CN117660717A - Converter smelting method with low molten iron ratio and oxygen lance - Google Patents
Converter smelting method with low molten iron ratio and oxygen lance Download PDFInfo
- Publication number
- CN117660717A CN117660717A CN202211062376.6A CN202211062376A CN117660717A CN 117660717 A CN117660717 A CN 117660717A CN 202211062376 A CN202211062376 A CN 202211062376A CN 117660717 A CN117660717 A CN 117660717A
- Authority
- CN
- China
- Prior art keywords
- converter
- oxygen
- blowing
- nozzle
- laval
- 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
- 239000001301 oxygen Substances 0.000 title claims abstract description 85
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 85
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 82
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000003723 Smelting Methods 0.000 title claims abstract description 32
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 31
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 75
- 239000010959 steel Substances 0.000 claims abstract description 75
- 238000007664 blowing Methods 0.000 claims abstract description 62
- 239000007789 gas Substances 0.000 claims abstract description 55
- 238000010438 heat treatment Methods 0.000 claims abstract description 15
- 238000003756 stirring Methods 0.000 claims abstract description 14
- 238000010079 rubber tapping Methods 0.000 claims abstract description 8
- 230000000295 complement effect Effects 0.000 claims abstract description 6
- 238000005261 decarburization Methods 0.000 claims abstract description 5
- 238000002485 combustion reaction Methods 0.000 claims abstract description 4
- 239000007921 spray Substances 0.000 claims description 67
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 18
- 239000000498 cooling water Substances 0.000 claims description 10
- 230000002093 peripheral effect Effects 0.000 claims description 10
- 229910052786 argon Inorganic materials 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 238000002844 melting Methods 0.000 claims description 5
- 230000008018 melting Effects 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 239000002893 slag Substances 0.000 abstract description 3
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 239000002699 waste material Substances 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000000428 dust Substances 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 238000009628 steelmaking Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- WKPSFPXMYGFAQW-UHFFFAOYSA-N iron;hydrate Chemical compound O.[Fe] WKPSFPXMYGFAQW-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/35—Blowing from above and through the bath
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/56—Manufacture of steel by other methods
- C21C5/562—Manufacture of steel by other methods starting from scrap
- C21C5/565—Preheating of scrap
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention discloses a converter smelting method with low molten iron ratio and an oxygen lance, wherein the method comprises the following steps: 1. two converters are selected, one converter is alternately used as a smelting furnace, and the other converter is used as a scrap steel preheating furnace; the added scrap steel in the scrap steel preheating furnace is 20-35% of the converter capacity; 2. preheating scrap steel in a preheating furnace by adopting high-temperature converter gas discharged from a smelting converter and blowing oxygen; heating the scrap steel to above 600 ℃; 3. after preheating, adding molten iron with the converter capacity of 65-80% into the preheating furnace to start converting: a. in the early stage and the middle stage of converter blowing, oxygen guns are used for full-oxygen blowing and are matched with strong bottom blowing and a shaking furnace operation process, so that molten steel stirring of a molten pool is enhanced, and scrap steel is facilitated to be quickly melted; b. in the later stage of converter blowing, oxygen guns are used for complementary heat blowing, and the temperature of molten steel is raised through secondary combustion complementary heat; the gas blown by the oxygen lance comprises converter gas and oxygen; 4. slag formation is carried out during blowing, dephosphorization, decarburization and heating operation are carried out, and tapping is carried out after the temperature and the components reach the standards.
Description
Technical Field
The invention belongs to the technical field of steel converter steelmaking, and particularly relates to a converter smelting method with a low molten iron ratio and an oxygen lance.
Background
The biggest challenge currently faced by the steel industry to cope with global climate change is to reduce carbon dioxide emissions.
The main process of the traditional long-flow iron and steel enterprises is to use iron ore and coke as raw materials and make reduction reaction in a blast furnace to produce molten iron. Molten iron and scrap steel are used as raw materials, and molten steel is smelted in a converter. In the converter steelmaking process, the molten iron ratio is reduced, the use amount of scrap steel is increased, the carbon emission can be effectively reduced, and the steel yield is increased. Therefore, the method has great significance for reducing the molten iron ratio of converter smelting, improving the steel yield and reducing the carbon emission for enterprises mainly making steel by the converter.
