KR100396089B1 - Method for Cleaning Line of Electric Furnace - Google Patents
Method for Cleaning Line of Electric Furnace Download PDFInfo
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- KR100396089B1 KR100396089B1 KR10-1999-0065309A KR19990065309A KR100396089B1 KR 100396089 B1 KR100396089 B1 KR 100396089B1 KR 19990065309 A KR19990065309 A KR 19990065309A KR 100396089 B1 KR100396089 B1 KR 100396089B1
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- furnace
- electric furnace
- cleaning operation
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- nickel
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- 238000004140 cleaning Methods 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 9
- 239000010436 fluorite Substances 0.000 claims abstract description 24
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 15
- 239000010959 steel Substances 0.000 claims abstract description 15
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 11
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims abstract description 8
- 238000006243 chemical reaction Methods 0.000 claims abstract description 8
- 229910004261 CaF 2 Inorganic materials 0.000 claims abstract description 4
- 229910001220 stainless steel Inorganic materials 0.000 claims description 8
- 239000010935 stainless steel Substances 0.000 claims description 5
- 239000002436 steel type Substances 0.000 claims description 2
- 230000003628 erosive effect Effects 0.000 abstract description 6
- 238000011017 operating method Methods 0.000 abstract description 2
- 238000002844 melting Methods 0.000 description 6
- 230000008018 melting Effects 0.000 description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 229910000863 Ferronickel Inorganic materials 0.000 description 1
- -1 and now Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- VNNRSPGTAMTISX-UHFFFAOYSA-N chromium nickel Chemical compound [Cr].[Ni] VNNRSPGTAMTISX-UHFFFAOYSA-N 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000003923 scrap metal Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- 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
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
-
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
Abstract
본 발명은 제조 강종 전환시 노체를 보호하기 위한 전기로 크리닝 조업 방법에 관한 것으로, 300계열 강종의 전기로 조업 방법에 있어서 400계열로의 강종 전환 직후에 니켈의 성분을 제거하기 위하여 실시하는 크리닝 조업에 있어서, 일정량의 형석(CaF2)을 강종 전환 직전의 히트(heat)에 투입함으로써, 노벽 및 노상의 극심한 마모와 침식을 줄일 수 있어 노체 수명을 향상시킬 수 있으며, 니켈의 범위를 제한하여 400계열 작업이 가능하게 한다.The present invention relates to an electric furnace cleaning operation method for protecting a furnace body when converting manufactured steel grades. In the electric furnace operating method of 300 series steel grades, a cleaning operation performed to remove a component of nickel immediately after converting steel grades to 400 series. By adding a certain amount of fluorite (CaF 2 ) to the heat immediately before the steel grade conversion, it is possible to reduce the extreme wear and erosion of the furnace wall and hearth, improve the furnace life, limit the range of nickel 400 Enable series work.
Description
본 발명은 스테인레스강 제조에 사용되는 전기로 조업에 관한 것으로, 특히 제조 강종 전환시 노체를 보호하기 위한 전기로 크리닝 조업 방법에 관한 것이다.The present invention relates to the operation of the furnace used in the production of stainless steel, and more particularly to an electric furnace cleaning operation method for protecting the furnace body in the production steel conversion.
일반적으로 스테인레스의 강종은 크게 오스테나이트(austenite) 강종의 300계열과, 마르텐사이트(martensite) 및 페라이트(ferrite) 강종의 400계열로 나누어진다.Generally, stainless steels are classified into 300 series of austenitic steels and 400 series of martensite and ferrite steels.
여기서, 300계열은 크롬-니켈계 스테인레스강으로 통상 70 ~ 80%의 생산 비중을 차지하는 데 약 8%의 니켈을 함유하며 저온의 전기로에서 용융되는 반면에,400계열은 크롬 스테인레스강으로 고온의 전기로에서 용융된다.Here, the 300 series are chromium-nickel stainless steels, which usually account for 70 to 80% of production, and contain about 8% nickel and are melted in low temperature electric furnaces, while the 400 series are chromium stainless steels. Is melted in.
