Smelting method of high-titanium iron-containing raw material

Abstract

The invention relates to a high-titanium iron-containing raw material smelting method which comprises the following steps: S1, sintering and burdening; S2, blast furnace smelting: the air supply top pressure is 250 kPa, and the pressure difference is not more than 195 kPa; the air volume is 3350 + / -50m < 3 > / min, and oxygen enrichment control is carried out; the mass content of silicon and titanium in the molten iron is controlled to be 0.25-0.5%; the mass content of sulfur in the molten iron is controlled to be 0.010-0.045%; the temperature of the molten iron is 1470-1500 DEG C; full-air-temperature operation is carried out, the oxygen enrichment rate is 5%-10%, and the operation coal ratio is 175-180 kg / t; the binary alkalinity of the blast furnace slag in the slagging process is 1.20-1.35; the mass content of aluminum in the blast furnace slag is 17.5% + / -0.3%, and the mass ratio of magnesium to aluminum in the blast furnace slag is 0.60 + / -0.03; s3, tapping iron and slag, wherein the depth of an iron notch is not lower than 2700 mm; and the tapping interval is controlled to be 8-15 minutes. And the limitation of blast furnace smelting on the charging titanium load is broken through, and effective utilization of the high-titanium iron-containing raw materials is realized by adjusting operation control parameters and carrying out combined batching calculation.

Description

Technical Field

[0001] The present invention belongs to the technical field of iron and steel smelting, and particularly relates to a smelting method for high-titanium iron-containing raw materials, especially applicable to a smelting process that breaks through the traditional titanium load limit. Background Art

[0002] In the existing iron and steel smelting technology, the blast furnace raw materials mainly include sinter, pellet, and iron ore lumps, and there are strict restrictions on the grade, strength, and trace elements (such as titanium) of the raw materials charged into the furnace. The traditional smelting process believes that a high titanium load will cause the fluidity of hot metal to deteriorate and the furnace condition to fluctuate. Therefore, most enterprises control the titanium load charged into the furnace at a low level (≤6 kg / t).

[0003] Chinese CN118480636A discloses a new ore blending method and a blast furnace ironmaking method for reducing the titanium load in the blast furnace. The ore blending method includes: at least dividing ore powders into two types, high-silicon low-titanium and low-silicon high-titanium, according to the silicon and titanium contents of the ore powders; adding the low-silicon high-titanium ore powder to the rotary kiln process to obtain pellets, and adding the high-silicon low-titanium ore powder to the sintering process to obtain sinter; by scientifically and reasonably diverting the ore powders with different silicon and titanium contents to the sintering process or the rotary kiln process for consumption, adding the high-silicon low-titanium one to the sintering process and the low-silicon high-titanium one to the rotary kiln process, and using the ore powders with different silicon and titanium contents respectively based on the phenomenon that the consumption ratio of pellets in the blast furnace is small and the consumption ratio of sinter in the blast furnace is large, it not only reduces the silicon in pellets and the titanium in sinter, but also reduces the titanium load in the blast furnace and improves the metallurgical properties of sinter and pellets, enhances the activity of the hearth, and is beneficial to the stable production of the ironmaking process and cost reduction. The above method controls the titanium load charged into the furnace <10 kg / t. There is still no way to control the titanium load charged into the furnace ≥10 kg / t.

[0004] However, with the reduction of rich iron ore resources and the increase in raw material costs, iron and steel enterprises urgently need to use low-cost raw materials with a relatively high titanium content (such as high-titanium iron concentrate powder, aluminum slag powder) to reduce costs. However, due to the lack of an adaptive control method for high-titanium raw materials in the existing technology, it is difficult to break through the titanium load limit while ensuring the stability of the furnace condition, resulting in enterprises being unable to effectively utilize such resources. Summary of the Invention

[0005] The limitation of the traditional blast furnace smelting technology on the titanium load (≤6 kg / t) hinders the large-scale application of low-cost high-titanium raw materials, resulting in high ironmaking costs. The present invention aims to achieve the efficient smelting of high-titanium iron-containing raw materials with a titanium load of 10 kg / t ≤ titanium load ≤ 12 kg / t by optimizing the burden calculation and operation parameters, while maintaining the stability of the furnace condition. The present invention provides a smelting method for high-titanium iron-containing raw materials.

[0006] The technical solution of the present invention:

[0007] A smelting method for high-titanium iron-containing raw materials, comprising the following steps:

[0008] S1. Calculate the sinter burden proportionally through the pre-ironmaking combined burden calculation. Modify the manual valve at the discharge opening of the disc feeder to adjust the opening degree. The opening degree of the valve should be able to ensure that there is no material spraying from the bin during the discharge of the disc feeder. The discharge speed is controlled at 10 - 20 Hz, and the material level in the burden bin is controlled at 1 / 3 - 1 / 2.

