FIG.

図４及び図５に示されるようにＣａ、ＭｇはＮａＯＨ濃度が高い（高ｐＨ）ほど溶解量が少なくなる。また、図２及び図３に示されるようにＳｉ、Ａｌは、ＮａＯＨ濃度が高い（高ｐＨ）ほど溶解量が多くなるが、溶解量は２００ｍｇ／Ｌ以下であり、量的にはそれほど多くない。これに対して、図１に示されるようにＳはＮａＯＨ濃度が高い（高ｐＨ）ほど溶解量が多くなり、且つその絶対量も非常に多い。すなわち、ＮａＯＨ濃度が高い（高ｐＨ）水溶液に溶銑脱硫スラグを浸漬させることにより、スラグに含まれる成分のうち、実質的に硫黄分のみを選択的に溶解させ、水溶液に抽出できることが判る。また、エージング期間（脱硫処理直後からの期間）に関わりなく、硫黄分を水溶液に抽出できることが判る。なお、図１に示されるＳ濃度はすべての酸化状態のＳを含む濃度である。   As shown in FIG. 4 and FIG. 5, the dissolved amount of Ca and Mg decreases as the NaOH concentration increases (high pH). Further, as shown in FIG. 2 and FIG. 3, Si and Al have a higher dissolved amount as the NaOH concentration is higher (higher pH), but the dissolved amount is 200 mg / L or less and is not so much quantitatively. . On the other hand, as shown in FIG. 1, the higher the NaOH concentration (higher pH), the greater the amount of S dissolved and the greater the absolute amount thereof. That is, it can be seen that, by immersing molten iron desulfurization slag in an aqueous solution having a high NaOH concentration (high pH), only the sulfur component of the components contained in the slag can be selectively dissolved and extracted into the aqueous solution. Moreover, it turns out that a sulfur content can be extracted to aqueous solution irrespective of an aging period (period immediately after a desulfurization process). The S concentration shown in FIG. 1 is a concentration including S in all oxidation states.

図６に水溶液のＮａＯＨ濃度とｐＨとの関係を示す。図７は、図１〜図５の結果に基づき、溶銑脱硫スラグ中の各成分（元素）の水溶液中への抽出率と水溶液ｐＨとの関係を示したものであり、ｐＨ１３．０以上でＳの抽出率が１０mass％以上となり、特にｐＨ１４．０以上では４０mass％以上となり、ｐＨ１４．５ではほぼ１００mass％となっている。また、Ｃａ、Ｓｉ、ＡｌおよびＭｇはほとんど抽出されない。   FIG. 6 shows the relationship between the NaOH concentration of the aqueous solution and the pH. FIG. 7 shows the relationship between the extraction rate of each component (element) in the hot metal desulfurization slag into the aqueous solution and the aqueous solution pH based on the results of FIGS. The extraction rate is 10 mass% or more, particularly 40 mass% or more at pH 14.0 or more, and almost 100 mass% at pH 14.5. Moreover, Ca, Si, Al, and Mg are hardly extracted.

一方、ＪＩＳ−Ａ５０１５に準拠したＭＳ２５の粒度分布をもつ未エージングの高炉徐冷スラグに、種々の濃度のＮａＯＨを添加した後、タンクリーチング試験（ＪＩＳ−Ｋ００５８−１）に供し、スラグ中の各成分（元素）の水溶液中への抽出率と水溶液ｐＨとの関係を調べた。その結果（Ｓの抽出率のみ）も図７に併せて示す。これによれば、Ｓの抽出率はｐＨ１３．０以上で３mass％以上となり、特にｐＨ１４以上では１０mass％以上となっている。図示しないが、溶銑脱硫スラグと同様、Ｃａ、Ｓｉ、ＡｌおよびＭｇの溶解量は２００ｍｇ／Ｌ以下であり、ほとんど抽出されなかった。高炉徐冷スラグの場合、Ｓの抽出率は溶銑脱硫スラグと比較して低いが、これは、粒度が大きいためである。水溶液のｐＨを１３．０とし、望ましくは１４．０以上とすることで、黄水が発生しないことが確認されており（ＪＩＳ−Ａ５０１５ 付属書１ 鉄鋼スラグの呈色判定試験方法）、本発明法を適用することにより、長期間のエージングなしで黄水を抑制することができる。   On the other hand, after adding various concentrations of NaOH to unaged blast furnace slow-cooled slag having a particle size distribution of MS25 in accordance with JIS-A5015, it was subjected to a tank leaching test (JIS-K0058-1), and each of the slag The relationship between the extraction rate of components (elements) into an aqueous solution and the aqueous solution pH was examined. The result (only the extraction rate of S) is also shown in FIG. According to this, the extraction rate of S is 3 mass% or more at pH 13.0 or more, and particularly 10 mass% or more at pH 14 or more. Although not shown, like the hot metal desulfurization slag, the dissolution amount of Ca, Si, Al, and Mg was 200 mg / L or less and was hardly extracted. In the case of blast furnace slow-cooled slag, the extraction rate of S is lower than that of hot metal desulfurization slag, but this is because the particle size is large. It has been confirmed that yellow water is not generated by setting the pH of the aqueous solution to 13.0, preferably 14.0 or more (JIS-A5015 Appendix 1 Coloring judgment test method for steel slag), and the present invention. By applying the method, yellow water can be suppressed without long-term aging.