스테인레스 전기로에서의 작업은 원료에서 로딩(loading)된 적입 실적을 토대로 스테인레스 스크랩(alloy scrap), 일반 스크랩, 차지 크롬(charge chrome), 페로 니켈(ferro nickel)을 주원료로 하여 전기로에 장입 후 용해 작업을 한다.The operation in the stainless steel furnace is based on the loading performance loaded from the raw materials, and the melting work after charging into the electric furnace using stainless scrap, general scrap, charge chrome, and ferro nickel as the main raw materials. Do it.
그리고, 크리닝 작업은 강종 전환시에 규제 성분의 상승을 막기 위해 적용되는 전기로 조업 패턴의 한 유형으로 행한다.The cleaning operation is performed by one type of electric furnace operation pattern which is applied to prevent the rise of the regulatory component at the time of steel type conversion.
따라서, 300계열 작업후에 400계열로 작업 전환시, 전기로에서 잔류 니켈의 0.5% 이하로 규제와 전극의 이동 등의 크리닝 작업 여하에 따라 성분 범위의 초과 여부가 결정될 만큼 중요하다.Therefore, when switching to 400 series after 300 series operations, it is important to determine whether the component range is exceeded depending on the cleaning operation such as regulation and electrode movement to 0.5% or less of residual nickel in the electric furnace.
도 3은 전기로에 노벽 지금 부착의 유형을 나타낸 평면도로, 전극(1)에서 아크 작업시 3상(R.S.T) 교류에서의 복사열에 의해 생기는 화점(hot spot)(2) 부분은 노벽의 노출이 심한 반면에, 냉점(cold spot) 부분에는 다량의 지금(splash)(3)이 부착되어 있다.FIG. 3 is a plan view showing the type of furnace wall attachment to the electric furnace, in which the hot spots 2 caused by the radiant heat in the three-phase (RST) alternating current during arcing operation at the electrode 1 have a high exposure to the furnace wall. On the other hand, a large amount of splash 3 is attached to the cold spot.
이러한 지금(3)은 300계열 작업이 끝난 후에 니켈의 잔류 형태로써, 내화물과 수냉판넬(4)에 넓게 분포하여 부착되어 통상 약 10ton 정도이나 과다할 경우 20ton 이상이 될 수도 있다.This now (3) is a residual form of nickel after the 300 series work is completed, and is widely distributed and attached to the refractory and the water-cooled panel (4) may be about 10 tons or more, if the excess is more than 20 tons.
상기 지금(3)을 제거하기 위한 크리닝 작업은 6연주의 경우에는 6-4, 6-5, 6-6에서 순차적으로 실시하고, 7연주의 경우에는 하기 표 1에서와 같이 7-1에서 7-4까지는 장입량을 97ton으로 하여 정상 작업을 하고, 7-5에서 7-7까지 3 히트(heats)에 걸쳐서 장입량을 2ton 줄여 93ton으로 장입하고 통전량을 2,000kwh를 추가로 한다.The cleaning operation to remove the now (3) is carried out sequentially in 6-4, 6-5, 6-6 in the case of six strings, 7-1 to 7 as shown in Table 1 in the case of seven strings -4 to normal operation with a loading of 97 tons, load 2 tons by 93 tons over 3 heats from 7-5 to 7-7 and add 2,000 kwh of electricity.
그리고, 각 히트에서는 도 4에서와 같은 통전패턴에 따라 용해 작업을 하며, 2차 용해 말기의 승온기에서 ①과 같이 13탭(tap)으로 하여 노벽 중심으로 크리닝을 하거나, ②와 같이 13탭과 8탭을 병렬로 하여 노벽과 노상의 지금을 크리닝한다.In each heat, the melting operation is performed according to the energization pattern as shown in FIG. 4, and the cleaning is performed at the center of the furnace wall with 13 taps as in ① in the temperature increaser at the end of the secondary melting, or 13 taps as in ②. Clean the furnace walls and the roadbed now with 8 taps in parallel.
