CN108424994A - A method of reducing molten iron drossing loss - Google Patents
A method of reducing molten iron drossing loss Download PDFInfo
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- CN108424994A CN108424994A CN201710075537.8A CN201710075537A CN108424994A CN 108424994 A CN108424994 A CN 108424994A CN 201710075537 A CN201710075537 A CN 201710075537A CN 108424994 A CN108424994 A CN 108424994A
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- molten iron
- slag
- sulphur
- sulfur content
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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
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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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
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- 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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Abstract
The present invention relates to a kind of methods of reduction molten iron drossing loss, include the following steps：The first step sets risk reserved value according to the requirement for smelting tapping steel grade finished product sulphur, second step determines the pretreated target desulfurization grade of molten iron, third step calculates after desulfurizing iron the gross mass of sulphur in clinker and allows the quality of sulphur in remaining clinker after skimming, it determines in turn and stays quantity of slag ratio after skimming, 4th step determines that theory is skimmed weight section, 5th step is skimmed operation early period, when taking off the quantity of slag and reaching the 50~70% of theoretical weight interval limit of skimming, carrying out blowing slag-removing and later stage skims operation, it is monitored using image pick-up device in operation process, 6th step obtains practical slag area ratio, and compared with target staying slag area ratio, it skims when the two is identical end, 7th step, which weighs, obtains weight of actually skimming, and judge whether weight of actually skimming skims in theory in weight section.It is an advantage of the invention that the rate that is smelt of sulphur reaches 100%.
Description
Technical field
The invention belongs to metallurgical technology fields, particularly, are related to a kind of method of reduction molten iron drossing loss.
Background technology
For most of steel grade, element sulphur is harmful element, it can reduce the processing performance of steel, deteriorates the weldering of steel
Performance is connect, " hot-short " and the hot cracking of steel are caused, in addition, the plasticity of steel can be also substantially reduced, in smelting iron and steel one
As require sulphur in molten steel more lower better.It is the essential technology hand of smelting low-sulfur clean steel that pre- desulfurization is carried out before converter smelting
Section.The desulfurization product that molten iron pre-desulfurization generates can all float in molten iron slag, cause the sulfur content of molten iron slag can be with molten iron
The increase of sulfur content and improve, the sulfur content of slag blast-melted in general is about 20~50 times of blast-melted sulfur content.Cause
And most of element sulphur can be removed by desulfurizing iron, the method skimmed before converter smelting.In the prior art, molten iron into
Row desulfurization, molten iron slag after skimming influence of the remaining residual quantity to converter terminal sulfur content it is very big, and due to converter smelting mistake
Need to be added a large amount of steel scrap and slag making auxiliary material in journey, the sulfur content of steel scrap and slag making auxiliary material can also produce converter terminal sulfur content
Raw large effect, and because these influences can not remove in converter steelmaking process, it must be by reducing into stove
Method of the molten iron with the quantity of slag reduces the influence to converter terminal sulphur such as steel scrap and slag making auxiliary material.
During smelting low-sulfur steel grade, molten iron slag is mainly taken off clean or simple root by conventional molten iron drossing method
Determine grade of skimming according to the finished product sulfur content for smelting steel grade, fail to consider comprehensively molten iron initial sulphur, molten iron with slag time sulphur etc. because
Influence of the element to converter terminal sulfur content.During molten iron drossing, the dregs that are removed would generally carry secretly weigh about 50% iron
Water, it is higher to cause metal consumption in this way, causes cost increase.Simultaneously as operation of skimming is artificial handwork, skim
There is very big difference in the band iron of process, and operating personnel lack quantization concepts to pulling down how many bits, can only by rule of thumb into
Row operation.If the amount of skimming is insufficient, can cause to return sulphur when steel-making, and then influence the quality of molten steel.By largely investigating and analysing discovery,
Return that sulfur content is basicly stable in converter steelmaking process caused by steel scrap and slag making auxiliary material, influence clinker sulphur concentration after desulfurization it is main because
Element is the initial sulfur content of molten iron, thus there is an urgent need to it is a kind of can be true according to the initial sulfur content of molten iron, the requirement of steel grade sulfur content
The method for staying the top of the slag to accumulate behind fixed rational molten iron drossing weight section and molten iron drossing.
Invention content
The technical problem to be solved by the present invention is to：Overcome the problems, such as of the existing technology, a kind of reduction molten iron is provided and is taken off
The method of slag loss, this method can not only determine that rational weight section of skimming, the weight that will actually skim are skimmed again with theory
Amount section is compared, and to control weight of skimming, reduces the band iron loss for process of skimming, additionally it is possible to first by staying after molten iron drossing
The top of the slag accumulates ratio quantization, stays the control of slag area ratio to take off the quantity of slag further according to quantization, residual after molten iron drossing to effectively control
Influence of the slag to time sulphur.
The technical solution that the present invention solves its technical problem is as follows：
A method of molten iron drossing loss is reduced, is included the following steps：
The requirement of the first step, steel grade finished product sulphur of being tapped according to smelting, sets converter terminal sulfur content, the steel grade finished product sulphur
Content is greater than converter terminal sulfur content (by percentage to the quality), and difference between the two is set as risk reserved value, and
It is denoted as SRisk is reserved%；Go to second step；
Second step, by percentage to the quality (if following % is mass percent without specified otherwise), by steel grade finished product
Sulfur content is denoted as SSteel grade finished product sulfur content%, the sulfur content that returns in converter steelmaking process are denoted as SSulfur content is returned in converter%, before converter smelting, molten iron pretreatment
Target desulfurization grade in the process is denoted as STarget desulfurization grade%, further according to steel grade finished product sulfur content SSteel grade finished product sulfur contentThe requirement of % and
SSulfur content is returned in converter%, SRisk is reserved% determines the pretreated target desulfurization grade of molten iron, and target desulfurization grade is made to meet formula (1),
STarget desulfurization grade%≤SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter% (1)
In above-mentioned STarget desulfurization gradeRound numbers in the calculating process of %；Go to third step；
Slag weight of the desulfurized molten iron in ladle with slag is denoted as M by third step, (31)The molten iron band quantity of slag, and counted according to formula (3)
The weight of slag in ladle after desulfurizing iron is calculated,
MThe molten iron band quantity of slag=SLadle area×hSlag is thick×ρMolten iron slag density (3)
Wherein SLadle areaFor the molten iron surface area in ladle, hSlag is thickFor the thickness of slag layer in ladle, ρMolten iron slag densityFor molten iron
