Calculation method for accurately determining converter tapping aluminum addition amount

Abstract

The invention discloses a calculation method for accurately determining the addition amount of converter tapping aluminum. The tapping aluminum adding amount can be decomposed into the aluminum amount needed for balancing the oxygen content at the end point of converter molten steel, the aluminum amount needed for balancing the oxygen content in converter roughing slag, the aluminum amount needed for analyzing aluminum alloying for the first time in a refining furnace and the aluminum amount supplemented by oxygen absorption in the converter tapping process and burning loss in the refining furnace power transmission process. The addition amount of the converter tapping aluminum can be accurately determined by accurately calculating the amount of the four parts of aluminum, it is guaranteed that the first analysis aluminum content of a refining furnace ranges from 0.040% to 0.045%, on the premise that it is guaranteed that molten steel is fully deoxidized, generation of secondary deoxidized products of the refining furnace is reduced, and the purity of the molten steel is improved. The method has the main advantages that by establishing the model, the converter tapping aluminum adding amount is accurately determined, the aluminum content of the refining furnace is analyzed to be 0.040%-0.045% for the first time, generation of secondary deoxidation products of the refining furnace is reduced on the premise that sufficient deoxidation of the molten steel is guaranteed, and the purity of the molten steel is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of steel smelting and relates to a calculation method for accurately determining the amount of aluminum added to converter steel. Background Art

[0002] Aluminum deoxidizers are widely used in steelmaking production. Aluminum, as a strong deoxidizer, can effectively remove oxygen from the molten steel after being added to the converter steel liquid, reduce inclusions in the steel, and improve the quality of the steel. If too little aluminum is added to the molten steel after the converter is tapped, the molten steel will not be completely deoxidized. A large amount of aluminum wire is added to the refining furnace, and the secondary deoxidation products generated are not easy to float, resulting in poor purity of the molten steel; if too much aluminum is added to the molten steel after the converter is tapped, the aluminum excess will result in a high aluminum content in the first analysis of the refining furnace, and aluminum loss during the refining process will also result in a large amount of secondary deoxidation products that pollute the molten steel. Therefore, how to accurately calculate the amount of aluminum added after the converter is tapped to ensure that the aluminum content in the first analysis of the refining furnace is within the controllable range of 0.040% to 0.045% is an urgent problem to be solved. Summary of the invention

[0003] The present invention discloses a method for calculating the amount of aluminum added to accurately determine the amount of aluminum added to the converter steel. The amount of aluminum added to the steel can be decomposed into four parts: the amount of aluminum required to balance the oxygen content of the converter steel liquid at the end, the amount of aluminum required to balance the oxygen content in the converter slag, the amount of aluminum required for the first analysis of aluminum alloying in the refining furnace, and the amount of aluminum replenished by oxygen absorption during the converter steel tapping process and burning during the refining furnace power transmission process. The four parts of aluminum can be accurately calculated to accurately determine the amount of aluminum added to the converter steel, ensure that the aluminum content of the first analysis of the refining furnace is between 0.040% and 0.045%, reduce the generation of secondary deoxidation products in the refining furnace under the premise of ensuring that the steel liquid is fully deoxidized, and improve the purity of the steel liquid.

[0004] The specific process measures taken are as follows:

[0005] (1) The amount of aluminum required to balance the oxygen content of the converter steel liquid at the end point is to analyze the carbon results of the converter steel sample. The oxygen content is calculated based on the carbon results of the steel and the current C-0 product equilibrium constant 28. The amount of aluminum required to balance the oxygen content of the converter steel liquid at the end point is calculated in combination with the amount of molten steel = carbon results of steel tapping / 28 × amount of molten steel;

[0006] (2) The amount of aluminum required to balance the oxygen content in the converter slag. The amount of converter slag is calculated as 500 kg. The FeO content in the slag is reduced from 20% to 0.5%. 3(Fe0)+2[Al]=(Al2O3)+3[Fe]. According to the law of conservation of mass, the amount of aluminum required to balance the oxygen content in the converter slag is calculated as 500 kg×(20%-0.5%)×54 / 216=24.4 kg.