이와 같은 크리닝 작업은 도 4의 ①과 ②를 비교하면 면적이 증가하여 정상 작업에 비해 전력의 사용량이 증가하고, 작업시간도 증가한다.In this cleaning operation, the area is increased when comparing the ① and ② of FIG. 4, the power consumption is increased and the working time is increased as compared with the normal operation.
즉, 크리닝 작업은 상기 표 1에 나타난 바와 같이, 통전량을 정상 작업에 비해 2,000kwh로 추가하여 사용함으로써 전력 사용의 증가를 가져왔고, 연속적으로 3 히트를 실시함에 따른 노벽 내화물의 마모 및 침식을 유발하게 되어 설비 수명 저하의 문제점이 있다.That is, the cleaning operation, as shown in Table 1 above, increased the use of electricity by using an additional current of 2,000 kwh compared to the normal operation, and the wear and erosion of the furnace wall refractory by performing three heat in succession There is a problem of deterioration of equipment life.
또한, 노벽 지금 제거가 불완전하게 실행되었을 경우 니켈의 상승으로 범위 초과 및 후공정 합탕에 의한 장시간의 공정 대기를 발생케 하여 생산성 저하를 초래하는 문제점이 있다.In addition, when the furnace wall removal is incompletely performed, there is a problem that the rise of nickel causes the process atmosphere for a long time due to over-range and post-process coalescence, resulting in a decrease in productivity.
본 발명은 상기한 바와 같은 문제점을 해결하기 위한 것으로, 그 목적은 강종 전환시 지금의 발생을 최소화함으로써 성분 범위의 초과 발생을 방지하고, 크리닝 단계를 줄임으로써 전기로 노벽의 손상을 줄여 내화물을 보호할 수 있는 전기로 크리닝 조업 방법을 제공하는 것이다.The present invention is to solve the problems as described above, the object is to prevent the occurrence of excess component range by minimizing the current occurrence in steel grade conversion, and to reduce the damage of the furnace wall furnace by reducing the cleaning step to protect the refractory It is to provide a cleaning operation method by which electricity can be performed.
도 1은 본 발명의 따라 바스켓에 형석을 적입한 모형도,1 is a model diagram incorporating fluorspar in the basket according to the present invention,
도 2a는 형석 투입량에 따른 노내 잔류 지금량을 나타낸 그래프,Figure 2a is a graph showing the residual current in the furnace according to the fluorspar input,
도 2b는 종래의 기술과 본 발명에 따른 전기로 크리닝 작업의 전력 투입량과 시간을 비교한 그래프,Figure 2b is a graph comparing the power input and the time of the electric furnace cleaning operation according to the prior art and the present invention,
도 3은 전기로에 노벽 지금 부착의 유형을 나타낸 평면도,3 is a plan view showing the type of furnace wall now attached to the furnace,
도 4는 일반 전기로 조업 패턴의 한 유형도이다.4 is a type diagram of a general furnace operation pattern.
상기와 같은 목적을 달성하기 위한 본 발명은,The present invention for achieving the above object,
300계열 강종의 전기로 조업 방법에 있어서 400계열로의 강종 전환 직후에 니켈의 성분을 제거하기 위하여 실시하는 크리닝 조업에 있어서, 일정량의 형석(CaF2)을 강종 전환 직전의 히트(heat)에 투입하는 것을 특징으로 한다.In a cleaning operation performed to remove nickel components immediately after converting steel grades to 400 series in an electric furnace operating method of 300 series steel grades, a certain amount of fluorite (CaF 2 ) is added to a heat immediately before the steel grade conversion. Characterized in that.
