KR100833268B1 - Desulphurization method of sulfur in hot metal using slag of pre-treating pig iron - Google Patents

Desulphurization method of sulfur in hot metal using slag of pre-treating pig iron Download PDF

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KR100833268B1
KR100833268B1 KR1020060136277A KR20060136277A KR100833268B1 KR 100833268 B1 KR100833268 B1 KR 100833268B1 KR 1020060136277 A KR1020060136277 A KR 1020060136277A KR 20060136277 A KR20060136277 A KR 20060136277A KR 100833268 B1 KR100833268 B1 KR 100833268B1
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slag
molten iron
hot metal
sulfur
reaction
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KR1020060136277A
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Korean (ko)
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유철종
조길동
전남성
이인귀
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주식회사 포스코
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/064—Dephosphorising; Desulfurising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/076—Use of slags or fluxes as treating agents
    • 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

Abstract

A desulfurization method of hot metal using slag of preliminarily treated hot metal is provided to improve desulfurization efficiency and reduce production costs by using expensive hot metal slag generated in the preliminary hot metal treatment process as it is and creating a reductive atmosphere from a reaction atmosphere without using an additional desulfurizer when performing a correcting desulfurization reaction. A desulfurization method of hot metal using slag of preliminarily treated hot metal comprises: a hot metal discharging step of discharging hot metal and hot metal slag into a ladle if higher than 30 ppm of sulfur is contained in hot metal that has completed a preliminary hot metal treatment; a subsidiary material injecting step of injecting an aluminum dross into the ladle to create a reductive atmosphere in which the hot metal slag contains 2 to 5% of iron oxides(T.Fe), the aluminum dross reacting with the iron oxides in the hot metal slag to remove oxygen in the iron oxides; a reaction step of agitating materials in the ladle, thereby performing a desulfurization reaction between the hot metal slag and the hot metal to obtain hot metal with a sulfur concentration of not higher than 30 ppm; a slag discharging step of discharging the hot metal slag after finishing the desulfurization reaction; and a completing step of charging desulfurized hot metal into a converter.

Description

용선예비처리 슬래그를 이용한 용선의 탈류방법{Desulphurization method of sulfur in hot metal using slag of Pre-Treating Pig Iron}Desulphurization method of sulfur in hot metal using slag of Pre-Treating Pig Iron}

도 1은 종래의 케이알 설비를 이용한 용선의 탈류방법을 나타내는 순서도이고,1 is a flowchart showing a method of degassing molten iron using a conventional KAL facility,

도 2는 본 발명에 따른 용선예비처리 슬래그를 이용한 용선의 탈류방법을 나타내는 순서도이다.Figure 2 is a flow chart showing a method of degassing the molten iron using the molten iron pre-treated slag according to the present invention.

본 발명은 용선예비처리 슬래그를 이용한 용선의 탈류방법에 관한 것으로서, 보다 상세하게는 용선예비처리를 마친 용선 중 황의 농도가 목표치를 만족하지 못하였을 때 케이알 설비에서 행하여 지는 보정탈류단계 중 용선예비처리시 발생된 용선슬래그를 이용하여 보정탈류를 실시하는 용선예비처리 슬래그를 이용한 용선의 탈류방법에 관한 것이다.The present invention relates to a method for degassing molten iron using molten iron preliminary slag, and more particularly, the molten iron preliminary treatment during the calibrating degassing step performed in the KAL facility when the concentration of sulfur in the molten iron after the molten iron preliminary treatment has not met the target value. The present invention relates to a method for degassing molten iron using a molten iron preliminary slag for performing corrected degassing using molten iron slag generated during heating.

일반적으로 고로에서 출탕된 용선은 용선예비처리를 실시한다. 상기 용선의 예비처리는 크게 용선의 탈류(황 제거), 탈규(규소 제거) 및 탈린(인 제거)으로 구분될 수 있는데, 특히 상기와 같은 용선예비처리를 실시했음에도 불구하고, 용선 중 황(S)의 농도가 목표값보다 높았을 때는 별도의 보정탈류를 실시하게 된다.In general, molten iron from the blast furnace is to be chartered. The preliminary treatment of the molten iron may be classified into the degassing of the molten iron (sulfur removal), the desulfurization (silicon removal), and the dephosphorization (phosphorus removal). In particular, although the molten iron preliminary treatment is performed, When the concentration of) is higher than the target value, a separate corrected dehydration is performed.

