CN114774614A - Converter steelmaking method - Google Patents
Converter steelmaking method Download PDFInfo
- Publication number
- CN114774614A CN114774614A CN202210395928.9A CN202210395928A CN114774614A CN 114774614 A CN114774614 A CN 114774614A CN 202210395928 A CN202210395928 A CN 202210395928A CN 114774614 A CN114774614 A CN 114774614A
- Authority
- CN
- China
- Prior art keywords
- slag
- steel
- smelting
- scrap
- mass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
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
-
- 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/005—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using exothermic reaction compositions
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention provides a converter steelmaking method, which relates to the technical field of converter steelmaking, and comprises the following steps of carrying out slag retention treatment on final slag of a previous furnace according to the mass of the retained slag being 30-70% of the total slag mass, and obtaining slag with the temperature of 1200-1500 ℃; mixing the slag, the silicon-containing heat-compensating agent, the scrap steel and the molten iron with the temperature of 1290-1310 ℃ and then carrying out bottom blowing stirring and top blowing oxygen for first smelting to obtain first smelting slag; carrying out slag discharging treatment on the first smelting furnace slag according to the condition that the slag discharging mass is 10-30% of the total slag mass to obtain slag discharging molten steel; and adding a first carbon-containing heat-supplementing agent and scrap steel into the slag-discharged molten steel, and performing bottom blowing stirring and top blowing oxygen for second smelting to finish converter steelmaking. The converter steelmaking method provided by the invention has the advantages that the ratio of the scrap to the steel is 35-40, the ratio of the scrap to the steel is large, the final slag amount is 80-90kg/t of steel, the final slag amount is low, the final carbon is 0.041-0.045%, the carbon oxygen product is 0.0015-0.0017, the stability of the production process is good, and the method is simple and easy to implement.
Description
Technical Field
The invention belongs to the technical field of converter steelmaking, and particularly relates to a converter steelmaking method.
Background
Converter steelmaking refers to the process of completing the steelmaking process in a converter by means of physical heat of molten iron and heat generated by chemical reactions among molten iron components without external energy sources from metal raw materials such as molten iron, scrap steel and ferroalloys. In the current production background, the price of the molten iron is generally higher than that of the scrap steel, so that the addition amount of the scrap steel is increased, namely the molten iron consumption can be reduced by increasing the scrap steel ratio, and the production cost of a converter is reduced; meanwhile, the dosage and the slag quantity of lime can be reduced, which is beneficial to reducing splashing in the converting process and improving the metallurgical yield; it can also reduce the blowing time, reduce oxygen consumption and increase the yield.
At present, the ratio of the steel scrap smelted by a converter is generally below 15%, in order to improve the ratio of the steel scrap, domestic iron and steel enterprises break through the traditional constraint, a full-process diversified mode of adding the steel scrap is created, links including an iron ladle, a steel scrap hopper, an LF furnace and the like are included, a full-process steel scrap management and processing and distribution system is established, the steel scrap is preheated, and the effect of improving the ratio of the steel scrap is achieved.
However, the above processes all have problems to a certain extent, for example, the addition of the scrap steel of the iron ladle and the LF furnace is very limited, the temperature drop is very large in the process of adding the scrap steel into the converter after preheating, the energy utilization efficiency is low, and the continuous process is difficult to ensure.
Disclosure of Invention
In order to solve the technical problems, the invention provides a converter steelmaking method which has the advantages of high scrap ratio and high heat utilization rate.
The invention provides a converter steelmaking method, which comprises the following steps,
carrying out slag retention treatment on the final slag of the previous furnace according to the condition that the mass of the retained slag is 30-70% of the total slag mass to obtain furnace slag with the temperature of 1200-1500 ℃;
mixing slag, a silicon-containing heat-repairing agent, scrap steel and molten iron with the temperature of 1290-1310 ℃ and then performing bottom blowing stirring and top blowing oxygen for first smelting to obtain first smelting slag;
carrying out slag discharging treatment on the first smelting furnace slag according to the condition that the slag discharging mass is 10-30% of the total slag mass to obtain slag discharging molten steel;
and adding a first carbon-containing heat-supplementing agent and scrap steel into the slag-discharged molten steel, and performing bottom blowing stirring and top blowing oxygen for second smelting to finish converter steelmaking.
Further, the mass fraction of Si in the molten iron is 0.3-0.32%.