The density of slag in packet, value range is in 1.9~3.5t/m3；Go to step (32)；
(32) gross mass of sulphur in the clinker after desulfurizing iron is set as MAfter desulfurizing iron in clinker sulphur gross mass, the clinker before desulfurizing iron
The content of middle sulphur is SBlast furnace slag sulfur content%, the weight of molten iron is M in ladleWeight of molten iron, the initial sulfur content of molten iron of converter smelting is
SThe initial sulphur of molten iron%, and according to formula (4) calculate desulfurizing iron after clinker in sulphur gross mass,
MAfter desulfurizing iron in clinker sulphur gross mass=(SThe initial sulphur of molten iron%-STarget desulfurization grade%) × MWeight of molten iron+SBlast furnace slag sulfur content% × MThe molten iron band quantity of slag(4)；It goes to
Step (33)；
(33) weight for the steel scrap being added in converter steelmaking process is set as MSteel scrap weight, the content of sulphur is in steel scrap
SSteel scrap sulfur content%, it is M to be added in converter steelmaking process after steel scrap and return the quality of sulphurSteel scrap returns sulphur quality, and steel scrap is calculated according to formula (5) and is returned
The quality of sulphur,
MSteel scrap returns sulphur quality=MSteel scrap weight×SSteel scrap sulfur content% × (1-AConverter desulfuration efficiency%) (5)
The weight for resetting the slag making auxiliary material being added in converter steelmaking process is MAuxiliary material weight, the content of sulphur is in auxiliary material
SAuxiliary material sulfur content%, it is M to be added in converter steelmaking process after slag making auxiliary material and return the quality of sulphurAuxiliary material returns sulphur quality, slag making is calculated according to formula (6)
Auxiliary material returns the quality of sulphur,
MAuxiliary material returns sulphur quality=MAuxiliary material weight×SAuxiliary material sulfur content% × (1-AConverter desulfuration efficiency%) (6)
Wherein, AConverter desulfuration efficiencyThe value range of % is 20~30%；Go to step (34)；
(34) set allow skim after return the quality of sulphur as M in remaining clinkerAllow the quality for staying the quantity of slag to return sulphur after skimming, and according to formula
(7) calculate allow skim after in remaining clinker sulphur quality,
MAllow the quality for staying the quantity of slag to return sulphur after skimming=(SSteel grade finished product sulfur content%-STarget desulfurization grade%-SRisk is reserved%) × (MWeight of molten iron+MSteel scrap weight)×
AMolten steel recovery rate-MSteel scrap returns sulphur quality-MAuxiliary material returns sulphur quality (7)
Wherein, AMolten steel recovery rateSteel quality to be generated in converter steelmaking process accounts for the percentage of molten iron and steel scrap gross mass,
General value is 95%；Go to step (35)；
(35) set stayed after skimming skim shared by the quality of sulphur in slag before in clinker sulphur gross mass mass percent as
AStay quantity of slag ratio, and calculated according to formula (8) and stay quantity of slag ratio A after skimmingStay quantity of slag ratio,
AStay quantity of slag ratio=MAllow the quality for staying the quantity of slag to return sulphur after skimming/MAfter desulfurizing iron in clinker sulphur gross mass (8)
Go to the 4th step；
4th step determines that theory is skimmed weight section, by the process of skimming according to by take off it is scaling-off in iron-holder be divided into early period
And the later stage, band iron coefficient of skimming is set as XBand iron coefficient, then the band iron coefficient of skimming of early period is 0.1~0.4, the band of skimming in later stage
Iron coefficient is 0.4~0.6, and it is M to reset and taken off scaling-off weight during skimmingTake off the quantity of slag, when current heat desulfurization is blown material
Quality be MIt is blown quality of material, then skimmed weight section according to formula (9) computational theory,
MTake off the quantity of slag=[MThe molten iron band quantity of slag+MIt is blown quality of material+MWeight of molten iron×(SThe initial sulphur of molten iron%-STarget desulfurization grade%)] × (1-AStay quantity of slag ratio)×(1+
XBand iron coefficient) (9)
Go to the 5th step；
5th step skim operation early period, skims under weight section when it is taken off the quantity of slag and reaches the theory of step 4 acquisition
Limit 50~70% when, carry out blowing slag-removing and later stage using blowing slag-removing device and skim operation, used in operation process of skimming
Image pick-up device is monitored, and the camera of image pick-up device, towards molten iron surface, image pick-up device obtains molten iron surface in ladle in real time
Image information and image information is transferred to the image processing module of control system；Go to the 6th step；
6th step, control system image processing module according to the image information on molten iron surface calculate obtain ladle in iron
The practical slag area ratio of water surface, the practical slag area ratio of control system stays slag area ratio with target, when practical slag
When area ratio stays slag area ratio identical with target, it is judged as reaching expected effect of skimming, end of skimming；Go to the 7th step；
Scaling-off weight is taken off in 7th step, weighing, obtains weight of actually skimming, and judges whether actually to skim weight in step
Rapid four theories obtained are skimmed in weight section, if so, explanation is skimmed, process band iron coefficient is skimmed quality in set interval
It is different, iron loss is advantageously reduced, if it is not, explanation band iron coefficient is skimmed second-rate not in set interval.
The present invention fully considers the factor for influencing back sulphur during skimming, according to molten iron with slag system number during skimming
Influence quantization to taking off the quantity of slag determines that skims stays the quantity of slag, is skimmed weight section with establishing, and according to the initial sulfur content of molten iron, at
The difference of product sulfur content come quantify determine molten iron drossing after stay slag area ratio, then by metering device weighing actually skim
Weight, and by the weight real-time Transmission of actually skimming for operation of skimming early period to display, so as to operating personnel's observation of skimming, specification
It skims the operation of operating personnel, guidance operating personnel's control of skimming is skimmed weight, is skimmed weight when actually taking off the quantity of slag and reaching theory
Interval limit 50~70% when, carry out the later stage using blowing slag-removing device and skim operation, supervised using high-resolution image pick-up device
It controls and calculates and actually stay slag area ratio during skimming, determine grade of skimming, will actually stay slag area ratio true with quantization
Fixed stays slag area ratio to be compared, and when the two is identical, terminates to skim, this method can not only accurately control area of skimming
And the quantity of slag is taken off, achieve the purpose that accurately control back sulphur and converter terminal sulfur content, moreover it is possible to make the rate that is smelt of sulphur reach 100%, drop
The low iron loss ton steel 2kg/t or so that skims.
Further perfect technical solution is as follows by the present invention：
Preferably, in the first step, converter terminal sulfur content is denoted as SConverter terminal sulfur content%, then converter terminal sulfur content need to expire
Sufficient formula (10),
SRisk is reserved%=SSteel grade finished product sulfur content%-SConverter terminal sulfur content% (10).
Preferably, in the first step, the SRisk is reservedThe value range of % is 0~0.005%.The present invention is initial according to molten iron
Sulfur content, the molten iron under the conditions of corresponding to different initial sulphur, and under the conditions of different steel grades stay slag area control molten iron slag to return sulphur, make
Converter terminal sulfur content is obtained with steel grade finished product sulfur content risk 0~0.005%, the purpose of setting risk reserved value is anti-rotation stop
Stove final sulfur content is higher, exceeds finished product sulfur content, the finished product sulfur content of steel is finally made to be difficult to reach steel grade standard.
