KR100536305B1 - Method of decreasing fluoride elution in steel-making slag - Google Patents
Method of decreasing fluoride elution in steel-making slag Download PDFInfo
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- KR100536305B1 KR100536305B1 KR10-2003-0067467A KR20030067467A KR100536305B1 KR 100536305 B1 KR100536305 B1 KR 100536305B1 KR 20030067467 A KR20030067467 A KR 20030067467A KR 100536305 B1 KR100536305 B1 KR 100536305B1
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- slag
- fluorine
- molten
- steel
- elution
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- 239000002893 slag Substances 0.000 title claims abstract description 48
- 238000009628 steelmaking Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000010828 elution Methods 0.000 title claims abstract description 9
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 title description 2
- 230000003247 decreasing effect Effects 0.000 title 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000011737 fluorine Substances 0.000 claims abstract description 24
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 16
- 239000001301 oxygen Substances 0.000 claims abstract description 16
- 238000002386 leaching Methods 0.000 abstract description 7
- 238000007664 blowing Methods 0.000 abstract description 4
- 238000012986 modification Methods 0.000 abstract description 2
- 230000004048 modification Effects 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 22
- 229910000831 Steel Inorganic materials 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 5
- 239000010436 fluorite Substances 0.000 description 4
- 238000010405 reoxidation reaction Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 2
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 description 2
- 239000013522 chelant Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 239000003517 fume Substances 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000012958 reprocessing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000003900 soil pollution Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B5/00—Treatment of metallurgical slag ; Artificial stone from molten metallurgical slag
- C04B5/06—Ingredients, other than water, added to the molten slag or to the granulating medium or before remelting; Treatment with gases or gas generating compounds, e.g. to obtain porous slag
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
본 발명은 제강슬래그에서의 불소 용출량을 저감하는 방법에 관한 것으로, 용융 제강슬래그에 산소를 취입하여 재산화시킴으로써 불소 용출을 저감시키는 방법에 관한 것이다. 본 발명에 따른 방법으로 제강슬래그에 외부물질을 첨가하거나 표면 개질 없이 슬래그를 개질하므로 불소 용출량을 획기적으로 줄일 수 있다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the amount of fluorine elution in steelmaking slag, and to a method for reducing fluorine elution by blowing oxygen into molten steelmaking slag and reoxidizing it. The method according to the present invention can significantly reduce the amount of fluorine leaching because the slag is modified without adding an external substance to the steelmaking slag or without surface modification.
Description
본 발명은 제강슬래그에서의 불소 용출량을 저감하는 방법에 관한 것이다. 보다 상세하게는 용융 제강슬래그에 산소를 취입하여 재산화시킴으로써 불소 용출을 저감시키는 방법에 관한 것이다. The present invention relates to a method for reducing the amount of fluorine leached from steelmaking slag. More specifically, the present invention relates to a method for reducing fluorine elution by blowing oxygen into molten steel slag and reoxidizing it.
용광로에서 생산된 용선에 산소를 취련하여 강을 만드는 전로 제강 공정에서는 슬래그가 발생된다. 용선 중의 규소 및 인이 산화되어 SiO2, P2O5가 되고 이것을 제거하기 위하여 생석회를 투입함으로써 슬래그가 생성된다. 이러한 제강슬래그는 토목 공사 재목으로 재이용되거나 혹은 폐기슬래그로서 매립 처리되어 왔다. 일반적인 제강과정에서, 슬래그의 융점을 내리고 유동성을 향상시키며, 용강과의 반응성을 향상시킬 목적으로 형석(CaF2)을 약간 첨가한다. 이로 인해서 제강 슬래그에는 불소가 불가피하게 함유되며, 이것이 물과 접촉하게 되면 미량이지만 불소가 용출된다.Slag is generated in the converter steelmaking process in which oxygen is blown into the molten iron produced in the furnace to make steel. Silicon and phosphorus in the molten iron are oxidized to become SiO 2 , P 2 O 5 , and slag is formed by adding quicklime to remove it. Such steelmaking slag has been reused as civil engineering timber or landfilled as waste slag. In general steelmaking, a small amount of fluorite (CaF2) is added for the purpose of lowering the melting point of slag, improving fluidity, and improving reactivity with molten steel. As a result, the steelmaking slag inevitably contains fluorine, and when it comes into contact with water, a small amount of fluorine is eluted.
