CN102337361A - Method for positioning discharged residual iron during overhaul of blast furnace - Google Patents
Method for positioning discharged residual iron during overhaul of blast furnace Download PDFInfo
- Publication number
- CN102337361A CN102337361A CN2011103174162A CN201110317416A CN102337361A CN 102337361 A CN102337361 A CN 102337361A CN 2011103174162 A CN2011103174162 A CN 2011103174162A CN 201110317416 A CN201110317416 A CN 201110317416A CN 102337361 A CN102337361 A CN 102337361A
- Authority
- CN
- China
- Prior art keywords
- temperature
- residual
- residual iron
- furnace
- iron
- 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
Links
Images
Landscapes
- Vertical, Hearth, Or Arc Furnaces (AREA)
Abstract
The invention discloses a method for positioning discharged residual iron during overhaul of a blast furnace, which aims to accurately determine an elevation position of a residual iron opening and shorten the overhaul construction period of the blast furnace. The method comprises the following steps of: calculating the elevation position of the residual iron opening and the storage quantity of the residual iron from the central line of the residual iron opening in the furnace to the bottom of the furnace by using a one-dimensional heat transmission formula; measuring the temperature of the surface of a furnace shell, determining the elevation position of the residual iron opening through a temperature curve, and further verifying relative data; measuring the temperature of the surface of a carbon brick, and accurately positioning the residual iron opening; after a discharged residual iron cooling wall and the furnace shell are removed, measuring the temperature of the surface of the exposed carbon brick by using a gridding scale through an infrared imaging temperature detector, and accurately positioning the residual iron opening after a position where the temperature is remarkably changed is measured; and tapping at the position by using a drill bit, sintering by using an oxygen pipe, and discharging the residual iron from the furnace.
Description
Technical field
The present invention relates in a kind of blast furnace ironmaking production blast furnace overhaul and put the localized method of residual iron.
Background technology
The iron-bearing material agglomerate of blast furnace, pellet, South Africa lump ore and coke are packed into through the belt transportation in the stove; High-temperature hot-air after the hotblast stove heat exchange is sent into blast furnace through the supply air system belly pipe and is produced coal gas of high temperature; Coal gas constantly carries out chemical reaction with iron-bearing material in uphill process, produce molten iron and slag, drops onto below the center, air port to the above zone of furnace bottom brick fuel; During ordinary production, blast furnace was from scum of iron mouth discharging in 2 hours.Blast furnace is produced the later stage (12 years lives of generation stove labour) of generation stove labour, because the restriction of problem such as water-cooled tube damage, cupola well bottom temperature height, furnace shell crack, air port be fragile, blast furnace need carry out furnace retaining, or repaiies in the blowing out.In furnace shutting down process, need the slag iron that the furnace charge of packing in the State of Blast Furnace produces is discharged totally, stockline is empty to below the medullary ray of air port, and in empty stockline process, blast furnace is no longer feeded.The slag iron that produce early stage leans on two iron mouth dischargings of blast furnace; Residual residue iron discharging in the following cupola well of iron mouth medullary ray can only be leaned on the two little cooling stave location back boring discharging in the design; Can slag iron discharge totally in the stove, directly influences construction speed in the maintenance process.The absolute altitude location of discharging residue iron is the important step of putting clean residual iron, and absolute altitude is crossed to hang down and possibly put the iron of not slagging tap, and can continue to locate hole burning; Increase operating personnel's labour intensity, it is unclean that the too high meeting of absolute altitude causes in the stove residual iron to put, the cooling because furnace roof is constantly sprayed water after the blowing out; And form large-area slag iron mixture, when removing cupola well, must carry out explosion; Can remove totally, the explosion meeting produces damaged influence to the cooling stave of not changing in stove, and directly influences the whole construction duration.
Summary of the invention
The present invention seeks to overcome the deficiency of above-mentioned prior art, provide a kind of and can accurately locate residual iron mouth absolute altitude position, shorten the blast furnace overhaul of blast furnace overhaul duration and put the localized method of residual iron.
