CN116004939A - Fluxing agent for semisteel steelmaking and slagging method thereof - Google Patents

Fluxing agent for semisteel steelmaking and slagging method thereof Download PDF

Info

Publication number
CN116004939A
CN116004939A CN202310050241.6A CN202310050241A CN116004939A CN 116004939 A CN116004939 A CN 116004939A CN 202310050241 A CN202310050241 A CN 202310050241A CN 116004939 A CN116004939 A CN 116004939A
Authority
CN
China
Prior art keywords
semisteel
fluxing agent
steelmaking
slag
converter
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
Application number
CN202310050241.6A
Other languages
Chinese (zh)
Inventor
梁新腾
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panzhihua University
Original Assignee
Panzhihua University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Panzhihua University filed Critical Panzhihua University
Priority to CN202310050241.6A priority Critical patent/CN116004939A/en
Publication of CN116004939A publication Critical patent/CN116004939A/en
Pending legal-status Critical Current

Links

Classifications

    • 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

  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

The invention provides a fluxing agent for semisteel steelmaking and a slagging method thereof, belonging to the technical field of metallurgy. A fluxing agent for semisteel steelmaking is characterized by comprising the following components: the weight percentages are as follows: siO (SiO) 2 ：60～70％，MgO：25～36％，Fe 2 O 3 ：1～10％，Al 2 O 3 : 1-5%, mnO: 1-2%, P:0.001 to 0.01 percent, S: 0.001-0.01% and the balance of unavoidable impurities. The fluxing agent for semisteel steelmaking and the slagging method thereof have good activity, improve dephosphorization and desulfurization capability of steelmaking slag, and have good social and economic benefits.