Preferably, in second step, target desulfurization grade also needs to meet formula (2),
(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade% >=0.001% (2).
It is further preferred that in second step, target desulfurization grade also needs to meet formula (11),
0.002%≤(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade%≤0.003% (11)
Wherein, SSulfur content is returned in converter% value ranges are 0.003%~0.006%.
In this way, being to be conducive to control the stability that molten iron slag returns sulphur to obtain suitable desulfurization depth.
Preferably, calculate converter steelmaking process returns sulfur content SSulfur content is returned in converter%, wherein SSulfur content is returned in converter% include steel scrap return sulfur content and
Auxiliary material returns sulfur content, and calculating converter according to formula (12) returns sulphur,
SSulfur content is returned in converter%=(MSteel scrap returns sulphur quality+MAuxiliary material returns sulphur quality)÷(MWeight of molten iron×AMolten steel recovery rate+MSteel scrap weight×AMolten steel recovery rate)(12)。
In addition, desulfurization coefficient (the i.e. A in converter steelmaking processConverter desulfuration efficiencyIt %) is calculated according to 20~30%, according to converter smelting
The pattern of refining can select converter desulfurization coefficient, and when converter smelting is using staying slag pattern to be smelted, converter desulfurization coefficient is
20%；When converter smelting is not using staying slag pattern to be smelted, converter desulfurization coefficient is 30%.
Preferably, further comprising the steps of between the 5th step and the 6th step：A, it calculates target and stays slag area ratio,
The initial sulfur content of the molten iron of converter smelting under the same conditions, is first denoted as by the pretreated target desulfurization grade of molten iron
SThe initial sulphur of molten iron 1%, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 3% ... SThe initial sulphur X of molten iron%, further according to corresponding in the initial sulfur content acquisition ladle of molten iron
Target stay slag area ratio, and stay slag area ratio to be denoted as A corresponding target1%, A2%, A3% ... AX%, then basis
Formula (13) calculate under same desulfurization rating conditions the initial sulfur content of molten iron be SThe initial sulphur X of molten ironTarget when % stays the top of the slag to accumulate ratio
Example AXThe value of %,
AX%=(A2%-A1%) × (SThe initial sulphur of molten iron 2%-SThe initial sulphur X of molten iron%) ÷ (SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%)+A2% (13)
Wherein, SThe initial sulphur of molten iron 2% ＞ SThe initial sulphur of molten iron 1%.
Preferably, in step a, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 1% also needs to meet formula (14),
20≤(SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%) × 1000≤50 (14).
Preferably, also there are following steps between step a, step 6：
B, setting the maximum in ladle stays slag area ratio as Amax%, and maximum stays slag area ratio to meet formula
(15),
Amax%≤80% (15)；Go to step c；
C, setting the minimum in ladle stays slag area ratio as Amin%, and minimum stays slag area ratio to meet formula
(16),
Amin% >=5% (16)；Go to the 6th step.
The maximum setting for staying the top of the slag to accumulate is the exposed surface in order to make to have certain in ladle in the present invention, in order to effectively control
Molten iron residue thickness processed, and then control converter and return sulphur；Minimum stay the top of the slag accumulate setting be in order to control skim during molten iron damage
Consumption prevents iron loss rising of skimming caused by staying slag area ratio too small.
Preferably, in the 5th step, the desulfurization before converter smelting, desulfurization are carried out according to the target desulfurization grade that step 2 obtains
After skim operation early period.
Preferably, in the 6th step, the specific image processing method of control system is as follows：Image processing module is calculated using otsu
Method obtains the area ratio of molten iron slag in image after handling and calculating.
The beneficial effects of the invention are as follows artificial judgment is replaced using the measures such as camera head monitor and Weighing system weighing, make
The rate that is smelt for obtaining sulphur reaches 100%.
Description of the drawings
Fig. 1 is the ladle surface picture skimmed and terminate rear camera shooting.
Fig. 2 is the schematic diagram of one embodiment of the invention.
Specific implementation mode
Present invention is further described in detail with reference to the accompanying drawings and in conjunction with the embodiments.But the present invention is not limited to be given
The example gone out.
As shown in Fig. 2, the method for the present invention, includes the following steps：
The first step, according to the requirement for smelting tapping steel grade finished product sulphur, setting converter terminal sulfur content (i.e. converter terminal when sulphur
Element accounts for the mass percent of molten steel total amount), smelting the steel grade finished product sulfur content of tapping, (i.e. element sulphur is shared in finished steel
Mass percent) it is greater than converter terminal sulfur content, difference between the two is set as risk reserved value, and be denoted as
SRisk is reserved% (SRisk is reserved% value ranges are 0~0.005%), converter terminal sulfur content is denoted as SConverter terminal sulfur content%, steel grade finished product
Sulfur content is denoted as SSteel grade finished product sulfur content%, then converter terminal sulfur content need to meet formula (10),
SRisk is reserved%=SSteel grade finished product sulfur content%-SConverter terminal sulfur content% (10).
The sulfur content that returns in converter steelmaking process (is returned to steel by second step, by percentage to the quality in converter steelmaking process
Element sulphur in water accounts for the mass percent of molten steel total amount) it is denoted as SSulfur content is returned in converter%, before converter smelting, in Hot Metal Pretreatment
Target desulfurization grade is denoted as STarget desulfurization grade(i.e. desulfurization process is expected the quality percentage that the element sulphur to be sloughed accounts for molten iron total amount to %
Than), further according to steel grade finished product sulfur content SSteel grade finished product sulfur contentThe requirement of % and SSulfur content is returned in converter%, SRisk is reserved% come determine molten iron pre-process
Target desulfurization grade, so that target desulfurization grade is met formula (1),
STarget desulfurization grade%≤SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter% (1)
In above-mentioned STarget desulfurization gradeRound numbers in the calculating process of %.Wherein, target desulfurization grade also needs to meet formula (2),
(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade% >=0.001% (2),
Target desulfurization grade preferably meets formula (11),
0.002%≤(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade%≤0.003% (11)
Wherein, SSulfur content is returned in converter% value ranges are 0.003%~0.006%.