불소가 대기중에 노출되는 경우에는 오존층 파괴의 원인이 되며, 매립 처리시에는 토양이 오염되며, 또한 식음료수 중에 2ppm 이상 함유되는 경우에는 인체에 해를 미치는 것으로 알려져 있다. 최근 일본에서는 이러한 용출 불소의 농도를 0.8ppm 이하로 엄격하게 규제하고 있다. When fluorine is exposed to the atmosphere, it causes ozone depletion, soil is contaminated during landfill treatment, and it is known to cause harm to the human body when it is contained in more than 2 ppm in food and beverage water. Recently, the concentration of such eluted fluorine is strictly regulated to 0.8 ppm or less.
따라서, 제강슬래그에서 용출되는 불소량을 감소시키기 위해서 제강 공정에서 형석을 사용하지 않는 무형석 조업이 진행되기도 하나, 이는 형석 대신에 유동성 향상제를 사용하여야 하므로 조업 비용이 상승하게 되고 실조업 채택은 환경 부담금 등을 고려해야 하는 실정이다. 따라서, 불소 용출억제를 위한 다양한 방법들이 개발되고 있다. Therefore, in order to reduce the amount of fluorine eluted from steelmaking slag, fluorite-free operation without fluorspar is carried out in the steelmaking process, but since the fluidity improver should be used instead of fluorspar, the operation cost is increased and the adoption of the actual industry is environmental. Contributions should be considered. Therefore, various methods for suppressing fluorine dissolution have been developed.
일본공개특허공보 제 2000-335946호에서는 불소를 포함하는 제강 슬래그에 칼슘알루미네이트와 같은 불소 고정제를 첨가하여 불소의 용출을 억제하는 방법이 개시되어 있으나, 칼슘 알루미네이트와 같은 물질을 사용하는 것은 대단히 고가이므로 실제 적용하기는 힘든 방법이다. 또한, 일본공개특허공보 제 2001-72447호에서는 킬레이트를 포함하는 수용액을 슬래그에 부착시키는 방법이 개시되어 있으나, 이 방법 역시 킬레이트 화합물이 대단히 고가이므로 실용화 가능성은 매우 적다. Japanese Laid-Open Patent Publication No. 2000-335946 discloses a method of suppressing the dissolution of fluorine by adding a fluorine fixing agent such as calcium aluminate to steelmaking slag containing fluorine, but using a material such as calcium aluminate It's very expensive, so it's hard to apply. In addition, Japanese Laid-Open Patent Publication No. 2001-72447 discloses a method of attaching an aqueous solution containing a chelate to slag, but this method also has very little practical use because the chelate compound is very expensive.
일본공개특허공보 제 2000-355711호에서는 개질제로서 실리카, 실리카-마그네시아계 물질, 망간 광석 중 1종 이상을 용융슬래그에 첨가 혼합하여 냉각 응고시키는 방법이 개시되고 있다. 그러나 이 방법은 냉각된 고체를 2~30% 첨가하여야 하므로 슬래그 개질중에 용융 슬래그의 유동성이 나빠질 우려가 있는 것이다.Japanese Laid-Open Patent Publication No. 2000-355711 discloses a method in which at least one of silica, silica-magnesia-based material, and manganese ore as a modifier is added to and mixed with the molten slag for cooling and solidifying. However, since this method requires the addition of 2 to 30% of the cooled solid, the flowability of molten slag may deteriorate during slag reforming.