Description

Fluxing agent for semisteel steelmaking and slagging method thereof
Technical Field
The invention relates to a fluxing agent for semisteel steelmaking and a slagging method thereof, belonging to the technical field of metallurgy.
Background
In the converter steelmaking process, in order to promote the rapid melting of lime, destroy dicalcium silicate crystallization or delay the formation of crust, a large amount of materials which are helpful for slag melting are added in the steelmaking production to perform slag melting, fluorite is generally used for slag melting in the converter steelmaking in the past, but because fluorite contains F - Fluoride ions are harmful to human bodies and equipment, so various slag melting materials have been studied to replace fluorite.
After vanadium is extracted from molten iron in Panxi area, the content of Si, ti, mn and other elements in semisteel is almost zero, so that the converter slag system is single, and the quick slag melting is not facilitated. In the semisteel steelmaking process, the earlier stage of converting slag accounts for about 20%, the middle stage of converting slag accounts for about 70%, and the whole process of converting returns to dryness to account for about 10%. Therefore, slag melting elements are required to be added so that the converter semisteel steelmaking process can be quickly melted. Meanwhile, the property of the final slag system is often related to the effect of the converter slag splashing protection, so that the MgO content of the final slag needs to be controlled in a proper range to obtain proper slag melting point and viscosity, and further the requirement of the converter slag splashing protection is met.
CN1291657a discloses a fluxing agent for converter slagging and a slagging process using the fluxing agent, wherein the fluxing agent comprises the following components: al (Al) 2 O 3 ≥45％，SiO 2 ≤30％，Fe 2 O 3 :7 to 8 percent, the balance being CaO, mgO, tiO 2 And P, S, the granularity is 5-30 mm, and the use amount is 1.6-9 kg of bauxite per ton of steel. The method has the following defects: the bauxite type cosolvent has a relatively stable slagging effect, but has the problems of serious corrosion to furnace lining, insignificant slagging effect and the like.
CN1298028A discloses a cooling and fluxing agent for converter steelmaking, the fluxing agent is an iron scale fluxing agent mainly composed of FeO, and the composition of the fluxing agent is: 70-90% of iron scale, 5-25% of ironmaking sludge and 1-5% of binder, and crushing, configuring, uniformly mixing and pressing the raw materials into balls. The method has the following defects: the iron fluxing agent has remarkable slagging effect, but has the problems of serious corrosion to furnace lining, large temperature drop of molten steel, short fluxing action time, incapability of continuously slagging and the like.
Disclosure of Invention
The invention solves the first technical problem of providing a fluxing agent for semisteel steelmaking.
A fluxing agent for semisteel steelmaking is characterized in that: the composition of the material is, in mass percent, siO 2 ：60～70％，MgO：25～36％，Fe 2 O 3 ：1～10％，Al 2 O 3 : 1-5%, mnO: 1-2%, P:0.001 to 0.01 percent, S: 0.001-0.01% and the balance of unavoidable impurities.
Wherein the melting point of the fluxing agent for semisteel steelmaking is 1300-1365 ℃.
Wherein the fluxing agent for semisteel steelmaking is a material rich in SiO at the same time 2 And MgO natural ore, the natural ore being talc。
The second technical problem solved by the invention is to provide a fluxing agent slagging method for semisteel steelmaking, which comprises the following steps:
a. mechanically crushing a large block of fluxing agent for semisteel steelmaking, and processing the large block of semisteel steelmaking fluxing agent into blocks with the granularity of 10-80 mm;
b. after the converter is discharged and slag splashing furnace protection is carried out, 7-12 kg/t of fluxing agent is added from a high-level bin of the converter at one time;
c. charging semisteel molten iron and scrap steel, and starting oxygen blowing steelmaking, wherein the oxygen flow is 30000Nm 3 /h; wherein the weight ratio of the semisteel molten iron to the scrap steel is 12.5-14.5:0.4-1;
d. two thirds of the total lime consumption, namely 10-17 kg/t steel and 10-15 kg/t steel of high magnesium lime are added into the converter by blowing, so as to meet the dephosphorization requirement of converter slag, and the rest one third of lime is added in batches in the smelting process.
Wherein step b facilitates rapid melting of the fluxing agent.
Wherein, in the step c, the semisteel molten iron comprises the following components: and C:3.2 to 4.1 percent, si:0.015 to 0.030 percent, mn: 0.02-0.04%, P: 0.06-0.08%, S: less than or equal to 0.015 percent.
Wherein, the charging temperature of the semisteel molten iron and the scrap steel in the step c is 1250-1360 ℃.
In the step d, lime is added when slag is more active so as to ensure sufficient fluidity and desulfurization and dephosphorization capability.
In the step d, compared with the conventional process, the consumption of lime is reduced by 1-2 kg/t of steel; because the talcum fluxing agent contains a large amount of magnesium oxide, the mass percent of MgO in the converter slag can be ensured to be 8-12 percent so as to meet the requirement of protecting the converter; compared with the conventional process, the consumption of high-magnesium lime is reduced by 6-14 kg/t steel; siO in converter slag can be ensured due to the large amount of silicon dioxide in the talcum fluxing agent 2 The content requirement can further meet the requirements of converter slagging and steelmaking dephosphorization, and compared with the conventional process, the consumption of composite slag or quartz sand is reduced by 5-10 kg/t steel.
In the step d, the alkalinity of primary slag is controlled to be 2.0-3.0, and the alkalinity of final slag is controlled to be 3.0-4.0.
Wherein, the distance between the oxygen lance nozzle and the metal liquid surface of the molten pool is 1.4-2 m, the blowing lance position is 1.4-1.8 m, the blowing lance position is 2m, and the carbon drawing lance position is 1.4m, so that the slag has good fluidity, and the purpose of rapid dephosphorization is achieved.
Wherein, the slag is taken 3 minutes after blowing begins, the slag taking time is shortened by 0.5 minutes compared with the conventional semisteel converter steelmaking, the slag is active, and the process is not dried and splashed.
The invention has the beneficial effects that:
1. the fluxing agent for semisteel steelmaking and the slagging method thereof provided by the invention have the advantages that the converter uses natural ore as the fluxing agent, the ore activity is good, the reaction is rapid, only one raw material talcum is used for replacing two semisteel steelmaking raw materials, namely high-magnesium lime and a composite slagging agent, and the consumption of steelmaking auxiliary materials is greatly reduced by 3-6 kg/t steel.
2. The fluxing agent for semisteel steelmaking and the slagging method thereof provided by the invention have extremely low phosphorus and sulfur contents in the talcum natural ore, improve dephosphorization and desulfurization capability of steelmaking slag, and have good social and economic benefits.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to specific examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The examples were conducted under conventional conditions, except that the specific conditions were not specified.
Example 1
HRB400E steel grade was smelted in a 120 ton new converter in a steel mill. The weight of the half-steel molten iron actually charged into the furnace is 130.6t, the weight of the scrap steel is 7t, and the tapping weight is 130.72t. The molten semisteel composition and temperature are shown in table 1; the amounts of the auxiliary materials and oxygen blowing amounts actually added are shown in Table 2; the tapping composition and tapping temperature are shown in Table 3.
TABLE 1 semisteel molten iron composition (%) and charging temperature (. Degree.C.)
C Si Mn P S Temperature of furnace charging
Semisteel molten iron 3.7 0.02 0.03 0.074 0.010 1320
TABLE 2 actual addition amount (kg) of semisteel steelmaking auxiliary materials and actual oxygen blowing amount (m) 3 )
Lime High magnesium lime Talc Oxygen blowing amount
2793 1596 1330 6210
TABLE 3 tapping molten steel composition (%) and tapping temperature (. Degree.C.)
C Si Mn P S Tapping temperature
Tapping molten steel 0.055 0.015 0.023 0.015 0.008 1685
After the converter finishes tapping steel and slag splashing protection, 1330 kg of all talcum natural ore is added from a high-level bin of the converter at one time. After smelting and blowing, adding two thirds of lime, namely 2793kg, and all high-magnesium lime into a converter, adding the rest one third of lime into the converter in 3-4 batches, and blowing for 2 minutes and 30 seconds to obtain slag, wherein the slag-forming time is 30 seconds earlier than that of the conventional operation adopting a composite slag former and high-magnesium lime. The process slag is active, and has stronger dephosphorization and desulfurization capability. And the conventional slag splashing furnace protection process is adopted at the end of tapping, and slag hanging on the furnace wall is good.
The final slag of the furnace smelting has an alkalinity of 3.5, the total iron in the final slag is 18.88 percent, and the oxygen activity is 500ppm. Obtaining better results.
Example 2
And smelting the steel of Q235 steel grade on a new 120 ton converter in a certain steel plant. The weight of the actual half-steel molten iron charged into the furnace is 140t, the weight of the scrap steel is 5t, and the tapping weight is 136.3t. The molten semisteel composition and temperature are shown in table 4; the amounts of the auxiliary materials and oxygen blowing amounts actually added are shown in Table 5; the tapping composition and tapping temperature are shown in Table 6.
TABLE 4 semisteel molten iron composition (%) and charging temperature (. Degree. C.)
C Si Mn P S Temperature of furnace charging
Semisteel molten iron 3.95 0.021 0.041 0.07 0.015 1300
TABLE 5 actual addition amount (kg) of semisteel steelmaking auxiliary materials and actual oxygen blowing amount (m) 3 )
Lime High magnesium lime Talc Oxygen blowing amount
2500 1600 1400 6400
TABLE 6 tapping molten steel composition (%) and tapping temperature (. Degree.C.)
C Si Mn P S Tapping temperature
Tapping molten steel 0.069 0.02 0.035 0.017 0.011 1682
After the converter finishes tapping steel and slag splashing protection, the whole talcum natural ore, namely 1400 kg, is added from a high-level bin of the converter at one time. After smelting and blowing, two-thirds of the total lime, namely 2500kg, and all high-magnesium lime are added into a converter, and the rest one third of lime is added into the converter in 3-4 batches, and slag is obtained after blowing for 2 minutes and 15 seconds, and compared with the conventional operation adopting a composite slag former and high-magnesium lime, the slag obtaining time is 45 seconds earlier. The process slag is active, and has stronger dephosphorization and desulfurization capability. And the conventional slag splashing furnace protection process is adopted at the end of tapping, and slag hanging on the furnace wall is good.
The final slag of the furnace smelting has an alkalinity of 3.6, the total iron in the final slag is 19.89%, and the oxygen activity is 450ppm. Obtaining better results.
Comparative example 1
YQ450 steel grade steel is smelted on a new 120 ton converter in a steel mill. The weight of the half-steel molten iron actually charged into the furnace is 133t, the weight of the scrap steel is 10t, and the tapping weight is 134.42t. The composition and temperature of the semisteel molten iron are shown in Table 7; the amounts of the auxiliary materials and oxygen blowing amounts actually added are shown in Table 8; the tapping composition and tapping temperature are shown in Table 9.
TABLE 7 semisteel molten iron composition (%) and charging temperature (. Degree. C.)
C Si Mn P S Temperature of furnace charging
Semisteel molten iron 3.88 0.02 0.025 0.072 0.015 1360
TABLE 8 actual addition amount (kg) of semisteel steelmaking auxiliary materials and actual oxygen blowing amount (m) 3 )
Lime High magnesium lime Acid composite slag Ladle slag Oxygen blowing amount
2750 2500 1500 1045 6600
TABLE 9 tapping molten steel composition (%) and tapping temperature (. Degree.C.)
C Si Mn P S Tapping temperature
Tapping molten steel 0.078 0.023 0.035 0.012 0.011 1690
1045kg of ladle slag, 1833kg of lime, 1667kg of high-magnesium lime and 1500 kg of acid composite slag are added into a converter after the furnace smelting is opened and blown for 4 minutes and 35 seconds to obtain slag, the alkalinity of the final slag of the furnace smelting is 3.93, the total iron in the final slag is 21%, and the oxygen activity is 500ppm.
The present embodiment is merely illustrative of the invention and not intended to be limiting, and those skilled in the art will make modifications or improvements on the basis of the present invention after reading the description of the invention, but are protected by the patent laws within the scope of the claims of the present invention.