상기 형석의 투입량을 전기로 전체 장입량의 0.3 ~ 0.5%로 하여 2차 장입 바스켓 하단부에 로딩하는 것이 바람직하다.It is preferable to load the fluorspar into the lower portion of the secondary charging basket at an electric charge of 0.3 to 0.5% of the total charge of the electric furnace.
이하, 본 발명을 보다 상세히 설명한다.Hereinafter, the present invention will be described in more detail.
본 발명은 300계열 강종에서 400계열 강종으로 전환시 일정량의 형석(CaF2)을 강종 전환 직전 히트의 2차 바스켓에 투입하여 용융을 실시함으로써, 강종 변환으로 인한 전기로의 크리닝 작업은 300계열 마지막 히트에서 한번만으로 이루어질 수 있다.In the present invention, when converting from 300 series steel grade to 400 series steel grade, a certain amount of fluorite (CaF 2 ) is added to the secondary basket of the heat just before the steel grade conversion, and the melting is performed. Can be done only once.
즉, 도 1에 도시된 바와 같이 300계열 마지막 히트의 2차 장입시 바스켓 하단에 스테인레스 스크랩을 먼저 5 ~ 6ton 정도를 깔고, 그 위에 고철, 지금, 코크스류와 함께 형석을 적입한 후, 일반 경량 스크랩(mild scrap), 차지 크롬, 스테인레스 스크랩의 순으로 상부에 적입한다.That is, as shown in FIG. 1, when the second charging of the 300 series last hit, the stainless steel scrap is first placed on the bottom of the basket about 5 to 6 tons, and the fluorspar is loaded with scrap metal, and now, coke on the bottom of the basket. Mild scrap, charged chromium and stainless scrap are applied in the top.
상기 형석은 지금의 유동성을 좋게 하여 반응성을 촉진함으로써, 지금에 포함된 니켈을 제거하는 역할을 한다.The fluorite serves to remove the nickel contained in the present by improving the current fluidity to promote reactivity.
그러나, 형석의 투입은 반드시 2차 장입의 바스켓에 적입하여야 한다.However, the fluorspar input must be loaded into the basket for the second charge.
이는 일반적으로 반응성이 양호한 슬래그를 만들기 위한 생석회의 투입량이 1차 장입시는 약 2ton 정도이고 2차 장입시는 약 4ton 정도이므로, 생석회의 투입량이 적은 1차 장입시 형석을 투입할 경우 생석회에 비해 형석의 투입량이 많아 지금 및 슬래그 등의 반응성을 촉진할 뿐만 아니라 노체 내화물의 침식를 가져올 수 있기 때문이다.In general, the amount of quicklime input to make slag with good reactivity is about 2ton at the time of the first charge and about 4tons at the time of the second charge. This is because a large amount of fluorite is added, which not only promotes reactivity such as now and slag, but also leads to erosion of the furnace refractory material.
그리고, 상기 형석의 투입량은 도 2에 나타난 바와 같이 전기로 전체 장입량의 0.3 ~ 0.5% 정도가 바람직하다. 즉, 전체 장입량을 100ton으로 하였을 때 형석의 투입량을 300 ~ 500kg로 하는 것이다.In addition, the amount of fluorspar is preferably about 0.3 to 0.5% of the total amount of the electric furnace as shown in FIG. In other words, when the total loading amount is 100 tons, the input amount of fluorspar is 300 to 500 kg.
이는 형석의 투입량이 500kg을 초과할 경우에는 노내 부착 지금이 과잉 제거 되어 노체 내화물의 침식이 발생하고, 300kg 미만인 경우에는 잔존 지금이 많아 니켈이 범위를 초과하여 400계열 작업을 할 수 없기 때문이다.This is because when the input of fluorspar exceeds 500 kg, the inside of the furnace is removed excessively and erosion of the furnace refractories occurs. When the amount of fluorspar is less than 300 kg, the residual current is much higher and nickel cannot exceed 400 to operate the series.
