A control method for 210t converter vanadium-titanium molten iron smelting

Abstract

This invention belongs to the field of steel production technology and relates to a control method for smelting vanadium-titanium iron in a 210t converter. Immediately after the converter is successfully ignited (30 seconds), all the required magnesium balls and lime for the current furnace are added. When the oxygen supply reaches 7% of the total oxygen supply, the oxygen supply intensity is adjusted to 2.4–2.6 m³ / h. 3 The oxygen supply lance position is adjusted to 100-200mm from the lowest smelting lance position. When the oxygen supply reaches 10% of the total oxygen supply, the oxygen supply lance position is immediately lowered to 50mm from the lowest smelting lance position, and the oxygen supply intensity is adjusted to 2.7-2.9m. 3 After the oxygen lance is lowered to the designated position, cold feed is added in batches, using a small-volume, multiple-times method. When the oxygen supply is 10%–60% of the total oxygen supply, the oxygen supply intensity is maintained at 2.7–2.9 m / min·t. 3 / min·t, the distance between the smelting lance and the lowest smelting lance position remains constant at 50mm; when the oxygen supply exceeds 60% of the total oxygen supply, the oxygen supply intensity is maintained at 3.3–5m. 3 / min·t, the smelting lance position is kept at the lowest smelting lance position until the blowing reaches the end point; it can effectively control the splashing during the smelting process and stabilize the composition of molten steel, reducing the splashing rate to ≤3%.

Description

Technical Field

[0001] This invention belongs to the field of steel production technology and relates to a control method for smelting vanadium-titanium molten iron in a 210t converter. Background Technology

[0002] Vanadium and titanium in molten iron form oxides with different properties during converter smelting, easily causing splashing during the process. This not only increases the consumption of steelmaking materials but also increases the consumption of auxiliary materials, heat loss, and equipment damage, hindering stable and smooth production. When the quality of molten iron fluctuates, especially when the vanadium and titanium content is high, the substances formed after vanadium oxidation raise the melting point of the slag, which is detrimental to the initial slag formation and easily leads to splashing. Titanium oxides combine with CaO in lime, reducing lime utilization and making the initial slag viscous, which is not conducive to dephosphorization. Therefore, suitable smelting operation processes are especially needed for vanadium and titanium-containing molten iron, and ensuring the quality of molten steel composition and controlling splashing are crucial. Summary of the Invention

[0003] In view of this, the purpose of this invention is to solve the problem of smelting splashing and to provide a control method for smelting vanadium-titanium molten iron in a 210t converter.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A control method for 210t converter vanadium-titanium iron smelting involves adding all the magnesium balls and lime required for the furnace 30 seconds after the converter is successfully ignited to accelerate the early slag formation.

[0006] When the oxygen supply reaches 7% of the total oxygen supply, the oxygen supply intensity should be adjusted to 2.4–2.6 m. 3 / min·t, adjust the oxygen supply gun position to 100-200mm away from the lowest smelting gun position;

[0007] When the oxygen supply reaches 10% of the total oxygen supply, immediately lower the oxygen supply lance position to 50mm from the lowest smelting lance position, and adjust the oxygen supply intensity to 2.7–2.9m. 3 / min·t, after the oxygen lance is lowered to the position, cold material is added in batches, using a small amount and multiple addition method;

[0008] When the oxygen supply is 10% to 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 2.7 to 2.9 m. 3 / min·t, the distance between the smelting lance position and the lowest smelting lance position remains unchanged at 50mm;

[0009] When the oxygen supply exceeds 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 3.3–5 m. 3 / min·t, the smelting lance position is kept at the lowest smelting lance position until the blowing reaches the end point.

[0010] Furthermore, the combination of titanium oxides with CaO in lime reduces lime utilization and makes the initial slag viscous, which is not conducive to dephosphorization. Therefore, the alkalinity during slag making should be controlled at 2.8 to 3.8 to avoid reclassification due to high phosphorus content.

[0011] Furthermore, the thermal effect of titanium is basically the same as that of silicon. When calculating the cold material, the titanium content should be taken into account. For every 0.100% increase in titanium content, the amount of ore (dust removal ash briquettes) used should be increased by 5 kg / t.

[0012] Furthermore, when production schedules permit, a double-slag operation is performed to remove titanium from the molten iron. The slag pouring temperature is controlled at 1350–1400℃, which does not affect subsequent normal smelting.