용강 중의 황(S)은 강 중에 존재하면서 편석되기 쉽고, 고온에서 취성을 유발시켜 인장율, 연신율, 충격치를 감소시키기 때문에, 보정탈류를 실시함으로써 황(S)을 최소화하여 용강의 청정화를 유도한다.Sulfur (S) in molten steel tends to segregate while being present in steel, causing brittleness at high temperatures to reduce tensile, elongation, and impact values, thereby minimizing sulfur (S) by inducing dehydration to induce purification of molten steel. .

상기에서 설명한 보정탈류란 일반적으로 전로 정련공정에서 제거할 수 없는 황(S)을 탈류제를 첨가한 용선을 기계적 교반(Kanvara Reactor, 이하 케이알 설비라 칭함)에 의해서 탈류반응이 이루어지도록 하는 것이다. The above-described correction degassing means that the molten iron to which sulfur (S), which cannot be removed in the converter refining process, is added with a desorbent, is subjected to a dehydration reaction by mechanical stirring (Kanvara Reactor, hereinafter referred to as a KAL facility).

상기의 케이알 설비는 탈류와 탈인을 위한 부원료(탈류제, 탈인제)가 신속하게 용선 중으로 침투하여 탈류, 탈규 반응을 일으키도록 레이들 내의 용선에 임펠러(내화물 날개)를 침지시킨 상태에서 일정한 속도로 회전시켜 와류를 발생시키는 구성을 갖는다.The KAL facility is operated at a constant speed while the impeller (refractory wing) is immersed in the molten iron in the ladle to infiltrate the molten iron for rapid degassing and dephosphorization to quickly infiltrate the molten metal and cause the desulfurization and de-silification reaction. It has a structure which rotates and produces a vortex.

상기 케이알 설비에서 용선 중의 황(S)은 환원반응에 의해서 제거된다.Sulfur (S) in the molten iron in the KAL facility is removed by a reduction reaction.

그럼, 보강탈류반응을 포함하는 종래의 용선 탈류방법을 설명한다.Next, a conventional molten iron degassing method including a reinforced desulfurization reaction will be described.

도 1은 종래의 케이알 설비를 이용한 용선의 탈류방법을 나타내는 순서도이다.1 is a flowchart illustrating a method of degassing molten iron using a conventional KAL facility.

도 1에 도시된 바와같이 용선예비처리가 완료된 용선은 성분검사를 하여 황(S)의 농도가 목표값 이하로 검출되는지를 판단한다. 일반적인 황(S)의 농도 목표값은 30 ~ 200ppm이다.As shown in FIG. 1, the molten iron having the molten iron preliminary treatment is inspected to determine whether the concentration of sulfur (S) is detected below the target value. Typical sulfur (S) concentration targets are 30 to 200 ppm.

그래서, 황(S)의 농도가 상기의 목표값보다 낮게 검출되면 토페도카(TLC: Torpedo Laddle Car)에 용선슬래그의 유출을 최소화하기 위한 티스토퍼(T-stopper)를 설치하고 용선을 레이들로 출선하며, 용선슬래그는 별도로 배재한다. 그리고, 레이들에 출선된 용선을 전로에 장입하게 된다.Therefore, when the concentration of sulfur (S) is detected lower than the target value, a T-stopper for minimizing the leakage of the molten iron slag in the Torpedo Laddle Car (TLC) is installed and the molten iron is ladleed. The chartered slag is excluded separately. Then, the chartered ship on the ladle is charged to the converter.

만약, 황(S)의 농도가 상기의 목표값보다 많이 검출되면 토페도카(TLC)를 케이알설비로 이동시킨 다음 티스토퍼를 설치하고 용선만을 케이알설비의 레이들에 출선시킨다.If the concentration of sulfur (S) is detected above the target value, the toppedo car (TLC) is moved to the KAL facility, then the tea stopper is installed and only the molten iron is sent out to the ladle of the KAL facility.

그리고, 케이알 설비의 임펠러를 회전시키면서 탈류제를 투입하여 보정탈류반응이 이루어지도록 한다. 약 10 ~ 15분 정도 보정탈류작업을 실시한다. 케이알설비에서 환원반응에 의해 보정탈류작업이 완료된 후 레이들에서 탈류된 슬래그를 배재하고, 용선만 남은 레이들을 전로에 장입하는 일련의 작업을 실시한다.Then, while the impeller of the KAL facility is rotated, a dehydrating agent is added to perform a corrected dehydration reaction. Carry out calibrated dehydration for about 10 to 15 minutes. After the corrected desulfurization work is completed by the reduction reaction in the KAL facility, the slag discharged from the ladle is discharged, and a series of works are carried out to charge the ladle with the remaining molten iron into the converter.

