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TREATMENT METHOD OF MOLTEN IRON DESULFURIZATION SLAG
To provide a method for treating molten iron desulfurization slag, by which elution of fluorine and selenium from the desulfurization slag can be suppressed so that an elution amount satisfies an environmental standard.SOLUTION: Provided is a method for treating desulfurization slag having a free lime content of 50% by mass or less, which is generated by a molten iron desulfurization treatment using a lime-based desulfurization agent. This treatment method has a sprinkling step for sprinkling water of 20 vol% or more of the slag amount to the desulfurization slag and an oxidation step for oxidizing the desulfurization slag before or/and after the sprinkling step. Fluorine is easily eluted into water in desulfurization slag having a small amount of free lime content. By sprinkling water to the slag in a predetermined condition, fluorine in the slag is dissolved and removed in the sprinkled water to reduce the amount of fluorine eluted in the slag after the treatment. Further, when the desulfurization slag is subjected to an oxidation step (further, a sprinkling step), free lime in the desulfurization slag is carbonated, and selenium is confined in the calcium carbonate in the course of the carbonation. As a result, the elution amount of selenium in the desulfurized slag can be reduced after the treatment.SELECTED DRAWING: Figure 2
【課題】脱硫スラグからのフッ素やセレンの溶出が抑制され、環境基準を満たす溶出量とすることができる溶銑脱硫スラグの処理方法を提供する。【解決手段】石灰系脱硫剤を用いた溶銑脱硫処理により発生した遊離石灰含有量が５０質量％以下の脱硫スラグの処理方法であって、脱硫スラグに対してスラグ量の２０体積％以上の水を散水する散水工程と、この散水工程前又は／及び散水工程後に脱硫スラグを酸化させる酸化工程を有する。遊離石灰含有量が少ない脱硫スラグはフッ素が水に溶出しやすいため、散水工程でスラグに所定の条件で散水することにより、スラグ中のフッ素が散水中に溶解して除去され、処理後のスラグのフッ素溶出量を低減できる。さらに、脱硫スラグが酸化工程（さらには散水工程）を経ることにより、脱硫スラグ中の遊離石灰が炭酸化し、その炭酸化の過程でセレンが炭酸カルシウム中に閉じ込められる結果、処理後の脱硫スラグのセレン溶出量を低減できる。【選択図】図２
TREATMENT METHOD OF MOLTEN IRON DESULFURIZATION SLAG
To provide a method for treating molten iron desulfurization slag, by which elution of fluorine and selenium from the desulfurization slag can be suppressed so that an elution amount satisfies an environmental standard.SOLUTION: Provided is a method for treating desulfurization slag having a free lime content of 50% by mass or less, which is generated by a molten iron desulfurization treatment using a lime-based desulfurization agent. This treatment method has a sprinkling step for sprinkling water of 20 vol% or more of the slag amount to the desulfurization slag and an oxidation step for oxidizing the desulfurization slag before or/and after the sprinkling step. Fluorine is easily eluted into water in desulfurization slag having a small amount of free lime content. By sprinkling water to the slag in a predetermined condition, fluorine in the slag is dissolved and removed in the sprinkled water to reduce the amount of fluorine eluted in the slag after the treatment. Further, when the desulfurization slag is subjected to an oxidation step (further, a sprinkling step), free lime in the desulfurization slag is carbonated, and selenium is confined in the calcium carbonate in the course of the carbonation. As a result, the elution amount of selenium in the desulfurized slag can be reduced after the treatment.SELECTED DRAWING: Figure 2
【課題】脱硫スラグからのフッ素やセレンの溶出が抑制され、環境基準を満たす溶出量とすることができる溶銑脱硫スラグの処理方法を提供する。【解決手段】石灰系脱硫剤を用いた溶銑脱硫処理により発生した遊離石灰含有量が５０質量％以下の脱硫スラグの処理方法であって、脱硫スラグに対してスラグ量の２０体積％以上の水を散水する散水工程と、この散水工程前又は／及び散水工程後に脱硫スラグを酸化させる酸化工程を有する。遊離石灰含有量が少ない脱硫スラグはフッ素が水に溶出しやすいため、散水工程でスラグに所定の条件で散水することにより、スラグ中のフッ素が散水中に溶解して除去され、処理後のスラグのフッ素溶出量を低減できる。さらに、脱硫スラグが酸化工程（さらには散水工程）を経ることにより、脱硫スラグ中の遊離石灰が炭酸化し、その炭酸化の過程でセレンが炭酸カルシウム中に閉じ込められる結果、処理後の脱硫スラグのセレン溶出量を低減できる。【選択図】図２
TREATMENT METHOD OF MOLTEN IRON DESULFURIZATION SLAG
溶銑脱硫スラグの処理方法
NAKAI YOSHIE (author) / KIKUCHI NAOKI (author) / MASAKI HIDEYA (author) / WATANABE KEIJI (author) / MIKI YUJI (author)
2019-10-24
Patent
Electronic Resource
Japanese
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