[0009] S2. Blast furnace smelting (blast furnaces in the 1000 - 2000 cubic meter level):

[0010] The top pressure of the blast is 250 kPa, and the differential pressure does not exceed 195 kPa; the blast volume is 3350 ± 50 m 3 / min, with oxygen enrichment control; the mass content of silicon (chemical heat) + titanium in the hot metal is controlled at 0.25 - 0.50%; the mass content of sulfur in the hot metal is controlled at 0.010 - 0.045%; the hot metal temperature (physical heat) is 1470 - 1500 °C; operating with full blast temperature, the oxygen enrichment rate is 5% - 10%, and the operating coal ratio is 175 - 180 kg / t.

[0011] S3. Tapping and slagging:

[0012] The depth of the taphole is not less than 2700 mm; the tapping interval is controlled at 8 - 15 minutes.

[0013] Preferably, the pre-ironmaking combined burden calculation for proportionally performing sinter burden means that the charging in S1 includes titanium-containing iron concentrate powder and aluminum slag powder, controlling the contents of SiO2, CaO, Al2O3, and MgO in the sinter, realizing the balance of the binary basicity and the magnesium-aluminum ratio of the blast furnace slag in S2, and making the binary basicity of the blast furnace slag be 1.20 - 1.35; when the aluminum content in the blast furnace slag is 17.5% ± 0.3%, the corresponding magnesium-aluminum ratio of the blast furnace slag is 0.60 ± 0.03, and the magnesium-aluminum ratio of the blast furnace slag can be appropriately adjusted according to the actual conditions of the blast furnace itself according to the change of the aluminum content.

[0014] Preferably, the titanium-containing iron concentrate powder has a grade of 60 - 69%; 50 - 80% of the proportion with a fineness of 200 mesh is used as the sintering raw material, and 70 - 90% of the proportion with a fineness of 200 mesh is used as the pellet production raw material.

[0015] Preferably, the titanium content in the aluminum slag powder is 3.5 - 4.5%, the aluminum content is 12 - 13%; the Fe grade ≥ 45%.

[0016] Preferably, the method is used for blast furnace smelting with an in-furnace titanium load of 10 kg / t ≤ in-furnace titanium load ≤ 12 kg / t.

[0017] Preferably, in the blast furnace smelting of S, the ferrous iron mass content in the sinter is controlled at 8.0 - 10.0%.

[0018] Preferably, in the blast furnace smelting of S2, for a 1000 m 3The drum index of sinter for blast furnaces of level

[0019] Unless otherwise specified in the present invention, the content not specifically specified refers to the mass content.

[0020] Advantages of the present invention:

[0021] The present invention breaks through the titanium load limit to ≤12 kg / t and ≥10 kg / t, significantly reducing the raw material cost; through the combined burden calculation before ironmaking, it ensures the balance of slag basicity and magnesium-aluminum, maintaining the stability of the furnace condition; realizes the precise control of hot metal composition and avoids the deterioration of fluidity; combined with the cost prediction model, it makes the ironmaking cost controllable and improves the profitability of the enterprise.

[0022] Titanium load: The total mass (kg) of titanium element in unit hot metal (ton).

[0023] Combined burden calculation before ironmaking: Integrate the burden calculations of sintering, pelletizing, and blast furnace processes, and optimize the raw material ratio with the balance of blast furnace slag items as the goal.

[0024] Binary basicity: The mass ratio of CaO / SiO2 in blast furnace slag.

[0025] Magnesium-aluminum ratio: The mass ratio of MgO / Al2O3 in blast furnace slag. Specific implementation mode

[0026] Example 1

[0027] Taking Rongxin Iron and Steel of Xinda Group as an example, for a 1500 m 3 level blast furnace, adding aluminum slag powder with a grade of 45% (TiO2 4%, Al2O3 12%, Fe≥45%):

[0028] The grade of titanium-containing iron concentrate powder is 65%, and the fineness of -200 mesh accounts for 60 - 80%.