하지만, 상기와 같은 보정탈류작업에서는 고가의 용선예비처리에서 미반응된 슬래그를 케이알설비에서의 보정탈류반응 전에 배재하고, 케이알 설비에 탈류제를 다시 투입함에 따라 용강의 제조원가를 상승시키는 문제점이 있었다.However, in the above-described corrected desulfurization operation, the unreacted slag in the expensive molten iron preliminary treatment is excluded before the corrected desulfurization reaction in the KAL facility, and there is a problem of increasing the manufacturing cost of molten steel as the desulfurizing agent is added to the KAL facility again. .

또한, 미반응된 슬래그가 용선과 같이 케이알 설비로 출선되는 것을 방지하기 위하여 티스토퍼를 거치하는데 많은 시간을 허비해야 하는 문제점도 있었다.In addition, in order to prevent unreacted slag from going out to the KAL facility, such as molten iron, there was a problem in that a large amount of time was required to mount the stopper.

본 출원인은 탈류반응에 대하여 지속적인 연구를 거듭한 결과 탈류반응시 투입되는 CaO계의 탈류제 양도 중요하지만 탈류반응시 환원성분위기를 조성하면 탈류반응이 보다 효율적으로 이루어진다는 사실을 확인하고 본 발명을 완성하게 되었다.Applicants have continued to study the dehydration reaction, and as a result, the amount of CaO-based desorbent added during the dehydration reaction is important, but the fact that the composition of the reducing component during the dehydration reaction makes the dehydration reaction more efficient and completes the present invention. Was done.

본 발명은 상기한 문제점을 해결하고자 안출된 것으로서, 용선예비처리를 완료했는데도 불구하고 용선 중 황의 농도가 목표값보다 높을 때 행하여 지는 보정탈류반응시에 별도의 탈류제를 사용하지 않고, 용선예비처리 공정에서 발생된 고가의 용선슬래그를 그대로 이용하고, 반응분위기를 환원성분위기로 조성함으로써 탈류효율을 향상시키고, 생산원가를 절감할 수 있는 용선예비처리 슬래그를 이용한 용선의 탈류방법를 제공하는데 그 목적이 있다.The present invention has been made to solve the above problems, and despite the completion of the molten iron preliminary treatment, the molten iron preliminary treatment without using a separate desulfurizing agent during the correction dehydration reaction is carried out when the concentration of sulfur in the molten iron is higher than the target value It is an object of the present invention to provide a method for degassing molten iron using molten iron preliminary slag that improves the degassing efficiency and reduces the production cost by using the expensive molten iron slag generated in the process as it is and forming the reaction atmosphere as a reducing component crisis. .

상기 목적을 달성하기 위한 본 발명에 따른 용선예비처리 슬래그를 이용한 용선의 탈류방법은 용선예비처리를 완료한 용선에서 황의 농도가 목표값 보다 높은 경우 용선과 용선슬래그를 레이들에 출선하는 출선단계와; 상기 레이들에 부원료를 투입하여 상기 용선슬래그를 환원성분위기로 만들어 주는 부원료 투입단계와; 상기 레이들 내를 교반시켜 용선슬래그에 의해 용선의 탈류반응을 일으키는 반응단계와; 탈류반응 완료 후 용선슬래그를 배재하는 배재단계와; 탈류된 용선을 전로로 장입하는 완료단계를 포함한다.The method of degassing the molten iron using the molten iron preliminary treatment slag according to the present invention for achieving the above object is the embarkation step of leaving the molten iron and molten iron slag on the ladle when the concentration of sulfur in the molten iron completed the molten iron preliminary treatment is higher than the target value; ; A secondary raw material input step of adding secondary raw materials to the ladle to make the molten iron slag into a reducing component crisis; A reaction step of stirring the ladle to cause degassing of the molten iron by molten iron slag; An exhausting step of excluding the molten iron slag after the completion of the dehydration reaction; Completion of charging the discharged molten iron to the converter.

그리고, 상기 부원료 투입단계에 투입되는 부원료는 용선슬래그 중 철산화물(T.Fe)과 반응하여 철산화물(T.Fe) 중 산소를 제거하는 알루미늄 드로스인 것을 특징으로 한다.In addition, the subsidiary material input to the subsidiary material input step is characterized in that the aluminum dross to remove oxygen from the iron oxide (T.Fe) by reacting with iron oxide (T.Fe) of the molten iron slag.