한편, 형석의 2차 바스켓 내의 로딩 위치를 가급적 하단부로 하는 것이 용해 작업에 바람직하다.On the other hand, it is preferable for the melting operation to make the loading position in the secondary basket of fluorite as the lower end as possible.
이는 형석이 부도체이므로 바스켓 상부에 적입할 경우 스크랩이 미리 용해되지 않은 상태에서 아크 작업이 선행되므로 부도체에 의한 통전 작업 지연이나 전극 절손에 의한 작업의 곤란성을 가져오기 때문이다.This is because when the fluorite is insulator, when it is loaded in the upper part of the basket, the arc work is performed in a state in which the scrap is not dissolved in advance, so that it is difficult to perform the work by delaying the energization work by the insulator or the electrode breakage.
(실시예)(Example)
전기로 크리닝 조업시 형석량을 달리하여 노내의 잔존 지금과 슬래그의 양을 조사하였다.The amount of fluorspar in the cleaning operation of the electric furnace was investigated to determine the remaining current and slag in the furnace.
도 2a는 형석 투입량에 따른 노내 잔류 지금량을 나타낸 그래프이다.Figure 2a is a graph showing the residual current amount in the furnace according to the fluorspar input amount.
상기 도면에 의하면, 형석의 투입량이 500kg을 초과할 경우에는 노내 부착 지금량이 1ton 이하가 되어 노체 내화물의 침식을 가중시킬 수 있으며, 형석 투입량이 300kg 미만인 경우에는 잔존 지금량이 2ton 이상이므로 크리닝 작업의 효과가 미비하다.According to the drawings, when the input amount of fluorspar exceeds 500kg, the amount of adhesion inside the furnace is 1 ton or less, which can increase the erosion of the furnace refractory.In the case where the fluorspar input is less than 300kg, the residual amount is more than 2 ton, so the effect of cleaning Is incomplete.
따라서, 형석의 투입량은 노내 부착 지금이 1 ~ 2ton 정도인 300 ~ 500kg 정도가 가장 적합하다.Therefore, the dosage of fluorspar is most suitably about 300 to 500 kg, which is about 1 to 2 tons in the furnace.
그리고, 도 2b는 종래의 기술과 본 발명에 따른 전기로 크리닝 작업의 전력 투입량과 시간을 비교한 그래프이다.And, Figure 2b is a graph comparing the power input and the time of the electric furnace cleaning operation according to the prior art and the present invention.
상기 도면에 의하면, 종래의 기술에 의해 크리닝 작업을 한 것에 비해 본 발명의 형석을 이용한 크리닝 작업을 수행할 경우 각 히트(heat)당 전기로 용해 시간이 5분 정도 절감됨으로써, 종래의 3 히트의 크리닝 조업에 비교하면 15분 정도의 작업시간이 절감되었고, 추가 전력 투입량도 120kwh/ton 감속시킬 수 있었다.According to the drawings, when the cleaning operation using the fluorspar of the present invention compared to the cleaning operation according to the prior art by reducing the melting time of the electric furnace per each heat (5 minutes), the conventional three heat of Compared to cleaning operations, 15 minutes of work time was saved and additional power input was reduced by 120 kwh / ton.
이상 설명한 바와 같이 본 발명에 따른 전기로 크리닝 조업 방법에 의하면, 노벽 및 노상의 극심한 마모와 침식을 줄일 수 있어 노체 수명을 향상시킬 수 있으며, 니켈의 범위를 제한하여 400계열 작업이 가능하게 한다.As described above, according to the electric furnace cleaning operation method according to the present invention, it is possible to reduce the extreme wear and erosion of the furnace wall and the hearth, thereby improving the life of the furnace body and limiting the range of nickel to enable 400 series operations.
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| KR10-1999-0065309A KR100396089B1 (en) | 1999-12-29 | 1999-12-29 | Method for Cleaning Line of Electric Furnace |
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| KR10-1999-0065309A KR100396089B1 (en) | 1999-12-29 | 1999-12-29 | Method for Cleaning Line of Electric Furnace |
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