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CN-122012848-A - Converter rapid slag forming method based on high-alkalinity casting residue

CN122012848ACN 122012848 ACN122012848 ACN 122012848ACN-122012848-A

Abstract

The invention discloses a converter rapid slag forming method based on high-alkalinity casting residues, which comprises the following specific steps of (1) calculating the required high-alkalinity casting residues based on heat charging information before converter smelting starts to control the Al2O3 content in the earlier-stage slag to be a target mass fraction, (2) synchronously charging high-alkalinity casting residues with lime, which are 40-60% of the required high-alkalinity casting residues, into a furnace before opening and blowing after the converter charging is completed, and (3) charging the rest high-alkalinity casting residues with the required high-alkalinity casting residues into the furnace when the smelting duration reaches 3-5 min. And calculating the feeding amount of the high-alkalinity casting residue based on the converter loading information, and adopting a batch feeding strategy to enable the slag to rapidly enter a liquid phase in the initial stage of blowing to form a high-alkalinity and high-fluidity slag system, thereby remarkably improving the slag forming and dephosphorizing efficiency.

Inventors

  • CHENG YUAN
  • XIONG LEI
  • XING DONGDONG
  • Xue shun
  • DU KEBIN
  • LI GUOJING
  • Hu Ruhui
  • CHEN TAO
  • XIE ZUYUAN

Assignees

  • 马鞍山钢铁有限公司

Dates

Publication Date
20260512
Application Date
20260226

Claims (9)

  1. 1. A converter rapid slagging method based on high-alkalinity casting residue is characterized by comprising the following steps: (1) Before converter smelting starts, calculating the required high-alkalinity casting residue addition amount based on the heat charging information so as to control the prior slag The content is the target mass fraction; (2) After the converter is filled, high-alkalinity casting residues accounting for 40% -60% of the required high-alkalinity casting residues are synchronously added into the converter with lime before blowing; (3) And when the smelting time reaches 3-5 min, adding the high-alkalinity casting residues with the residual required high-alkalinity casting residues into the furnace.
  2. 2. The method for rapid slagging in a converter for high alkalinity casting residues according to claim 1, wherein the primary slag is The target mass fraction determining method of (1) specifically comprises the following steps: (11) Detecting in sampled slag of a current furnace Mass fraction, and testing the liquidus temperature of the sample slag, maintaining the continuous multi-furnace slag thereafter The quality fraction is unchanged, and the detection is carried out at the current time Lining erosion thickness in mass fraction; (12) Changing the next slag Mass fraction, executing step (11); (13) Obtaining slag in different ways by the steps (11) to (12) The liquidus temperature in mass fraction and the erosion thickness of furnace lining; (14) Selecting slag with small lining erosion thickness and low liquidus temperature Mass fraction as in the early slag Is a target mass fraction of (c).
  3. 3. The method for rapid slagging in a converter for high alkalinity casting residues according to claim 1, wherein the primary slag is The target mass fraction of (2) was 5%.
  4. 4. The method for rapidly forming slag in a converter according to claim 1, wherein the addition ratio of the high-alkalinity casting slag in the step (2) is decreased when the silicon content of the molten iron is high, and the addition ratio of the high-alkalinity casting slag in the step (2) is increased when the silicon content of the molten iron is low.
  5. 5. The method for rapidly forming slag in a converter with high alkalinity casting slag as claimed in claim 1, wherein the lance position of the oxygen lance in the step (2) is controlled to be 1.9 m-2.1 m.
  6. 6. The method for rapidly forming the high-alkalinity casting residue in the converter according to claim 1, wherein the lance position of the oxygen lance is controlled to be 1.7 m-2.0 m in the later stage of smelting, and 200-300 kg of lime is added when the smelting time reaches 12-14 min.
  7. 7. The method for rapidly forming slag in a converter according to claim 1, wherein the total slag amount and the addition amount of the high-basicity casting slag at the total slag amount are calculated based on the material balance.
  8. 8. The method for rapidly forming slag in a converter with high alkalinity casting residue according to claim 7, wherein the total slag amount is The calculation formula is as follows: ; Wherein, the Representing the total slag amount; representing the total weight of the molten iron of the current heat; representing the mass fraction of Si in molten iron; representing mass fraction of Mn in molten iron; Indicating the addition amount of auxiliary materials; Representing the slag amount of the molten iron in the converter; Representing the mass fraction of FeO in the slag.
  9. 9. The method for rapid slagging in a converter for highly basic cast slag according to claim 8, wherein the required quantity of highly basic cast slag is The calculation formula is specifically as follows: ; Wherein, the Representing the required high-alkalinity casting residue addition amount; Indicating that the molten iron is in the slag of the converter Mass fraction; representing the early stage slag Is determined by the target mass fraction of (c), Indicating high alkalinity in the casting residue Mass fraction.