Disclosure of Invention
The technical problem to be solved by the invention is to provide the converter smelting method with low iron-water ratio, which can effectively utilize waste steel resources to make steel, reduce carbon emission in the converter steelmaking production process and effectively improve the steel yield.
The technical problems to be solved by the method can be implemented by the following technical schemes.
The converter smelting method with low molten iron ratio is characterized by comprising the following steps:
1) Selecting two converters, wherein one converter is used as a smelting furnace, and the other converter is used as a scrap steel preheating furnace in an alternating mode; wherein the weight of the scrap steel added into the scrap steel preheating furnace is 20-35% of the converter capacity;
2) Preheating scrap steel in a scrap steel preheating furnace by adopting high-temperature converter gas discharged from a smelting converter and blowing oxygen; heating the scrap steel to above 600 ℃;
3) After the scrap steel preheating is finished, adding molten iron with the converter capacity of 65-80% into a scrap steel preheating furnace, and starting converting; wherein,
a. in the early stage and the middle stage of converter blowing, oxygen guns are utilized to carry out full-oxygen blowing, and the strong bottom blowing and the shaking furnace operation process are matched, so that the stirring of molten steel in a molten pool is enhanced, and the rapid melting of scrap steel is facilitated;
b. in the later stage of converter blowing, oxygen guns are utilized to carry out complementary heat blowing, and the temperature of molten steel is raised through secondary combustion complementary heat; the gas blown by the oxygen lance comprises converter gas and oxygen;
4) And adding slag-making materials while blowing to finish dephosphorization, decarburization and heating operation, wherein the temperature and the components reach the target requirements, and finally tapping.
As a further improvement of the technical proposal, the high-temperature converter gas in the step 2) is blown in from the central hole of the oxygen lance nozzle, and the flow rate of the converter gas is 1000-10000 m 3 And/h, the temperature of the converter gas is above 1000 ℃, and the mass percentage of CO in the converter gas is 50-80%, CO 2 15-20%; the oxygen blowing amount is 1000-20000 m 3 /h。
Preferably, in the step a of the step 3), the furnace shaking operation process comprises the following operation processes:
in the blowing process of the converter, the maximum inclination angle of the front and the rear of the converter is 5-8 degrees, the tilting angular speed is 5-10 degrees/min, and the tilting stirring is carried out after the residence for 10-30S at the maximum inclination angle.
Preferably, in the step b of the step 3), a laval nozzle at a central position and six laval nozzles circumferentially and uniformly distributed around the nozzle at the central position are arranged on a nozzle of the oxygen lance for supplementary heat blowing, and during supplementary heat blowing, converter gas is blown through the nozzle at the central position and oxygen is blown through the nozzle at the circumferential position.
Further, in the step a) of the step 3), the total flow rate of the oxygen of the nozzle is 60000-75000 m 3 And/h, wherein the flow rate of the Laval type spray hole in the center of the spray head is independently controlled to be 3000-15000 m 3 And/h, the pipeline pressure is 0.9-1.5 Mpa, and the oxygen flow of six Laval nozzles uniformly distributed in the circumferential direction of the nozzle is 45000-60000 m 3 And/h, pipeline pressure is 0.7-0.9 MPa; the strong bottom blowing is to blow argon into the bottom air opening of the converter, and the total flow of the bottom blowing is 800-2500 m 3 /h。
Still further, in the step b) of the step 3), the flow rate of the Laval hole blowing converter gas in the center of the nozzle is 3000 to 10000m 3 And/h, the temperature of the converter gas is above 1000 ℃, the pipeline pressure is 0.9-1.0 Mpa, and six nozzles are uniformly distributed along the circumferential directionOxygen is blown by Laval nozzle, the total flow of the circumferential nozzle is 3000-60000 m 3 And/h, the pipeline pressure is 0.7-0.9 MPa, the CO content in the converter is increased, and the converter is post-combusted to increase the temperature of molten steel; argon is blown into the bottom tuyere of the converter, and the total flow of bottom blowing is 1500-2500 m 3 /h。
The invention aims to provide an oxygen lance structure for the converter smelting method, which comprises a lance body and a spray head, wherein the lance body sequentially comprises a central pipeline, a first layer of annular seam, a second layer of annular seam and a third layer of annular seam from inside to outside; the spray head comprises a first Laval type spray hole and a plurality of second Laval type spray holes, wherein the first Laval type spray hole is positioned at the center of the spray head, and the second Laval type spray holes circumferentially surround the first Laval type spray hole; the first Laval type spray hole is communicated with a central pipeline of the gun body, and the central pipeline is used for blowing oxygen or converter gas; the second Laval type spray holes are communicated with the first layer of circular seams, and pipelines of the first layer of circular seams are used for blowing oxygen; the second layer circumferential seam and the third layer circumferential seam are oxygen lance cooling water channels and are communicated to form a water inlet channel and a water outlet channel of cooling water respectively.