[0007] (3) The amount of aluminum required for the first analysis of aluminum alloying by the refining furnace. The aluminum content of the first analysis of the target refining furnace is 0.045%. The amount of aluminum required for the first analysis of aluminum alloying by the refining furnace is calculated based on the amount of molten steel = 0.045% × the amount of molten steel;

[0008] (4) The amount of aluminum replenished by oxygen absorption during the converter steel-making process and aluminum burned during the refining furnace power supply process is divided into two types according to whether aluminum is used as the diffusion deoxidizer of the refining furnace. If the refining furnace uses aluminum diffusion deoxidizer, the amount of aluminum replenished by oxygen absorption during the converter steel-making process and aluminum burned during the refining furnace power supply process is calculated as 20kg; if the refining furnace does not use aluminum diffusion deoxidizer, the amount of aluminum replenished by oxygen absorption during the converter steel-making process and aluminum burned during the refining furnace power supply process is calculated as 40kg.

[0009] Inventive points and analysis of the present invention:

[0010] The addition of aluminum deoxidizer during converter steelmaking is an important part of deoxidation. If too little aluminum is added to the molten steel after steelmaking, the molten steel will not be completely deoxidized. A large amount of aluminum wire will be added to the refining furnace, and the secondary deoxidation products generated will not float up easily, resulting in poor purity of the molten steel. If too much aluminum is added to the molten steel after converter steelmaking, the excess aluminum will cause the refining furnace to analyze the high aluminum content for the first time, and the aluminum will be lost during the refining process, which will also form a large amount of secondary deoxidation products to pollute the molten steel. Therefore, it is necessary to accurately calculate the amount of aluminum added after converter steelmaking to ensure that the aluminum content of the first analysis of the refining furnace is within a controllable range of 0.040% to 0.045%. The present invention solves the above problems by decomposing the aluminum addition during steelmaking into four parts: the amount of aluminum required to balance the oxygen content of the converter molten steel end point, the amount of aluminum required to balance the oxygen content in the slag under the converter, the amount of aluminum required for the first analysis of aluminum alloying in the refining furnace, and the amount of aluminum supplied by oxygen absorption during converter steelmaking and burning during the power supply process of the refining furnace. Two aluminum adding models are summarized. For the varieties of refining furnace using aluminum diffusion deoxidizer, the amount of aluminum added to the steel = carbon result of steel tapping / 28×the amount of molten steel+24.4kg+0.045%×the amount of molten steel+20kg; for the varieties of refining furnace not using aluminum diffusion deoxidizer, the amount of aluminum added to the steel tapping = carbon result of steel tapping / 28×the amount of molten steel+24.4kg+0.045%×the amount of molten steel+40kg.

[0011] The main advantages of the present invention are:

[0012] According to whether the refining furnace uses aluminum diffusion deoxidizer, two converter tapping aluminum adding models are established. The amount of aluminum added to the refining furnace using aluminum diffusion deoxidizer = tapping carbon result / 28×molten steel volume + 24.4kg + 0.045% × molten steel volume + 20kg; the amount of aluminum added to the refining furnace not using aluminum diffusion deoxidizer = tapping carbon result / 28×molten steel volume + 24.4kg + 0.045% × molten steel volume + 40kg. Through the establishment of the model, the amount of aluminum added to the converter tapping is accurately determined. The aluminum content of the refining furnace is analyzed for the first time between 0.040% and 0.045%. The formation of secondary deoxidation products in the refining furnace is reduced on the premise of ensuring sufficient deoxidation of the molten steel, thereby improving the purity of the molten steel. DETAILED DESCRIPTION

[0013] Example 1

[0014] (1) The amount of aluminum required to balance the oxygen content of the converter steel liquid at the end point:

[0015] The carbon content of the steel tapped from the converter is 0.10%, the amount of molten steel tapped is 110 tons, and the amount of aluminum required to balance the oxygen content of the converter molten steel end point = 0.10% / 28×110×1000kg=39.28kg;

[0016] (2) The amount of aluminum required to balance the oxygen content in the converter slag:

[0017] According to the law of conservation of mass, the amount of aluminum required to balance the oxygen content in the slag of the converter is calculated = 500kg × (20% - 0.5%) × 54 / 216 = 24.4kg;

[0018] (3) The amount of aluminum required for the first analysis of aluminum alloying in the refining furnace:

[0019] The amount of aluminum required for the first analysis of aluminum alloying by the refining furnace is calculated based on the amount of molten steel = 0.045% × 110 × 1000kg = 49.5kg;

[0020] (4) The amount of aluminum supplied by oxygen absorption during the converter steel-making process and by burning during the refining furnace power supply process:

[0021] This type of refining furnace uses aluminum diffusion deoxidizer, so the amount of aluminum replenished by oxygen absorption during the converter steel-making process and burning during the refining furnace power supply process is 20kg.