Further, the charging amount of the molten iron is 60-70% of the total charging amount.
Further, in the first smelting, the charging amount of the scrap steel is 16-22% of the total charging amount.
Further, when the first smelting is started, adding a second carbon-containing heat supplement agent into the molten steel for heating, wherein the adding mass of the second carbon-containing heat supplement agent is 10-20kg/t of steel, and the mass fraction of carbon in the second carbon-containing heat supplement agent is 75-90%.
Further, the first smelting time is 3-6min, and in the first smelting, the bottom blowing strength is 0.08-0.12Nm3/t/min。
Further, in the first smelting, the volume of top blown oxygen is 25-30% of the total oxygen volume used for steelmaking of the converter.
Furthermore, the mass of the first carbon-containing heat-supplementing agent is 5-15kg/t steel.
Further, in the second smelting, the charging amount of the scrap steel is 12-18% of the total charging amount.
Further, the second smelting time is 8-12min, and in the second smelting, the bottom blowing flow is 0.04-0.11Nm3/t/min。
Further, the bottom blowing strength is 0.04-0.06Nm for the first 60-70% of the second smelting3The bottom blowing strength is 0.09-0.11 Nm/min, 30-40% of the time after the second smelting3/t/min。
One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:
the invention provides a converter steelmaking method, which provides heat through slag retention treatment; the waste steel is added twice, so that the problem that a large amount of bonding of the waste steel in the converter is not beneficial to melting the waste steel caused by adding a large amount of waste steel once is solved; the treatment of adding the heat-supplementing agent twice solves the problems that the heat-supplementing agent is difficult to dissolve and the process is not favorable for smooth operation due to the fact that scrap steel is added once; since the scrap steel is not preheated, the problem of low heat utilization efficiency does not exist. The converter steelmaking method provided by the invention has the advantages that the ratio of the scrap to the steel is 30-40%, the ratio of the scrap to the steel is large, the final slag amount is 80-120kg/t of steel, the end point temperature is 1600-1660 ℃, the end point carbon is 0.03-0.08%, and the end point P is 0.0080-0.0120%, so that the converter steelmaking method has good dephosphorization effect, the final slag amount is low, and the method is simple and easy to implement.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a diagram of a converter steelmaking process according to an embodiment of the present invention.
Detailed Description
The present invention will be specifically explained below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented thereby. It will be understood by those skilled in the art that these specific embodiments and examples are illustrative of the invention and are not to be construed as limiting the invention.
Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
It is noted that, in this document, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
In order to solve the technical problems, the embodiment of the invention provides the following general ideas:
an embodiment of the present invention provides a converter steelmaking method, which, with reference to fig. 1, includes,
s1, performing slag retention treatment on the final slag of the previous furnace according to the mass of the remaining slag as 30-70% of the total slag mass to obtain furnace slag with the temperature of 1200-1500 ℃;
the slag remaining treatment is carried out on the smelting molten steel of the previous furnace, the heat in the remaining slag can be used for smelting of the next furnace, and the temperature drop of the molten iron can be caused by adding the waste steel, so the adding quality of the waste steel can be improved by the slag remaining treatment, and the waste steel ratio is improved; on the other hand, the slag retention treatment can reduce the adding quality of cold materials such as lime, dolomite and other slagging materials, ensure the surplus of the temperature in the converter and improve the utilization rate of heat; on the other hand, the slag remaining treatment can ensure the early slagging effect of the converter, and is favorable for improving the dephosphorization effect under the condition of large scrap steel ratio. The total slag mass in step S1 refers to the final slag mass of the last furnace.
The mass of the remained slag is too large, the temperature rise of the slag needs heat, and the effect of large scrap ratio cannot be realized;
the slag remaining quality is too low, and the effect of reducing the slag amount cannot be achieved.