Iron-smelting blast furnace furnace bottom and cupola well all adopt the composite corindon ceramic cup to add the composite structure of microporous carbon brick; Iron one's intention as revealed in what one says oral region adopts the corundum-mullite modular tile.The corresponding two-layer ring in two-layer carbon brick of furnace bottom lower floor laid on end and edge is built brick fuel and is gone up the 15 and 16 two-layer brick fuels that encircle block most and select the semi-graphited brick fuel for use, and laid on end brick fuel and 3 to 14 layers of ring are built brick fuel and all adopted microporous carbon brick on the furnace bottom.Cupola well ceramic cup structure is the boundary with the Tie Kou center, below uses the corundum-mullite brick, and more than with compound brown corundum brick, iron mouth, air port modular tile are the corundum-mullite brick, outer one deck high alumina brick resist of building.Brick fuel is adorned cast-iron cooling wall circulation cooling outward, cooling stave external application HS welding steel parcel, and thickness is 40-60mm.Be designed with two little cooling staves at one deck cooling stave position, blast furnace west, use for putting residual iron specially.
The residual Tie Kou band of position is at two little cold drawing places of cupola well one deck; For further confirming residual iron mouth absolute altitude; Need to adopt the method for theoretical calculation, furnace shell surface temperature measurement method and the triplicity of brick fuel surface temperature measurement method, key is that measurement brick fuel surface temperature finds residual iron mouth absolute altitude to confirm the optimum position of residual iron mouth after cutting away furnace shell, cooling stave.
The inventive method is specifically:
(1) the residual Tie Kou of Theoretical Calculation position absolute altitude is prepared so that carry out to produce; Before in decision, repairing blowing out, the thermal conductivity of furnace bottom center each layer brick fuel temperature value, various refractory materialss utilizes the one dimensional heat transfer formula during according to ordinary production, calculates the absolute altitude position and the following iron deposit amount to furnace bottom of the interior iron mouth medullary ray of stove of residual iron mouth:
Q＝λc(t
1-t
2)/(L
1-L
2) (I)
X＝λ2(T-t
1)/Q (II)
In the formula: Q is a furnace bottom vertical direction heat flow rate per unit area, W/m
2t
1Be furnace bottom second layer carbon brick upper surface center (L
1Absolute altitude) temperature of locating; t
2Be furnace bottom carbon brick lower surface center (L
2Absolute altitude) locates temperature; X is furnace bottom second layer carbon brick upper surface center (L
1Absolute altitude) to molten iron encroachment line distance; λ c is the brick fuel thermal conductivity, and λ 2 is a corundum-mullite brick thermal conductivity; T is a molten iron encroachment line temperature; L
1Designed elevation for two-layer brick fuel upper surface; L
2Designed elevation for two-layer brick fuel bottom;
(2) furnace shell surface temperature measurement, and confirm residual Tie Kou position absolute altitude through temperature curve, further verify related data; Before blowing out, furnace shell place outside putting two little cooling stave positions of residual iron, every separated 100mm establishes a mounting points, shows casing temperature through the Central Control Room computingmachine, checks its trend; Make vertical coordinate according to absolute altitude (+6.2 meters～+ 7.8 meters), casing temperature is made X-coordinate, confirms the temperature flex point from temperature curve, confirms residual iron mouth approximate location according to the outer casing temperature flex point of cupola well;
When temperature curve is confirmed the temperature flex point, observe temperature curve, along with constantly rising in the absolute altitude position, temperature is progressively improving, and significantly raising appears in most temperature spots near residual Tie Kou position, and curvilinear motion obviously aggravates; Because it is serious that this position is corroded by molten iron, temperature sharply raises and changes greatlyyer, can judge, the position that significantly changes occurs in temperature, is exactly residual Tie Kou position, and absolute altitude is generally in the scope of 7.2-7.6 rice.
(3) measure the brick fuel surface temperature, residual Tie Kou position is accurately located; After residual iron cooling stave and furnace shell are put in excision, utilize latticed scale, through the infrared imaging temperature measuring appearance thermometric is carried out on the brick fuel surface of exposing, measure the violent position of temperature variation after, accurately locate residual Tie Kou position; , burn with oxygen hose subsequently and lead in this position perforate with drill bit, emit slag iron in the stove.
