Method for preventing explosion leakage of dust compact produced by converter using dust

Abstract

The application discloses a method for preventing explosion leakage of dusting ash briquetting used in a converter, and the method is characterized in that: by optimizing the iron mixing mode, the instantaneous pressure generated at the converter mouth is slowed down, and the mixed concentration of CO and O2 in the converter flue gas is controlled to be below the explosion limit. The purpose of the application is to meet the requirement of "no solid waste leaving the factory", reduce the explosion leakage of the positive pressure of the dry deduster by using the dusting ash briquetting, and the application combines the actual production to summarize a method for preventing the explosion leakage of the dusting ash.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of converter steelmaking on-site production, and particularly relates to a method for preventing explosion leakage caused by using dust compact of a converter. BACKGROUND

[0002] A large amount of smoke dust is generated in the process of converter steelmaking, the first part of which with relatively coarse particles is collected through an evaporative cooler, and the remaining part is collected through an electrostatic precipitator, so that converter dust with fine particle size and high iron content can be obtained. Originally, many enterprises returned the converter dust to sintering and used it as a raw material to recycle TFe, C, CaO, MgO and the like in the dust, but the harmful components such as Zn, K and Na contained therein bring many influences on the blast furnace system and the sintering system, form alkali enrichment, cause sintering "paste grate bar", reduce the yield and quality of sintered ore, increase the energy consumption of the process, and the harmful elements are recycled and enriched in the blast furnace, which affects the smooth operation of the blast furnace. With the development of blast furnace smelting technology, the harmfulness of K, Na and Zn to the blast furnace production is paid more and more attention, and many steel plants prohibit the recycling of dust containing many harmful elements in the blast furnace system, which causes the dust to be discharged or stacked in the plant area. Strengthening the total utilization of dust solid waste resources is a difficult problem that must be solved by steel and iron metallurgical enterprises. At present, the main methods for steel plants to treat converter dust include mixing it into iron-containing raw materials for sintering treatment as a briquetting treatment and using it as a converter slagging agent and coolant. Since the dust compact has a certain powder rate, and has strong water absorption and oxidizing property, during the iron charging process or after the iron charging process, a violent reaction occurs in the furnace, resulting in positive pressure of the dry dust collector and even explosion leakage accident. Therefore, it is urgent to solve the important problem of how to use the existing production equipment to avoid the positive pressure accident of the dry dust collector. SUMMARY

[0003] In order to meet the requirement of "no solid waste out of the plant", use the dust compact to reduce the positive pressure of the dry dust collector and prevent explosion leakage, the purpose of the present application is to provide a method for preventing explosion leakage caused by using dust compact of a converter, which optimizes the iron charging mode, slows down the instantaneous pressure generated at the converter mouth, and controls the mixed concentration of CO and O2 in the converter flue gas to be below the explosion limit.

[0004] To solve the above technical problems, the present application adopts the following technical scheme:

[0005] The present application provides a method for preventing explosion leakage caused by using dust compact of a converter, which comprises the following steps:

[0006] 1) Before iron charging, the oxygen lance is set at a position of 100-300 mm (such as 100 mm, 150 mm, 180 mm, 200 mm, 220 mm, 250 mm, 280 mm or 300 mm) on the waiting position, so that the nitrogen gas stream blown out by the oxygen lance covers the converter mouth;

[0007] 2) In the process of mixing iron, manually open the top blowing nitrogen valve, adjust the valve opening degree to 28-22%, the flow rate is 25-35%, use the pressure generated by nitrogen flow to offset the pressure generated by the explosion of dust compact powder, at the same time, disrupt the airflow and inhibit the influence of explosion pressure on the electric field;

[0008] 3) After the end of mixing iron, nitrogen sweeps the flue, use nitrogen to form a piston type flue gas column to push the residual air in the flue gas pipeline to the diffusion chimney;

[0009] 4) Close the nitrogen cut-off valve first, then exhaust the nitrogen in the oxygen lance pipeline, and then close the nitrogen valve; avoid mixing nitrogen in the blowing process and cause quality accidents.