S2, mixing the slag, the silicon-containing heat-repairing agent, the scrap steel and the molten iron with the temperature of 1290-1310 ℃ and then blowing oxygen from the top to perform first smelting to obtain first smelting slag;
adding the steel scrap in 2 steps, wherein the steel scrap is added in the step so as to ensure the smooth process; the silicon-containing heat-compensating agent is added, so that the aim of realizing the rapid temperature rise in the earlier stage of the converter, ensuring the melting effect of the scrap steel and ensuring the good carburizing effect of the converter is fulfilled. The adding mass of the silicon-containing heat-supplementing agent is based on that the Si mass fraction in the target loading amount is 0.5-0.6%, and if the adding mass of the silicon-containing heat-supplementing agent is excessive, the early-stage slag amount is too large and the splashing is serious; if the added mass of the silicon-containing heat-compensating agent is too small, the melting of the scrap steel cannot be ensured. In the invention, the silicon-containing heat-supplementing agent can be Si-Fe, Si-containing leftover materials and the like, and the Si content is generally required to be more than or equal to 75 percent. The temperature of the molten iron is controlled, so that certain heat in the converter can be ensured, and the melting effect of the scrap steel is ensured. If the temperature of the molten iron is too low, the scrap steel is difficult to melt.
As an embodiment of the invention, the mass fraction of Si in the molten iron is 0.3-0.32%.
Si in the molten iron is oxidized in the smelting process of the converter, heat is released, the temperature of the molten steel is increased, a heat source can be provided, and scrap steel is melted; the excessive mass fraction of silicon in the molten iron can cause the excessive slag amount and is easy to splash; the mass fraction of silicon in the molten iron is too small, and the heat is insufficient.
As an implementation manner of the embodiment of the invention, the charging amount of the molten iron is 60 to 70% of the total charging amount.
In one embodiment of the present invention, the charging amount of the scrap in the first smelting is 16 to 22% of the total charging amount. The excessive loading amount of the scrap steel in the first smelting can cause the scrap steel to be difficult to melt; the charging amount of scrap is too small, and it is difficult to increase the scrap ratio.
As an implementation mode of the embodiment of the invention, when the first smelting is started, a second carbon-containing heat-supplementing agent is added into the molten steel for heating, the mass of the second carbon-containing heat-supplementing agent is 10-20kg/t of steel, and the mass fraction of carbon in the second carbon-containing heat-supplementing agent is 75-90%.
Carbon in the carbon-containing heat-supplementing agent and top-blown oxygen are subjected to chemical reaction to release heat, so that the converter is heated to melt the scrap steel. The second carbon-containing heat-supplementing agent is added with too little mass and insufficient heat; the adding quality of the second carbon-containing heat-supplementing agent is too high, so that the smelting time is too long to hit the end-point carbon, and the production efficiency is influenced.
As an implementation mode of the embodiment of the invention, the first smelting time is 3-6min, and in the first smelting, the bottom blowing flow rate is 0.08-0.12Nm3/t/min。
The first smelting process aims at realizing the quick temperature rise of the converter, controlling the bottom blowing flow rate to provide strong stirring and realizing the quick melting of the scrap steel; the bottom blowing flow is too large, the cost is increased, and the improvement effect is not obvious; the bottom blowing flow is too small, which is not beneficial to the rapid melting of the scrap steel. The large bottom blowing flow is adopted in the first smelting period, so that the reaction can be promoted to be rapidly carried out, the converter can be rapidly heated, and the scrap steel can be rapidly melted, so that the scrap steel ratio is improved; if the bottom blowing flow rate in the first smelting is too small, the reaction is slow, and the production efficiency is affected.
As an implementation mode of the embodiment of the invention, in the first smelting, the volume of top blown oxygen is 25-30% of the total oxygen volume used for steelmaking of the converter.
As an implementation mode of the embodiment of the invention, in the first smelting, lime, light burned dolomite and the like are added, and the feeding amount is controlled to be 40-50% of the total feeding amount.
The feeding quality of auxiliary materials in the first smelting is controlled, so that the temperature drop can be reduced, and the temperature of a molten pool can be increased; the adding quality of the auxiliary materials is excessive, the temperature of a molten pool is low, and the melting of the scrap steel is not facilitated; the added quality of the auxiliary materials is too low, and the dephosphorization effect is reduced.
S3, carrying out slag discharging treatment on the first smelting slag according to the condition that the slag discharging mass is 10-30% of the total slag mass to obtain slag discharging molten steel;
the excessive slag amount is not beneficial to the subsequent smelting, so the smooth process can be ensured through slag discharge. The slag discharge amount is too large, so that the slag discharge time is prolonged, and the production efficiency is influenced; the slag discharge amount is too small to ensure the smooth operation of the process.
