Semi-steel smelting method for inhibiting foaming of converter slag

Abstract

The invention discloses a semisteel smelting method for inhibiting converter slag foaming, which comprises the following steps: 1) after converter iron blending is finished, setting a gun position to an initial blowing gun position; (2) after blowing is started, a first batch of slagging materials are added in the initial stage of smelting; and 3) when the audio value is reduced to the audio value V sound, pressing the gun and adding the residual slagging material. According to the method, slagging materials are added in batches according to the weight and temperature information of semi-steel in the initial stage of smelting, and when an audio value is reduced to a certain value, a gun is pressed in time, and the FeO content in slag is reduced; particularly, the residual slagging material is added while the gun is pressed, so that the viscosity of the slag is further improved. By pressing the gun in time and increasing the later-stage slag adding amount, the FeO content in the slag is reduced, the viscosity of the slag is improved, slag foaming is inhibited economically, efficiently and simply, the molten steel yield is increased, the tapping slag overflowing risk is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to a converter steelmaking method, in particular to a semi-steelmaking method for suppressing converter slag foaming. Background Art

[0002] Semi-steel converter steelmaking uses semi-steel, scrap steel, slag material, and oxygen as raw materials. The steelmaking process is completed using the physical heat of the semi-steel and the heat of oxidation reactions of carbon and phosphorus. Semi-steel has a lower carbon content than molten iron, and the presence of slag-forming elements such as silicon, titanium, and manganese in semi-steel is minimal. Therefore, the slag is difficult to melt in the early stages of semi-steel smelting, slagging occurs late, and the dephosphorization rate is low. To shorten the slag formation time, semi-steel smelting adopts an iron-based slag formation process. This involves using high-lance blowing in the early stages to increase the FeO content in the slag and shorten the slag formation time. The increased FeO content in the slag decreases the melting temperature and viscosity of the slag. While this facilitates the formation of foamy slag, it also increases the risk of spattering during the smelting process. In actual production, converter operators primarily rely on observing changes in the furnace mouth flame to predict the occurrence of spattering. However, this method is not ideal because flame changes are often affected by multiple factors and cannot accurately reflect the actual conditions within the furnace. Therefore, in order to more effectively suppress splashing and improve the safety and efficiency of smelting, the industry has been exploring more accurate and reliable prediction and control methods.

[0003] With the rapid development of digital and information technology, and the continuous emergence of advanced monitoring equipment, the use of these high-tech means to indirectly monitor the state of slag has become an effective way to improve the accuracy of splashing prediction and control during the semi-steel converter steelmaking process and enhance smelting safety and efficiency.

[0004] Chinese patent application number 201210239184.8 discloses a "method for suppressing slag foaming." During the converter pouring process, a carbonaceous material is brought into contact with the foamed slag on the surface of the molten steel to control slag foaming and ensure safe slag discharge. However, this method does not fundamentally eliminate the phenomenon of slag foaming during the converter smelting process.

[0005] Chinese patent application number 201010185921.1 discloses a "Converter Slag Depressant and Method." The invention involves adding 2.5 to 8.5 kg of this agent per ton of molten steel to the converter after oxygen is shut off. This reduces slag overflow during converter tapping. However, this method also fails to fundamentally eliminate slag foaming during the converter smelting process. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an economical, efficient and effective semi-steel smelting method for suppressing the foaming of converter slag.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention includes the following steps:

[0008] 1) After the converter is charged with iron, set the lance position to the initial blowing lance position;

[0009] 2) After blowing begins, the first batch of slag material is added at the beginning of smelting. The weight W1 of the first batch of slag material is calculated using the following formula (A):

[0010] W1=32×W 半 ×(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196) (A)

[0011] Where: W1 is the weight of the first batch of slag material, kg; W 半 is the weight of half steel, kg; T 半 is the semi-steel temperature when the first batch of slag material is added, ℃;

[0012] 3) When the audio value drops to the audio value V 音 When the gun is pressed and the remaining slag material is added; the audio value V 音 Calculated using the following formula (B):

[0013] V 音 =62.5×H 枪 -12.5×H 枪 2 -52 (B)

[0014] Where: V 音 is the audio value; H 枪 is the initial blowing gun position, m.