또한, 상기 부원료 투입단계에서 알루미늄 드로스의 투입양은 용선슬래그 중 철산화물(T.Fe)의 함율이 2 ~ 5%가 되도록 조절하는 것이 바람직하다.In addition, the input amount of aluminum dross in the secondary raw material input step is preferably adjusted so that the content of iron oxide (T.Fe) in molten iron slag is 2 to 5%.

그리고, 상기 알루미늄 드로스의 투입량은 상기 용선슬래그의 양과 용선슬래그 중의 철산화물(T.Fe) 양을 이용하여 소정의 수학식에 의해 결정되는 것이 바람직하다.In addition, the dose of the aluminum dross is preferably determined by a predetermined equation using the amount of molten iron slag and the amount of iron oxide (T.Fe) in the molten iron slag.

이하, 본 발명에 따른 용선예비처리 슬래그를 이용한 용선의 탈류방법을 도면을 참조하여 설명하면 다음과 같다. Hereinafter, a method of degassing the molten iron using the molten iron preliminary slag according to the present invention will be described with reference to the accompanying drawings.

도 2는 본 발명에 따른 용선예비처리 슬래그를 이용한 용선의 탈류방법을 나타내는 순서도이다.Figure 2 is a flow chart showing a method of degassing the molten iron using the molten iron pre-treated slag according to the present invention.

본 발명에 따른 용선예비처리 슬래그를 이용한 용선의 탈류방법은 크게 용선예비처리단계와, 용선 중 황의 농도를 측정하여 재탈류 여부를 판단하는 판단단계와, 상기 판단단계서 재탈류가 필요치 않는 경우 용선을 전로에 장입하는 전로장입단계와, 상기 판단 단계에서 재탈류가 필요한 경우 용선을 케이알 설비에서 보정탈류를 실시한 다음 탈류된 용선을 전로에 장입하는 보정탈류단계를 포함하여 이루어진다.The method of degassing the molten iron using the molten iron preliminary slag treatment according to the present invention includes a molten iron preliminary treatment step, a determination step of determining whether or not to reflow by measuring the concentration of sulfur in the molten iron, and a molten iron when reflow is not necessary in the determination step. It includes a converter charging step of charging the converter, and if the de-reflow is necessary in the determination step, the correction charter degassing the molten iron in the KAL facility and then charged into the converter.

1. 용선예비처리단계1. Charter preparation process

고로에서 생산된 용선을 전로에서 정련시키기 전 용선의 탈류(황 제거), 탈규(규소 제거) 및 탈린(인 제거) 작업을 실시한다.Before refining the molten iron from the blast furnace, the molten iron is degassed (sulfur removed), desulfurized (silicon removed) and dephosphorized (phosphorus removed).

2. 판단단계2. Decision stage

용선예비처리를 완료한 용선의 성분을 측정하여 재탈류 여부를 판단하는 단계로, 본 발명에서는 용선 중 황(S)의 농도를 측정하여 황(S)의 농도의 농도가 목표값보다 낮은지 여부를 판단한다.In the present invention, the concentration of sulfur (S) in the molten iron is measured to determine whether the concentration of sulfur (S) is lower than a target value. Judge.

일반적으로 보통강의 경우 황(S)의 농도는 30ppm 이하가 되도록 조절하는 것이 바람직하다.In general, the concentration of sulfur (S) is preferably adjusted to 30 ppm or less.

3. 전로장입단계3. Conversion stage

상기 판단단계에서 황(S)의 농도를 측정하여 황의 농도가 상기 목표값 보다 낮게 검출되면 일련의 공정에 의해서 용선예비처리된 용선을 전로에 장입한다.In the determination step, the concentration of sulfur (S) is measured, and when the concentration of sulfur is detected to be lower than the target value, the molten iron preliminary molten iron is charged into the converter by a series of processes.

이때 통상 황(S)의 농도가 상기 목표값 이하로 검출되는 경우는 토페도카(TLC)에 티스토퍼(T-stopper)를 설치하여 용선예비처리 시 발생된 슬래그(이하, 용선슬래그라 칭함.)의 배재를 최소화할 수 있도록 한 다음 레이들에 용선을 출선한다.At this time, when the concentration of sulfur (S) is detected below the target value, the slag generated during the preliminary treatment of the molten iron by installing a T-stopper on the topedoca (TLC) (hereinafter, referred to as molten iron slag). To minimize exclusion, and then charter the ladle.

그리고, 용선슬래그를 별도로 배재하여 처리한다.The molten iron slag is separately disposed and treated.

그런다음, 상기 용선이 출선된 레이들을 전로에 장입한다.Then, the chartered ladle is loaded into the converter.