In addition, converter steelmaking process returns sulfur content SSulfur content is returned in converter% includes that steel scrap returns sulfur content and auxiliary material time sulfur content, according to formula
(12) it calculates converter and returns sulphur,
SSulfur content is returned in converter%=(MSteel scrap returns sulphur quality+MAuxiliary material returns sulphur quality)÷(MWeight of molten iron×AMolten steel recovery rate+MSteel scrap weight×AMolten steel recovery rate)(12)。
Third step, (31) consider influence of the molten iron with the quantity of slag to sulphur concentration in slag after desulfurizing iron itself, will be in ladle
Slag weight of the desulfurized molten iron with slag is denoted as MThe molten iron band quantity of slag, and measure and iron after desulfurizing iron is calculated according to formula (3) after thickness of slag layer
The weight of slag in water packet,
MThe molten iron band quantity of slag=SLadle area×hSlag is thick×ρMolten iron slag density (3)
Wherein SLadle areaFor the molten iron surface area in ladle, hSlag is thickFor the thickness of slag layer in ladle, ρMolten iron slag densityFor molten iron
The density of slag in packet, value range is in 1.9~3.5t/m3；Go to step (32)；
(32) gross mass of sulphur in the clinker after desulfurizing iron is set as MAfter desulfurizing iron in clinker sulphur gross mass, the clinker before desulfurizing iron
The content of middle sulphur is SBlast furnace slag sulfur content%, the weight of molten iron is M in ladleWeight of molten iron, the initial sulfur content of molten iron of converter smelting is
SThe initial sulphur of molten iron%, and according to formula (4) calculate desulfurizing iron after clinker in sulphur gross mass,
MAfter desulfurizing iron in clinker sulphur gross mass=(SThe initial sulphur of molten iron%-STarget desulfurization grade%) × MWeight of molten iron+SBlast furnace slag sulfur content% × MThe molten iron band quantity of slag(4)；It goes to
Step (33)；
(33) weight for the steel scrap being added in converter steelmaking process is set as MSteel scrap weight, the content of sulphur is in steel scrap
SSteel scrap sulfur content%, it is M to be added in converter steelmaking process after steel scrap and return the quality of sulphurSteel scrap returns sulphur quality, and steel scrap is calculated according to formula (5) and is returned
The quality of sulphur,
MSteel scrap returns sulphur quality=MSteel scrap weight×SSteel scrap sulfur content% × (1-AConverter desulfuration efficiency%) (5)
The weight for resetting the slag making auxiliary material being added in converter steelmaking process is MAuxiliary material weight, the content of sulphur is in auxiliary material
SAuxiliary material sulfur content%, it is M to be added in converter steelmaking process after slag making auxiliary material and return the quality of sulphurAuxiliary material returns sulphur quality, slag making is calculated according to formula (6)
Auxiliary material returns the quality of sulphur,
MAuxiliary material returns sulphur quality=MAuxiliary material weight×SAuxiliary material sulfur content% × (1-AConverter desulfuration efficiency%) (6)
Wherein, AConverter desulfuration efficiencyThe value range of % is 20~30%, and desulfurization coefficient is (i.e. in converter steelmaking process
AConverter desulfuration efficiencyIt %) is calculated according to 20~30%, converter desulfurization coefficient can be selected according to the pattern of converter smelting, work as converter smelting
When using staying slag pattern to be smelted, converter desulfurization coefficient is 20%；When converter smelting is not using staying slag pattern to be smelted,
Converter desulfurization coefficient is 30%；Go to step (34)；
(34) set allow skim after return the quality of sulphur as M in remaining clinkerAllow the quality for staying the quantity of slag to return sulphur after skimming, and according to formula
(7) calculate allow skim after in remaining clinker sulphur quality,
MAllow the quality for staying the quantity of slag to return sulphur after skimming=(SSteel grade finished product sulfur content%-STarget desulfurization grade%-SRisk is reserved%) × (MWeight of molten iron+MSteel scrap weight)×
AMolten steel recovery rate-MSteel scrap returns sulphur quality-MAuxiliary material returns sulphur quality (7)
Wherein, AMolten steel recovery rateSteel quality to be generated in converter steelmaking process accounts for the percentage of molten iron and steel scrap gross mass,
General value is 95%；Go to step (35)；
(35) set stayed after skimming skim shared by the quality of sulphur in slag before in clinker sulphur gross mass mass percent as
AStay quantity of slag ratio, and calculated according to formula (8) and stay quantity of slag ratio A after skimmingStay quantity of slag ratio,
AStay quantity of slag ratio=MAllow the quality for staying the quantity of slag to return sulphur after skimming/MAfter desulfurizing iron in clinker sulphur gross mass (8)。
In this way according to the molten iron band quantity of slag, molten iron slag sulfur content, desulfurized molten iron band slag before the initial sulfur content of molten iron, desulfurization
The requirement of time sulfur content and steel grade finished product sulphur determines in amount, converter steelmaking process stays quantity of slag ratio formula, calculating to reach after skimming
Allow remaining residue ratio when to setting converter terminal sulfur content.
4th step determines that theory is skimmed weight section, by the process of skimming according to by take off it is scaling-off in iron-holder be divided into early period
And the later stage, band iron coefficient of skimming is set as XBand iron coefficient, then the band iron coefficient of skimming of early period is 0.1~0.4, the band of skimming in later stage
Iron coefficient is 0.4~0.6, and it is M to reset and taken off scaling-off weight during skimmingTake off the quantity of slag, when current heat desulfurization is blown material
Quality be MIt is blown quality of material, then skimmed weight section according to formula (9) computational theory,
MTake off the quantity of slag=[MThe molten iron band quantity of slag+MIt is blown quality of material+MWeight of molten iron×(SThe initial sulphur of molten iron%-STarget desulfurization grade%)] × (1-AStay quantity of slag ratio)×(1+
XBand iron coefficient) (9)。
Since the process of skimming inevitably takes away partial molten iron, it is therefore necessary to determine the band iron coefficient for product of skimming,
Due to skimming early period, the process quantity of slag is big, and iron-holder is less in slag again, it is thus determined that the band iron coefficient of skimming of early period is 0.1~0.4,
When a large amount of molten iron slags, which are pulled down, is finely skimmed, its iron-holder is higher, thus the later stage skim band iron coefficient be 0.4~
0.6, according to band iron coefficient when staying quantity of slag ratio and skimming, the weight section of skimming when skimming can be obtained.
5th step carries out the desulfurization before converter smelting according to the target desulfurization grade that step 2 obtains, and desulfurization terminates laggard
Row is skimmed operation early period, and the weight for being unplugged slag is weighed in skimming operation process early period, reaches step 4 when actually taking off the quantity of slag
The theory of acquisition skim weight interval limit 50~70% when, continue blowing slag-removing and later stage using blowing slag-removing device
Skim operation, blowing slag-removing and later stage skim operation when control deslagging head insertion depth be 150~250mm, should take in elder generation
Between after the sequence on both sides skim, deslagging head is often taken off need to pause 2~3 seconds in tank mouth, contribute to reduce damage of skimming in this way
Iron, later stage are skimmed and are monitored using image pick-up device in operation process, and the camera of image pick-up device is towards molten iron surface, image pick-up device
The image information on molten iron surface is obtained in ladle in real time and by image information (i.e. in ladle the molten iron top of the slag product situation of change)
The image processing module for being transferred to control system carries out image procossing, and the angle of tumbling for forward and backward ladle of skimming remains unchanged.
