A Dephosphorization Method for High-Phosphorus Hot Metal with High Carbon-Pulling in a Top-Blown Converter

Abstract

The present invention belongs to the technical field of steel metallurgy and steelmaking production process, and discloses a dephosphorization method for a high-carbon drawing process of high-phosphorus hot metal in a top-blown converter, so as to solve the problems of difficulty in dephosphorization, difficulty in coordination of "carbon and phosphorus", and difficulty in achieving stable control of slag composition during the production of high-carbon steel by the high-phosphorus hot metal and high-carbon drawing process in the top-blown converter. The present invention effectively improves the phosphorus removal efficiency in the process of smelting high-carbon steel using high-phosphorus hot metal in a top-blown converter by adjusting the slag retention amount, oxygen supply intensity, auxiliary material structure and gun position control. The dephosphorization efficiency can stably reach more than 90% during the smelting process, and the temperature and end point C of the molten steel can be controlled within the standard range. The alloy yield in the process of smelting high-carbon steel by the top-blown converter with high-carbon drawing is improved and the number of inclusions in the steel is reduced, saving production process costs; and the slag composition in the smelting process can be stably controlled, and the end point of the molten steel in the smelting process of the top-blown converter with high-carbon drawing can be stably controlled.

Description

Technical Field

[0001] The invention belongs to the technical field of steel metallurgy and steelmaking production processes, and in particular relates to a dephosphorization method for a top-blown converter high-phosphorus molten iron high-carbon drawing process. Background Art

[0002] There are two methods for producing high-carbon steel in a converter: recarburization and high-draw carbon supplemental blowing. The recarburization method easily controls endpoint phosphorus content, but due to the low carbon content and high oxidizing properties of the molten steel, a large amount of recarburizer must be added after tapping. This results in uneven carbon yields, fluctuating composition, and complicates subsequent production processes.

[0003] High-carbon steel produced using the high-draw carbon supplementary blowing method boasts low oxygen content, reduced inclusions, high alloy yield, and significant savings in recarburizer. However, due to the high carbon content at the end of blowing, and the rapid carbon removal rate at that point, the iron oxide content in the slag decreases rapidly, resulting in poor slag fluidity. This reduces dephosphorization efficiency in the later stages of smelting and makes it difficult to achieve target phosphorus levels at the end. To further enhance slag dephosphorization, more lime is required for the same molten iron conditions. However, excessive lime increases the melting point of the slag, making slag removal difficult and achieving effective dephosphorization results difficult.

[0004] In addition, the end point of the high-drawing blowing process is in a stage of rapid carbon reduction, which is not conducive to achieving the simultaneous achievement of the end-point phosphorus and carbon standards, that is, "carbon and phosphorus" are not easy to coordinate. This incoordination phenomenon is more prominent when a top-blown converter uses high-phosphorus molten iron and high-drawing carbon method to produce high-carbon steel.

[0005] The patent is titled "A method for dephosphorizing a converter of high-phosphorus, low-silicon molten iron" (publication number: CN104878153A) and discloses the following technologies: (1) establishing a final slag retention system and a refined white slag addition system, with the final slag retention amount controlled at 20-60 kg / t steel; refined white slag and scrap steel are added simultaneously, with the addition amount controlled at 10-30 kg / t steel; (2) determining the amount of the first batch of slag-making materials to be added: dolomite is added in an amount of 10-15 kg / t steel, lime is added in an amount of 14-18 kg / t steel, and the initial alkalinity is controlled between 1.8 and 2.5; at the same time, according to the molten iron temperature, 0-30 kg / t steel of sintered return ore or ore is added to control the initial temperature between 1330°C and 1400°C; (3) oxygen supply control: oxygen blowing is carried out at the same time as the first batch of slag-making materials is added, and 3.3- The smelting is carried out at an oxygen supply intensity of 3.6Nm3 / t.min and a low gun position to enhance stirring. After the first batch of slag-making materials is added, the gun position is raised to promote slag formation and ensure good slag formation in the early stage. (4) Control of the amount of the second batch of slag-making materials added: After slagging, 4-8kg / t steel of white ash is added, and the gun position is lowered to the normal gun position. According to the temperature of the molten steel, 0-15kg / t steel of ore or sintered return ore is added to control the final slag temperature. The final steel temperature is controlled at 1580℃~1660℃, the final slag basicity is controlled at 3.0~4.0, and the TFe in the slag is controlled at 16~18%; (5) Oxygen blowing control in the middle and late stages: If dry-out occurs or is about to occur during the smelting process, the oxygen supply intensity is reduced to 3.0~3.3Nm3 / t.min; in the late stage of blowing, the carbon-oxygen reaction weakens, and the gun position is lowered to the stirring gun position to ensure stirring intensity and decarburization speed.

