Blast furnace smelting method for reducing nitrogen consumption per ton of iron

Abstract

The invention discloses a blast furnace smelting method for reducing nitrogen consumption per ton of iron, relates to the field of blast furnace smelting, and solves the problems that the nitrogen consumption per ton of iron is difficult to reduce and the product quality is difficult to be excellent in the existing blast furnace smelting method. The blast furnace smelting method comprises the following steps: carrying out back flushing and ash conveying on the furnace-front and furnace-back dust removal system by using air pressure; starting back flushing of a cloth bag in the gas room, and setting preset parameters; starting a coal injection and pulverizing system, carrying out leakage point detection, and controlling the oxygen content of the system; starting a nitrogen and air pressure flow monitoring system to track and detect nitrogen and air pressure flow; and smelting is started for preset time, and smelting is finished. The smelting method is optimized, nitrogen consumption is reduced from multiple stages of smelting, and parameters such as pressure and frequency of air pressure and system oxygen content are controlled; a flow monitoring system is introduced to monitor and warn the used nitrogen; and leakage point detection is carried out in the smelting process, so that nitrogen waste is reduced.

Description

Technical Field

[0001] The invention relates to the field of blast furnace smelting, and in particular to a blast furnace smelting method for reducing nitrogen consumption per ton of iron. Background Art

[0002] It is well known that nitrogen consumption is high in blast furnace smelting, which is a large production cost for enterprises. However, in the existing technology, the method of reducing nitrogen consumption per ton of iron often reduces the quality of the finished product due to the reduced nitrogen consumption. How to achieve the goal of reducing nitrogen consumption per ton of iron while ensuring good product quality is a difficult problem in the existing blast furnace smelting field.

[0003] It can be seen that the existing blast furnace smelting method has the defect that it is difficult to reduce the nitrogen consumption per ton of iron while maintaining excellent product quality. Summary of the invention

[0004] The invention aims to solve the problem that it is difficult to reduce nitrogen consumption per ton of iron and achieve excellent product quality in the existing blast furnace smelting method.

[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0006] A blast furnace smelting method for reducing nitrogen consumption per ton of iron comprises the following steps:

[0007] S1. Use air compressor to back-blow and transport ash to the dust removal system before and after the furnace;

[0008] S2, start the gas room bag backflush and set it to the preset parameters;

[0009] S3, start the coal injection pulverizing system and conduct leakage detection to control the oxygen content of the system;

[0010] S4, start the nitrogen and air pressure flow monitoring system to track and detect the nitrogen and air pressure flow;

[0011] S5, start smelting, smelt for a preset time, and end smelting.

[0012] Furthermore, in S1, the air pressure used for backblowing is 0.5-0.8 MPa, and the frequency is 20 minutes / time.

[0013] Furthermore, in S1, the air pressure used for ash conveying is 0.5-0.8 MPa, and the frequency is 2h / time.

[0014] Furthermore, in S2, the preset parameters include that the frequency of nitrogen backflushing is 58 to 65 minutes per time.

[0015] Furthermore, in S2, the preset parameters also include that the pressure of nitrogen backflush is 0.5-0.8 MPa.

[0016] Furthermore, in S3, the leakage point detection is used to reduce gas leakage in the system.

[0017] Furthermore, in S3, the oxygen content is less than or equal to 8%.

[0018] Furthermore, the nitrogen and air pressure flow monitoring system is used to monitor the nitrogen and air pressure flow and issue an alarm when the flow is high.

[0019] Furthermore, in S5, the blast furnace slag bin during the smelting process is purged using air pressure.

[0020] Furthermore, the blast furnace slag bin is purged using air pressure, and the pressure of the air pressure is 0.5-0.8MPa.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] 1. The present invention relates to a blast furnace smelting method for reducing nitrogen consumption per ton of iron. By optimizing the smelting method, the nitrogen consumption is first reduced in multiple stages of smelting, and the pressure, frequency, oxygen content of the system and other parameters of the air compressor are controlled; at the same time, a flow monitoring system is introduced to monitor and warn the nitrogen used; in addition, leakage point detection is performed during the smelting process to reduce nitrogen waste.

[0023] By approaching from multiple angles and dimensions, we can effectively reduce nitrogen consumption while obtaining finished products with stable and excellent quality, thus achieving the dual advantages of reducing production costs and ensuring product quality.

[0024] It should be particularly noted that the smelting method of the present invention does not simply adjust the amount of nitrogen to solve the problem of reducing nitrogen consumption and improving the quality of packaging products, but is a linkage effect that starts from multiple angles.

[0025] The blast furnace smelting method of the present invention solves the problem that the existing blast furnace smelting method is difficult to achieve the goal of reducing nitrogen consumption per ton of iron while achieving excellent product quality.

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. DETAILED DESCRIPTION

[0028] In an embodiment of the present invention, a blast furnace smelting method for reducing nitrogen consumption per ton of iron comprises the following steps:

[0029] S1. Use air compressor to back-blow and transport ash to the dust removal system before and after the furnace;

[0030] S2, start the gas room bag backflush and set it to the preset parameters;

[0031] S3, start the coal injection pulverizing system and conduct leakage detection to control the oxygen content of the system;

[0032] S4, start the nitrogen and air pressure flow monitoring system to track and detect the nitrogen and air pressure flow;

[0033] S5, start smelting, smelt for a preset time, and end smelting.

[0034] It can be understood that the blast furnace smelting method for reducing nitrogen consumption per ton of iron involved in the present invention optimizes the smelting method, firstly reduces nitrogen consumption from multiple stages of smelting, and controls parameters such as air compression pressure, frequency, and system oxygen content; at the same time, introduces a flow monitoring system to monitor and warn the nitrogen used; in addition, leak point detection is performed during the smelting process to reduce nitrogen waste.

[0035] By approaching from multiple angles and dimensions, we can effectively reduce nitrogen consumption while obtaining finished products with stable and excellent quality, thus achieving the dual advantages of reducing production costs and ensuring product quality.

[0036] It should be particularly noted that the smelting method of the present invention does not simply adjust the amount of nitrogen to solve the problem of reducing nitrogen consumption and improving the quality of packaging products, but is a linkage effect that starts from multiple angles.

[0037] The blast furnace smelting method of the present invention solves the problem that the existing blast furnace smelting method is difficult to achieve the goal of reducing nitrogen consumption per ton of iron while achieving excellent product quality.

[0038] In certain embodiments of the present invention, in S1, the pressure of the air pressure used for backblowing is 0.5-0.8 MPa, and the frequency is 20 minutes / time.

[0039] In certain embodiments of the present invention, in S1, the air pressure used for ash conveying is 0.5-0.8 MPa, and the frequency is 2h / time.

[0040] It is understandable that adjusting the dust removal system before and after the furnace, using air compression for backblowing and ash conveying, and adjusting its pressure and frequency can reduce nitrogen consumption and ensure the quality of the finished product.

[0041] In certain embodiments of the present invention, in S2, the preset parameters include that the frequency of nitrogen backflushing is 58 to 65 minutes per time.

[0042] In certain embodiments of the present invention, in S2, the preset parameters also include that the pressure of nitrogen backflush is 0.5-0.8 MPa.

[0043] In certain embodiments of the present invention, in S3, the leak point detection is used to reduce gas leakage in the system.

[0044] In certain embodiments of the present invention, in S3, the oxygen content is ≤8%, that is, the oxygen content is less than or equal to 8%.

[0045] In certain embodiments of the present invention, the nitrogen and compressed air pressure flow monitoring system is used to monitor the nitrogen and compressed air pressure flow and issue an alarm when the flow is high.

[0046] In certain embodiments of the present invention, the nitrogen and air pressure flow monitoring system used in the present invention is specifically as follows: back-blowing adopts timed pulses, pressure adopts a pressure transmitter, and the flow meter adopts an "orifice flow meter".

[0047] In certain embodiments of the present invention, in S5, the blast furnace slag bin in the smelting process is purged using air pressure, and the pressure of the air pressure is 0.5-0.8 MPa.

[0048] In certain embodiments of the present invention, the blast furnace slag bin is purged using air pressure, and the pressure of the air pressure is. It can be understood that nitrogen is used to purge the blast furnace slag bin in the prior art, and the use of air pressure for purge can effectively reduce the consumption of nitrogen. At the same time, the pressure of the blast furnace slag bin is controlled to be, which can make the purge efficiency high.

[0049] Example 1

[0050] In this embodiment, smelting is carried out at Desheng Iron and Steel Plant from June 2022 to January 2023, and the smelting method is a conventional smelting method in the prior art. The 3# blast furnace system has 1 mill, 1 set of gas bag dust removal box, 1 furnace front dust removal box, and 1 furnace rear dust removal box. Nitrogen is used to provide bag back-blowing gas source and security nitrogen gas source for smelting. The blast furnace produces about 4050 tons of iron per day and the nitrogen consumption is counted.

[0051] After statistics, it is found that the monthly nitrogen consumption is 62m 3 / tFe. (Weighted value from June 2022 to January 2023)

[0052] Example 2

[0053] In this embodiment, smelting is carried out at Desheng Iron and Steel Plant in February 2023, and the smelting method includes the following steps:

[0054] S1. Use air compressor to back-blow and transport ash to the dust removal system before and after the furnace;

[0055] S2, start the gas room bag backflush and set it to the preset parameters;

[0056] S3, start the coal injection pulverizing system and conduct leakage detection to control the oxygen content of the system;

[0057] S4, start the nitrogen and air pressure flow monitoring system to track and detect the nitrogen and air pressure flow;

[0058] S5, start smelting, smelt for a preset time, and end smelting.

[0059] Statistics on nitrogen consumption. From February to August 2023, the monthly nitrogen consumption is 53.33m 3 / tFe. (Weighted value from February to August)

[0060] In summary, by comparing Example 1 and Example 2, it can be seen that the smelting method of the present invention can effectively reduce the consumption of nitrogen, thereby solving the problem that the existing blast furnace smelting method is difficult to achieve low nitrogen consumption per ton of iron while maintaining good product quality.

[0061] The above embodiment is only one implementation of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A blast furnace smelting method for reducing nitrogen consumption per ton of iron, characterized in that: The following steps are involved: S1. Use air compressor to back-blow and transport ash to the dust removal system before and after the furnace; S2, start the gas room bag backflush and set it to the preset parameters; S3, start the coal injection pulverizing system and conduct leakage detection to control the oxygen content of the system; S4, start the nitrogen and air pressure flow monitoring system to track and detect the nitrogen and air pressure flow; S5, start smelting, smelt for a preset time, and end smelting.

2. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: In S1, the air pressure used for back-blowing is 0.5-0.8 MPa, and the frequency is 20 minutes / time.

3. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 2, characterized in that: In S1, the air pressure used for ash conveying is 0.5-0.8 MPa, and the frequency is 2h / time.

4. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: In S2, the preset parameters include that the frequency of nitrogen backflushing is 58 to 65 minutes per time.

5. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 4, characterized in that: In S2, the preset parameters also include that the pressure of nitrogen backflush is 0.5-0.8 MPa.

6. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: In S3, the leak point detection is used to reduce gas leakage in the system.

7. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: In S3, the oxygen content is less than or equal to 8%.

8. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: The nitrogen and air pressure flow monitoring system is used to monitor the nitrogen and air pressure flow and issue an alarm when the flow is high.

9. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 1, characterized in that: In S5, the blast furnace slag bin in the smelting process is purged using air pressure.

10. A blast furnace smelting method for reducing nitrogen consumption per ton of iron according to claim 9, characterized in that: The blast furnace slag bin is purged using air pressure, and the pressure of the air pressure is 0.5-0.8MPa.