The absolute altitude of the residual Tie Kou of Theoretical Calculation position is the brick fuel temperature value during according to ordinary production, the thermal conductivity of various refractory materialss, the calculated value of releasing through the heat transfer formula, and release iron deposit amount in the stove in view of the above, and prepare so that produce, there is not actual verification; Furnace shell surface temperature measurement method has just further been verified the absolute altitude scope of residual Tie Kou position; Can measuring residual Tie Kou position, the accurate location of brick fuel surface temperature then be the part of most critical, directly determined put clean residual iron, and the three progressively advances, and increases the relation of factor of assurance.
The inventive method can accurately be located residual iron mouth absolute altitude position, effectively solves to put residual iron absolute altitude location and forbidden the problem that causes, shortens the duration that stove is torn in the blast furnace overhaul construction open, for the overhaul smooth construction is saved time.
Description of drawings
Fig. 1 is a residual Tie Kou position casing temperature trend map.
Fig. 2 is little cooling stave position grid shape thermometric synoptic diagram.
Fig. 3 is put residual iron position and absolute altitude synoptic diagram.
Among the figure: 1, one deck cold drawing, 2, two layers of cold drawing, 3, water cooling tube, 4, residual metal trough position, 5, residual Tie Kou position, 6, need cutting part.
Embodiment
Before in decision, repairing blowing out,, utilize the one dimensional heat transfer formula, calculate the iron deposit amount that arrives furnace bottom in coming out of the stove below the iron mouth medullary ray earlier according to furnace bottom brick fuel temperature; Carry out Theoretical Calculation according to furnace bottom depth of erosion theory in the blast furnace iron-making process reckoner:
The carbon brick furnace bottom calculates by one dimensional heat transfer when erosion reaches steady state:
Q＝λc(t
1-t
2)/(L
1-L
2) (I)
X＝λ2(T-t
1)/Q (II)
In the formula: t
1Be L
1The temperature at absolute altitude place, average out to is 728 ℃ when the blast furnace ordinary production, t
2Medial temperature is 167 ℃ when the blast furnace ordinary production; L
1The absolute altitude value is 7.293m; L
2The absolute altitude value is 5.53m.λ c is the brick fuel thermal conductivity, gets 10W/m ℃; λ 2 is a corundum-mullite brick thermal conductivity, gets 1.5W/m ℃; T is a molten iron encroachment line temperature, gets 1200 ℃ of the freezing point temperatures of molten iron.Substitution (I), (II) Shi Kede:
X=0.222m, promptly residual Tie Kou position absolute altitude is: 7.293+0.222=7.515m; Residual iron amount is calculated as 490 tons.
Before the blowing down in advance, the measurement of cutting off the water supply.During blowing down in advance, take off stove skin, cooling stave, measure once more, find out vertex.Accompanying drawing 1 is a residual Tie Kou position casing temperature trend map, observes curvilinear motion among the figure, can find the maximum absolute altitude scope of residual Tie Kou position temperature variation.
Carrying out thermometric before and after cutting away little cooling stave and furnace shell:, cuts off the water supply to this place's cooling stave in order further to confirm residual iron mouth absolute altitude at two little cold drawing places of cupola well one deck in residual Tie Kou position; Measure temperature; Find out flex point, concrete operation method is the little cooling stave place of putting residual iron at two, from absolute altitude 6.8m to the 7.8m vertical direction; Every at a distance from the 100mm thermometric straight line that draws; This position has 8 standpipes (4 standpipes of a little cold drawing), and is laterally every at a distance from the 100mm thermometric line that draws in this standpipe zone, and two lines intersect and are final point for measuring temperature.