[0022] The cumulative sum of the aluminum addition of the four parts = 39.28kg + 24.4kg + 49.5kg + 20kg = 133.18kg. The aluminum addition amount of the converter steel with the steel flow is 133.18kg. The aluminum content of the first analysis in the refining furnace is 0.045%, reaching the expected design target aluminum content.

[0023] Example 2

[0024] (1) The amount of aluminum required to balance the oxygen content of the converter steel liquid at the end point:

[0025] The carbon content of the steel tapped from the converter is 0.12%, the amount of molten steel tapped is 115 tons, and the amount of aluminum required to balance the oxygen content of the converter molten steel end point = 0.12% / 28×115×1000kg=49.28kg;

[0026] (2) The amount of aluminum required to balance the oxygen content in the converter slag:

[0027] According to the law of conservation of mass, the amount of aluminum required to balance the oxygen content in the slag of the converter is calculated = 500kg × (20% - 0.5%) × 54 / 216 = 24.4kg;

[0028] (3) The amount of aluminum required for the first analysis of aluminum alloying in the refining furnace:

[0029] The amount of aluminum required for the first analysis of aluminum alloying by the refining furnace is calculated based on the amount of molten steel = 0.045% × 115 × 1000kg = 51.75kg;

[0030] (4) The amount of aluminum supplied by oxygen absorption during the converter steel-making process and by burning during the refining furnace power supply process:

[0031] This type of refining furnace does not use aluminum diffusion deoxidizer, so the amount of aluminum replenished by oxygen absorption during the converter steel-making process and burning during the refining furnace power supply process is 40kg.

[0032] The cumulative amount of aluminum added in the four parts = 49.28kg + 24.4kg + 51.75kg + 40kg = 165.43kg. The amount of aluminum added with the steel flow when the converter is discharged is 165.43kg. The aluminum content was first analyzed in the refining furnace and was 0.045%, reaching the expected design target aluminum content.

Claims

1. A method for accurately determining the amount of aluminum added to a converter, characterized in that: The amount of aluminum added to steel can be decomposed into four parts: the amount of aluminum required to balance the oxygen content of the converter steel liquid at the end, the amount of aluminum required to balance the oxygen content in the converter slag, the amount of aluminum required for the first analysis of aluminum alloying in the refining furnace, and the amount of aluminum replenished by oxygen absorption during the converter steel tapping process and burning during the refining furnace power supply process. Accurately calculating the four parts of aluminum can accurately determine the amount of aluminum added to the converter steel, ensuring that the aluminum content of the first analysis of the refining furnace is between 0.040% and 0.045%.

2. According to claim 1, a calculation method for accurately determining the amount of aluminum added in converter steelmaking, characterized in that: The amount of aluminum required to balance the oxygen content of the converter molten steel end point is determined by sampling and analyzing the carbon result of the converter steel tapping, and the oxygen content is calculated according to the carbon result of the steel tapping according to the current C-0 product equilibrium constant 28, and then the amount of aluminum required to balance the oxygen content of the converter molten steel end point is calculated in combination with the amount of molten steel = carbon result of steel tapping / 28×the amount of molten steel; The amount of aluminum required to balance the oxygen content in the slag of the converter is calculated based on the amount of slag from the converter for steelmaking at 500 kg. The FeO content in the slag is reduced from 20% to 0.5%, 3(FeO)+2[Al]=(Al2O3)+3[Fe]. According to the law of conservation of mass, the amount of aluminum required to balance the oxygen content in the slag of the converter is calculated to be 500 kg×(20%-0.5%)×54 / 216=24.4 kg. The refining furnace first analyzes the amount of aluminum required for aluminum alloying. The target refining furnace first analyzes the aluminum content of 0.045%. The amount of aluminum required for the first analysis of aluminum alloying by the refining furnace is calculated according to the amount of molten steel = 0.045% × the amount of molten steel; The amount of aluminum replenished by oxygen absorption during the converter steel-out process and by burning during the refining furnace power supply process is divided into two types according to whether the refining furnace diffusion deoxidizer uses aluminum: the refining furnace uses aluminum diffusion deoxidizer, and the refining furnace does not use aluminum diffusion deoxidizer.

3. According to claim 2, a calculation method for accurately determining the amount of aluminum added in converter steelmaking, characterized in that: The amount of aluminum replenished by the refining furnace using aluminum diffusion deoxidizer during the converter steel-tapping process and the aluminum burned during the refining furnace power supply process is calculated as 20kg; the amount of aluminum replenished by the refining furnace not using aluminum diffusion deoxidizer during the converter steel-tapping process and the aluminum burned during the refining furnace power supply process is calculated as 40kg.