S4, adding a first carbon-containing heat-repairing agent and scrap steel into the slag-off molten steel, and performing bottom blowing stirring and top blowing oxygen gas to perform second smelting to complete converter steelmaking.
The first carbon-containing heat supplementing agent is added to supplement heat and increase the temperature of the molten steel, so that the waste steel added in the second smelting is melted; and secondly, the carbon content of the molten steel is increased, and the accelerated melting of the scrap steel is facilitated under the condition that the temperature of a molten pool is increased. In the present invention, the first carbon-containing heat-replenishing agent may be coke, graphite nodules, or the like.
The scrap steel is added in two steps, so that the problem that a large amount of bonding of the scrap steel in the converter is not beneficial to scrap steel melting caused by adding a large amount of scrap steel at one time is solved; for one-time direct addition of the carbonaceous heat-compensating agent, one-time blowing is completed, and because too much material is added at one time, the slag quantity at the early stage of smelting is large, so that converter splashing is generated, and the blowing process is unstable; for the situation that the carbonaceous heat-supplementing agent is directly added at one time, the carbonaceous heat-supplementing agent is not easy to melt when the bottom of the furnace is blown at one time, so that the FeO content in the furnace slag is reduced, the fluidity of the furnace slag is poor, the stability of the blowing process is influenced, the waste steel ratio is difficult to improve, and the waste steel ratio can only reach 30 percent at most in the process; the treatment of adding the heat-supplementing agent twice solves the problems that the heat-supplementing agent is difficult to dissolve and the process is not favorable for smooth operation due to the fact that scrap steel is added once.
As an implementation mode of the embodiment of the invention, the added mass of the first carbon-containing heat-repairing agent is 5-15kg/t steel.
The first carbon-containing heat-supplementing agent is added with excessive mass and is not easy to melt, so that resource waste is caused;
the first carbon-containing heat-supplementing agent has too low addition quality to play a role of heat supplementation
In one embodiment of the present invention, the charging amount of the scrap in the second smelting is 12 to 18% of the total charging amount.
The charging amount of the scrap steel in the second smelting is too much, so that the best heat matching cannot be realized, and the scrap steel cannot be melted;
the charging amount of the scrap steel in the second smelting is too small, and the effect of improving the scrap steel ratio cannot be achieved.
As an implementation mode of the embodiment of the invention, the second smelting time is 8-12min, and in the second smelting, the bottom blowing strength is 0.04-0.11Nm3/t/min。
As an embodiment of the present invention, the bottom-blowing intensity is 0.04-0.06Nm for the first 60-70% of the second smelting3T/min, the time of the second smelting is 30-40%, and the bottom blowing strength is 0.09-0.11Nm3/t/min。
And low-flow bottom blowing is adopted in the earlier stage of the second smelting, so that the heat loss is reduced, the bottom blowing flow is increased in the later stage, the scrap steel melting effect is improved, and the final point of the converter is guaranteed.
As an implementation mode of the embodiment of the invention, when the second smelting is started, materials such as lime, light burned dolomite and the like are added, and the adding amount is controlled according to 50-60% of the total adding amount.
In addition, the scrap in the embodiment of the present invention refers to light and thin scrap or baling scrap, and the length of the scrap in the embodiment of the present invention is within 0.7m, and the weight per unit is within 700 kg. The capacity of the converter is 80-300 t. The scrap steel loading amount actually represents the loading quality of scrap steel, and the total loading amount refers to the total metal mass of molten iron, scrap steel and alloy added in the converter steelmaking, and specifically includes the total metal mass added in the first smelting process and the second smelting process.
According to the invention, the slag is left for treatment, heat is provided, and the scrap steel is added twice, so that the problem that a large amount of bonding of the scrap steel in the converter is not beneficial to melting of the scrap steel caused by adding a large amount of scrap steel once is solved; the treatment of adding the heat-supplementing agent twice solves the problems that the heat-supplementing agent is difficult to dissolve and the process is not favorable for smooth operation due to the fact that scrap steel is added once.
A converter steelmaking method according to the present invention will be described in detail with reference to examples, comparative examples and experimental data.