After residual iron cooling stave and furnace shell are put in excision; Utilize latticed scale; With the infrared imaging temperature measuring appearance thermometric is carried out on the brick fuel surface of exposing; After measuring the violent position of temperature variation, accurately locate residual Tie Kou position, following table 1 has reflected the iron work 4# of Taiyuan Iron & Steel (Group) Co., Ltd. stove absolute altitude temperature on the vertical direction between final two cooling staves confirming after get cold drawing during 9-10 day in October, 2010:
Table 1: vertical direction subscript high-temperature between final two cooling staves confirming
Through the measurement of taking pictures of IR survey appearance, follow the tracks of infrared temperature, the analyzed area temperature through contrast, screening, analyze and find out vertex, is carried out actual field and is measured.Fig. 2 is little cooling stave position grid shape thermometric synoptic diagram, has indicated measurement brick fuel surface location temperature spot, can accurately locate residual Tie Kou position.Fig. 3 SD residual Tie Kou position.
Above-mentioned three combined confirm residual iron mouth corner position.Theoretical Calculation confirms that residual iron mouth absolute altitude is 7.515 meters; The furnace shell thermometric confirms that further iron mouth absolute altitude scope exists: between 7.2～7.6 meters; Measure brick fuel surface temperature extreme higher position at 7.5 meters after taking down furnace shell and cooling stave; The temperature corner position is 7.4 meters of absolute altitudes: four thermometric situation of carrying out with the IR survey appearance after take down little cooling stave are seen; From 6.9 meters of absolute altitudes to 7.5 meters temperature of absolute altitude in continuous rising, wherein 7.3 meters of absolute altitudes are 10.5 ℃ to 7.4 meters temperature difference maximums of absolute altitude; Its temperature value sharply changes explanation and corrodes the most serious at this position molten iron; The heat that spreads out of in the stove is maximum, and temperature is the highest, therefore finally confirms that residual iron mouth position of opening is 7.4 meters of absolute altitudes.
Claims (1)
1. a blast furnace overhaul is put residual definitely method for position, it is characterized in that:
(1) the residual Tie Kou of Theoretical Calculation position absolute altitude is prepared so that carry out to produce; Before in decision, repairing blowing out, the thermal conductivity of furnace bottom center each layer brick fuel temperature value, various refractory materialss utilizes the one dimensional heat transfer formula during according to ordinary production, calculates the absolute altitude position and the following iron deposit amount to furnace bottom of the interior iron mouth medullary ray of stove of residual iron mouth:
Q＝λc(t
1-t
2)/(L
1-L
2) (I)
X＝λ2(T-t
1)/Q (II)
In the formula: Q is a furnace bottom vertical direction heat flow rate per unit area, W/m
2t
1Be furnace bottom second layer carbon brick upper surface center (L
1Absolute altitude) temperature of locating; t
2Be furnace bottom carbon brick lower surface center (L
2Absolute altitude) locates temperature; X is furnace bottom second layer carbon brick upper surface center (L
1Absolute altitude) to molten iron encroachment line distance; λ c is the brick fuel thermal conductivity, and λ 2 is a corundum-mullite brick thermal conductivity; T is a molten iron encroachment line temperature; L
1Designed elevation for two-layer brick fuel upper surface; L
2Designed elevation for two-layer brick fuel bottom;
(2) furnace shell surface temperature measurement, and confirm residual Tie Kou position absolute altitude through temperature curve, further verify related data; Before blowing out, furnace shell place outside putting two little cooling stave positions of residual iron, every separated 100mm establishes a mounting points, shows casing temperature through the Central Control Room computingmachine, checks its trend; Make vertical coordinate according to absolute altitude, casing temperature is made X-coordinate, confirms the temperature flex point from temperature curve, confirms residual iron mouth approximate location according to the outer casing temperature flex point of cupola well;