4. 보정탈류단계4. Calibrated Discharge Step

상기 판단단계에서 황(S)의 농도를 측정하여 황의 농도가 상기 목표값 보다 높게 검출되면 재탈류를 실시하는 단계로서, 본 발명에서는 별도의 탈류제를 투입하지 않고, 탈류가 잘 일어날 수 있는 환원성분위기를 조성하여 용선예비처리 시 발생된 용선슬래그만을 이용하여 효율적인 탈류반응을 이루어낸다.Measuring the concentration of sulfur (S) in the judging step is carried out when the concentration of sulfur is detected higher than the target value to perform the re-flow, in the present invention, without the addition of a separate desorbing agent, the reductibility that can occur well By creating an atmosphere, efficient dehydration reaction is achieved using only molten iron slag generated during molten iron preliminary treatment.

4-1. 출선단계4-1. Starting stage

상기 판단단계에서 황(S)의 농도가 목표값 보다 높게 검출되어 보정탈류가 결정되면, 용선이 수강된 토페도카(TLC)를 케이알 설비로 이송시킨다.When the concentration of sulfur (S) is detected to be higher than the target value in the determination step and the corrected degassing is determined, the molten iron taken topedoka (TLC) is transferred to the KAL facility.

그리고, 토페도카(TLC)에 수강된 용선 및 용선슬래그를 차례로 레이들에 출선시킨다.Then, the molten iron and the molten iron slag taken to Topedoca (TLC) are first unloaded to the ladle.

이때 비중이 높은 용선이 먼저 토페도카(TLC)의 와구를 통하여 레이들 내로 출선되고, 출선이 완료된 다음 용선슬래그를 레이들로 배재시켜 용선과 용선슬래그가 함께 레이들에 수강되도록 한다.At this time, the charter boat with a high specific gravity is first derailed into the ladle through the torpedo of TPE, and after the completion of the boat, the charter slag is discharged to the ladle so that the charter boat and the charter slag are taken together in the ladle.

4-2. 부원료 투입단계4-2. Subsidiary input stage

상기 부원료 투입단계에서는 레이들 내부로 부원료를 투입하여 용선슬래그를 환원성분위기로 조성시키는 단계이다.In the subsidiary material input step, the subsidiary material is introduced into the ladle to form molten iron slag as a reducing component crisis.

통상 상기 판단단계에서 황(S)의 농도가 목표값 보다 높게 검출되는 용선 슬래그의 조성은 다음의 표 1과 같다.In general, the composition of the molten iron slag in which the concentration of sulfur (S) is detected to be higher than a target value is shown in Table 1 below.

성분ingredient SiO2 SiO 2 CaOCaO MgOMgO Al2O3 Al 2 O 3 P2O5 P 2 O 5 MnOMnO T.FeT.Fe SS 함유율(%)Content rate (%) 10~2010-20 45~5545-55 0.8~1.20.8 ~ 1.2 1~21 ~ 2 0.1~0.30.1-0.3 0.2~0.30.2 ~ 0.3 10~1310-13 2~32 ~ 3

상기 표 1과 같이 철산화물(T.Fe)이 상대적으로 높은 것이 탈류효율을 떨어트리는 하는 원인이 된다.As shown in Table 1, the relatively high iron oxide (T.Fe) is a cause of lowering the dehydration efficiency.

철산화물(T.Fe)의 함유율이 높을 경우 탈류효율이 떨어지는 이유는, 탈류작업은 환원반응에 의해서 이루어지는데 철산화물(T.Fe) 중 산소가 산화반응을 일으키려는 성질을 갖기 때문에 용선슬래그와 용선계면 사이의 반응이 제대로 이루어지지 않아 탈류효율이 저하되기 때문이다.If the content of iron oxide (T.Fe) is high, the efficiency of degassing is lowered. The degassing is carried out by a reduction reaction, because the oxygen in the iron oxide (T.Fe) tends to cause an oxidation reaction. This is because the reaction between the molten iron interface is not properly performed and the deflow efficiency is lowered.

한편, 본 발명에서는 용선슬래그를 배재하지 않고, 탈류반응시 용선슬래그를 그대로 이용하기 때문에, 용선슬래그에 과도하게 포함된 철산화물(T.Fe)의 양을 줄여서 철산화물(T.Fe) 중에 함유된 산소의 양을 감소시킴으로써 용선슬래그를 환원성분위기로 조성해야 한다.On the other hand, in the present invention, since the molten iron slag is used as it is during the degassing reaction without excluding molten iron slag, the amount of iron oxide (T.Fe) contained in the molten iron slag is reduced and contained in iron oxide (T.Fe). By reducing the amount of oxygen produced, molten iron slag should be formed as a reducing component crisis.