[0013] Furthermore, regardless of whether the slag has melted well in the early stages of smelting, the oxygen lance should be advanced as soon as possible, and a low lance position and low flow rate should be used to promote stirring of the molten pool, make the composition and temperature uniform, and prevent splashing caused by prolonged high lance position operation.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention employs a low-lance position and low-flow operation mode during converter smelting, and adds cold materials in small, multiple batches. This effectively controls splashing during the smelting process and stabilizes the composition of the molten steel, reducing the splashing rate to ≤3% and significantly reducing steel material consumption. The substances generated after vanadium oxidation increase the slag melting point, which is detrimental to early slag formation and easily leads to splashing. Adding sufficient magnesium-containing resources in the early stages is beneficial for slag melting.

[0016] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Detailed Implementation

[0017] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0018] A control method for smelting vanadium-titanium iron in a 210t converter involves adding all the magnesium balls and lime required for the furnace 30 seconds after the converter is successfully ignited to accelerate the initial slag formation; adding sufficient magnesium resources in the early stage is beneficial for slag melting.

[0019] When the oxygen supply reaches 7% of the total oxygen supply, the oxygen supply intensity should be adjusted to 2.4–2.6 m. 3 / min·t, adjust the oxygen supply gun position to 100-200mm away from the lowest smelting gun position;

[0020] When the oxygen supply reaches 10% of the total oxygen supply, immediately lower the oxygen supply lance position to 50mm from the lowest smelting lance position, and adjust the oxygen supply intensity to 2.7–2.9m. 3 / min·t, after the oxygen lance is lowered to the position, cold material is added in batches, using a small amount and multiple addition method;

[0021] When the oxygen supply is 10% to 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 2.7 to 2.9 m. 3 / min·t, the distance between the smelting lance position and the lowest smelting lance position remains unchanged at 50mm;

[0022] When the oxygen supply exceeds 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 3.3–5 m. 3 / min·t, the smelting lance position is kept at the lowest smelting lance position until the blowing reaches the end point.

[0023] Titanium oxides combine with CaO in lime, reducing lime utilization and making the initial slag viscous, which is detrimental to dephosphorization. Therefore, the alkalinity during slag formation is controlled between 2.8 and 3.8 to avoid high phosphorus levels causing adverse reactions. The thermal effect of titanium is basically the same as that of silicon. When calculating cold feed, the titanium content is taken into account. For every 0.100% increase in titanium content, the amount of dust removal ash briquettes used increases by 5 kg / t.

[0024] When production schedule allows, double-slag operation is performed to remove titanium from the molten iron. The slag pouring temperature is controlled at 1350-1400℃, which does not affect subsequent normal smelting.

[0025] In this invention, regardless of whether the slag has melted well in the early stage of smelting, the oxygen lance should be introduced as soon as possible, and the operation should be carried out in a low lance position and low flow rate mode to promote the stirring of the molten pool, make the composition and temperature uniform, and prevent splashing caused by prolonged high lance position operation.

[0026] Finally, it should be noted that 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 present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A control method for smelting vanadium-titanium iron in a 210t converter, characterized in that: Add all the magnesium balls and lime required for the furnace 30 seconds after the converter is successfully ignited to accelerate the initial slag formation. When the oxygen supply reaches 7% of the total oxygen supply, the oxygen supply intensity should be adjusted to 2.4~2.6m. 3 / min·t, adjust the oxygen supply gun position to 100~200mm away from the lowest smelting gun position; When the oxygen supply reaches 10% of the total oxygen supply, immediately lower the oxygen supply lance position to 50mm from the lowest smelting lance position, and adjust the oxygen supply intensity to 2.7~2.9m. 3 / min·t, after the oxygen lance is lowered to the position, cold material is added in batches, using a small amount and multiple addition method; When the oxygen supply is 10% to 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 2.7 to 2.9 m. 3 / min·t, the distance between the smelting lance position and the lowest smelting lance position remains unchanged at 50mm; When the oxygen supply exceeds 60% of the total oxygen supply, the oxygen supply intensity should be maintained at 3.3~5m. 3 / min·t, the smelting lance position is kept at the lowest smelting lance position until the blowing reaches the end point; During the slag-making process, the alkalinity is controlled between 2.8 and 3.8 to avoid reclassification due to high phosphorus levels; The thermal effect of titanium is basically the same as that of silicon. When calculating the cold material, the titanium content should be taken into account. For every 0.100% increase in titanium content, the amount of ore used should be increased by 5 kg / t.

2. The control method for smelting vanadium-titanium iron in a 210t converter according to claim 1, characterized in that: When production schedule allows, double slag operation is performed to remove titanium from the molten iron. The slag pouring temperature is controlled at 1350~1400℃, which does not affect subsequent normal smelting.

3. The control method for smelting vanadium-titanium iron in a 210t converter according to claim 1, characterized in that: In the early stages of smelting, regardless of whether the slag has melted well, the oxygen lance should be advanced as soon as possible, using a low lance position and low flow rate to promote stirring of the molten pool, ensure uniform composition and temperature, and prevent splashing caused by prolonged high lance position operation.