When temperature curve is confirmed the temperature flex point, observe temperature curve, along with constantly rising in the absolute altitude position, temperature is progressively improving, and significantly raising appears in most temperature spots near residual Tie Kou position, and curvilinear motion obviously aggravates; Because it is serious that this position is corroded by molten iron, temperature sharply raise change bigger; Can judge, the significantly position of variation occur in temperature, be exactly residual Tie Kou position;
(3) measure the brick fuel surface temperature, residual Tie Kou position is accurately located; After residual iron cooling stave and furnace shell are put in excision, utilize latticed scale, through the infrared imaging temperature measuring appearance thermometric is carried out on the brick fuel surface of exposing, measure the violent position of temperature variation after, accurately locate residual Tie Kou position; , burn with oxygen hose subsequently and lead in this position perforate with drill bit, emit slag iron in the stove.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011103174162A CN102337361A (en) | 2011-10-13 | 2011-10-13 | Method for positioning discharged residual iron during overhaul of blast furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011103174162A CN102337361A (en) | 2011-10-13 | 2011-10-13 | Method for positioning discharged residual iron during overhaul of blast furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102337361A true CN102337361A (en) | 2012-02-01 |
Family
ID=45513310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011103174162A Pending CN102337361A (en) | 2011-10-13 | 2011-10-13 | Method for positioning discharged residual iron during overhaul of blast furnace |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102337361A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107119158A (en) * | 2017-06-09 | 2017-09-01 | 河钢股份有限公司承德分公司 | A kind of residual iron placing method of schreyerite steelmaking furnace |
| CN107858466A (en) * | 2017-11-11 | 2018-03-30 | 江阴兴澄特种钢铁有限公司 | The Forecasting Methodology of charge level depth during a kind of blast furnace level-lowering blowing out |
| CN108085440A (en) * | 2017-12-14 | 2018-05-29 | 安徽马钢设备检修有限公司 | Stove method is taken off in a kind of blast furnace overhaul |
| CN108342533A (en) * | 2017-01-23 | 2018-07-31 | 宝山钢铁股份有限公司 | A kind of blast furnace safety residual iron placing shedding control method |
| CN109266800A (en) * | 2018-11-09 | 2019-01-25 | 唐山钢铁集团有限责任公司 | Brick fuel and ceramic-lined Thickness Design Method in blast furnace crucibe masonry |
| CN111702660A (en) * | 2020-06-23 | 2020-09-25 | 宝武装备智能科技有限公司 | Online ultrahigh-pressure water jet cutting method for blast furnace shell and cooling wall |
| CN111809012A (en) * | 2020-07-04 | 2020-10-23 | 北京首钢建设集团有限公司 | Construction method for removing accumulated iron in iron-making blast furnace by using residual iron discharging mode |
| CN113430316A (en) * | 2021-06-07 | 2021-09-24 | 山西太钢不锈钢股份有限公司 | Online drainage device and drainage method for blast furnace shell |
| CN114686625A (en) * | 2022-01-29 | 2022-07-01 | 北京首钢股份有限公司 | Method for discharging residual iron from blast furnace |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201485479U (en) * | 2009-09-10 | 2010-05-26 | 宝山钢铁股份有限公司 | Blast furnace residual iron shedding device |
-
2011
- 2011-10-13 CN CN2011103174162A patent/CN102337361A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201485479U (en) * | 2009-09-10 | 2010-05-26 | 宝山钢铁股份有限公司 | Blast furnace residual iron shedding device |
Non-Patent Citations (4)
| Title |
|---|
| 吕宏: "大型高炉常规短期化大修施工技术", 《中国新技术新产》, no. 18, 30 September 2011 (2011-09-30), pages 113 - 114 * |
| 张聪山 等: "宣钢8#高炉大修放残铁实践", 《2004年全国炼铁生产技术暨炼铁年会文集》, 31 December 2004 (2004-12-31), pages 466 - 469 * |
| 王志军: "太钢4#高炉大修停炉实践", 《山西冶金》, no. 82, 31 December 2001 (2001-12-31), pages 14 - 16 * |
| 王成国 等: "邯钢4#高炉大修停炉实践", 《河北冶金》, no. 152, 31 December 2006 (2006-12-31) * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108342533A (en) * | 2017-01-23 | 2018-07-31 | 宝山钢铁股份有限公司 | A kind of blast furnace safety residual iron placing shedding control method |