Claims (7)

1. The fluxing agent for semisteel steelmaking is characterized in that: the composition of the material is, in mass percent, siO 2 ：60～70％，MgO：25～36％，Fe 2 O 3 ：1～10％，Al 2 O 3 : 1-5%, mnO: 1-2%, P:0.001 to 0.01 percent, S: 0.001-0.01% and the balance of unavoidable impurities.
2. The flux for semisteel production according to claim 1, wherein the melting point of the flux for semisteel production is 1300 to 1365 ℃.
3. The fluxing agent slagging method for semisteel steelmaking is characterized by comprising the following steps of:
a. mechanically crushing a large block of fluxing agent for semisteel steelmaking, and processing the large block of semisteel steelmaking fluxing agent into blocks with the granularity of 10-80 mm;
b. after the converter is discharged and slag splashing furnace protection is carried out, 7-12 kg/t of fluxing agent is added from a high-level bin of the converter at one time;
c. charging semisteel molten iron and scrap steel, and starting oxygen blowing steelmaking, wherein the oxygen flow is 30000Nm 3 /h; wherein the weight ratio of the semisteel molten iron to the scrap steel is 12.5-14.5:0.4-1;
d. two thirds of the total lime consumption, namely 10-17 kg/t steel and 10-15 kg/t steel of high magnesium lime are added into the converter by blowing, so as to meet the dephosphorization requirement of converter slag, and the rest one third of lime is added in batches in the smelting process.
4. The fluxing agent slagging method for semisteel steelmaking according to claim 3, wherein the oxygen lance nozzle is 1.4-2 m away from the basic lance position of the molten pool metal level, the blowing lance position is 1.4-1.8 m, the blowing lance position is 2m, and the carbon drawing lance position is 1.4m.
5. The fluxing agent slagging method for semisteel steelmaking according to claim 3, wherein in step c the semisteel molten iron has the composition: and C:3.2 to 4.1 percent, si:0.015 to 0.030 percent, mn: 0.02-0.04%, P: 0.06-0.08%, S: less than or equal to 0.015 percent.
6. The fluxing agent slagging method for semisteel steelmaking according to claim 3, wherein the temperature of the semisteel molten iron and scrap in step c is 1250-1360 ℃.
7. The fluxing agent slagging method for semisteel steelmaking according to claim 3, wherein in step d, the primary slag alkalinity is controlled to be 2.0-3.0, and the final slag alkalinity is controlled to be 3.0-4.0.
CN202310050241.6A 2023-02-01 2023-02-01 Fluxing agent for semisteel steelmaking and slagging method thereof Pending CN116004939A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310050241.6A CN116004939A (en) 2023-02-01 2023-02-01 Fluxing agent for semisteel steelmaking and slagging method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310050241.6A CN116004939A (en) 2023-02-01 2023-02-01 Fluxing agent for semisteel steelmaking and slagging method thereof

Publications (1)

Publication Number Publication Date
CN116004939A true CN116004939A (en) 2023-04-25

Family

ID=86031790

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310050241.6A Pending CN116004939A (en) 2023-02-01 2023-02-01 Fluxing agent for semisteel steelmaking and slagging method thereof

Country Status (1)

Country Link
CN (1) CN116004939A (en)

Similar Documents

Publication Publication Date Title
CN102264919B (en) Method for reclaiming iron and phosphorus from steelmaking slag
CN112760550B (en) Production method of nickel-free copper-phosphorus weathering steel casting blank
CN105483316B (en) The method of chrome ore DIRECT ALLOYING in Converter
CN109722589B (en) Production method for semisteel smelting weathering steel
JP2000160233A (en) Method for desulfurize-refining stainless steel
CN108842027B (en) Gasification dephosphorization method and smelting method for final slag of dephosphorization converter
CN108754063B (en) Dephosphorization production process for H08A series steel
Duan et al. EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime
JP2947063B2 (en) Stainless steel manufacturing method
CN105986054A (en) Method for modifying and reducing converter final slag
CN116004939A (en) Fluxing agent for semisteel steelmaking and slagging method thereof
CN104328361A (en) Anti-seismic steel bar and preparation method thereof
CN110205434B (en) Method for smelting steel bar with low cost
CN116024402A (en) Fluxing agent for semisteel steelmaking and slagging method thereof
JP3511808B2 (en) Stainless steel smelting method
CN111020115A (en) Method for refining molten steel outside furnace by using liquid blast furnace slag
JP2000109924A (en) Method for melting extra-low sulfur steel
CN115652184B (en) Method for smelting ultra-pure ferrite stainless steel by using slag melting agent in AOD converter
JP3063537B2 (en) Stainless steel manufacturing method
CN111411191B (en) Method for directly alloying manganese ore in semisteel steelmaking converter
CN112458237B (en) Steelmaking method for reducing slag quantity and modifying slag components on line
JPH10265827A (en) Regenerating/utilizing method of refined slag in chromium-containing steel and regenerating/utilizing method of metallic component contained in the slag
CN115948634A (en) Method for extracting vanadium element in low-silicon high-chromium iron water
CN113025773A (en) Dephosphorization method for semisteel steelmaking
JP2882236B2 (en) Stainless steel manufacturing method

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