[0015] Furthermore, in step 3), the remaining slag material weight W 剩 Calculated using the following formula (C):

[0016] W 剩 =32×W 半 ×(1-(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196)) (C)

[0017] Where: W 剩 is the weight of the remaining slag material, kg; W 半 is the weight of half steel, kg; T 半 The semi-steel temperature when the first batch of slag-making material is added, ℃.

[0018] Furthermore, in step 1), the initial blowing gun position H 枪 1.8~2.2m.

[0019] Furthermore, in step 2), when the first batch of slag-making materials is added, the semi-steel temperature is 1250° C. to 1370° C.

[0020] Furthermore, in step 3), the gun is pressed to a gun position of 1.0 to 1.4 m.

[0021] The beneficial effects of the above technical solution are as follows: The present invention adds slag-forming material in batches at the initial stage of smelting based on the weight and temperature of the semi-steel. When the audio frequency value drops to a certain value, the lance is promptly closed to reduce the FeO content in the slag. In particular, the remaining slag-forming material is added while the lance is closed to further increase the viscosity of the slag. By timely closing the lance and increasing the amount of slag added later, the present invention reduces the FeO content in the slag and increases the viscosity of the slag. This economically, efficiently, and simply suppresses slag foaming, reducing the slag foaming rate from 20% to 27% in conventional processes to 2% to 8%, thereby improving molten steel yield, reducing the risk of slag overflow during tapping, and lowering production costs. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to specific embodiments.

[0023] The semi-steel smelting method for suppressing converter slag foaming comprises the following steps:

[0024] 1) The weight of the semi-steel added to the converter is 120t~140t; after the converter iron is added, the gun position is set to the initial blowing gun position, the initial blowing gun position H 枪 The lance position is the distance between the oxygen lance nozzle and the steel liquid surface.

[0025] 2) After blowing begins, the first batch of slag material is added at the beginning of smelting according to the temperature and weight of the semi-steel to form slag quickly; when the first batch of slag material is added, the semi-steel temperature is 1250℃~1370℃, and the weight W1 of the first batch of slag material is calculated using the following formula (A):

[0026] W1=32×W 半 ×(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196) (A)

[0027] Where: W1 is the weight of the first batch of slag material, kg; W 半 is the weight of half steel, t; T 半 The semi-steel temperature when the first batch of slag-making material is added, ℃.

[0028] 3) When the audio value drops to the audio value V 音 When the pressure gun is pressed, the distance from the gun position is 1.0 to 1.4 m, preferably 1.3 m; the remaining slag-making material is added to the gun to break the foam and increase the viscosity of the slag; the audio value V 音 Calculated using the following formula (B):

[0029] V 音 =62.5×H 枪 -12.5×H 枪 2 -52 (B)

[0030] Where: V 音 is the audio value, which is detected by the sonar slag system; H 枪 is the initial blowing gun position, m;

[0031] The remaining slag material weight W 剩 Calculated using the following formula (C):

[0032] W 剩 =32×W 半 ×(1-(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196)) (C)

[0033] Where: W 剩 is the weight of the remaining slag material, kg; W 半 is the weight of half steel, T; T 半 The semi-steel temperature when the first batch of slag-making material is added, ℃.

[0034] 4) After adopting this method, the slag foaming rate is reduced to 8% or less.

[0035] Example 1: The semi-steel smelting method for suppressing converter slag foaming is specifically described as follows.

[0036] 1) After the converter is charged with iron, the weight of the semi-steel is 140t, and the initial blowing gun position is set to 1.8m.

[0037] 2) After the blowing process begins, the collected semi-steel temperature is 1370°C. The weight of the first batch of slag material is calculated according to formula (A): W1 = 32 × 140 × (0.0118 × 1370 - 3.968 × 10 -6 ×1370×1370-8.196)=4480×(16.166-7.4475392-8.196)=2340.62kg; add the first batch of slag material 2340.62kg.

[0038] 3) Calculate V according to the above formula (B) 音 =62.5×1.8-12.5×1.8×1.8-52=20, calculate the weight of the remaining slag material W according to the above formula (C) 剩 =32×140×(1-(0.0118×1370-3.968×10 -6 ×1370×1370-8.196))=2139.38; observe the audio slagging curve. When the audio value drops to 20, slowly press the gun to 1.0m in time; while pressing the gun, add the remaining slag-making material, the addition amount is 2141.44kg, to break the foam and increase the viscosity of the slag.

[0039] 4) The slag foaming rate in this embodiment is 2.3%.