[0029] Bunker transformation: The special bunker is equipped with double cleaners and electric shock devices. The manual valve at the discharge opening of the disc feeder is modified to adjust the opening degree. The opening degree of the valve is required to meet the condition that there is no material spraying from the bunker during the discharging of the disc feeder, and the discharging speed is controlled at 10 - 20 Hz, and the material level in the batching bunker is controlled at 1 / 3 - 1 / 2;

[0030] Batch calculation: Through the pre-iron combined batching and cost prediction table, first, adjust the CaO content of the sinter (lime (raw lime powder) can be added - MgO content 3.3%, SiO2 content 0.8%, CaO 88%, the ratio is controlled at 5-8% according to the alkalinity balance), second, adjust the MgO content of the sinter (add magnesite powder - MgO content 44%, SiO2 content 3.5%, CaO content 2.3%, the ratio is 3-5%; or add dolomite powder - MgO content 20%, SiO2 content 5%, CaO content 30%, the ratio is 8-11%) to ensure that the binary alkalinity of the slag is 1.30, the aluminum content of the blast furnace slag is 17.5%, the magnesium-aluminum ratio of the blast furnace slag is 0.60, and the drum index of the sinter is 73%;

[0031] Blast furnace parameters: The top pressure of the blast is 250 kPa, and the differential pressure does not exceed 195 kPa; the blast volume is 3350 ± 50 m 3 / min, with 9% oxygen enrichment;

[0032] The mass content of silicon + titanium in the hot metal is controlled at 0.25 - 0.35%; the mass content of sulfur in the hot metal is controlled at 0.010 - 0.045%; the hot metal temperature is 1470°C - 1500°C; operating with full blast temperature, the coal injection rate is 177 kg / t; tapping and slagging: the depth of the taphole is not less than 2700 mm; the tapping interval is controlled at 15 minutes.

[0033] Implementation effect: The titanium load into the furnace is increased to 11 kg / t, the raw material cost is reduced by 1.28%, the hot metal cost is reduced by 0.58%, and the furnace condition is stable and smooth.

[0034]

[0035]

[0036] Prediction results of the pre-iron batching and cost prediction table

[0037] Prediction results of batching and cost for a titanium load of 8 kg

[0038] Prediction results of batching and cost for a titanium load of 11 kg

[0039] The comparison of the calculation results through the pre-iron batching and cost prediction table is as follows:

[0040]

[0041]

[0042] Example 2

[0043] Taking Rongxin Iron and Steel of Xinda Group as an example, for a 1000m 3 blast furnace, adding aluminum slag powder with a grade of 45% (TiO2 3.5%, Al2O3 13%, Fe≥40%): the grade of titanium-containing iron concentrate powder is 69% and the fineness is 80 microns.

[0044] Bunker transformation: The special bunker is equipped with double cleaners and electric shock devices, with a rotation speed of 10 - 20Hz and the material level maintained at 1 / 3 - 1 / 2;

[0045] Moisture adjustment: The water addition in the first mixing is lowered by 0.3%;

[0046] Batch calculation: Through the pre-iron combined batching and cost prediction table, first, adjust the CaO content of the sinter (lime powder (quicklime powder) with MgO content of 3.3%, SiO2 content of 0.8%, CaO 88% can be added, and the ratio is controlled at 5 - 8% according to the alkalinity balance), second, adjust the MgO content of the sinter (adding magnesite powder with MgO content of 44%, SiO2 content of 3.5%, CaO content of 2.3%, ratio 3 - 5%; or adding dolomite powder with MgO content of 20%, SiO2 content of 5%, CaO content of 30%, ratio 8 - 11%) to ensure that the binary alkalinity of the slag is 1.2 and the magnesium-aluminum ratio of the blast furnace slag is 0.63.

[0047] The drum index of the sinter is 74%;

[0048] Blast furnace parameters: The top blowing pressure is 250 kPa and the pressure difference does not exceed 195 kPa; the air volume is 3350±50m 3 / min, with oxygen enrichment control;

[0049] The mass content of silicon + titanium in the hot metal is controlled at 0.5%; the mass content of sulfur in the hot metal is controlled at 0.015%; the hot metal temperature is 1480°C; operating with full blast temperature, the operating coal ratio is 180 kg / t;

[0050] Tapping and slagging: The depth of the taphole is not less than 2700 mm; the tapping interval is controlled within 10 minutes.

[0051] Implementation effect: The titanium load into the furnace is increased to 12 kg / t, the raw material cost is reduced by 14%, and the furnace condition is stable and smooth.

[0052] Example 3

[0053] Taking Rongxin Iron and Steel of Xinda Group as an example, for a 1000m 3Grade 0 blast furnace, adding aluminum slag powder with a grade of 45% (TiO2 4.5%, Al2O3 12.5%, Fe≥40%): The grade of titanium-containing iron concentrate powder is 60%, and the fineness is 50 microns.

[0054] Bunker transformation: The special bunker is equipped with double cleaners and electric shock devices, with a rotation speed of 10 - 20 Hz, and the material level is maintained at 1 / 3 - 1 / 2;

[0055] Moisture adjustment: The water level in the first mixing is lowered by 0.4%;

[0056] Batch calculation: Through the combined batching before ironmaking and the cost prediction table, first, adjust the CaO content of the sinter (lime (quicklime powder) can be added - MgO content 3.3%, SiO2 content 0.8%, CaO 88%, and the ratio is controlled at 5 - 8% according to the alkalinity balance), second, adjust the MgO content of the sinter (add magnesite powder - MgO content 44%, SiO2 content 3.5%, CaO content 2.3%, ratio 3 - 5%; or add dolomite powder - MgO content 20%, SiO2 content 5%, CaO content 30%, ratio 8 - 11%) to ensure that the binary alkalinity of the slag is 1.3, the magnesium-aluminum ratio of the blast furnace slag is 0.57, and the drum index of the sinter is 72%;

[0057] Blast furnace parameters: The top pressure of the blast is 250 kPa, and the pressure difference does not exceed 195 kPa; The air volume is 3350 ± 50 m 3 / min, with oxygen enrichment control;

[0058] The mass content of silicon + titanium in the hot metal is controlled at 0.4%; The mass content of sulfur in the hot metal is controlled at 0.045%; The hot metal temperature is 1500 °C; Operating with full blast temperature, the operation coal ratio is 175 kg / t;

[0059] Tapping and slagging: The depth of the taphole is not less than 2700 mm; The tapping interval is controlled at 8 minutes.

[0060] Implementation effect: The titanium load in the furnace is increased to 11.5 kg / t, the raw material cost is reduced by 16%, and the furnace condition is stable and smooth.

[0061] Comparative example 1

[0062] Taking Rongxin Iron and Steel of Xinda Group as an example, a 1000 m 3 Grade blast furnace, adding aluminum slag powder with a grade of 45% (TiO2 4%, Al2O3 12%, Fe≥40%):

[0063] The grade of titanium-containing iron concentrate powder is 65%, and the fineness is 65 microns.

[0064] Bunker transformation: The special bunker is equipped with double cleaners and electric shock devices, with a rotation speed of 10 - 20 Hz, and the material level is maintained at 1 / 3 - 1 / 2;

[0065] Moisture adjustment: The middle line of the water addition in the first mixing is lowered by 0.5%;

[0066] Batch calculation: Through the combined batching before ironmaking and the cost prediction table, first, adjust the CaO content of the sinter (lime (quicklime powder) can be added - MgO content 3.3%, SiO2 content 0.8%, CaO 88%, and the ratio is controlled at 5 - 8% according to the alkalinity balance), second, adjust the MgO content of the sinter (add magnesite powder - MgO content 44%, SiO2 content 3.5%, CaO content 2.3%, ratio 3 - 5%; or add dolomite powder - MgO content 20%, SiO2 content 5%, CaO content 30%, ratio 8 - 11%) to ensure that the binary basicity of the slag is 1.0, the magnesium - aluminum ratio of the blast - furnace slag is 0.60, and the drum index of the sinter is 73%;

[0067] Blast - furnace parameters: The top - blowing pressure is 250 kPa, and the pressure difference does not exceed 195 kPa; the air volume is 3350 ± 50 m 3 / min, with oxygen enrichment control;

[0068] The mass content of silicon + titanium in hot metal is controlled at 0.25%; the mass content of sulfur in hot metal is controlled at 0.030%; the hot - metal temperature is 1470 °C; full - blast - temperature operation, and the operation coal ratio is 177 kg / t;

[0069] Tapping and slagging: The depth of the taphole is not less than 2700 mm; the tapping interval is controlled within 15 minutes.

[0070] Implementation effect: The titanium load into the furnace is increased to 12 kg / t, the raw - material cost is reduced by 4%, and the furnace condition is stable and smooth.

[0071] Comparative example 2

[0072] Taking Rongxin Iron and Steel of Xinda Group as an example, for a 1000 m 3 grade blast - furnace, adding aluminum - slag powder with a grade of 45% (TiO2 4%, Al2O3 12%, Fe≥40%):

[0073] The grade of titanium - containing iron concentrate is 65%, and the fineness is 65 microns.

[0074] Bunker transformation: The special bunker is equipped with double cleaners and an electric shock device, the rotation speed is 10 - 20 Hz, and the material level is maintained at 1 / 3 - 1 / 2;

[0075] Moisture adjustment: The middle line of the water addition in the first mixing is lowered by 0.5%;

[0076] Batch calculation: Through the combined burden calculation before ironmaking and the cost prediction table, first, adjust the CaO content of sinter (lime (quicklime powder) with 3.3% MgO content, 0.8% SiO2 content, and 88% CaO can be added, and the ratio is controlled at 5-8% according to the basicity balance), and second, adjust the MgO content of sinter (add magnesite powder with 44% MgO content, 3.5% SiO2 content, and 2.3% CaO content, with a ratio of 3-5%; or add dolomite powder with 20% MgO content, 5% SiO2 content, and 30% CaO content, with a ratio of 8-11%) to ensure that the binary basicity of the slag is 1.25, the magnesium-aluminum ratio of the blast furnace slag is 0.50, and the tumbler index of sinter is 73%;

[0077] Blast furnace parameters: The top pressure of the blast is 250 kPa, and the differential pressure does not exceed 195 kPa; the blast volume is 3350 ± 50 m 3 / min, with oxygen enrichment control;

[0078] The mass content of silicon + titanium in hot metal is controlled at 0.25%; the mass content of sulfur in hot metal is controlled at 0.030%; the hot metal temperature is 1470 °C; full blast temperature operation, with an operating coal ratio of 177 kg / t;

[0079] Tapping and slagging: The depth of the taphole is not less than 2700 mm; the tapping interval is controlled at 15 minutes.

[0080] Implementation effect: The titanium burden charged into the furnace is increased to 12 kg / t, the raw material cost is reduced by 6%, and the furnace condition is stable and smooth.

[0081] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A smelting method for high-titanium iron-containing raw materials, characterized in that, It includes the following steps: S1. Conduct sintering burdening in proportion through pre-iron combined burdening calculation. The opening of the manual valve at the discharge opening of the disc feeder is adjusted. The opening of the valve should ensure that there is no material spraying from the bin during the discharge of the disc feeder. The discharge speed is controlled at 10 - 20 Hz, and the material level in the burdening bin is controlled at 1 / 3 - 1 / 2. S2. Blast furnace smelting: The top pressure of the blast is 250 kPa, and the pressure difference does not exceed 195 kPa; the air volume is 3350 ± 50 m 3 / min, and the oxygen enrichment is controlled at 100 - 120 m 3 / ton of iron; The silicon + titanium content in the hot metal is controlled at 0.25 - 0.5%; the sulfur content in the hot metal is controlled at 0.010 - 0.045%; the hot metal temperature is 1470 - 1500 °C; full blast temperature operation, oxygen enrichment rate of 5% - 10%, and the operating coal ratio is 175 - 180 kg / t. S3. Tapping and slagging: The depth of the taphole is not less than 2700 mm; the tapping interval is controlled at 8 - 15 minutes.

2. The smelting method of a high-titanium iron-containing raw material according to claim 1, characterized in that Conducting sintering burdening in proportion through pre-iron combined burdening calculation means that the charging in S1 includes titanium-containing iron concentrate powder and aluminum slag powder, controlling the contents of SiO2, CaO, Al2O3, and MgO in the sinter, realizing the balance of the binary basicity and the magnesium-aluminum ratio of the blast furnace slag in S2, and making the binary basicity of the blast furnace slag be 1.20 - 1.35; the aluminum content in the blast furnace slag is 17.5% ± 0.3%, and the corresponding magnesium-aluminum ratio is 0.60 ± 0.

03.

3. The smelting method of a high-titanium iron-containing raw material according to claim 2, characterized in that, The titanium-containing iron concentrate has a grade of 60 - 69%; 50 - 80% of the volume with a fineness of 200 mesh is used as sintering raw material, and 70 - 90% of the volume with a fineness of 200 mesh is used as pellet production raw material.

4. The smelting method of a high-titanium iron-containing raw material according to claim 2, characterized in that, The titanium mass content in the aluminum slag powder is 3.5 - 4.5%, the aluminum mass content is 12 - 13%; the Fe grade ≥ 45%.

5. A smelting method for a high-titanium iron-containing raw material according to claim 1, characterized in that, The method is used for blast furnace smelting with an in-furnace titanium load of 10 kg / t ≤ ≤ 12 kg / t.

6. The smelting method of a high-titanium iron-containing raw material according to claim 1, characterized in that, In S2 blast furnace smelting, the ferrous iron mass content in the sinter is controlled at 8.0 - 10.0%.

7. A smelting method for a high-titanium iron-containing raw material according to claim 1, characterized in that, In the smelting of BF S2, the drum index of sinter for blast furnaces of 1000m 3 level or above shall not be lower than 72%.

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