이때 환원성분위기를 조성하기 위해서는 철산화물(T.Fe)의 함유율을 2 ~ 5%로 유지시키는 것이 바람직하다.In this case, in order to form a reducing component crisis, the content of iron oxide (T.Fe) is preferably maintained at 2 to 5%.

따라서, 철산화물(T.Fe)의 함유율을 낮추기 위하여 본 발명에서는 철산화물과 반응하여 철산화물(T.Fe) 중의 산소를 제거할 수 있는 부원료를 투입한다.Therefore, in order to lower the content of iron oxide (T.Fe), in the present invention, a secondary material capable of reacting with the iron oxide to remove oxygen in the iron oxide (T.Fe) is added.

이때 투입되는 부원료는 철산화물(T.Fe) 중의 산소를 제거할 수 있는 부원료이면 어떠한 것이어도 무방하나, 본 발명에서는 알루미늄 드로스(Al dross)를 투입하였다.At this time, any input material may be any auxiliary material capable of removing oxygen in iron oxide (T.Fe), but in the present invention, aluminum dross is added.

알루미늄 드로스의 조성은 다음의 표 2와 같다.The composition of the aluminum dross is shown in Table 2 below.

성분ingredient AlAl Al2O3Al2O3 MgOMgO SiO2SiO2 SS 함유율(%)Content rate (%) ≥35≥35 ≤40≤40 ≤8≤8 ≤15≤15 ≤0.4≤0.4

상기 표 2와 같은 조성을 갖는 알루미늄 드로스는 용선슬래그 중 철산화물(T.Fe)과 하기의 반응식 1 및 2와 같은 반응을 하여 철산화물(T.Fe) 중 산소를 제거한다.The aluminum dross having the composition shown in Table 2 removes oxygen from iron oxide (T.Fe) by reacting iron oxide (T.Fe) with molten iron slag with the reaction schemes 1 and 2 below.

2Al + 3FeO = 3Fe + Al2O3 2Al + 3FeO = 3Fe + Al 2 O 3

2Al + Fe2O2 = 2Fe + Al2O3 2Al + Fe 2 O 2 = 2Fe + Al 2 O 3

상기 반응식 1 및 2와 같은 반응을 하여 용선슬래그 중의 산소를 제거하는 역할을 한다.Reaction as in Schemes 1 and 2 serves to remove oxygen in the molten iron slag.

또한, 상기 반응식 1 및 2의 반응은 발열반응으로 용선의 온도를 상승시키는 효과를 준다.In addition, the reaction of Schemes 1 and 2 has the effect of raising the temperature of the molten iron by exothermic reaction.

그리고, 철산화물(T.Fe)을 원하는 수준의 양으로 조절하기 위해서는 투입되는 알루미늄 드로스의 양을 조절해야 하는데, 투입되는 알루미늄 드로스의 양의 하기의 수학식 1에 의해 결정할 수 있다.And, in order to adjust the iron oxide (T.Fe) to the desired level of amount to adjust the amount of aluminum dross to be added, the amount of aluminum dross to be added can be determined by the following equation (1).

Figure 112006097564911-pat00001
Figure 112006097564911-pat00001

상기 수학식 1에 의해서 결정되는 알루미늄 드로스의 투입량을 레이들에 투입한다.The dose of aluminum dross determined by Equation 1 is added to the ladle.

4-3. 반응단계4-3. Reaction step

케이알 설비의 임펠러를 이용하여 용선 및 용선슬래그를 교반시켜며 탈류반응을 시키는 단계이다.This is a step of degassing the molten iron and molten iron slag using the impeller of the KAL facility.

이때 탈류반응은 용선슬래그 중의 CaO계 성분과 용선 중 FeS 성분이 환원반 응을 하여 이루어진다.At this time, the degassing reaction is carried out by reducing the CaO-based component in the molten iron slag and the FeS component in the molten iron.

하기의 반응식 3 내지 4는 용선 중의 황(S)과 탈류제의 반응식을 나타낸 것이다.The following Reaction Schemes 3 to 4 show reaction schemes of sulfur (S) and desorbents in molten iron.

CaO + FeS = CaS + FeOCaO + FeS = CaS + FeO

CaCO3 + FeS = CaS + FeO + CO2 CaCO 3 + FeS = CaS + FeO + CO 2

그리고, 용선의 탈류조건은 고온일수록, 용선슬래그의 염기도가 높을수록, 환원성분위기일수록 좋아진다.In addition, the degassing condition of the molten iron is improved the higher the temperature, the higher the basicity of the molten iron slag, the more the reducing component crisis.