Further, the first Laval type spray hole is taken as a central spray hole, the second Laval type spray hole is taken as a peripheral spray hole, and the included angle alpha between the axis of the peripheral spray hole and the axis of the central spray hole is 15-25 degrees (preferably 15 degrees).
Preferably, the first laval nozzle is composed of a shrinkage section with a smaller opening, a laryngeal section with a uniform opening and an expansion section with a larger opening from inside to outside in sequence, and/or the second laval nozzle is composed of a shrinkage section with a smaller opening, a laryngeal section with a uniform opening and an expansion section with a larger opening from inside to outside in sequence.
As a preferred embodiment of the present invention, the inner diameter D1 of the throat section of the first laval nozzle and/or the second laval nozzle is 40-58mm; the outlet diameter D2 of the expansion section of the first Laval type spray hole and/or the second Laval type spray hole is 50-68mm.
Compared with the prior art, the converter smelting method with low molten iron ratio adopting the technical scheme has the following beneficial effects:
1. the high-temperature converter gas and oxygen discharged from the smelting converter are adopted to preheat the scrap steel, the temperature of the converter gas is more than 1000 ℃, oxygen is blown into the converter gas to burn and release heat, and the scrap steel is heated to more than 600 ℃, so that a good foundation is provided for reducing molten iron.
2. The strong stirring process in the early and middle stages of converter blowing is beneficial to the rapid melting of scrap steel. The secondary combustion heating process in the later blowing period of the converter further supplements heat for molten steel, and effectively ensures the rapid melting and blowing stop temperature of the scrap steel under the condition of low molten iron ratio.
3. The invention can realize that the molten iron ratio of converter smelting is below 75%, effectively uses waste steel resources, reduces carbon emission and effectively improves steel yield.
Drawings
FIG. 1 is a schematic diagram of a low iron to water ratio converter smelting process of the invention;
FIG. 2 is a schematic view of the structure of the oxygen lance of the present invention;
FIG. 3 is a bottom view of FIG. 2;
in the figure: 1. an oxygen lance; 2. a converter; 3. a gas line; 4. a high temperature dust separator; 5. a smoke hood; 6. Scrap steel; 7. a bottom blowing port; 8. a gas regulating valve; 9. molten steel;
1-1, an oxygen lance cooling water channel; 1-2, peripheral jet orifice oxygen pipeline; 1-3, peripheral Laval nozzle; 1-4, a central jet orifice oxygen or gas pipeline; 1-5, a central spray hole; 1-7, a cooling water channel; 1-8, cooling water channel.
Detailed Description
The invention provides a converter smelting method with low molten iron ratio, referring to FIG. 1, two converters are selected, one of the converters is used as a smelting furnace in an alternating mode, and the other converter is used as a scrap steel preheating furnace; as shown in fig. 1, the left converter 2 is a scrap preheating furnace, the right converter is a smelting furnace, and after tapping and deslagging in the left converter are completed, scrap 6 is added to the converter, and the weight of the scrap is 20 to 35% of the capacity of the converter.
The novel oxygen lance 1 provided by the invention has the specific structure shown in fig. 2 and 3, the lance body structure comprises a lance body and a spray head, the lance body comprises a four-layer steel pipe structure consisting of a middle pipeline (namely a central spray hole oxygen or gas pipeline 1-4 in the figure), three layers of circular seams and an external pipeline, the middle pipeline is filled with oxygen or converter gas, the 2 nd layer of circular seams (namely peripheral spray hole oxygen pipelines 1-2 in the figure) are oxygen, and the 3 rd and 4 th layer of circular seams are filled with cooling water from inside to outside, and are communicated to form water inlet and water outlet channels of the cooling water respectively.