Example 1
Example 1 provides a converter steelmaking method, wherein the converter capacity is 210t, the total loading is 230t, and the specific steps are as follows:
1. performing slag remaining operation on the final slag smelted by the previous converter, wherein the slag remaining amount is controlled to be 30% of the total mass of the final slag, then performing slag splashing protection operation, wherein slag is not poured after slag splashing is finished, and the temperature of the remaining slag is 1200 ℃;
2. sequentially loading scrap steel, a silicon-containing heat-supplementing agent, molten iron and a carbon-containing heat-supplementing agent into the converter after slag splashing and furnace protection in the step (1), then blowing oxygen from the top of a descending gun and blowing nitrogen from the bottom for smelting for 3min, wherein specifically, the loading amount of the scrap steel is 16% of the total loading amount, and the Si content of the Si-containing heat-supplementing agent is controlled according to the target total loading amount, namely 0.5%; the molten iron loading is 70% of the total loading; wherein the molten iron temperature is 1300 ℃, the Si mass fraction in the molten iron is 0.31 percent, the addition amount of the C-containing heat-supplementing agent is 10kg/t steel, and the bottom blowing strength is 0.1Nm3T/min; the feeding amount (lime and light-burned dolomite) is 40 percent of the total feeding amount.
3. When the oxygen supply proportion reaches 35%, the gun is lifted, the slag discharge operation is carried out, and the slag discharge amount is carried out according to 10% of the total slag amount;
4. after deslaggingAdding 5kg/t of steel C-containing heat-compensating agent and scrap steel into a converter, wherein the loading amount of the scrap steel is 14% of the total loading amount, then blowing oxygen at the top of a secondary descending lance and blowing nitrogen at the bottom for blowing for 14min, wherein the loading amount (lime and light-burned dolomite) is 55% of the total loading amount; the first 9Min bottom blowing flow rate is 0.05Nm3At a flow rate of 0.1 Nm/Min and a bottom-blowing rate of 5Min3/t/min
5. Tapping the steel by the converter and finishing smelting.
Example 2
Example 2 provides a converter steelmaking method, wherein the converter capacity is 210t, the total loading is 230t, and the specific steps are as follows:
1. performing slag remaining operation on the final slag smelted by the previous converter, wherein the slag remaining amount is controlled to be 50% of the total mass of the final slag, then performing slag splashing protection operation, wherein slag is not poured after slag splashing is finished, and the temperature of the remaining slag is 1400 ℃;
2. sequentially loading scrap steel, a silicon-containing heat-supplementing agent, molten iron and a carbon-containing heat-supplementing agent into the converter after slag splashing and furnace protection in the step 1, then lowering a lance to blow oxygen at the top and blowing nitrogen at the bottom for smelting for 5min, wherein specifically, the loading amount of the scrap steel is 20% of the total loading amount, and the Si content of the Si-containing heat-supplementing agent is controlled according to the target total loading amount, wherein the Si content of the Si-containing heat-supplementing agent is 0.5%; the molten iron loading is 65% of the total loading; wherein the molten iron temperature is 1350 ℃, the Si mass fraction in the molten iron is 0.35%, the addition amount of the C-containing heat-supplementing agent is 15kg/t steel, and the bottom blowing strength is 0.1Nm3T/min; the feeding amount (lime and light-burned dolomite) is 42 percent of the total feeding amount.
3. When the oxygen supply proportion reaches 30%, the gun is lifted, slag discharge is carried out, and the slag discharge amount is carried out according to 20% of the total slag amount;
4. after deslagging, adding 8kg/t of steel C-containing heat-compensating agent and scrap steel into the converter, wherein the loading amount of the scrap steel is 15% of the total loading amount, then blowing oxygen at the top of a secondary descending lance and blowing nitrogen at the bottom for blowing for 12min, wherein the feeding amount (lime and light-burned dolomite) is 55% of the total feeding amount; the first 8Min bottom blowing flow rate is 0.05Nm3at/t/Min, a bottom blowing flow rate of the latter 4Min of 0.1Nm3/t/min；