溶銑脱硫スラグから硫黄を分離・除去すると、残分は脱硫能を持つスラグとなるので、本発明法により硫黄が抽出された溶銑脱硫スラグ（硫黄の一部又は全部が分離・除去されたスラグ）を、乾燥後に再び溶銑予備処理における脱硫フラックスとして用いることができる。すなわち、利材化しにくい粉状の溶銑脱硫スラグをリサイクル利用することが可能となる。
また、本発明法により硫黄が抽出された溶銑脱硫スラグ（硫黄の一部又は全部が分離・除去されたスラグ）は焼結原料として用いることもでき、このような焼結原料を使用することで、焼結鉱製造時のＳＯｘの発生を抑えることができる。 When sulfur is separated and removed from the hot metal desulfurization slag, the residue becomes slag having desulfurization ability, so the hot metal desulfurization slag from which sulfur has been extracted by the method of the present invention (slag from which part or all of the sulfur has been separated and removed) Can be used again as a desulfurization flux in the hot metal pretreatment after drying. That is, it becomes possible to recycle the powdered hot metal desulfurization slag that is difficult to use as a material.
Moreover, hot metal desulfurization slag from which sulfur has been extracted by the method of the present invention (slag from which part or all of sulfur has been separated and removed) can also be used as a sintering raw material. By using such a sintering raw material, In addition, the generation of SOx during the production of sintered ore can be suppressed.

撹拌機を有する処理容器内に、ＮａＯＨを添加して種々のｐＨに調整した水溶液（液温：５〜９５℃）を２０〜２００Ｌ入れ、そこに溶銑脱硫スラグ（ＣａＯ：５０mass％、ＳｉＯ２：１０mass％、ＭｇＯ：２ｍass％、Ｓ：２mass％、最大粒度：０．０７５〜５ｍｍ）又は未エージングの高炉徐冷スラグ（ＣａＯ：４２mass％、ＳｉＯ２：３３mass％、ＭｇＯ：７ｍass％、Ｓ：１mass％、最大粒度：２５ｍｍ）を２ｋｇ投入し、撹拌機で水溶液を撹拌しながら１〜２４時間浸漬処理した。処理後の水溶液中の硫黄濃度を測定し、硫黄の抽出率を測定した。その結果を、試験条件（水溶液のｐＨなど）とともに表１に示す。
発明例１１については、Ｓ抽出直後及び１ヵ月後に呈色試験を実施したが、呈色は確認されなかった。これに対して、比較例２では呈色が確認された。 In a processing vessel having a stirrer, 20 to 200 L of an aqueous solution (liquid temperature: 5 to 95 ° C.) adjusted to various pH by adding NaOH is added, and hot metal desulfurization slag (CaO: 50 mass%, SiO 2 : 10mass%, MgO: 2mass%, S: 2mass%, maximum particle size: 0.075~5mm) or non-aged blast furnace slowly cooled slag (CaO: 42mass%, SiO 2 : 33mass%, MgO: 7mass%, S: 1mass %, Maximum particle size: 25 mm) was added, and immersion treatment was performed for 1 to 24 hours while stirring the aqueous solution with a stirrer. The sulfur concentration in the aqueous solution after the treatment was measured, and the sulfur extraction rate was measured. The results are shown in Table 1 together with the test conditions (such as the pH of the aqueous solution).
For Invention Example 11, a color test was conducted immediately after S extraction and after 1 month, but no color was confirmed. On the other hand, in Comparative Example 2, coloration was confirmed.

Figure 2013028520
Figure 2013028520

Claims (4)

溶銑脱硫スラグ、高炉徐冷スラグの中から選ばれる１種以上のスラグをｐＨ１３．０以上の水溶液中に浸漬し、水溶液にスラグ中の硫黄分を溶解させ、硫黄分を抽出することを特徴とする硫黄含有スラグからの硫黄の抽出方法。   One or more types of slag selected from hot metal desulfurization slag and blast furnace slow cooling slag are immersed in an aqueous solution having a pH of 13.0 or more, and the sulfur content in the slag is dissolved in the aqueous solution to extract the sulfur content. To extract sulfur from sulfur-containing slag. 水溶液がｐＨ調整剤として水酸化ナトリウム、水酸化カリウムの中から選ばれる１種又は２種を含むことを特徴とする請求項１に記載の硫黄含有スラグからの硫黄の抽出方法。   The method for extracting sulfur from sulfur-containing slag according to claim 1, wherein the aqueous solution contains one or two kinds selected from sodium hydroxide and potassium hydroxide as a pH adjuster. 請求項１又は２に記載の抽出方法により硫黄が抽出された溶銑脱硫スラグを、溶銑予備処理における脱硫フラックスとして用いることを特徴とする溶銑脱硫スラグのリサイクル方法。   A method for recycling hot metal desulfurization slag, wherein the hot metal desulfurization slag from which sulfur has been extracted by the extraction method according to claim 1 or 2 is used as a desulfurization flux in hot metal pretreatment. 請求項１又は２に記載の抽出方法により硫黄が抽出された溶銑脱硫スラグを、焼結原料として用いることを特徴とする溶銑脱硫スラグのリサイクル方法。   A hot metal desulfurization slag recycling method, wherein the hot metal desulfurization slag from which sulfur is extracted by the extraction method according to claim 1 or 2 is used as a sintering raw material.
JP2012090736A 2011-06-24 2012-04-12 Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag Pending JP2013028520A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2012090736A JP2013028520A (en) 2011-06-24 2012-04-12 Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2011140380 2011-06-24
JP2011140380 2011-06-24
JP2012090736A JP2013028520A (en) 2011-06-24 2012-04-12 Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag

Publications (1)

Publication Number Publication Date
JP2013028520A true JP2013028520A (en) 2013-02-07

Family

ID=47785941

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2012090736A Pending JP2013028520A (en) 2011-06-24 2012-04-12 Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag

Country Status (1)

Country Link
JP (1) JP2013028520A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104120272A (en) * 2014-07-01 2014-10-29 昆明理工大学 Comprehensive utilization method of sulfur slag generated in hyperbaric oxygen leaching of zinc concentrate
JP2016047957A (en) * 2014-08-28 2016-04-07 株式会社神戸製鋼所 Method for removing sulfur from steel by-product
JP2018020943A (en) * 2016-08-05 2018-02-08 デンカ株式会社 Dusting slag, cement admixture using the same and manufacturing method therefor
JP2018131672A (en) * 2017-02-17 2018-08-23 新日鐵住金株式会社 Desulfurization method of sulfur-containing slag, manufacturing method of civil engineering construction material utilizing sulfur-containing slag and manufacturing method of slag construction body
CN111250518A (en) * 2020-02-21 2020-06-09 江苏沙钢集团有限公司 Method for efficiently recycling KR desulfurization slag
CN115215300A (en) * 2021-04-20 2022-10-21 中南大学 Method for recovering elemental sulfur from high-sulfur slag

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104120272A (en) * 2014-07-01 2014-10-29 昆明理工大学 Comprehensive utilization method of sulfur slag generated in hyperbaric oxygen leaching of zinc concentrate
JP2016047957A (en) * 2014-08-28 2016-04-07 株式会社神戸製鋼所 Method for removing sulfur from steel by-product
JP2018020943A (en) * 2016-08-05 2018-02-08 デンカ株式会社 Dusting slag, cement admixture using the same and manufacturing method therefor
JP2018131672A (en) * 2017-02-17 2018-08-23 新日鐵住金株式会社 Desulfurization method of sulfur-containing slag, manufacturing method of civil engineering construction material utilizing sulfur-containing slag and manufacturing method of slag construction body
CN111250518A (en) * 2020-02-21 2020-06-09 江苏沙钢集团有限公司 Method for efficiently recycling KR desulfurization slag
CN115215300A (en) * 2021-04-20 2022-10-21 中南大学 Method for recovering elemental sulfur from high-sulfur slag
CN115215300B (en) * 2021-04-20 2023-08-01 中南大学 Method for recycling elemental sulfur from high-sulfur slag

Similar Documents

Publication Publication Date Title
JP2013028520A (en) Method for extracting sulfur from sulfur-containing slag and method for recycling hot metal desulfurization slag
JP4196997B2 (en) Hot metal processing method
JP6064341B2 (en) How to remove sulfur from desulfurized slag
CN113373275A (en) Internal recycling method for KR desulfurization slag steel plant
JP6230531B2 (en) Method for producing metallic chromium
JP6003911B2 (en) Phosphate fertilizer raw material, phosphate fertilizer and production method thereof
JP2006274442A (en) Method for dephosphorize-treating molten iron
JP4837536B2 (en) Hot metal desulfurization refining agent and desulfurization method
JP5493335B2 (en) Hot copper decoppering method
JP2013189688A (en) Method for removing sulfur from desulfurization slag
JP5884186B2 (en) Desulfurization slag regeneration method and desulfurization slag recycling method
JP4998677B2 (en) Reuse method of desulfurization slag
JP2008308754A (en) Sulfer removal method for used slag
CN110527789B (en) Vacuum induction furnace desulfurization and dephosphorization process
JP5337956B2 (en) Method for treating chromium oxide-containing material
JP2008050700A (en) Method for treating chromium-containing steel slag
JP2017001894A (en) Slag suppressed in componential elution
JP6466869B2 (en) Operation method of copper smelting furnace
JP2017071858A (en) Recovery method of refining flux from molten iron desulfurized slag and dephosphorization/desulfurization method
CN115852090B (en) Method for modifying and recycling metallurgical refining waste residues
TWI398525B (en) De-sulfur agent for ladle furnace of refining process and method for removing sulfur from the molten steel in ladle furnace
JP6665654B2 (en) Silica removal method
JP5828506B2 (en) Hot metal desulfurization refining agent and hot metal desulfurization method
KR101618305B1 (en) Flux for removing copper and method for removing copper using the same
JP6175911B2 (en) Method of adding titanium to molten iron