A, calculate target stay slag area ratio, the pretreated target desulfurization grade of molten iron under the same conditions, first will turn
The initial sulfur content of molten iron (mass percent of molten iron total amount shared by Sulfur Content in Hot Iron element i.e. before converter smelting) that stove is smelted is denoted as
SThe initial sulphur of molten iron 1%, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 3% ... SThe initial sulphur X of molten iron%, further according to corresponding in the initial sulfur content acquisition ladle of molten iron
Converter smelting before, the target after molten iron drossing stay slag area ratio (area percentage, that is, after skimming the top of the slag product accounts for molten iron table
The percentage of area), and stay slag area ratio to be denoted as A corresponding target1%, A2%, A3% ... AX% obtains A1%, A2% with
And value (such as the S of the initial sulfur content of molten ironThe initial sulphur of molten iron 1%, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 3% ... SThe initial sulphur X of molten iron%), then according to public affairs
Formula (13) calculate under same desulfurization rating conditions the initial sulfur content of molten iron be SThe initial sulphur X of molten ironTarget when % stays slag area ratio
AXThe value of %,
AX%=(A2%-A1%) × (SThe initial sulphur of molten iron 2%-SThe initial sulphur X of molten iron%) ÷ (SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%)+A2% (13)
Wherein, SThe initial sulphur of molten iron 2% ＞ SThe initial sulphur of molten iron 1%, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 1% also needs to meet formula (14),
20≤(SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%) × 1000≤50 (14).
B, setting the maximum in ladle stays slag area ratio as Amax%, and maximum stays slag area ratio to meet formula
(15),
Amax%≤80% (15)；Go to step c；
C, setting the minimum in ladle stays slag area ratio as Amin%, and minimum stays slag area ratio to meet formula
(16),
Amin% >=5% (16).
6th step, control system image processing module according to the image information on molten iron surface calculate obtain ladle in iron
The practical slag area ratio of water surface, the specific image processing method of control system are as follows：Image processing module or software use
Otsu algorithms (also known as maximum variance between clusters, Otsu algorithm, it is considered to be the optimal algorithm of carrying out image threshold segmentation calculates letter
It is single, do not influenced by brightness of image and contrast and mistake point rate is minimum) handle and calculate after obtain the area of molten iron slag in image
Ratio.Then the practical slag area ratio of control system stays slag area ratio with target, when practical slag area ratio and target
When staying slag area ratio identical, it is judged as reaching expected effect of skimming, end of skimming.
Scaling-off weight is taken off in 7th step, weighing, obtains weight of actually skimming, and judges whether actually to skim weight in step
Rapid four theories obtained are skimmed in weight section, if so, explanation is skimmed, process band iron coefficient is skimmed quality in set interval
It is different, iron loss is advantageously reduced, if it is not, explanation band iron coefficient is skimmed second-rate not in set interval.
Embodiment
Certain steel grade is produced, steel grade sulphur requires SSteel grade finished product sulfur content% is 0.0125%, and converter terminal sulphur requires SConverter terminal sulfur content%
For 0.0095%, SSulfur content is returned in converter% is 0.003%~0.006%.Current heat SThe initial sulphur of molten iron% is 0.025%, and the sulphur in steel scrap contains
Measure (SSteel scrap sulfur contentIt is %) 0.025%, steel scrap weight (MSteel scrap weight) it is 38 tons, weight of molten iron (MWeight of molten iron) it is 252 tons, sulphur in molten iron slag
Mass percent (SBlast furnace slag sulfur contentIt is %) 0.9%, the inside molten iron surface area (S of ladle area, that is, ladleLadle area) be
15.2m2, measure the thickness (h of current heat molten iron slagSlag is thick) it is 0.06m, the density (ρ of molten iron slagMolten iron slag density) it is 2.0t/m3,
AMolten steel recovery rateValue 95%, AConverter desulfuration efficiencyThe value 20% of %, XBand iron coefficientValue range 0.2~0.5.
1. staying quantity of slag ratio under the conditions of determining different initial sulphur：First according to steel grade finished product sulfur content and converter terminal sulphur
Content determines SRisk is reserved%=0.003%.Again, sulfur content is returned according to steel scrap and auxiliary material returns sulfur content and calculates returning for converter steelmaking process
Sulfur content SSulfur content is returned in converter%=(MSteel scrap returns sulphur quality+MAuxiliary material returns sulphur quality)÷(MWeight of molten iron×AMolten steel recovery rate+MSteel scrap weight×AMolten steel recovery rate)=(0.0076t+
0.00264t) ÷ (252t × 95%+38t × 95%)=0.0037%, then SSulfur content is returned in converter% is in 0.003%~0.006% model
In enclosing.In addition, SSulfur content is returned in converterAccording to desulfurization grade S when % is maximizedTarget desulfurization grade%≤SSteel grade finished product sulfur content%-SRisk is reserved%-
SSulfur content is returned in converterThe principle of %, STarget desulfurization grade%≤0.0035%.SSulfur content is returned in converterWhen % is 0.0037%, SSteel grade finished product sulfur content%-SRisk is reserved%-
SSulfur content is returned in converter%=0.0125%-0.003%-0.0037%=0.0058%, meet (SSteel grade finished product sulfur content%-SRisk is reserved%-
SSulfur content is returned in converter%)-STarget desulfurization grade% >=0.001% is preferably selected 0.002%≤(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-
STarget desulfurization grade%≤0.003%, 0.0058%-0.003≤STarget desulfurization grade%≤0.0058-0.002, i.e., 0.0028≤
STarget desulfurization grade%≤0.0038, here STarget desulfurization grade% round numbers 0.003%, therefore STarget desulfurization grade% values 0.003% are reasonable.
Secondly, consider influence of the molten iron with the quantity of slag to sulphur concentration in slag after desulfurizing iron itself, calculate and obtain desulfurizing iron
Afterwards in ladle slag weight MThe molten iron band quantity of slag=SLadle area×hSlag is thick×ρMolten iron slag density=15.2 ㎡ × 0.06m × 2.0t/m3=
1.824t, then in clinker after desulfurizing iron sulphur gross mass MAfter desulfurizing iron in clinker sulphur gross mass=(SThe initial sulphur of molten iron%-STarget desulfurization grade%) ×
MWeight of molten iron+SBlast furnace slag sulfur content% × MThe molten iron band quantity of slag=(0.025%-0.003%) × 252t+0.9% × 1.824t=0.071856t.So
Afterwards, the mass M that steel scrap returns sulphur is calculatedSteel scrap returns sulphur quality=MSteel scrap weight×SSteel scrap sulfur content% × (1-AConverter desulfuration efficiency%)=38t × 0.025% ×
(1-20%)=0.0076t, while calculating the mass M that slag making auxiliary material returns sulphurAuxiliary material returns sulphur quality=MAuxiliary material weight×SAuxiliary material sulfur content% × (1-
AConverter desulfuration efficiency%)=5t × 0.035% × (1-20%)+3t × 0.035% × (1-20%)+2t × 0.02% × (1-20%)
=0.00264t, supplementary product consumption (MAuxiliary material weight) it is 10 tons, including lime, light dolomite and ore, the sulfur content of wherein lime are
0.035%, lime consumption 5t, light dolomite sulfur content be 0.035%, light dolomite dosage be 3t, ore sulphur
Content is 0.02%, and ore dosage is 2t.After what is so allowed skim in remaining clinker sulphur mass MAllow the quality for staying the quantity of slag to return sulphur after skimming=
(SSteel grade finished product sulfur content%-STarget desulfurization grade%-SRisk is reserved%) × (MWeight of molten iron+MSteel scrap weight)×AMolten steel recovery rate-MSteel scrap returns sulphur quality-MAuxiliary material returns sulphur quality=
(0.0125%-0.003%-0.003%) × (252t+38t) × 95%-0.0076t-0.00264t=0.0076675t.Most
Afterwards, it calculates after skimming and stays quantity of slag ratio AStay quantity of slag ratio=MAllow the quality for staying the quantity of slag to return sulphur after skimming/MAfter desulfurizing iron in clinker sulphur gross mass=10.67%.
The weight section 2. determination theory is skimmed：Computational theory is skimmed weight section MTake off the quantity of slag=[MThe molten iron band quantity of slag+MIt is blown quality of material+
MWeight of molten iron×(SThe initial sulphur of molten iron%-STarget desulfurization grade%)] × (1-AStay quantity of slag ratio)×(1+XBand iron coefficient)=[1.824t+0.4t+252t ×
(0.025%-0.003%)] × (1-10.67%) × (1+0.2~0.5)=2.443t~3.054t, wherein MIt is blown quality of materialBe by
It is determined according to realistic model, different model values is different.
3. carrying out the desulfurization before converter smelting according to target desulfurization grade, operation of skimming early period is carried out after desulfurization,
It skims early period the weight for weighing in operation process and being unplugged slag, reaches theoretical weight interval limit of skimming when actually taking off the quantity of slag
When 50% (i.e. 1.2215t), continue blowing slag-removing using blowing slag-removing device and the later stage skim operation, blowing slag-removing and after
Phase skim operation when control deslagging head insertion depth be 150~250mm, the sequence of first intermediate and then both sides should be taken to be taken off
Slag, deslagging head is often taken off need to pause 2~3 seconds in tank mouth, contribute to reduce damage iron of skimming in this way.
It is monitored using image pick-up device in operation process 4. the later stage skims, the camera of image pick-up device is taken the photograph towards molten iron surface
The image information on molten iron surface in ladle is obtained in real time as device and image information is transferred to the image procossing mould of control system
Block carries out image procossing, while staying slag area ratio under the conditions of determining different initial sulphur：When the initial sulphur of the molten iron of converter smelting
Content SThe initial sulphur of molten iron 2When %=0.05%, according to STarget support flow%=0.003% carries out desulphurization control, chooses in converter steelmaking process
SSulfur content is returned in converterHeats of the % between 0.003%~0.006% obtains the initial sulfur content S of molten iron by cameraThe initial sulphur of molten iron 2%=
Molten iron under 0.05% level stays slag area ratio A2%=30%；As the initial sulfur content S of molten ironThe initial sulphur of molten iron 1When %=0.010%,
According to STarget desulfurization grade%=0.003% carries out desulphurization control, chooses S in converter steelmaking processSulfur content is returned in converter% levels 0.003%~
Heat between 0.006% obtains the initial sulfur content S of molten iron by cameraThe initial sulphur of molten iron 1Molten iron under %=0.010% levels
Stay slag area ratio A1%=70%, final obtain in initial sulfur content is SThe initial sulphur X of molten ironTarget stays slag area ratio under the conditions of %
AX%=(A2%-A1%) × (SThe initial sulphur of molten iron 2%-SThe initial sulphur X of molten iron%) ÷ (SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%)+A2%=(70%-
30%) × (0.05%-Sx%) ÷ (0.05%-0.01%)+30%.So, as the initial sulfur content S of molten ironThe initial sulphur x of molten iron%=
When 0.02%, it is A that corresponding target, which stays slag area ratio,X%=(70%-30%) × (0.05%-0.02%) ÷
(0.05%-0.01%)+30%=60%.In summary, the initial sulfur content of molten iron discharging can be obtained by above-mentioned formula
SThe initial sulphur x of molten iron% stays slag area ratio in the target of different level, the results are shown in Table 1.
Target under the conditions of the initial sulphur of the different molten iron of table 1 stays slag area ratio
5. the image processing module of control system calculates according to the image information on molten iron surface and obtains molten iron table in ladle
The practical slag area ratio in face, the specific image processing method of control system are as follows：Image processing module or software use otsu
The area ratio of molten iron slag in image is obtained after algorithm process and calculating.As shown in Figure 1, otsu algorithms the specific steps are：First
Gradation of image number is divided by two parts by gray level using the thought of cluster so that the difference between two parts is maximum, and two
The difference of a partial interior is minimum (this is to divide rank by the calculating of variance to find a suitable gray scale), it is further assumed that T
It is the threshold value of setting, divides rank for suitable gray scale, W0 is the ratio that molten iron pixel number accounts for image after dividing, and U0 is segmentation
The average gray of molten iron afterwards, W1 are the ratios that scum pixel accounts for image after dividing, and U1 is the average gray of scum after segmentation,
Middle W0, U0, W1, U1, it is obtained in shooting image pixel information by predetermined threshold value T.T, L value ranges are traversed from L gray level
For 0~255 integer value so that when T is some value, the variance of molten iron and scum is maximum, then required by this T value is exactly us
The threshold value obtained.Wherein, the calculation formula of variance is as follows：
G=W0 × W1 × (U0-U1) 2
T value calculating is carried out to great amount of images is taken on site by otsu algorithms, it is 25 to obtain molten iron and scum segmentation threshold
Molten iron and scum can effectively be divided when~70.Divide and dye using being done to shooting image when T values, actual value>It is iron when 70
Water, it is scum that actual value, which is in 25~70 constantly, and it is molten iron region to be reflected in figure red, and green is scum region.Use COUNT
(f=is red) indicates molten iron pixel number, indicates scum pixel number with COUNT (f=greens), then scum area ratio can be such as
Lower calculating：
Then, the practical slag area ratio of control system and target stay slag area ratio, when practical slag area ratio with
When target stays slag area ratio identical, it is judged as reaching expected effect of skimming, end of skimming.For example, working as the initial sulfur content of molten iron
When being 0.022%, it is corresponding stay slag area ratio be 58%, calculate molten iron slag in ladle in real time by image processing software
Area ratio terminates to skim when slag area ratio reaches 58%.
6. scaling-off weight is taken off in weighing, acquisition is actually skimmed weight, and whether the weight that judges actually to skim takes off in theory
In slag weight section, if so, explanation is skimmed, for process band iron coefficient in set interval, good quality of skimming advantageously reduces iron
Damage, if it is not, explanation band iron coefficient is skimmed second-rate not in set interval.
In short, being reached according to the influence of steel scrap, auxiliary material to time sulphur, calculating in the initial sulfur content of molten iron and converter steelmaking process
The mass ratio for allowing remaining sulphur when to setting converter terminal sulfur content, obtains after allowing remaining sulphur mass ratio, by true
Surely the stacking factor of product of skimming further determines that rational weight section of skimming, and then carries out desulfurization, before being carried out after desulfurization
Phase skims operation, and is skimmed weight by the Weighing system real-time Transmission on hot-metal car, skims weight when weight of skimming reaches theory
When measuring the 50%~70% of interval limit, carries out blowing slag-removing and later stage using blowing slag-removing device and skim operation, operation of skimming
When using camera obtain ladle in the molten iron top of the slag accumulate, while in real time calculate the molten iron top of the slag product, according to the initial sulfur content of molten iron,
The difference of steel grade finished product sulfur content determines that different targets stays slag area ratio, and the top of the slag is stayed when actual iron grain slag area reaches target
Terminate to skim when product.
In addition to the implementation, the present invention can also have other embodiment.It is all to use equivalent substitution or equivalent transformation shape
At technical solution, fall within the scope of protection required by the present invention.
Claims (10)
1. a kind of method reducing molten iron drossing loss, characterized in that include the following steps：
The requirement of the first step, steel grade finished product sulphur of being tapped according to smelting, the steel grade finished product sulfur content are greater than converter terminal sulphur and contain
Amount, is set as risk reserved value, and be denoted as S by difference between the twoRisk is reserved%；Go to second step；
Second step, by percentage to the quality, S is denoted as by steel grade finished product sulfur contentSteel grade finished product sulfur content% returns sulphur in converter steelmaking process
Amount is denoted as SSulfur content is returned in converter%, the target desulfurization grade in Hot Metal Pretreatment are denoted as STarget desulfurization grade% contains further according to steel grade finished product sulphur
Measure SSteel grade finished product sulfur contentThe requirement of % and SSulfur content is returned in converter%, SRisk is reserved% determines the pretreated target desulfurization grade of molten iron, keeps target de-
Sulphur grade meets formula (1),
STarget desulfurization grade%≤SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter% (1)
Go to third step；
Slag weight of the desulfurized molten iron in ladle with slag is denoted as M by third step, (31)The molten iron band quantity of slag, and iron is calculated according to formula (3)
The weight of slag in water desulfurized molten iron packet,
MThe molten iron band quantity of slag=SLadle area×hSlag is thick×ρMolten iron slag density (3)
Wherein SLadle areaFor the molten iron surface area in ladle, hSlag is thickFor the thickness of slag layer in ladle, ρMolten iron slag densityFor in ladle
The density of slag；Go to step (32)；
(32) gross mass of sulphur in the clinker after desulfurizing iron is set as MAfter desulfurizing iron in clinker sulphur gross mass, sulphur in the clinker before desulfurizing iron
Content be SBlast furnace slag sulfur content%, the weight of molten iron is M in ladleWeight of molten iron, the initial sulfur content of molten iron of converter smelting is
SThe initial sulphur of molten iron%, and according to formula (4) calculate desulfurizing iron after clinker in sulphur gross mass,
MAfter desulfurizing iron in clinker sulphur gross mass=(SThe initial sulphur of molten iron%-STarget desulfurization grade%) × MWeight of molten iron+SBlast furnace slag sulfur content% × MThe molten iron band quantity of slag(4)；Go to step
Suddenly (33)；
(33) weight for the steel scrap being added in converter steelmaking process is set as MSteel scrap weight, the content of sulphur is S in steel scrapSteel scrap sulfur content% turns
The quality of sulphur is returned as M after steel scrap is added in stove smelting processSteel scrap returns sulphur quality, and the quality that steel scrap returns sulphur is calculated according to formula (5),
MSteel scrap returns sulphur quality=MSteel scrap weight×SSteel scrap sulfur content% × (1-AConverter desulfuration efficiency%) (5)
The weight for resetting the slag making auxiliary material being added in converter steelmaking process is MAuxiliary material weight, the content of sulphur is S in auxiliary materialAuxiliary material sulfur content%,
The quality of sulphur is returned as M after slag making auxiliary material is added in converter steelmaking processAuxiliary material returns sulphur quality, slag making auxiliary material is calculated according to formula (6) and returns sulphur
Quality,
MAuxiliary material returns sulphur quality=MAuxiliary material weight×SAuxiliary material sulfur content% × (1-AConverter desulfuration efficiency%) (6)
Wherein, AConverter desulfuration efficiencyThe value range of % is 20~30%；Go to step (34)；
(34) set allow skim after return the quality of sulphur as M in remaining clinkerAllow the quality for staying the quantity of slag to return sulphur after skimming, and counted according to formula (7)
Calculate allow skim after in remaining clinker sulphur quality,
MAllow the quality for staying the quantity of slag to return sulphur after skimming=(SSteel grade finished product sulfur content%-STarget desulfurization grade%-SRisk is reserved%) × (MWeight of molten iron+MSteel scrap weight)×AMolten steel recovery rate-
MSteel scrap returns sulphur quality-MAuxiliary material returns sulphur quality (7)
Wherein, AMolten steel recovery rateSteel quality to be generated in converter steelmaking process accounts for the percentage of molten iron and steel scrap gross mass, generally
Value is 95%；Go to step (35)；
(35) set stayed after skimming skim shared by the quality of sulphur in slag before in clinker sulphur gross mass mass percent as AStay quantity of slag ratio,
And it is calculated according to formula (8) and stays quantity of slag ratio A after skimmingStay quantity of slag ratio,
AStay quantity of slag ratio=MAllow the quality for staying the quantity of slag to return sulphur after skimming/MAfter desulfurizing iron in clinker sulphur gross mass (8)
Go to the 4th step；
4th step determines that theory is skimmed weight section, by the process of skimming according to by take off it is scaling-off in iron-holder be divided into early period and after
Phase sets band iron coefficient of skimming as XBand iron coefficient, then the band iron coefficient of skimming of early period is 0.1~0.4, the band iron system that skims in later stage
Number is 0.4~0.6, and it is M to reset and taken off scaling-off weight during skimmingTake off the quantity of slag, the matter of material is blown when current heat desulfurization
Amount is MIt is blown quality of material, then skimmed weight section according to formula (9) computational theory,
MTake off the quantity of slag=[MThe molten iron band quantity of slag+MIt is blown quality of material+MWeight of molten iron×(SThe initial sulphur of molten iron%-STarget desulfurization grade%)] × (1-AStay quantity of slag ratio)×(1+XBand iron coefficient)
(9)
Go to the 5th step；
5th step skim operation early period, skims weight interval limit when it is taken off the quantity of slag and reaches the theory of step 4 acquisition
When 50~70%, carries out blowing slag-removing and later stage using blowing slag-removing device and skim operation, using camera shooting in operation process of skimming
Device is monitored, and the camera of image pick-up device, towards molten iron surface, image pick-up device obtains the figure on molten iron surface in ladle in real time
The image processing module of control system is transferred to as information and by image information；Go to the 6th step；
6th step, control system image processing module according to the image information on molten iron surface calculate obtain ladle in molten iron table
The practical slag area ratio in face, the practical slag area ratio of control system stay slag area ratio with target, when the practical top of the slag accumulates
When ratio stays slag area ratio identical with target, it is judged as reaching expected effect of skimming, end of skimming；Go to the 7th step；
Scaling-off weight is taken off in 7th step, weighing, obtains weight of actually skimming, and judges whether actually to skim weight in step 4
The theory of acquisition is skimmed in weight section, if so, explanation is skimmed, process band iron coefficient is in set interval, good quality of skimming,
Iron loss is advantageously reduced, if it is not, explanation band iron coefficient is skimmed second-rate not in set interval.