The nozzle body is provided with 6 laval nozzle holes (i.e., peripheral laval nozzle holes 1-3 in the figure) uniformly along the circumferential direction thereof. The center of the spray head is provided with a Laval type spray hole (namely a central spray hole 1-5 in the figure), each Laval type spray hole consists of a contraction section, a throat and an expansion section from inside to outside, and the longitudinal section of the throat is rectangular.
The included angle alpha between the axes of the peripheral spray holes and the axis of the spray head main body is 15-25 degrees (preferably 15 degrees), the central spray head and 6 Laval spray holes which are uniformly distributed in the circumferential direction are provided, the diameter D1 of the throat opening is 40-58mm (preferably 48 mm), and the diameter D2 of the outlet is 50-68mm (preferably 58 mm).
The scrap steel 6 is preheated by adopting high-temperature converter gas and oxygen discharged from a right converter which is smelting, the high-temperature converter gas is blown in from a central hole of a nozzle of a left converter oxygen lance (namely a novel oxygen lance 1), the temperature of the converter gas is above 1000 ℃, and the components are mainly as follows: CO: 50-80% of CO 2 : 15-20% of an impurity.
The high temperature converter gas discharged from the smelting converter is blown in through a high temperature dust remover (such as a fume hood 5 and a high temperature dust separator 4 in fig. 1) through a central hole of an oxygen lance nozzle of the preheating converter, and a gas pipeline 3 in fig. 1 is connected with the upper part of a novel oxygen lance 1 of one converter and the high temperature dust separator of the other converter, and is used for conveying the converter gas, and the flow rate of the converter gas is controlled by a gas regulating valve 8. Argon is blown in from the bottom of the converter through a bottom blowing port 7.
6 spray holes uniformly distributed on the circumference of the spray head blow in 1000-20000 m oxygen 3 Heating the steel scraps by carrying heat with the high-temperature converter gas, heating the steel scraps by chemical reaction of the converter gas and oxygen to release heat, preheating for 5-20min, heating the steel scraps to above 600 ℃, and then convertingAdding high-temperature molten iron;
the process comprises the steps of strong stirring and converting of a molten pool in the earlier period of a converter: novel oxygen guns are used in the early stage and the middle stage of converter blowing, and the total flow of oxygen of a nozzle is 60000-75000 m 3 And/h, wherein the flow rate of the central hole of the spray head independently controls the oxygen flow rate to be 3000-15000 m 3 And/h, the pipeline pressure is 0.9-1.5 Mpa, the oxygen flow of 6 spray holes is 30000-60000 m, and the circumferential direction of the spray head is evenly distributed 3 And/h, the pipeline pressure is 0.7-0.9 MPa, and the penetration depth and stirring strength of the molten pool are enhanced. Argon is blown into the bottom tuyere of the converter, and the total flow of bottom blowing is 800-2500 m 3 And/h, carrying out strong stirring on the molten pool.
The converter shaking operation process includes the steps of rotating the converter at 5-8 deg. of maximum inclination angle, tilting the converter at 5-10 deg/min of angular speed, and stopping the converter at the maximum inclination angle for 10-30S for pulsating tilting to raise the stirring strength of molten steel in the molten pool, so that the molten steel in the molten pool is fast melted.
In the later stage of converter blowing, a novel oxygen gun is adopted to carry out a supplementary heat blowing process: the novel oxygen lance is used in the later stage of converter blowing, wherein the central hole of the nozzle blows converter gas with the flow rate of 3000-10000 m 3 And/h, the temperature of the converter gas is more than 1000 ℃, and the components of the converter gas are mainly as follows: CO: 50-80% of CO 2 : 15-20% of impurities and the other impurities, the pipeline pressure is 0.9-1.0 Mpa, 6 spray holes are evenly distributed on the circumference of the spray head for blowing oxygen, and the flow is 3000-60000 m 3 And/h, the pipeline pressure is 0.7-0.9 MPa, the CO content in the converter is increased, and the converter is post-combusted to increase the temperature of molten steel. Argon is blown into the bottom tuyere of the converter, and the total flow of bottom blowing is 1500-2500 m 3 And/h, carrying out strong stirring on the molten pool.
And (3) adding slag making materials twice during blowing, completing decarburization, dephosphorization and heating operation, enabling the temperature and the components to reach target requirements, and finally tapping.