5. Tapping by a converter, and finishing smelting.
Example 3
Example 3 provides a converter steelmaking method, wherein the converter capacity is 210t, the total loading is 232t, and the specific steps are as follows:
1. performing slag remaining operation on the final slag smelted by the previous converter, wherein the slag remaining amount is controlled to be 60% of the total mass of the final slag, then performing slag splashing protection operation, wherein slag is not poured after slag splashing is finished, and the temperature of the remaining slag is 1500 ℃;
2. sequentially loading scrap steel, a silicon-containing heat-supplementing agent, molten iron and a carbon-containing heat-supplementing agent into the converter after slag splashing and furnace protection in the step 1, then lowering a lance to blow oxygen at the top and blowing nitrogen at the bottom for smelting for 6min, wherein specifically, the loading amount of the scrap steel is 22% of the total loading amount, and the Si content of the Si-containing heat-supplementing agent is controlled according to the target total loading amount, wherein the Si content of the Si-containing heat-supplementing agent is 0.6%; the charging amount of the molten iron is 60 percent of the total charging amount; wherein the molten iron temperature is 1380 ℃, the Si mass fraction in the molten iron is 0.45 percent, the addition amount of the C-containing heat-supplementing agent is 20kg/t steel, and the bottom blowing strength is 0.1Nm3T/min; the feeding amount (lime and light-burned dolomite) is 50 percent of the total feeding amount.
3. When the oxygen supply proportion reaches 30%, the gun is lifted, the slag discharge operation is carried out, and the slag discharge amount is carried out according to 30% of the total slag amount;
4. after deslagging, adding 10kg/t of steel C-containing heat-repairing agent and scrap steel into the converter, wherein the loading amount of the scrap steel is 18% of the total loading amount, then blowing oxygen from the top of a secondary descending lance and blowing nitrogen from the bottom for blowing for 12min, wherein the loading amount (lime and light-burned dolomite) is 50% of the total loading amount; the first 8Min bottom blowing intensity is 0.05Nm3A post-4 Min bottom blowing intensity of 0.1 Nm/Min3/t/min
5. Tapping by a converter, and finishing smelting.
Comparative example 1
Comparative example 1 provides a converter steelmaking process as follows:
1. performing slag remaining operation on the final slag smelted by the previous converter, wherein the slag remaining amount is controlled to be 30% of the total mass of the final slag, then performing slag splashing protection operation, wherein slag is not poured after slag splashing is finished, and the temperature of the remaining slag is 1200 ℃;
2. and (2) sequentially loading scrap steel, a silicon-containing heat-repairing agent, molten iron and a carbon-containing heat-repairing agent into the converter after slag splashing and furnace protection in the step (1) for smelting.
3. Tapping by a converter, and finishing smelting.
TABLE 1
| Number of | Scrap to scrap ratio | Final slag amount/kg/t steel | End point carbon/%) | Carbon oxygen deposit |
| Example 1 | 35 | 90 | 0.042 | 0.0016 |
| Example 2 | 35 | 85 | 0.045 | 0.0015 |
| Example 3 | 40 | 80 | 0.041 | 0.0017 |
| Comparative example 1 | 30 | 95 | 0.043 | 0.0024 |
As is clear from the data in Table 1, in the converter steelmaking method according to examples 1 to 3 of the present invention, the scrap ratio is 35 to 40, the scrap ratio is large, the final slag amount is 80 to 90kg/t steel, the final carbon is 0.041 to 0.045%, and the carbon oxygen product is 0.0015 to 0.0017.
In the steelmaking method provided in comparative example 1, the scrap ratio was 30, which is lower than that in examples 1 to 3 of the present invention, the final slag amount was 95kg/t steel, the final carbon was 0.0024%, and the carbon oxygen product was 0.0024. The steelmaking process provided in comparative example 1, in which the scrap ratio is lower than that in examples 1 to 3 of the present invention and the carbon oxygen product is higher than that in examples 1 to 3 of the present invention, shows that the converter end point control stability of comparative example 1 is inferior to that in examples 1 to 3 of the present invention.
The carbonaceous heat-compensating agent is directly added at one time, and the bottom is blown at one time, so that the slag quantity at the early stage of smelting is large, converter splashing is generated, and the blowing process is unstable; for the situation that the carbonaceous heat-compensating agent is directly added at one time and is blown to the end at one time, the carbonaceous heat-compensating agent is not easy to melt, so that the FeO content in the slag is reduced, the fluidity of the slag is poor, the stability of the blowing process is influenced, and the waste steel ratio is difficult to improve, wherein the waste steel ratio can only reach 30% at most in the process; the invention provides a converter steelmaking method, which provides heat through slag retention treatment; the waste steel is added twice, so that the problem that a large amount of bonding of the waste steel in the converter is not beneficial to melting the waste steel caused by adding a large amount of waste steel once is solved; the treatment of adding the heat-supplementing agent twice solves the problems that the heat-supplementing agent is difficult to dissolve and the process is not favorable for smooth operation due to the fact that scrap steel is added once. The converter steelmaking method provided by the invention has the advantages that the ratio of the scrap to the steel is 35-40, the ratio of the scrap to the steel is large, the final slag amount is 80-90kg/t of steel, the final slag amount is low, the final carbon is 0.041-0.045%, the carbon oxygen product is 0.0015-0.0017, the stability of the production process is good, and the method is simple and easy to implement.