또한, 일본공개특허공보 제 2000-180073호에서는 50℃이상의 온수를 슬래그에 뿌리는 방법 및 제 2001-26470호에서는 슬래그 표면을 탄산화시키는 방법등이 개시되고 있으나, 이는 처리된 슬래그를 사용하기 위하여 트럭으로 운반하여 덤핑하는 경우, 슬래그 표면이 마모되거나 슬래그 자체가 분쇄되어 새로운 표면이 나타나므로 실사용에서 효과를 얻기가 어려운 단점이 있다.In addition, Japanese Laid-Open Patent Publication No. 2000-180073 discloses a method of spraying hot water over 50 ° C. on slag and a method of carbonating a slag surface in 2001-26470. In the case of transporting by dumping, the surface of the slag is worn out or the slag itself is crushed, resulting in a new surface, which makes it difficult to obtain an effect in practical use.
따라서 종래의 방법과 같이 외부 물질 첨가에 따른 온도저하 및 원가상승을 고려하지 않아도 되며, 또한, 실제 사용시 덤핑(dumping)을 하여도 전혀 문제가 없는 새로운 처리방법이 요구된다.Therefore, as in the conventional method, it is not necessary to consider the temperature drop and the cost increase due to the addition of the external material, and a new treatment method that does not have any problem even when dumping in actual use is required.
이에 본 발명의 목적은 대기 및 토양 오염을 일으키는 슬래그 중의 불소 용출을 억제하기 위하여, 용융된 제강슬래그의 FeO를 산소로 재산화시켜 불소 용출량을 저감시키는 방법을 제공하는 것이다. Accordingly, it is an object of the present invention to provide a method of reducing the amount of fluorine leaching by reoxidizing FeO of molten steelmaking slag with oxygen in order to suppress fluorine leaching in the slag causing air and soil pollution.
본 발명은The present invention
용융 제강슬래그에 산소를 취입하여 FeO를 Fe2O3로 재산화 시킴을 특징으로 하는 제강슬래그의 불소 용출 저감방법에 관한 것이다.The present invention relates to a method for reducing fluorine elution of steelmaking slag by blowing oxygen into molten steelmaking slag to reoxidize FeO to Fe 2 O 3 .
이하 본 발명에 대하여 상세히 설명하고자 한다. Hereinafter will be described in detail with respect to the present invention.
본 발명의 구현에 있어서, 제강슬래그중의 불소 용출량을 감소시키기 위하여 용융 제강슬래그 내에 산소를 취입하여 용융슬래그 내의 FeO가 Fe2O3로 재산화되도록 한다. 산화반응을 위한 공급원으로 공기를 사용하여도 무방하나 공기 중 질소에 의한 냉각과 NOx 발생을 염려하여 산소를 사용하는 것이 바람직하다.In an embodiment of the present invention, oxygen is blown into the molten steel slag in order to reduce the amount of fluorine leaching in the steelmaking slag so that FeO in the molten slag is reoxidized to Fe 2 O 3 . Although air may be used as a source for the oxidation reaction, it is preferable to use oxygen in consideration of cooling by nitrogen in the air and generation of NOx.
용융 제강슬래그 중에 존재하는 철분관련 성분은 다음 표 1과 같다. Iron-related components present in the molten steelmaking slag are shown in Table 1 below.
[표 1] (단위: wt %)TABLE 1 (unit: wt%)
상기 표 1에 나타낸 바와 같이, 용융슬래그중에 FeO로 존재하는 철분은 약 16%임을 알 수 있으며, 이러한 FeO를 산소로 재산화시켜 Fe2O3를 형성하게 된다. 이때의 산화 반응은 발열반응이므로 용융된 상태를 유지하기 위해 별도의 열을 가하지 않아도 되며, 이에 따라 용융슬래그 온도가 상승하여 균일하게 개질된다.As shown in Table 1, it can be seen that iron present as FeO in the molten slag is about 16%, and this FeO is reoxidized with oxygen to form Fe 2 O 3 . At this time, since the oxidation reaction is exothermic, it is not necessary to apply a separate heat to maintain the molten state, and thus the molten slag temperature is raised to be uniformly modified.