따라서, 용선슬래그의 염기도가 변하지 않는다는 가정하에, 상기 부원료 투입단계에서와 같이 알루미늄 드로스를 투입하여 상기 반응식 1 및 2와 같은 반응을 시킴으로써, 용선의 온도를 향상시키고, 용선슬래그를 환원성분위기로 만들기 때문에 탈류를 보다 효율적으로 이루어지게 한다.Therefore, under the assumption that the basicity of the molten iron slag does not change, the aluminum dross is added in the same manner as in the sub-material addition step to perform the reaction as in Schemes 1 and 2, thereby improving the temperature of the molten iron and making the molten iron slag as a reducing component crisis. This makes the discharge more efficient.

4-4. 배재단계4-4. Exclusion stage

탈류반응 완료 후 용선슬래그를 배재하는 처리하는 단계이다.After the dehydration reaction is completed, the molten slag is treated.

4-5. 완료단계4-5. Completion step

탈류된 용선을 전로에 장입하는 단계이다.It is the step of charging the deflowed molten iron in a converter.

이하, 본 발명을 다양한 실시예와 비교예를 비교하여 설명한다.Hereinafter, the present invention will be described by comparing various examples with comparative examples.

실시예 1 내지 5와 비교예 1 내지 5 모두 용선예비처리단계에서 탈류제를 2500Kg 투입하는 중탈류를 실시하였으며, 용선예비처리단계를 완료한 상태에서 황(S)의 함유량이 30ppm보다 많은 경우에 대하여 보정탈류반응을 실시하였다.In Examples 1 to 5 and Comparative Examples 1 to 5 were subjected to heavy degassing to inject 2500Kg of desorbent in the molten iron preliminary treatment step, when the sulfur (S) content in the state of completing the molten iron preliminary treatment step is more than 30ppm Corrected dehydration reaction was carried out.

이때 실시예 1 내지 5는 본 발명에 따라 알루미늄 드로스를 투입하여 환원성 분위기를 조성한 다음 용선슬래그만을 이용하는 보정탈류반응을 실시하였고, 비교예 1 내지 5는 용선슬래그를 배재한 다음 탈류제를 투입하여 보정탈류반응을 실시하였다.At this time, Examples 1 to 5 was added to the aluminum dross according to the present invention to form a reducing atmosphere and then subjected to the correction dehydration reaction using only molten iron slag, Comparative Examples 1 to 5 by excluding the molten iron slag and then by adding a desorbent A calibrated dehydration reaction was carried out.

보다 구체적인 알루미늄 드로스의 투입량 및 탈류제의 투입량과 탈류반응 후의 용선 중 황(S)의 함유량 및 탈류반응 후 배재시킨 슬래그의 양을 하기의 표 3에 나타내었다.More specifically, the amount of aluminum dross, the amount of desorbent, the amount of sulfur (S) in the molten iron after the deflow reaction and the amount of slag excreted after the deflow reaction are shown in Table 3 below.

구분  division 예비처리Pretreatment KRKR 기타  Etc 탈류제 투입량(Kg)Desorbent Input (Kg) 탈류후황 함유량(ppm)Desulfurization Sulfur Content (ppm) 탈류제 투입량(Kg)Desorbent Input (Kg) Al-Dross 투입량(Kg)Al-Dross input amount (Kg) 슬래그 배재량(Kg)Slag Displacement (Kg) 탈류후황 함유량(ppm)Desulfurization Sulfur Content (ppm) 비교예1Comparative Example 1 25002500 101101 10001000 -- 12001200 4343 재탈류Reflow 비교예2Comparative Example 2 25002500 7979 800800 -- 10001000 3030 비교예3Comparative Example 3 25002500 8888 900900 -- 10001000 3030 비교예4Comparative Example 4 25002500 4747 500500 -- 600600 2828 비교예5Comparative Example 5 25002500 8989 900900 -- 10001000 3636 재탈류Reflow 실시예1Example 1 25002500 8585 -- 200200 72007200 1919 실시예2Example 2 25002500 5353 -- 215215 80008000 2525 실시예3Example 3 25002500 6868 -- 215215 81008100 2323 실시예4Example 4 25002500 112112 -- 200200 75007500 1717 실시예5Example 5 25002500 8888 -- 220220 80008000 2323

표 3에서 알 수 있듯이, 비교예에서는 용선슬래그를 배재하고 다시 탈류제를 투입하여 탈류를 실시하기 때문에 탈류제 재화에 실패할 경우에는 목표탈류보다 황의 함유량이 높게 실적되어 재탈류를 하는 경우가 발생되었다.As can be seen from Table 3, in the comparative example, the molten slag is removed and the desorbent is added again to perform the dehydration. Therefore, when the desorbent material fails, the sulfur content is higher than the target desulfurization, resulting in reflow. It became.