| CN107119158A (en) * | 2017-06-09 | 2017-09-01 | 河钢股份有限公司承德分公司 | A kind of residual iron placing method of schreyerite steelmaking furnace |
| CN107858466A (en) * | 2017-11-11 | 2018-03-30 | 江阴兴澄特种钢铁有限公司 | The Forecasting Methodology of charge level depth during a kind of blast furnace level-lowering blowing out |
| CN107858466B (en) * | 2017-11-11 | 2019-12-27 | 江阴兴澄特种钢铁有限公司 | Method for predicting charge level depth of blast furnace during charge level lowering and blowing out |
| CN108085440A (en) * | 2017-12-14 | 2018-05-29 | 安徽马钢设备检修有限公司 | Stove method is taken off in a kind of blast furnace overhaul |
| CN108085440B (en) * | 2017-12-14 | 2019-07-02 | 安徽马钢设备检修有限公司 | Furnace method is taken off in a kind of blast furnace overhaul |
| CN109266800A (en) * | 2018-11-09 | 2019-01-25 | 唐山钢铁集团有限责任公司 | Brick fuel and ceramic-lined Thickness Design Method in blast furnace crucibe masonry |
| CN111702660A (en) * | 2020-06-23 | 2020-09-25 | 宝武装备智能科技有限公司 | Online ultrahigh-pressure water jet cutting method for blast furnace shell and cooling wall |
| CN111809012A (en) * | 2020-07-04 | 2020-10-23 | 北京首钢建设集团有限公司 | Construction method for removing accumulated iron in iron-making blast furnace by using residual iron discharging mode |
| CN113430316A (en) * | 2021-06-07 | 2021-09-24 | 山西太钢不锈钢股份有限公司 | Online drainage device and drainage method for blast furnace shell |
| CN113430316B (en) * | 2021-06-07 | 2022-11-25 | 山西太钢不锈钢股份有限公司 | Online drainage device and drainage method for blast furnace shell |
| CN114686625A (en) * | 2022-01-29 | 2022-07-01 | 北京首钢股份有限公司 | Method for discharging residual iron from blast furnace |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102337361A (en) | Method for positioning discharged residual iron during overhaul of blast furnace | |
| CN104327881B (en) | Liquid continuous slag-removal fixed bed gasification furnace and gasification method thereof | |
| CN102399926B (en) | Furnace halt residue iron outlet method for middle and large-sized blast furnaces | |
| CN106435073B (en) | A kind of blast furnace lining monolithic casting construction method for substituting spray paint and refractory brick | |
| CN100567511C (en) | Electric arc furnace | |
| CN100595284C (en) | Maintaining method for blast furnace | |
| JP4728165B2 (en) | Skirt seal structure in converter exhaust gas treatment equipment | |
| CN108570524A (en) | The blast funnace hot blast stove pipe lining checkout and diagnosis of resistance to material technique | |
| CN102311237A (en) | Method for repairing mechanical shaft kiln lining | |
| CN101921887B (en) | Maintenance method of blast furnace liner | |
| CN111394531B (en) | Technological operation method for discharging residual iron in hearth | |
| CN106702073A (en) | Hot replacement method for converter bottom blowing element | |
| CN105779672B (en) | It is a kind of for controlling the stopper of molten slag flow | |
| CN110184412B (en) | Method for replacing bottom blowing brick cup of converter | |
| CN101851692B (en) | Construction method for curing non-aqueous slurry at normal temperature in blast furnace | |
| CN201697470U (en) | Furnace lining structure for ore furnace cooling method technology | |
| CN115758624A (en) | Method for prolonging service life of blast furnace waist and furnace belly cooling wall | |
| Geyer et al. | Blast furnace tapping practice at arcelor mittal South Africa, vanderbijlpark works | |
| CN201605279U (en) | Blast furnace grouting device capable of measuring temperature | |
| CN104328236B (en) | A kind of method changing cooling device in the case of shaft furnace charging | |
| CN203550585U (en) | Furnace bottom refractory material structure for liquid deslagging step-type heating furnace | |
| CN106350629B (en) | A kind of guard method of HIsmelt techniques melting and reducing inner lining of furnace | |
| CN102134620A (en) | Blast furnace shaft upper part rapid hot wet method for producing lining | |
| CN112325653A (en) | Repairing method of metal mixer lining | |
| CN203200295U (en) | Device for measuring zero position of oxygen lance of newly-built steelmaking converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120201 |