상기와 같이 용융슬래그에 산소를 취입하여 재산화 시킨 후 용융 제강슬래그 중의 철분관련 성분을 다음 표 2에 나타내었다. After injecting oxygen into molten slag and reoxidizing it, iron-related components in molten steel slag are shown in Table 2 below.
[표 2] (단위: wt %)TABLE 2 (unit: wt%)
상기 표 2에 나타낸 바와 같이, 재산화 후에는 FeO가 거의 대부분 Fe2O3로 재산화 된다.As shown in Table 2 above, after reoxidation, FeO is almost always reoxidized to Fe 2 O 3 .
상기와 같이 용융된 제강슬래그의 FeO가 Fe2O3로 재산화되어 용융 제강슬래그 중의 Fe2O3의 함량이 많아지면, 불소의 용출량이 현저하게 감소된다. 이는 재산화 시 생성되는 Fe2O3에 의해서 형석성분이 안정화되는 것으로 이해된다.The FeO in the molten slag as described above is the property screen as Fe 2 O 3 increases when the content of Fe 2 O 3 in the molten steel slag is reduced the amount of elution of the fluoride significantly. It is understood that the fluorspar component is stabilized by Fe 2 O 3 generated during reoxidation.
이하, 실시예를 통하여 본 발명에 대하여 상세히 설명한다.Hereinafter, the present invention will be described in detail through examples.
실시예Example
용융제강슬래그를 담은 래들 내에 내화물로 된 산소랜스를 담그고 산소를 취입하였다. 산소를 취입하면 FeO가 Fe2O3로 산화되면서 퓸(fume)가 발생한다. 계속하여 산소를 취입하여 재산화가 종료되면 퓸 발생이 거의 없어지게 된다. 이때 산소취입을 중지하고 용융슬래그를 배재장에 비교적 얇게 붓는다. 이를 냉각한 다음 분쇄하고 시료를 채취하여 재산화 시키지 않은 것과 비교하였다. 불소 용출은 폐기물 공정시험방법에 따라 용출시켰다. 그 결과를 표 3에 나타내었다.A refractory oxygen lance was immersed in the ladle containing the molten steel slag and oxygen was blown. When oxygen is blown, FeO is oxidized to Fe 2 O 3 to generate fume. When oxygen is continuously blown and reoxidation is completed, there is almost no fume. At this time, the oxygen blowing is stopped and the molten slag is poured relatively thinly into the abatement site. It was cooled, then crushed and sampled to compare it with no reoxidation. Fluorine leaching was eluted according to the waste process test method. The results are shown in Table 3.
[표 3]TABLE 3
본 발명의 방법에 따라 재산화 처리된 제강슬래그의 불소용출량은 미처리 슬래그의 1/70으로 감소하였다. 또 이 용출량은 일본 규제치인 0.8ppm 이하였다. The fluorine leaching amount of the steelmaking slag reoxidized according to the method of the present invention was reduced to 1/70 of the untreated slag. The amount of leaching was below 0.8 ppm, which is the Japanese regulation.
본 발명에 의하여 제강슬래그의 불소용출량 저감방법이 제공된다. 즉 외부물질 첨가나 표면 개질 없이 용융상태에서 산소만을 취입하는 대단히 간단하고 염가의 방법으로 슬래그를 개질하므로 불소 용출량을 획기적으로 줄일 수 있다.According to the present invention, there is provided a method for reducing fluorine elution amount of steelmaking slag. In other words, the slag is reformed in a very simple and inexpensive manner in which only oxygen is blown in the molten state without the addition of external substances or surface modification, thereby significantly reducing the amount of fluorine leached.
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| KR10-2003-0067467A KR100536305B1 (en) | 2003-09-29 | 2003-09-29 | Method of decreasing fluoride elution in steel-making slag |
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