The following are specific examples of the present invention.
Example 1:
1) After tapping and deslagging of a 300t converter (left side) are completed, adding scrap steel into the converter, and loading 90t of steel with the weight of the converter capacity;
2) The novel oxygen lance with the low molten iron ratio comprises a lance body and a spray head, wherein the lance body comprises a four-layer steel pipe structure consisting of a middle pipeline, three-layer circular seams and an external pipeline, oxygen or converter gas is introduced into the middle pipeline, the 2 nd-layer circular seam is oxygen, and cooling water is introduced into the 3 rd-layer circular seam and the 4 th-layer circular seam from inside to outside. The peripheral spray hole axis with shower nozzle main part axis contained angle α15, central shower nozzle and circumference evenly distributed 6 Laval type spray holes, its laryngeal diameter is D1:48mm, outlet diameter D2:58mm.
3) Preheating waste steel of a converter (left side) by adopting high-temperature converter gas and oxygen discharged from the smelting converter (right side), blowing 1000 ℃ high-temperature converter gas into a central hole of an oxygen lance of the side converter, and controlling the flow to be 8000m 3 And (3) the converter gas mainly comprises the following components: CO: 50-80% of CO 2 : 15-20% of an impurity. 6 spray holes uniformly distributed on the circumference of the spray head blow oxygen with the flow of 6000m 3 Heating the waste steel by carrying heat with the high-temperature converter gas, and simultaneously, heating the waste steel by chemical reaction of the converter gas and oxygen to release heat, wherein the preheating time is 15min, heating the waste steel to 700 ℃, and then adding high-temperature molten iron at 1325 ℃ into the converter;
4) The converter blowing early stage and the converter blowing medium stage: total flow 65000m of oxygen in the spray nozzle 3 /h, wherein the flow rate of oxygen at the central hole of the nozzle is independently controlled to be 15000m 3 And/h, the pipeline pressure is 1.0Mpa, and the oxygen flow of 6 spray holes uniformly distributed in the circumferential direction of the spray head is 50000m 3 And/h, the pipeline pressure is 0.8MPa, the gun position is 1.8m, and the penetration depth and stirring intensity of the molten pool are enhanced. Argon is blown into a tuyere at the bottom of the converter, and the total flow of bottom blowing is 1000m 3 And/h, carrying out strong stirring on the molten pool. In the converter shaking operation process, the front and back of the converter are tilted at the maximum tilt angle of 5 degrees and the tilting angular speed of 10 degrees/min, and stay at the maximum tilt angle for 10S for tilting stirring, so that the stirring intensity of molten steel in a molten pool is increased, and the quick melting of waste steel in the molten pool is facilitated.
5) In the later stage of converter blowing, a novel oxygen gun is adopted to carry out a supplementary heat blowing process: the novel oxygen lance is used in the later stage of converter blowing, wherein the central hole of the nozzle blows converter gas with the flow of 8000m 3 And/h, the temperature of the converter gas is more than 1000 ℃, and the components of the converter gas are mainly as follows: CO: 50-80% of CO 2 : 15-20% and othersThe pressure of the pipeline is 0.9Mpa, the circumferential direction of the nozzle is evenly distributed with 6 spray holes for blowing oxygen, and the flow is 50000m 3 And/h, the pipeline pressure is 0.8MPa, the gun position is 2.2m, the C0 content in the converter is increased, and the converter is post-combusted to increase the temperature of molten steel. Argon is blown into a tuyere at the bottom of the converter, and the total flow of bottom blowing is 1500m 3 /h。
6) Slag making materials are added twice during blowing, decarburization, dephosphorization and heating operation are completed, the temperature and the components reach the target requirements (C-0.04%, P-0.01% and tapping temperature 1650 ℃), and finally tapping is performed. The converter smelting with low molten iron ratio can be realized, the molten iron ratio can be up to 70%, the waste steel resources are effectively used, the carbon emission is reduced, and the steel yield is effectively improved.