Description

Converter rapid slag forming method based on high-alkalinity casting residue Technical Field The invention belongs to the technical field of converter steelmaking, and particularly relates to a converter rapid slag forming method based on high-alkalinity casting slag. Background In the converter steelmaking process, a slag making system is a key link for ensuring the smooth smelting and realizing the control of end point components. When in blowing, oxygen and elements such as carbon, silicon, manganese, phosphorus and the like in molten iron are subjected to oxidation reaction, and the generated oxide is required to be combined with fluxes such as lime, dolomite and the like to form slag. The reasonable slagging system should rapidly generate a liquid slag system at the initial stage of blowing so as to wrap and fix oxidation products, and thermodynamic and kinetic conditions are provided for dephosphorization, desulfurization and inclusion removal by regulating alkalinity and oxidability. Lime is generally used as the primary slag forming material to increase alkalinity and promote phosphorus ingress into the slag, and dolomite supplements MgO to stabilize the furnace lining. However, in actual production, the converter generally faces the problems of low early slag forming speed, low lime melting speed and the like, so that dephosphorization reaction power is insufficient, slag system formation lag causes great fluctuation of early slag components, stable high alkalinity and reasonable viscosity are difficult to maintain, and dephosphorization efficiency and smelting process stability are directly influenced. Therefore, how to quickly form a high-alkalinity liquid slag system in the initial stage of converter blowing is a key problem of optimizing a slag making system and improving smelting quality and process stability. In order to improve the early slag formation deficiency of the converter, a certain amount of fluxing agent is usually added in the production, and the common fluxing agent mainly comprises fluorite, sinter, premelting slag and the like. The fluorite can obviously reduce the viscosity of slag and improve the fluidity, but has high fluorine content, and can volatilize fluoride gas easily at high temperature, thereby not only corroding a furnace lining, but also bringing serious environmental protection problems, the sintered ore is used as an iron-containing flux, can supplement an iron source and accelerate lime melting, has extremely strong reactivity, often causes molten iron splashing and slag overflow, affects the operation safety, and the premelting slag has high cost and is difficult to popularize on a large scale although the components are stable. Therefore, the existing fluxing agent is difficult to meet the requirements of rapid slagging, smelting stability, economy and environmental protection. Compared with the traditional fluxing agent, the high-alkalinity casting residue has natural advantages. The high alkalinity casting residue is slag left after the pouring of the steel ladle, and the components are CaO and CaOMainly, the alkalinity is generally above 5, and under the condition of converter blowing temperature, high-alkalinity casting residue can quickly enter liquid phase, so that the problem of slow lime melting can be overcome, the fluidity of a slag system can be obviously improved, and the slag forming speed can be increased. At present, the application of high-alkalinity casting residues in a converter still has the following defects that 1) the slag system is lack of pairsScientific control of the content, easy occurrence ofToo high a content results in too low slag viscosity, difficulty in slag-iron separation, orAnd 2) the control of the adding time is not standard, and the adding is usually carried out once or randomly, so that the blowing rhythm is difficult to match, and the slag reaction is unbalanced. Disclosure of Invention The invention provides a converter rapid slagging and dephosphorization method based on high-alkalinity casting residues, and aims to solve at least one of the problems. The invention discloses a converter rapid slag forming method based on high-alkalinity casting residues, which is characterized by comprising the following steps of: (1) Before converter smelting starts, calculating the required high-alkalinity casting residue addition amount based on the heat charging information so as to control the prior slag The content is the target mass fraction; (2) After the converter is filled, high-alkalinity casting residues accounting for 40% -60% of the required high-alkalinity casting residues are synchronously added into the converter with lime before blowing; (3) And when the smelting time reaches 3-5 min, adding the high-alkalinity casting residues with the residual required high-alkalinity casting residues into the furnace. Further, in the early slagThe target mass fraction determining method of (1) specifically comprises the following