[0006] The invention adopts a smelting process that combines retaining part of the final slag with the early addition of refined white slag, with the final slag retention amount being 20-60 kg / t steel and the refined white slag addition amount being 10-30 kg / t steel. At the same time, by controlling the amount and time of slag-making material addition, and adjusting the oxygen supply intensity and gun position during the smelting process, the dephosphorization rate of high-phosphorus molten iron in smelting is achieved to be above 90%, and the final phosphorus content of the converter can be stably controlled within 0.015%. The invention makes full use of the pre-melting characteristics of refined white slag and the fact that it contains more Al2O3 and a certain amount of CaF2 to reduce the melting point of the slag, increase the fluidity of the slag, and improve the kinetic conditions for dephosphorization. It also makes full use of the higher alkalinity of refined white slag to form high-alkalinity slag earlier, thereby improving the thermodynamic conditions for dephosphorization. The invention can effectively reduce the cost of converter steelmaking because it can recycle refined white slag.

[0007] While this invention can, to a certain extent, form high-basicity slag earlier, improving the thermodynamic conditions for dephosphorization and effectively reducing converter steelmaking costs, the weight percentages of the refined white slag components added in this invention are: CaO: 40-60%; SiO2: 10-25%; Al2O3: 10-30%; CaF2: 3-10%; MgO: 5-15%; MnO: 0.05-0.4%; and TFe: 0.1-1.0%. In the CaO-SiO2-Al2O3 ternary slag system, only by controlling the Al2O3 content within the range of 10-20% and simultaneously keeping the slag basicity within a low range can the slag melting point be effectively lowered. According to this invention, the composition of refined white slag is relatively complex, and the composition of refined white slag fluctuates greatly between different refining heats. After adding it to the converter, the Al2O3 content in the slag during the smelting process cannot be accurately controlled within the 10-20% low melting point range, thus failing to lower the slag melting point in the early stages of smelting. Furthermore, the smelting process introduces a large amount of SiO2, which increases the slagging time and lime usage during the smelting process. If the refined white slag added is cold slag, the addition of a large amount of cold material will undoubtedly prolong the initial slagging time, affect the slagging speed, and reduce the initial dephosphorization efficiency, thereby affecting the dephosphorization effect of the entire smelting process.

[0008] It can be seen that the addition of refined white slag during the smelting process will make the slag composition and slag formation process in the entire smelting process very complicated, and it is difficult to achieve stable control of the slag composition in the industrial process, thereby affecting the stability of the entire smelting process and the dephosphorization effect of the smelting process. Summary of the Invention

[0009] To address the difficulties in dephosphorization and carbon-phosphorus coordination during the production of high-carbon steel using a top-blown converter high-phosphorus hot metal high-carbon drawing process, as well as the difficulty in achieving stable control of slag composition during industrialized smelting of refined white slag, the present invention achieves efficient phosphorus removal in the high-carbon steel production process using a top-blown converter high-phosphorus hot metal high-carbon drawing process by adjusting slag retention, oxygen supply intensity, auxiliary material structure, and gun position control. This also achieves coordinated control of molten steel temperature and endpoint carbon content. This achieves stable control of slag composition during the smelting process and achieves good dephosphorization results. The specific implementation process is as follows:

[0010] A dephosphorization method for a top-blown converter high-phosphorus hot metal high-carbon drawing process, comprising high-phosphorus hot metal, specifically comprising the following steps:

[0011] Step 1: After tapping the converter, slag is left, and the amount of slag left in the converter is 15-20 kg / t steel;

[0012] Step 2: Add scrap steel and iron, with the amount of scrap steel added being 5-10t and the amount of molten iron added being 50-54t; Lower the lance to blow oxygen, add the first batch of slag, add lime at 20-30kg / t steel, control the slag basicity to 3-5, add iron oxide balls at 6-8kg / t steel, control the Fe2O3 content in the slag to 10-20%, control the lance position in the early stage within the range of 1.5-1.6m to increase the oxidizability of the slag and accelerate the melting of the slag; after blowing at a high lance position for 1-2min, lower the lance position to 0.7-0.8m to fully stir the molten pool and increase the dephosphorization effect in the early stage; operate at a low lance position for 1-2min to control the slag pouring temperature below 1400℃;

[0013] Step 3: After blowing for 2 to 4 minutes in step 2, the slag is dumped, and the amount of the slag dumped is 65% to 85% of the total slag amount;

[0014] Step 4: Blow oxygen with the lance for the second time, add 10-20kg / t steel of lime to the converter, add Al2O3 in several batches, and the addition amount of Al2O3 in each batch is 5-8kg / t steel; in the early stage of blowing, the lance position is controlled at 0.7-0.8m and the blowing is 1-2min; in the middle stage of blowing, the lance position is controlled at 1.5m-1.6m, and limestone is added in multiple batches, with a total amount of limestone added of 20-30kg / t steel, the slag basicity is controlled at 3-5, and the furnace temperature is controlled not to exceed 1500℃; in the middle and late stages of blowing, iron oxide balls are added in multiple batches, with an addition amount of 1-2kg / t steel in each batch, the lance position is controlled at 1.0-1.2m, and the carbon pulling time is controlled at 2-3min;

[0015] Step 5: adding lime during the converter tapping process, with the amount of lime added being 5-8 kg / t steel.

[0016] The phosphorus content of the high-phosphorus molten iron is 0.100-0.120%, and the silicon content is 0.40-0.80%. During the smelting process, the oxygen flow rate of the oxygen lance is constant at 21,000-22,000 m3 / h.

[0017] In the step 2, 20-30 kg / t steel of lime is added to the converter to control the slag basicity to 3-5; 6-8 kg / t steel of iron oxide balls are added to the converter to control the Fe2O3 content in the slag to 10-20%.

[0018] In the step 4, 10 to 20 kg / t steel of lime is added to the converter in the early stage of smelting to control the slag basicity at 1 to 2; Al2O3 raw materials are added in two to three batches, and the amount of Al2O3 raw materials added in each batch is 5 to 8 kg / t steel. The Al2O3 content in the slag is 10 to 20%, so that the early slag enters the low melting point area and the melting speed of the slag is accelerated. Limestone is added in batches in the middle stage of blowing, and the decomposition of limestone is used to control the furnace temperature to no more than 1500°C, and the slag basicity is 3 to 5. In the later stage of blowing, iron oxide balls are added to control the Fe2O3 content in the slag to 10 to 20% to prevent the slag from drying out and returning to phosphorus.

[0019] The Al2O3 raw material refers to a 30×50×50mm spherical briquette with an Al2O3 content greater than 95%; the iron oxide ball has a total iron content greater than 65% and a particle size of 10 to 20mm; the CaCO3 content in the limestone is greater than 98% and the block size is 5 to 50mm.

[0020] Beneficial effects of the present invention: By adjusting the slag retention amount, oxygen supply intensity, auxiliary material structure and gun position control, the present invention effectively improves the phosphorus removal efficiency in the process of smelting high-carbon steel using high-phosphorus molten iron in a top-blown converter with high carbon drawing. The dephosphorization efficiency during the smelting process can stably reach more than 90%, and the temperature and end point C of the molten steel can be controlled within the standard range. The alloy yield in the process of smelting high-carbon steel with high carbon drawing in a top-blown converter is improved and the number of inclusions in the steel is reduced, saving production process costs; and the slag composition during the smelting process can be stably controlled, and the end point of the molten steel can be controlled within the range of carbon content > 0.55% and P content < 0.012%, thus achieving stable control of the end point of the molten steel in the smelting process of the top-blown converter with high carbon drawing. DETAILED DESCRIPTION

[0021] Example 1

[0022] Taking a 60t top-blown converter as an example, the implementation process of the present invention is described in combination with the specific smelting process of 82B:

[0023] Step 1: After tapping the converter, slag is left, and the amount of slag left in the converter is 15 kg / t steel;

[0024] Step 2: Add scrap steel and iron. The amount of scrap steel added is 5t, the amount of molten iron charged is controlled at 50t, the lance is lowered and blowing is started, and the first batch of lime and iron oxide balls are added. The amount of lime added is 20kg / t steel, and the target slag basicity is controlled to 3; the amount of iron oxide balls added is 6kg / t steel, and the Fe2O3 content in the slag is controlled to 10%. The early lance position is controlled at 1.5m to increase the oxidizability of the slag and accelerate the melting of the slag. After blowing at 1.5m for 1 minute, the lance position is lowered to 0.7m and blown for 1 minute to fully stir the molten pool and increase the dephosphorization effect in the early stage. The target slag pouring temperature in the early stage is controlled to 1400℃.

[0025] Step 3: After blowing in step 2, pour out the slag, pour out 65% of the total slag;

[0026] Step 4: Lower the gun for the second time and start blowing, and add lime and Al2O3 raw materials. The lime is added at 10kg / t steel, and the target slag basicity is controlled at 1. At the same time, Al2O3 raw materials are used to lower the slag melting point to achieve rapid slag formation. The Al2O3 raw materials used are added in two batches, and the amount of Al2O3 raw materials added is 5kg / t steel. The target Al2O3 content in the slag is 10%. To ensure that the slag is completely melted, the gun position is controlled at 0.7m in the early stage and blown for 1min to fully stir the molten pool, fully mix the steel slag, and accelerate the slag formation speed. The gun position is controlled at 1.5m in the middle stage of blowing to rapidly increase the oxidizability of the slag. , increase the dephosphorization capacity of the slag, and add limestone in small batches according to the principle of multiple batches, and use the decomposition of limestone to control the furnace temperature. The total amount of limestone added is 20kg / t, the slag basicity target is controlled at 3, and the furnace temperature is controlled at 1500℃; in the middle and late stages of blowing, iron oxide balls are added in small batches to increase the oxidizing property of the slag. The amount of iron oxide balls added is 1kg / t steel per batch, and the Fe2O3 content in the slag is controlled at 15%. The gun position is controlled at 1.0m, and the carbon pulling time is controlled at 2min to prevent the slag from drying out and returning to phosphorus; the terminal temperature is controlled at 1552℃, the terminal carbon content is controlled at 0.65%, and the slag basicity target is controlled at 3;

[0027] Step 5: Add lime during the steel tapping process to increase the basicity of the final slag and prevent rephosphorization. The amount of lime added is 5kg / t steel.

[0028] In this embodiment, the phosphorus content of the high-phosphorus hot metal is 0.100-0.114%, and the silicon content is 0.40-0.60%. During the smelting process, the oxygen flow rate of the oxygen lance is constant at 21,000 m³ / h. The Al₂O₃ raw material is 30×50×50 mm spherical briquettes with an Al₂O₃ content greater than 95%; the iron oxide pellets have a total iron content greater than 65% and a particle size of 10 mm; and the limestone has a CaCO₃ content greater than 98% and a lumpy size of 5 mm. The above process can achieve efficient dephosphorization of high-carbon steel using the high-phosphorus hot metal high-carbon drawing process. The dephosphorization efficiency of different heat smelting processes is shown in the table below.

[0029]

[0030] Example 2

[0031] Taking a 60t top-blown converter as an example, the implementation process of the present invention is described in combination with the 75# specific smelting process:

[0032] Step 1: After tapping the converter, slag is left, and the amount of slag left in the converter is 20 kg / t steel;

[0033] Step 2: Add scrap steel and iron. The amount of scrap steel added is 10t. The amount of molten iron charged is controlled at 54t. The lance is lowered and blowing is started. The first batch of lime and iron oxide balls are added. The amount of lime added is 30kg / t steel. The target slag basicity is controlled at 5. The amount of iron oxide balls added is 8kg / t steel. The target Fe2O3 content in the slag is controlled at 20%. The lance position is controlled at 1.6m in the early stage to increase the oxidizability of the slag and accelerate the melting of the slag. After blowing at 1.6m for 2 minutes, the lance position is lowered to 0.8m and blown for 2 minutes to fully stir the molten pool and increase the dephosphorization effect in the early stage. The target slag pouring temperature is controlled at 1380℃.

[0034] Step 3: After blowing for 4 minutes in step 2, pour out the slag, and pour out 85% of the total slag;

[0035] Step 4: Lower the gun for the second time and start blowing, and add lime and Al2O3 raw materials. The lime is added at 20kg / t steel, and the target slag basicity is controlled at 2. At the same time, Al2O3 raw materials are used to lower the slag melting point to achieve rapid slagging of the slag. The Al2O3 raw materials used are added in three batches, and the amount of Al2O3 raw materials added is 8kg / t steel. The target Al2O3 content in the slag is 20%. To ensure that the slag is completely melted, the gun position is controlled at 0.8m in the early stage and blown for 2min to fully stir the molten pool, fully mix the steel slag, and accelerate the slagging speed. The gun position is controlled at 1.6m in the middle stage of blowing to rapidly increase the oxidizability of the slag. , increase the dephosphorization capacity of the slag, and add limestone in small batches according to the principle of multiple batches, and use the decomposition of limestone to control the furnace temperature. The total amount of limestone added is 30kg / t, the slag basicity target is controlled at 5, and the furnace temperature is controlled at 1480℃; in the middle and late stages of blowing, iron oxide balls are added in small batches to increase the oxidizing property of the slag. The amount of iron oxide balls added is 2kg / t steel per batch, and the Fe2O3 content in the slag is controlled at 18%. The gun position is controlled at 1.2m, and the carbon pulling time is controlled at 3min to prevent the slag from drying out and returning to phosphorus; the terminal temperature is controlled at 1564℃, the terminal carbon content is controlled at 0.61%, and the slag basicity target is controlled at 5;

[0036] Step 5: Add lime during the steel tapping process to increase the basicity of the final slag and prevent rephosphorization. The amount of lime added is 8kg / t steel.

[0037] In this embodiment, the phosphorus content of the high-phosphorus hot metal is 0.103-0.120%, and the silicon content is 0.52-0.80%. During the smelting process, the oxygen flow rate of the oxygen lance is constant at 22,000 m³ / h. The Al₂O₃ raw material is 30×50×50 mm spherical briquettes with an Al₂O₃ content greater than 95%; the iron oxide pellets have a total iron content greater than 65% and a particle size of 20 mm; the limestone has a CaCO₃ content greater than 98% and a lumpy size of 50 mm. The above process achieves efficient dephosphorization of high-carbon steel using the high-phosphorus hot metal high-carbon drawing process. The dephosphorization efficiency of different heat smelting processes is shown in the table below.

[0038]

[0039] Example 3

[0040] Taking a 60t top-blown converter as an example, the implementation process of the present invention is described in combination with the specific smelting process of 82B:

[0041] Step 1: After tapping the converter, slag is left, and the amount of slag left in the converter is 17 kg / t steel;

[0042] Step 2: Add scrap steel and iron. The amount of scrap steel added is 6 tons. The amount of molten iron charged is controlled at 52 tons. The lance is lowered and blown. The first batch of lime and iron oxide balls are added. The amount of lime added is 25kg / t steel. The target slag basicity is controlled at 4. The amount of iron oxide balls added is 7kg / t steel. The target Fe2O3 content in the slag is controlled at 16%. The lance position is controlled at 1.55m in the early stage to increase the oxidizability of the slag and accelerate the melting of the slag. After blowing at 1.55m for 1.5 minutes, the lance position is lowered to 0.75m and blown for 1.5 minutes to fully stir the molten pool and increase the dephosphorization effect in the early stage. The target slag pouring temperature in the early stage is controlled at 1350℃.

[0043] Step 3: After blowing for 3 minutes in step 2, pour out the slag, and pour out 75% of the total slag;

[0044] Step 4: Lower the gun for the second time and start blowing, and add lime and Al2O3 raw materials. The lime is added at 15kg / t steel, and the target slag basicity is controlled at 1.5. At the same time, Al2O3 raw materials are used to lower the slag melting point to achieve rapid slag formation. The Al2O3 raw materials used are added in two batches, and the amount of Al2O3 raw materials added is 7kg / t steel. The target Al2O3 content in the slag is 15%. To ensure that the slag is completely melted, the gun position is controlled at 0.75m in the early stage and blown for 1.5min to fully stir the molten pool, fully mix the steel slag, and accelerate the slag formation speed. The gun position is controlled at 1.55m in the middle stage of blowing to rapidly increase the oxidizability of the slag. To increase the dephosphorization capacity of the slag, limestone was added in small batches, and the furnace temperature was controlled by decomposition of the limestone. The total amount of limestone added was 25 kg / t, the slag basicity was controlled to 4, and the furnace temperature was controlled to 1450°C. In the middle and late stages of blowing, iron oxide balls were added in small batches to increase the oxidizing property of the slag. The amount of iron oxide balls added was 1.5 kg / t of steel per batch. The Fe2O3 content in the slag was controlled to 18%. The gun position was controlled at 1.5 m, and the carbon pulling time was controlled at 2.5 minutes to prevent the slag from drying out and rephosphorizing. The endpoint temperature was controlled within the range of 1557°C, the endpoint carbon content was controlled at 0.71%, and the slag basicity was controlled to 5.

[0045] Step 5: Add lime during the steel tapping process to increase the basicity of the final slag and prevent rephosphorization. The amount of lime added is 7kg / t steel.

[0046] In this embodiment, the phosphorus content of the high-phosphorus hot metal is 0.101-0.117%, and the silicon content is 0.51-0.74%. During the smelting process, the oxygen flow rate of the oxygen lance is maintained at a constant 21,500 m³ / h. The Al₂O₃ raw material is 30×50×50 mm spherical briquettes with an Al₂O₃ content greater than 95%. The iron oxide pellets have a total iron content greater than 65% and a particle size of 15 mm. The limestone has a CaCO₃ content greater than 98% and a briquette size of 45 mm. The above process enables efficient dephosphorization of high-carbon steel produced using the high-phosphorus hot metal high-carbon drawing process. The dephosphorization efficiency of different heats is shown in the table below.

[0047]

Claims

1. A dephosphorization method for a top-blown converter high-phosphorus hot metal high-carbon drawing process, characterized in that: Including high phosphorus molten iron, specifically including the following steps: Step 1: After tapping the converter, slag is left, and the amount of slag left in the converter is 15-20 kg / t steel; Step 2: Add scrap steel and iron, with the amount of scrap steel added being 5-10 tons and the amount of molten iron added being 50-54 tons; Lower the lance to blow oxygen, add 20-30 kg / t of steel of lime and 6-8 kg / t of steel of iron oxide balls into the converter, control the lance position within the range of 1.5-1.6 m, blow for 1-2 minutes, then lower the lance position to 0.7-0.8 m and blow for 1-2 minutes, controlling the slag temperature in the early stage to be below 1400°C; Step 3: dumping the slag after blowing in step 2, with the amount of slag dumped being 65% to 85% of the total slag amount; Step 4: Blow oxygen with the lance for the second time, add 10-20kg / t steel of lime into the converter, add Al2O3 raw materials in several batches, and the addition amount of Al2O3 in each batch is 5-8kg / t steel; in the early stage of blowing, the lance position is controlled at 0.7-0.8m and blowing is carried out for 1-2min; in the middle stage of blowing, the lance position is controlled at 1.5m-1.6m, and limestone is added in multiple batches, and the total amount of limestone added is 20-30kg / t steel; in the middle and late stages of blowing, iron oxide balls are added in multiple batches, and the addition amount of iron oxide balls in each batch is 1-2kg / t steel, the lance position is controlled at 1.0-1.2m, and the carbon pulling time is controlled at 2-3min; Step 5: adding lime during the converter tapping process, with the amount of lime added being 5-8 kg / t steel; The phosphorus content of the high-phosphorus molten iron is 0.100-0.120%; the silicon content is 0.40-0.80%.

2. The dephosphorization method of a top-blown converter high-phosphorus hot metal high-carbon drawing process according to claim 1, characterized in that: During the smelting process, the oxygen flow rate of the oxygen lance is constant at 21,000 to 22,000 m3 / h.

3. The dephosphorization method of a top-blown converter high-phosphorus hot metal high-carbon drawing process according to claim 1, characterized in that: In the step 2, 20-30 kg / t steel of lime is added to the converter to control the slag basicity to 3-5; 6-8 kg / t steel of iron oxide balls are added to the converter to control the Fe2O3 content in the slag to 10-20%.

4. The dephosphorization method of a top-blown converter high-phosphorus hot metal high-carbon drawing process according to claim 1, characterized in that: In the step 4, 10 to 20 kg / t steel of lime is added to the converter in the early stage of smelting to control the slag basicity to 1 to 2; Al2O3 raw material is added in two to three batches, with the addition amount of each batch of Al2O3 raw material being 5 to 8 kg / t steel, and the Al2O3 content in the slag being 10 to 20%; limestone is added in multiple batches in the middle stage of blowing to control the furnace temperature to be no higher than 1500°C and the slag basicity to be 3 to 5; and iron oxide balls are added in the late stage of blowing to control the Fe2O3 content in the slag to be 10 to 20%.

5. The dephosphorization method of a top-blown converter high-phosphorus hot metal high-carbon drawing process according to claim 1, characterized in that: The Al2O3 raw material refers to a 30×50×50mm spherical briquette with an Al2O3 content greater than 95%; the iron oxide ball has a total iron content greater than 65% and a particle size of 10 to 20mm; the CaCO3 content in the limestone is greater than 98% and the block size is 5 to 50mm.

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