Claims (10)
1. The converter smelting method with low molten iron ratio is characterized by comprising the following steps:
1) Selecting two converters, wherein one converter is used as a smelting furnace, and the other converter is used as a scrap steel preheating furnace in an alternating mode; wherein the weight of the scrap steel added into the scrap steel preheating furnace is 20-35% of the converter capacity;
2) Preheating scrap steel in a scrap steel preheating furnace by adopting high-temperature converter gas discharged from a smelting converter and blowing oxygen; heating the scrap steel to above 600 ℃;
3) After the scrap steel preheating is finished, adding molten iron with the converter capacity of 65-80% into a scrap steel preheating furnace, and starting converting; wherein,
a. in the early stage and the middle stage of converter blowing, oxygen guns are utilized to carry out full-oxygen blowing, and the strong bottom blowing and the shaking furnace operation process are matched, so that the stirring of molten steel in a molten pool is enhanced, and the rapid melting of scrap steel is facilitated;
b. in the later stage of converter blowing, oxygen guns are utilized to carry out complementary heat blowing, and the temperature of molten steel is raised through secondary combustion complementary heat; the gas blown by the oxygen lance comprises converter gas and oxygen;
4) And adding slag-making materials while blowing to finish dephosphorization, decarburization and heating operation, wherein the temperature and the components reach the target requirements, and finally tapping.
2. The low molten iron according to claim 1The specific converter smelting method is characterized in that the high-temperature converter gas in the step 2) is blown in from the central hole of the oxygen lance nozzle, and the flow rate of the converter gas is 1000-10000 m 3 And/h, the temperature of the converter gas is above 1000 ℃, and the mass percentage of CO in the converter gas is 50-80%, CO 2 15-20%; the oxygen blowing amount is 1000-20000 m 3 /h。
3. The converter smelting method with low molten iron ratio according to claim 1, wherein in the step a) of the step 3), the shaking furnace operation process comprises the following operation procedures:
in the blowing process of the converter, the maximum inclination angle of the front and the rear of the converter is 5-8 degrees, the tilting angular speed is 5-10 degrees/min, and the molten steel is stirred in a tilting way after staying for 10-30S at the maximum inclination angle.
4. A converter smelting method with low molten iron ratio according to claims 1-3, characterized in that in step 3), a laval type spray hole at the center position and six laval type spray holes circumferentially and uniformly distributed around the spray hole at the center position are arranged on the spray head of the oxygen lance, and in the process of supplementary heat blowing, the spray hole at the center position blows converter gas, and the spray hole at the circumferential position blows oxygen.
5. The method for smelting a low molten iron ratio converter according to claim 4, wherein in step a) of step 3), the total flow rate of oxygen at the nozzle is 60000 to 75000m 3 And/h, wherein the flow rate of the Laval type spray hole in the center of the spray head is independently controlled to be 3000-15000 m 3 And/h, the pipeline pressure is 0.9-1.5 Mpa, and the oxygen flow of six Laval nozzles uniformly distributed in the circumferential direction of the nozzle is 45000-60000 m 3 And/h, pipeline pressure is 0.7-0.9 MPa; the strong bottom blowing is to blow argon into the bottom air opening of the converter, and the total flow of the bottom blowing is 800-2500 m 3 /h。
6. The method for smelting a low molten iron ratio converter according to claim 4, wherein in the step b) of the step 3), the laval hole at the center of the nozzle blows the converter gas at a flow rate of 3000 to 10000m 3 And/h, the temperature of the converter gas is above 1000 ℃, the pipeline pressure is 0.9-1.0 Mpa, six Laval nozzles which are uniformly distributed along the circumferential direction of the nozzle blow oxygen, and the total flow rate of the circumferential nozzle is 30000-60000 m 3 And/h, the pipeline pressure is 0.7-0.9 MPa, the CO content in the converter is increased, and the converter is post-combusted to increase the temperature of molten steel; argon is blown into the bottom tuyere of the converter, and the total flow of bottom blowing is 1500-2500 m 3 /h。
7. An oxygen lance structure for use in a converter smelting process according to any one of claims 1 to 6, comprising a lance body and a lance head, wherein the lance body comprises a central pipe, a first layer of circumferential seams, a second layer of circumferential seams and a third layer of circumferential seams in sequence from inside to outside; the spray head comprises a first Laval type spray hole and a plurality of second Laval type spray holes, wherein the first Laval type spray hole is positioned at the center of the spray head, and the second Laval type spray holes circumferentially surround the first Laval type spray hole; the first Laval type spray hole is communicated with a central pipeline of the gun body, and the central pipeline is used for blowing oxygen or converter gas; the second Laval type spray holes are communicated with the first layer of circular seams, and pipelines of the first layer of circular seams are used for blowing oxygen; the second layer circumferential seam and the third layer circumferential seam are oxygen lance cooling water channels and are communicated to form a water inlet channel and a water outlet channel of cooling water respectively.