Finally, it should be further noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A converter steelmaking method, characterized in that it comprises,
carrying out slag retention treatment on the final slag of the previous furnace according to the condition that the mass of the retained slag is 30-70% of the total slag mass to obtain furnace slag with the temperature of 1200-1500 ℃;
mixing slag, a silicon-containing heat-repairing agent, scrap steel and molten iron with the temperature of 1290-1310 ℃ and then performing bottom blowing stirring and top blowing oxygen for first smelting to obtain first smelting slag;
carrying out slag discharging treatment on the first smelting furnace slag according to the condition that the slag discharging mass is 10-30% of the total slag mass to obtain slag discharging molten steel;
and adding a first carbon-containing heat-supplementing agent and scrap steel into the slag-discharged molten steel, and performing bottom blowing stirring and top blowing oxygen for second smelting to finish converter steelmaking.
2. The converter steelmaking method according to claim 1, wherein the mass fraction of Si in the molten iron is 0.3 to 0.32%.
3. The converter steelmaking method according to claim 1, wherein the charged amount of the molten iron is 60 to 70% of the total charged amount.
4. The converter steelmaking method according to claim 1, wherein the charge amount of the scrap in the first smelting is 16 to 22% of the total charge amount.
5. The converter steelmaking method of claim 1, wherein a second carbon-containing heat supplement is added to the molten steel for temperature rise at the beginning of the first smelting, the mass of the second carbon-containing heat supplement is 10-20kg/t of steel, and the mass fraction of carbon in the second carbon-containing heat supplement is 75-90%.
6. The converter steelmaking method according to claim 1, wherein the first smelting time is 3 to 6min, and the bottom blowing flow rate in the first smelting is 0.08 to 0.12Nm3/t/min。
7. The method of making steel by a converter of claim 1, wherein the volume of top-blown oxygen in the first smelting is 25-30% of the total volume of oxygen used in making steel by the converter.
8. The converter steelmaking method of claim 1 in which the mass of the first carbon-containing heat patch added is 5-15kg/t steel.
9. The converter steelmaking method according to claim 1, wherein in the second smelting, the charge amount of the scrap is 12 to 18% of the total charge amount, and the bottom-blowing strength is 0.04 to 0.11Nm3The second smelting time is 8-12 min.
10. The converter steelmaking process of claim 1 in which the first 60 to 70% of the time of the second smelt has a bottom blowing strength of 0.04 to 0.06Nm3T/min, 30-40% of the time after the second smelting, bottom blowing strengthThe degree is 0.09-0.11Nm3/t/min。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210395928.9A CN114774614A (en) | 2022-04-14 | 2022-04-14 | Converter steelmaking method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210395928.9A CN114774614A (en) | 2022-04-14 | 2022-04-14 | Converter steelmaking method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114774614A true CN114774614A (en) | 2022-07-22 |
Family
ID=82430198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210395928.9A Pending CN114774614A (en) | 2022-04-14 | 2022-04-14 | Converter steelmaking method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114774614A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115537491A (en) * | 2022-07-29 | 2022-12-30 | 马鞍山钢铁股份有限公司 | Converter blowing method for low-temperature low-silicon molten iron |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0432504A (en) * | 1990-05-28 | 1992-02-04 | Sumitomo Metal Ind Ltd | Production of molten low sulfur iron |
| CN109321704A (en) * | 2018-10-30 | 2019-02-12 | 华北理工大学 | It is a kind of to reduce the smelting process for smelting finishing slag phosphorus content using slag splashing |
| CN109852760A (en) * | 2018-12-03 | 2019-06-07 | 江苏省沙钢钢铁研究院有限公司 | A kind of converter preheating scrap improves the smelting process of scrap ratio |
| CN110387448A (en) * | 2019-08-19 | 2019-10-29 | 中天钢铁集团有限公司 | A kind of method that converter rapid low consumption produces low-phosphorous special steel |