그러나 탈류제를 대신하여 용선슬래그를 사용한 실시예에서는 슬래그 배재량은 증가하였으나, 재화된 슬래그를 다시 사용하기 때문에 모두 목표로 한 황의 함유량 30ppm 이하로 실적되었다.However, in the example in which molten iron slag was used instead of the desorbing agent, the slag excretion was increased, but all of the targeted sulfur content was 30 ppm or less because the reused slag was used again.

이상에서 설명한 것과 같이 본 발명은 용선슬래그를 보정탈류반응에 적용함으로써 용선슬래그를 폐기하지 않고 재활용 할 수 있으며, 보정탈류반응시 미리 재화된 용선슬래그를 이용하여 탈류를 실시하기 때문에 탈류효율을 향상시킬 수 있는 효과를 얻을 수 있다.As described above, the present invention can recycle the molten iron slag without discarding it by applying the molten iron slag to the corrected degassing reaction. The effect can be obtained.

또한, 보정탈류반응시 용선슬래그의 배재단계를 생략할 수 있어 공정시간을 단축할 수 있는 효과가 있다.In addition, since the exclusion step of the molten iron slag during the correction deflow reaction can be omitted, there is an effect that can reduce the process time.

Claims (4)

용선예비처리를 완료한 용선에서 황의 농도가 30ppm 보다 높은 경우 용선과 용선슬래그를 레이들에 출선하는 출선단계와;A step of starting the molten iron and the molten iron slag on the ladle when the concentration of sulfur is higher than 30 ppm in the molten iron which has completed the molten iron preliminary treatment; 용선슬래그 중 철산화물(T.Fe)과 반응하여 철산화물(T.Fe) 중 산소를 제거하는 알루미늄 드로스를 상기 레이들에 투입하여 상기 용선슬래그 중 철산화물(T.Fe)의 함율이 2 ~ 5%가 되는 환원성분위기로 만들어 주는 부원료 투입단계와;Aluminum dross, which reacts with iron oxide (T.Fe) in the molten iron slag to remove oxygen in the iron oxide (T.Fe), is added to the ladle to have a content of iron oxide (T.Fe) in the molten iron slag. Subsidiary input step to create a reducing component crisis is ~ 5%; 상기 레이들 내를 교반시켜 용선슬래그에 의해 용선의 탈류반응을 일으켜서 황의 농도가 30ppm 이하가 되도록 하는 반응단계와;A reaction step of stirring the ladle to cause degassing of the molten iron by molten iron slag so that the concentration of sulfur is 30 ppm or less; 탈류반응 완료 후 용선슬래그를 배재하는 배재단계와;An exhausting step of excluding the molten iron slag after the completion of the dehydration reaction; 탈류된 용선을 전로로 장입하는 완료단계를 포함하는 용선예비처리 슬래그를 이용한 용선의 탈류방법.A method of degassing molten iron using a molten iron preliminary slag including a completion step of charging the degassed molten iron into a converter. 삭제delete 삭제delete 삭제delete
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KR20180074347A (en) * 2016-12-23 2018-07-03 주식회사 포스코 Method for flue gas desulfurization using kanvara reactor powder and flue gas desulfurization apparatus using the same

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KR20000067071A (en) * 1999-04-23 2000-11-15 이구택 Method for improving desulphurization efficiency in KR
KR20010036627A (en) * 1999-10-11 2001-05-07 이구택 Method for improving desulfurization ratio of desiliconized molten pig iron in hot metal pretreatment

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KR20000067071A (en) * 1999-04-23 2000-11-15 이구택 Method for improving desulphurization efficiency in KR
KR20010036627A (en) * 1999-10-11 2001-05-07 이구택 Method for improving desulfurization ratio of desiliconized molten pig iron in hot metal pretreatment

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Publication number Priority date Publication date Assignee Title
KR20180074347A (en) * 2016-12-23 2018-07-03 주식회사 포스코 Method for flue gas desulfurization using kanvara reactor powder and flue gas desulfurization apparatus using the same
KR101967964B1 (en) 2016-12-23 2019-04-10 주식회사 포스코 Method for flue gas desulfurization using kanvara reactor powder and flue gas desulfurization apparatus using the same

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