2. a kind of method reducing molten iron drossing loss according to claim 1, it is characterized in that：In the first step, by converter end
Point sulfur content is denoted as SConverter terminal sulfur content%, then converter terminal sulfur content need to meet formula (10),
SRisk is reserved%=SSteel grade finished product sulfur content%-SConverter terminal sulfur content% (10).
3. a kind of method reducing molten iron drossing loss according to claim 2, it is characterized in that：It is described in the first step
SRisk is reservedThe value range of % is 0~0.005%.
4. a kind of method reducing molten iron drossing loss according to claim 1, it is characterized in that：In second step, target desulfurization
Grade also needs to meet formula (2),
(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade% >=0.001% (2).
5. a kind of method reducing molten iron drossing loss according to claim 4, characterized in that in second step, target desulfurization
Grade also needs to meet formula (11),
0.002%≤(SSteel grade finished product sulfur content%-SRisk is reserved%-SSulfur content is returned in converter%)-STarget desulfurization grade%≤0.003% (11).
6. a kind of method reducing molten iron drossing loss according to claim 1, it is characterized in that：Calculate converter steelmaking process
Return sulfur content SSulfur content is returned in converter%, wherein SSulfur content is returned in converter% includes that steel scrap returns sulfur content and auxiliary material time sulfur content, and calculating converter according to formula (12) returns
Sulphur,
SSulfur content is returned in converter%=(MSteel scrap returns sulphur quality+MAuxiliary material returns sulphur quality)÷(MWeight of molten iron×AMolten steel recovery rate+MSteel scrap weight×AMolten steel recovery rate) (12)。
7. a kind of method reducing molten iron drossing loss according to claim 1, it is characterized in that：The 5th step and the 6th step it
Between, it is further comprising the steps of：A, it calculates target and stays slag area ratio, in the identical condition of the pretreated target desulfurization grade of molten iron
Under, the initial sulfur content of the molten iron of converter smelting is first denoted as SThe initial sulphur of molten iron 1%, SThe initial sulphur of molten iron 2%, SThe initial sulphur of molten iron 3% ... SThe initial sulphur X of molten iron%,
Slag area ratio is stayed further according to corresponding target in the initial sulfur content acquisition ladle of molten iron, and stays the top of the slag to accumulate ratio corresponding target
Example is denoted as A1%, A2%, A3% ... AX%, it is S then to be calculated in the initial sulfur content of molten iron according to formula (13)The initial sulphur X of molten ironWhen %
Target stays slag area ratio AXThe value of %,
AX%=(A2%-A1%) × (SThe initial sulphur of molten iron 2%-SThe initial sulphur X of molten iron%) ÷ (SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%)+A2% (13)
Wherein, SThe initial sulphur of molten iron 2% ＞ SThe initial sulphur of molten iron 1%.
8. a kind of method reducing molten iron drossing loss according to claim 7, it is characterized in that：In step a, SThe initial sulphur of molten iron 2%,
SThe initial sulphur of molten iron 1% also needs to meet formula (14),
20≤(SThe initial sulphur of molten iron 2%-SThe initial sulphur of molten iron 1%) × 1000≤50 (14).
9. a kind of method reducing molten iron drossing loss according to claim 7, characterized in that between step a, step 6
Also there are following steps：
B, setting the maximum in ladle stays slag area ratio as Amax%, and maximum stays slag area ratio to meet formula (15),
Amax%≤80% (15)；Go to step c；
C, setting the minimum in ladle stays slag area ratio as Amin%, and minimum stays slag area ratio to meet formula (16),
Amin% >=5% (16)；Go to the 6th step.
10. a kind of method reducing molten iron drossing loss according to claim 1, it is characterized in that：In 5th step, according to step
The two target desulfurization grades obtained carry out the desulfurization before converter smelting, and operation of skimming early period is carried out after desulfurization；In 6th step,
The specific image processing method of control system is as follows：Image processing module is obtained using otsu algorithm process and after calculating in image
The area ratio of molten iron slag.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110893458A (en) * | 2018-09-13 | 2020-03-20 | 宝山钢铁股份有限公司 | Composite multi-channel spray gun in hot-metal ladle and efficient air blowing and slag removing method thereof |
| CN111050117A (en) * | 2019-10-15 | 2020-04-21 | 河钢股份有限公司承德分公司 | System and method for analyzing deslagging effect of desulfurized molten iron |
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| CN114574660A (en) * | 2022-02-21 | 2022-06-03 | 山东钢铁股份有限公司 | KR intelligent control method based on-demand desulfurization |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110893458A (en) * | 2018-09-13 | 2020-03-20 | 宝山钢铁股份有限公司 | Composite multi-channel spray gun in hot-metal ladle and efficient air blowing and slag removing method thereof |
| CN110893458B (en) * | 2018-09-13 | 2021-11-16 | 宝山钢铁股份有限公司 | Composite multi-channel spray gun in hot-metal ladle and efficient air blowing and slag removing method thereof |
| CN112017145A (en) * | 2019-05-31 | 2020-12-01 | 宝山钢铁股份有限公司 | Efficient molten iron pretreatment automatic slag skimming method and system |
| WO2020238714A1 (en) * | 2019-05-31 | 2020-12-03 | 宝山钢铁股份有限公司 | Efficient automatic slag skimming method and system for hot metal pretreatment |
| CN112017145B (en) * | 2019-05-31 | 2023-08-11 | 宝山钢铁股份有限公司 | Efficient automatic slag skimming method and system for molten iron pretreatment |
| CN111050117A (en) * | 2019-10-15 | 2020-04-21 | 河钢股份有限公司承德分公司 | System and method for analyzing deslagging effect of desulfurized molten iron |
| CN111349753A (en) * | 2020-05-08 | 2020-06-30 | 衡阳镭目科技有限责任公司 | Hot metal ladle slag-raking control system, slag-raking machine and automatic slag-raking control method for hot metal ladle |
| CN114574660A (en) * | 2022-02-21 | 2022-06-03 | 山东钢铁股份有限公司 | KR intelligent control method based on-demand desulfurization |
| CN114574660B (en) * | 2022-02-21 | 2023-02-03 | 山东钢铁股份有限公司 | KR intelligent control method based on-demand desulfurization |
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