| RU2731710C1 (en) * | 2020-03-11 | 2020-09-08 | Акционерное общество "Научно-производственная корпорация "Уралвагонзавод" имени Ф.Э. Дзержинского" | Charge for steel melting in basic open-hearth furnace |
-
2022
- 2022-04-14 CN CN202210395928.9A patent/CN114774614A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0432504A (en) * | 1990-05-28 | 1992-02-04 | Sumitomo Metal Ind Ltd | Production of molten low sulfur iron |
| CN109321704A (en) * | 2018-10-30 | 2019-02-12 | 华北理工大学 | It is a kind of to reduce the smelting process for smelting finishing slag phosphorus content using slag splashing |
| CN109852760A (en) * | 2018-12-03 | 2019-06-07 | 江苏省沙钢钢铁研究院有限公司 | A kind of converter preheating scrap improves the smelting process of scrap ratio |
| CN110387448A (en) * | 2019-08-19 | 2019-10-29 | 中天钢铁集团有限公司 | A kind of method that converter rapid low consumption produces low-phosphorous special steel |
| RU2731710C1 (en) * | 2020-03-11 | 2020-09-08 | Акционерное общество "Научно-производственная корпорация "Уралвагонзавод" имени Ф.Э. Дзержинского" | Charge for steel melting in basic open-hearth furnace |
Non-Patent Citations (1)
| Title |
|---|
| 杨树棠;: "氧气转炉吃废钢技术", 鞍钢技术 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115537491A (en) * | 2022-07-29 | 2022-12-30 | 马鞍山钢铁股份有限公司 | Converter blowing method for low-temperature low-silicon molten iron |
| CN115537491B (en) * | 2022-07-29 | 2024-04-12 | 马鞍山钢铁股份有限公司 | Converter converting method of low-temperature low-silicon molten iron |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110129517B (en) | Method for smelting high-silicon iron water based on converter duplex method to improve dephosphorization rate of desiliconization furnace | |
| CN109280731B (en) | Method for producing steel with converter end point P less than or equal to 0.01% by smelting high-phosphorus molten iron by adopting less slag materials | |
| CN105525055B (en) | A kind of control method of converter less-slag melting carbon period splash | |
| CN112626306B (en) | Method for reducing total iron in slag based on high molten iron ratio electric furnace steelmaking | |
| CN103352101B (en) | Low-cost smelting technology of converter | |
| CN103627842B (en) | Method for enhancing end point carbon content in smelting medium-carbon steel from semisteel and semisteel steelmaking method | |
| CN102212643A (en) | Converter less-slag smelting process | |
| CN101314805A (en) | High-efficiency dephosphorization smelting method for medium phosphor hot metal revolving furnace | |
| CN101993980A (en) | Method for smelting ultralow-phosphorous steel | |
| CN103397146A (en) | Production method of pipeline steel | |
| CN1775959A (en) | Electric furnace to converter steel making production process | |
| CN102943145A (en) | Converter smelting method of ultra-low phosphorus steel | |
| CN104313309A (en) | Technology and system for producing stainless steel by submerged arc furnace and AOD furnace duplex process | |
| CN111635978A (en) | Method for reducing end point carbon and oxygen deposit of electric furnace | |
| CN101671763A (en) | Method for increasing nitrogen for smelting high nitrogen stainless steel in argon oxygen decarburizing furnace | |
| CN105132611B (en) | Method for producing ultra-low phosphorous steel through single slag of converter | |
| CN112708717A (en) | Method for smelting low-phosphorus molten steel by single-converter duplex method | |
| CN108411063A (en) | A kind of method of electric furnace smelting Low-phosphorus Steel under the conditions of low molten iron proportion | |
| CN103642966B (en) | Method for improving high-carbon high-manganese steel converter smelting endpoint carbon content and steelmaking method | |
| CN114774614A (en) | Converter steelmaking method | |
| CN102994685B (en) | Method for opening steel converter | |
| CN103966387B (en) | Adopt the method for semi-steel making | |
| CN108384916B (en) | Method for improving control capability of steelmaking converter blowing end point carbon | |
| CN110699511A (en) | Method for smelting high-silicon molten iron | |
| CN114807497A (en) | Method for smelting high-silicon molten iron by using bottom oxygen blowing and lime powder combined blowing converter |
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 |