[0040] Example 2: The semi-steel smelting method for suppressing converter slag foaming is specifically described as follows.

[0041] (1) After the converter is charged with iron, the weight of the semi-steel is 120t, and the initial blowing gun position is set to 2.2m.

[0042] (2) After the blowing process begins, the collected semi-steel temperature is 1250°C. According to formula (A), the weight of the first batch of slag material is calculated as W1 = 32 × 120 × (0.0118 × 1250 - 3.968 × 10 -6 ×1250×1250-8.196)=1359.36, the first batch of slag making material is added in the initial stage, and the added amount is 1359.36 kg.

[0043] (3) Calculate V according to the above formula (B) 音 =62.5×2.2-12.5×2.2×2.2-52=25, calculate the weight of the remaining slag material W according to the above formula (C) 剩 =32×120×(1-(0.0118×1250-3.968×10 -6 ×1250×1250-8.196))=3840×(1-(14.75-6.2-8.196)=2480.64;Observe the audio slagging curve. When the audio value drops to 25, slowly press the gun to 1.3m in time. While pressing the gun, add the remaining slag-making material, the addition amount is 2480.64kg, to break the foam and increase the viscosity of the slag.

[0044] (4) The slag foaming rate in this embodiment is 2.7%.

[0045] Example 3: The semi-steel smelting method for suppressing converter slag foaming is specifically described as follows.

[0046] (1) After the converter is charged with iron, the weight of the semi-steel is 130t, and the initial blowing gun position is set to 2.0m.

[0047] (2) After the blowing process begins, the collected semi-steel temperature is 1300°C. According to formula (A), the weight of the first batch of slag material is calculated as W1 = 32 × 130 × (0.0118 × 1300 - 3.968 × 10 -6 ×1300×1300-8.196)=1822.41. The first batch of slag-making material is added in the initial stage, and the added amount is 1822.41 kg.

[0048] (3) Calculate V according to the above formula (B) 音 =62.5×2.0-12.5×2.0×2.0-52=23, calculate the weight of the remaining slag material W according to the above formula (C) 剩 =32×130×(1-(0.0118×1300-3.968×10 -6 ×1300×1300-8.196))=4160×(1-(15.34-6.70592-8.196)=2337.59; observe the audio slagging curve. When the audio value drops to 25, slowly press the gun to 1.4m in time; while pressing the gun, add the remaining slag-making material, the addition amount is 2337.59kg, to break the foam and increase the viscosity of the slag.

[0049] (4) The slag foaming rate in this embodiment is 3.4%.

Claims

1. A semi-steel smelting method for suppressing converter slag foaming, characterized in that: The steps include: 1) After the converter is charged with iron, set the lance position to the initial blowing lance position; 2) After blowing begins, the first batch of slag material is added at the beginning of smelting. The weight W1 of the first batch of slag material is calculated using the following formula (A): W1=32×W 半 ×(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196) (A) Where: W1 is the weight of the first batch of slag material, kg; W 半 is the weight of half steel, kg; T 半 is the semi-steel temperature when the first batch of slag material is added, ℃; 3) When the audio value drops to the audio value V 音 When the gun is pressed and the remaining slag material is added; the audio value V 音 Calculated using the following formula (B): V 音 =62.5×H 枪 -12.5×H 枪 2 -52 (B) Where: V 音 is the audio value; H 枪 is the initial blowing gun position, m.

2. A semi-steel smelting method for suppressing converter slag foaming according to claim 1, characterized in that: In the step 3), the remaining slag material weight W 剩 Calculated using the following formula (C): W 剩 =32×W 半 ×(1-(0.0118×T 半 -3.968×10 -6 ×T 半 2 -8.196)) (C) Where: W 剩 is the weight of the remaining slag material, kg; W 半 is the weight of half steel, kg; T 半 The semi-steel temperature when the first batch of slag-making material is added, ℃.

3. The semi-steel smelting method for suppressing converter slag foaming according to claim 1, characterized in that: In step 1), the initial blowing gun position H 枪 1.8~2.2m.

4. The semi-steel smelting method for suppressing converter slag foaming according to claim 1, characterized in that: In the step 2), when the first batch of slag-making materials is added, the semi-steel temperature is 1250° C. to 1370° C.

5. A semi-steel smelting method for suppressing converter slag foaming according to any one of claims 1 to 4, characterized in that: In the step 3), the gun is pressed to a gun position of 1.0 to 1.4 m.