8. The oxygen lance structure of claim 7, wherein the first laval nozzle is a central nozzle and the second laval nozzle is a peripheral nozzle, the axis of the peripheral nozzle being at an angle α of 15-25 ° to the axis of the central nozzle.
9. The oxygen lance structure of claim 7, wherein the first laval nozzle orifice is composed of a convergent section with a smaller opening, a laryngeal section with a uniform opening and an divergent section with a larger opening in sequence from inside to outside, and/or the second laval nozzle orifice is composed of a convergent section with a smaller opening, a laryngeal section with a uniform opening and an divergent section with a larger opening in sequence from inside to outside.
10. The oxygen lance structure of claim 9, wherein the inner diameter D1 of the throat section of the first and/or second laval nozzle is 40-58mm; the outlet diameter D2 of the expansion section of the first Laval type spray hole and/or the second Laval type spray hole is 50-68mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211062376.6A CN117660717A (en) | 2022-08-31 | 2022-08-31 | Converter smelting method with low molten iron ratio and oxygen lance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211062376.6A CN117660717A (en) | 2022-08-31 | 2022-08-31 | Converter smelting method with low molten iron ratio and oxygen lance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117660717A true CN117660717A (en) | 2024-03-08 |
Family
ID=90077661
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211062376.6A Pending CN117660717A (en) | 2022-08-31 | 2022-08-31 | Converter smelting method with low molten iron ratio and oxygen lance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117660717A (en) |
-
2022
- 2022-08-31 CN CN202211062376.6A patent/CN117660717A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107419051B (en) | Promote the smelting process of converter scrap melting using gasification dephosphorized slag | |
| CN106566907B (en) | The production method and melting reduction device of the direct smelt iron of iron ore | |
| WO2019029136A1 (en) | Clean and rapid smelting method for all scrap steel electric arc furnace | |
| CN114574651A (en) | Rotational flow iron wall melting smelting device and method | |
| CN102732668B (en) | Oxygen furnace steel method capable of improving jet velocity through preheated oxygen | |
| CN109628689A (en) | High hot metal ratio electric furnace method for supplying oxygen | |
| CN105624358A (en) | Method for producing low-phosphorous steel by single converter and double oxygen lances | |
| CN114350865A (en) | Ultrahigh oxygen-enriched low-carbon smelting method | |
| CN111763794B (en) | Method for smelting stainless steel by mixed blowing of chromium ore powder and carbon powder in TSR converter | |
| CN201924035U (en) | Swirl bottom-blowing air supply element for combined blown converter | |
| CN111378809A (en) | Equipment and method for electric arc furnace steelmaking by using oxygen combustion lance | |
| CN116103466B (en) | Top powder spraying high-efficiency steelmaking method and system for large-scale electric arc furnace | |
| CN117660717A (en) | Converter smelting method with low molten iron ratio and oxygen lance | |
| CN208829713U (en) | A kind of single channel Oxygen Lance With Secondary Combustion improving converter scrap ratio | |
| CN212864831U (en) | Equipment for electric arc furnace steelmaking by using oxygen combustion gun | |
| CN108977620A (en) | A kind of single channel Oxygen Lance With Secondary Combustion and its application method improving converter scrap ratio | |
| CN114196798B (en) | Single-channel secondary combustion oxygen lance and use method thereof | |
| CN109680118A (en) | Coaxial double supersonic flows of oxygen coherent oxygen lances | |
| WO2000044943A1 (en) | Method for direct steelmaking | |
| CN108842027A (en) | A kind of dephosphorization converter finishing slag gasification dephosphorization method and smelting process | |
| JPH0480311A (en) | Smelting reduction furnace | |
| CN103392013B (en) | Manufacture molten iron and the method and apparatus of steel | |
| CN115652017A (en) | Converter high-cold-material-ratio low-carbon smelting device and smelting method | |
| RU2319749C2 (en) | Method of the direct production of iron, in particular steels, and installation for its implementation | |
| CN2288182Y (en) | Steel side bottom blowing blast furnace |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |