Method for removing residual element sb from steel with te

Abstract

The present application provides a method for removing residual element Sb in steel by Te. The method is as follows: smelting the steel containing residual element Sb under inert atmosphere and at a smelting temperature of 1530-1680 DEG C; then adding Te particles into the molten steel after deoxidation treatment, and stirring for a certain reaction time, so that the removal rate of residual element Sb in the molten steel reaches 10.6-36.3%. Compared with traditional dilution method, calcium reaction method, sulfide flux treatment method and reduced pressure treatment method, the method has the advantages of low requirement for iron ore grade, easier control of steel composition, avoidance of S increase in molten steel and omission of slag removal operation, etc. Meanwhile, the method overcomes the shortcomings of high requirement for equipment, high cost and difficult operation in the production of clean steel. The method is very simple to operate, omits many complicated smelting processes, makes the production process simpler and more controllable, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of iron and steel smelting technology, and in particular to a method for removing residual element Sb from steel using Te. Background Technology

[0002] With the gradual depletion of high-grade iron ore and the rapid development of electric arc furnace steelmaking technology, scrap steel, as a direct source of ferrite, is increasingly accounting for a larger proportion of raw materials used in steelmaking. However, antimony, one of the main residual elements in scrap steel, is difficult to remove through oxidation in traditional steelmaking processes, posing a challenge to the production of pure steel. Consequently, antimony accumulates in steel, leading to a continuous increase in its residual element content. At the same time, excessively high antimony content in steel negatively impacts the hot plasticity, temper brittleness, and processing performance of most steel grades. Therefore, developing processes for removing antimony (Sb) during steelmaking is of great significance for the research and production of high-quality pure steel.

[0003] Currently, the most common method used by most steel mills in China to reduce the residual element content in steel is the dilution method, which involves adding a large amount of direct reduced iron. However, this method still requires sufficient high-quality iron ore resources. With the increasing depletion of high-grade iron ore resources and the gradual increase in scrap steel consumption and recycling, the dilution method for controlling residual elements in steel is outdated. In addition, the calcium reaction method, sulfide flux treatment method, and vacuum treatment method have also been proposed for removing antimony from steel. The former reduces antimony to Ca3Sb2 and removes it, but calcium has very low solubility in molten steel. Studies have shown that calcium-containing fluxes such as Ca-CaCl2-Al2O3 and CaO-CaF2 are less effective at removing antimony. The sulfide flux treatment method is mainly based on the fact that residual elements have a higher affinity for sulfur than iron. By achieving a balanced distribution of residual elements between the flux and the molten steel, the goal of removing residual elements from the molten steel can be achieved. Although this method is effective in removing antimony, it cannot prevent the increase of sulfur content in the molten iron, leading to the generation of a large amount of sulfur-containing slag, making subsequent treatment of the sulfur-containing slag difficult. The vacuum treatment method not only requires strict vacuum levels during smelting and sophisticated equipment, but also has a long processing time and inevitably causes the volatilization of Mn in the molten steel, making it difficult to control the composition of the molten steel.

[0004] In view of this, it is necessary to design a method for removing residual element Sb from steel using Te to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention aims to provide a method for removing residual element Sb from steel using Te. By forming an intermetallic compound with Te (tellurium) under certain smelting conditions, residual element Sb in molten steel can be removed without the addition of harmful elements such as S, which is beneficial for subsequent control of steel composition.

[0006] To achieve the above objectives, the present invention provides a method for removing residual element Sb from steel using Te, comprising the following steps:

[0007] S1. Under an inert atmosphere and at a predetermined smelting temperature, molten steel containing residual element Sb is smelted.

[0008] S2. Add a predetermined amount of aluminum ingots to the molten steel that has been melted in step S1, and perform deoxidation treatment. After reacting for a predetermined time, refined molten steel is obtained.

[0009] S3. Add a predetermined amount of Te particles to the refined molten steel and stir for a predetermined time. Start stirring to obtain the target molten steel.

[0010] Further, the predetermined amount of Te particles in step S3 is: the molar ratio of the Te particles to the residual element Sb in the refined steel liquid is 3:2 to 5:2.

[0011] Furthermore, after stirring in step S3, the removal rate of residual element Sb in the target molten steel reaches 10.6% to 36.3%.

[0012] Furthermore, the stirring time in step S3 is 20 to 40 minutes.

[0013] Furthermore, the predetermined smelting temperature in step S1 is 1530–1680°C.

[0014] Further, the elemental composition and content of the steel containing residual element Sb mentioned in step S1 are as follows: C: 0.35-1.65 wt%, Si: 0.10-0.35 wt%, Mn: 0.10-0.40 wt%, P: ≤0.045 wt%, S: ≤0.050 wt%, Sb: 0.100-1.00 wt%, O: 0.01-0.03 wt%.

[0015] Furthermore, in step S2, the purity of the aluminum ingot is greater than or equal to 99 wt%; the predetermined amount of the aluminum ingot is 0.001% to 0.005% of the mass of the molten steel.

[0016] Further, the predetermined time for the deoxidation treatment in step S2 is 10 to 30 minutes; after the deoxidation treatment, the acid-soluble aluminum content in the refined steel liquid is controlled at 0.0008 to 0.004 wt%; and the total oxygen content in the refined steel liquid is controlled at 5 to 100 ppm.

[0017] Furthermore, the stirring method described in step S3 includes one or more of Ar blowing stirring, mechanical stirring, and electromagnetic stirring.

[0018] The beneficial effects of this invention are:

[0019] 1. The method for removing residual Sb from steel using Te provided by this invention involves melting steel containing residual Sb under an inert atmosphere and at a smelting temperature of 1530–1680°C; then, after deoxidation treatment of the melted steel, Te particles are added. After a reaction time of 20–40 minutes, the removal rate of residual Sb from the molten steel can reach 10.6–36.3%. Compared with traditional sulfide treatment methods, this method avoids the introduction of harmful elements such as S into the molten steel, thus making it easier to control the steel composition subsequently. At the same time, it overcomes the disadvantages of clean steel production, such as high equipment requirements, high costs, and difficult operation. This invention is so simple to operate, omitting many cumbersome smelting processes such as slag removal, making the production process simpler and more controllable, and suitable for large-scale industrial production.

[0020] 2. The method for removing residual element Sb from steel using Te provided by the present invention involves adding Te element after deoxidation of molten steel, so that it reacts with residual element Sb to form intermetallic compounds; and as the steelmaking process proceeds, the formed compounds can rise to the surface of molten steel and be directly removed without the assistance of other additives. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments.

[0022] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0023] This invention provides a method for removing residual element Sb from steel using Te, comprising the following steps:

[0024] S1. Under an inert atmosphere and at a smelting temperature of 1530–1680°C, molten steel containing residual element Sb is purified.

[0025] S2. Add a predetermined amount of aluminum ingots to the molten steel that has been melted in step S1 and perform deoxidation treatment. After reacting for 10 to 30 minutes, refined molten steel is obtained. After deoxidation treatment, the acid-soluble aluminum content in the refined molten steel is controlled at 0.0008 to 0.004 wt% and the total oxygen content in the refined molten steel is controlled at 5 to 100 ppm.

[0026] The aluminum ingot has a purity of ≥99wt%; the predetermined amount of the aluminum ingot is 0.001% to 0.005% of the mass of the molten steel.

[0027] S3. Add a predetermined amount of Te particles to the refined molten steel and stir for 20 to 40 minutes to obtain the target molten steel; the removal rate of residual element Sb in the target molten steel can reach 10.6 to 36.3%.

[0028] This design prevents harmful elements such as sulfur from entering the molten steel, making it easier to control the steel's composition. Simultaneously, it overcomes the drawbacks of clean steel production, such as high equipment requirements, high costs, and difficult operation. The process is simplified, omitting many cumbersome smelting steps, making production simpler and more controllable, suitable for large-scale industrial production. Furthermore, because element tetramine (Te) is commonly used in the microalloying of steel, it can also improve the machinability of certain steel grades, thus enhancing the quality of the steel.

[0029] Specifically, in some embodiments of the present invention, the predetermined amount of Te particles in step S3 is: the molar ratio of the Te particles to the residual element Sb in the refined steel liquid is 3:2 to 5:2.

[0030] This setup allows Te to react with residual Sb during steelmaking to form intermetallic compounds. As the steelmaking process progresses, these compounds rise to the surface of the molten steel without the need for other additives and are then directly removed. However, adding too much Te not only leads to excessively high production costs but also hardly increases the removal rate of Sb. On the other hand, too low a Te content cannot completely react with residual Sb, thus reducing the removal efficiency.

[0031] Specifically, in some embodiments of the present invention, the elemental composition and content of the molten steel containing residual element Sb in step S1 are as follows: C: 0.35-1.65 wt%, Si: 0.10-0.35 wt%, Mn: 0.10-0.40 wt%, P: ≤0.045 wt%, S: ≤0.050 wt%, Sb: 0.10-1.00 wt%, O: 0.01-0.03 wt%.

[0032] Specifically, in some embodiments of the present invention, the stirring method in step S3 includes one or more of Ar blowing stirring, mechanical stirring, and electromagnetic stirring.

[0033] This setup can accelerate the reaction rate between Sb and Te, thereby further improving the efficiency of removing residual elements.

[0034] The method for removing residual element Sb from steel using Te provided by the present invention will be specifically described below with reference to embodiments.

[0035] Example 1

[0036] In this embodiment, the steel containing residual element Sb has the following elemental composition and content: C: 0.96wt%, Si: 0.22wt%, Mn: 0.30wt%, P: 0.017wt%, S: 0.006wt%, Sb: 0.6wt%, O: 0.02wt%.

[0037] This embodiment provides a method for removing residual element Sb from steel using Te, specifically including the following steps:

[0038] S1. Under an inert atmosphere and at a smelting temperature of 1530℃, molten steel containing residual element Sb is purified.

[0039] S2. Add aluminum ingots to the molten steel that has been melted in step S1 for deoxidation treatment. After reacting for 30 minutes, refined molten steel is obtained. After deoxidation treatment, the acid-soluble aluminum content in the refined molten steel is controlled at 0.0016 wt% and the total oxygen content in the refined molten steel is controlled at 25 ppm.

[0040] The aluminum ingot has a purity of ≥99wt% and the aluminum content is 0.002% of the mass of the molten steel.

[0041] S3. Add Te particles to the refined molten steel and stir for 20 minutes to obtain the target molten steel; wherein the molar ratio of Te particles to the residual element Sb in the refined molten steel is 3:2.

[0042] According to the test, the removal rate of residual element Sb in the target molten steel in this embodiment can reach 10.6%.

[0043] Example 2

[0044] This embodiment uses the same steel grade containing the residual element Sb as in Embodiment 1.

[0045] This embodiment provides a method for removing residual element Sb from steel using Te, specifically including the following steps:

[0046] S1. Under an inert atmosphere and at a smelting temperature of 1600℃, molten steel containing residual element Sb is purified.

[0047] S2. Add aluminum ingots to the molten steel that has been melted in step S1 for deoxidation treatment. After reacting for 30 minutes, refined molten steel is obtained. After deoxidation treatment, the acid-soluble aluminum content in the refined molten steel is controlled at 0.0024 wt% and the total oxygen content in the refined molten steel is controlled at 20 ppm.

[0048] The aluminum ingot has a purity of ≥99wt% and the aluminum content is 0.003% of the mass of the molten steel.

[0049] S3. Add Te particles to the refined molten steel and stir for 20 minutes to obtain the target molten steel; wherein the molar ratio of Te particles to the residual element Sb in the refined molten steel is 5:2.

[0050] According to the test, the removal rate of residual element Sb in the target molten steel in this embodiment can reach 30.5%.

[0051] Example 3

[0052] This embodiment provides a method for removing residual element Sb from steel using Te. Compared with Embodiment 1, the difference lies in the content of Te particles added in step S3. In this embodiment, the molar ratio of Te particles to residual element Sb in the refined steel liquid is 2:1. The remaining steps and parameters are the same as in Embodiment 1 and will not be repeated here.

[0053] According to the test, the removal rate of residual element Sb in the target molten steel in this embodiment can reach 11.8%.

[0054] Example 4

[0055] This comparative example provides a method for removing residual element Sb from steel using Te. The difference from Example 1 lies in the content of Te particles added in step S3. In this comparative example, the molar ratio of Te particles to residual element Sb in the refined steel liquid is 5:2. The remaining steps and parameters are consistent with Example 1 and will not be repeated here.

[0056] Tests showed that, after stirring, the removal rate of residual element Sb in the molten steel in this comparative example was 15.3%.

[0057] Example 5

[0058] This comparative example provides a method for removing residual Sb from steel using Te. The difference between this method and Example 2 lies in the smelting temperature in step S1; in this comparative example, the smelting temperature is 1680℃. The remaining steps and parameters are the same as in Example 2 and will not be repeated here.

[0059] Tests showed that, after stirring, the removal rate of residual element Sb in the molten steel in this comparative example was 36.3%.

[0060] Comparative Example 1

[0061] This comparative example provides a method for removing residual element Sb from steel using Te. The difference between this method and Example 1 lies in the content of Te particles added in step S3. In this comparative example, the molar ratio of Te particles to residual element Sb in the refined steel liquid is 3:1. The remaining steps and parameters are consistent with Example 1 and will not be repeated here.

[0062] Tests showed that, after stirring, the removal rate of residual Sb in the molten steel in this comparative example was only 15.9%.

[0063] Comparative studies of Examples 1, 3-4, and Comparative Example 1 revealed that as the Te particle content increased, the Te removal rate in the molten steel first increased, then slightly decreased, and remained within a relatively stable range. This indicates that an appropriate amount of Te can remove residual Sb from the molten steel, but excessive Te addition not only leads to excessively high production costs but also hardly increases the Sb removal rate. Comparative studies of Examples 2 and 5 show that, under the influence of Te, increasing the temperature also benefits the Sb removal rate in the molten steel.

[0064] In summary, the method for removing residual Sb from steel using Te provided by this invention involves melting and cleaning the molten steel containing residual Sb under an inert atmosphere and at a smelting temperature of 1530–1680°C; then, after deoxidation treatment of the cleaned molten steel, adding Te particles and stirring for 20–40 minutes, achieving a removal rate of 10.6–36.3% for residual Sb. Compared with traditional sulfide flux treatment methods, this method avoids the introduction of harmful elements such as S into the molten steel, making it easier to control the steel composition; simultaneously, it overcomes the disadvantages of clean steel production, such as high equipment requirements, high costs, and difficult operation. This invention is so simple to operate, omitting many cumbersome smelting processes, making the production process simpler and more controllable, and suitable for large-scale industrial production. By adding Te after deoxidation of the molten steel, it reacts with residual Sb to form intermetallic compounds; and as the steelmaking process proceeds, the formed compounds rise to the surface of the molten steel and are directly removed without the assistance of other additives.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for removing residual element Sb from steel using Te, characterized in that, Includes the following steps: S1. Under an inert atmosphere and at a predetermined smelting temperature, molten steel containing residual element Sb is smelted. S2. A predetermined amount of aluminum ingots is added to the molten steel that has been melted in step S1 for deoxidation treatment. After reacting for a predetermined time, refined molten steel is obtained. After the deoxidation treatment, the acid-soluble aluminum content in the refined molten steel is controlled at 0.0008wt%~0.004wt%; the total oxygen content in the refined molten steel is controlled at 5~100ppm. S3. Add a predetermined amount of Te particles to the refined molten steel and stir for a predetermined time to obtain the target molten steel.

2. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The predetermined amount of Te particles in step S3 is: the molar ratio of the Te particles to the residual element Sb in the refined steel liquid is 3:2 to 5:

2.

3. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: After stirring in step S3, the removal rate of residual element Sb in the target molten steel reaches 10.6%~36.3%.

4. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The stirring time in step S3 is 20-40 minutes.

5. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The predetermined smelting temperature mentioned in step S1 is 1530~1680℃.

6. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The elemental composition and content of the steel containing residual element Sb mentioned in step S1 are as follows: C: 0.35wt%~1.65wt%, Si: 0.10wt%~0.35wt%, Mn: 0.10wt%~0.40wt%, P: ≤0.045wt%, S: ≤0.050wt%, Sb: 0.10wt%~1.00wt%, O: 0.01wt%~0.03wt%.

7. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The purity of the aluminum ingot in step S2 is greater than or equal to 99 wt%; the predetermined amount of the aluminum ingot is 0.001% to 0.005% of the mass of the molten steel.

8. The method for removing residual element Sb from steel using Te according to claim 7, characterized in that: The predetermined time for the deoxygenation treatment in step S2 is 10~30 min.

9. The method for removing residual element Sb from steel using Te according to claim 1, characterized in that: The stirring method described in step S3 includes one or more of Ar blowing stirring, mechanical stirring, and electromagnetic stirring.