[0010] Further, in the step 2), the flow rate is controlled at 12000-15000nm 3 / h (such as 12000nm 3 / h, 13000nm 3 / h, 14000nm 3 / h, 15000nm 3 / h).

[0011] Further, in the step 3), nitrogen sweeps the flue for 1-2 minutes after the end of mixing iron.

[0012] Further, in the step 3), use non-explosive nitrogen to separate the CO-rich converter flue gas generated by the converter from O2 in the air, and control the mixing concentration of CO and O2 outside the explosion limit range.

[0013] Further, the method does not generate positive pressure.

[0014] Compared with the prior art, the beneficial technical effects of the present application are:

[0015] The present application effectively reduces or eliminates the explosion of the converter when using dust compact.

[0016] Protect the electric field equipment state and improve the service life of the equipment.

[0017] Reduce production interruption due to explosion and effectively improve the production efficiency of the converter. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application will be further described below in conjunction with the drawings.

[0019] Figure 1 The electric field curve when the dust compact explodes;

[0020] Figure 2The electric field curve of the dust removal ash compactor after using the method of this patented invention. Detailed Implementation

[0021] A method for preventing explosions caused by the use of dust collector ash briquettes in converters includes:

[0022] 1. Before adding iron, set the oxygen lance to a position 100-300mm above the waiting position so that the nitrogen stream blown out by the oxygen lance covers the converter mouth.

[0023] 2. During the iron mixing process, manually open the top-blown nitrogen valve, adjust the valve opening to 20%, and set the flow rate to approximately 30% (12000-15000 nm). 3 / h). The pressure generated by the nitrogen stream is used to counteract and eliminate the pressure generated by the explosion of dust and ash briquettes, while simultaneously disrupting the airflow and suppressing the impact of the explosion pressure on the electric field;

[0024] 3. After the iron-boiling furnace is finished, the flue is purged with nitrogen for 1-2 minutes. The purpose is to use nitrogen to form a piston-like flue gas column, which continuously pushes the residual air in the flue gas pipe to be discharged to the vent chimney. The non-explosive nitrogen is used to isolate the CO-rich converter flue gas produced by the converter from the O2 in the air, and to control the mixed concentration of CO and O2 outside the explosion limit range.

[0025] 4. First, close the nitrogen shut-off valve to purge the nitrogen from the oxygen lance pipeline, then close the main nitrogen valve. This is to prevent nitrogen from entering during the blowing process and causing quality accidents.

[0026] like Figure 1 The figure shows the electric field curve during the explosion venting process using dust collector ash briquettes, generating a positive pressure of 30.51 Pa. Figure 2 As shown, the electric field curve of the dust removal ash block after using the method of this patented invention is shown. No positive pressure is generated, and the electric field pressure is -0.99pa.

[0027] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method of preventing an explosion venting from a compacting of dust from a converter, characterized in that: It comprises the following steps: 1) Set the oxygen lance at the waiting position 100-300 mm before iron feeding, so that the nitrogen stream blown by the oxygen lance covers the converter mouth; 2) Manually open the top blowing nitrogen valve during iron feeding, adjust the valve opening degree to 28-22%, and the flow to 25-35%, use the pressure generated by the nitrogen stream to offset the pressure generated by the dust compact powder explosion, at the same time, disrupt the airflow and inhibit the influence of the explosion pressure on the electric field; 3) After the iron feeding and stirring are completed, the nitrogen is used to blow the flue again, and a piston type flue gas column is formed to push the residual air in the flue gas pipeline to the exhaust chimney; 4) First, close the nitrogen cut-off valve to exhaust the nitrogen in the oxygen lance pipeline, and then close the nitrogen main valve; avoid mixing nitrogen during blowing, which may cause quality accidents; In the step 3), the non-explosive nitrogen is used to isolate the CO-rich converter flue gas generated by the converter from O2 in the air, and the mixing concentration of CO and O2 is controlled outside the explosive limit range.

2. The method of preventing an explosion venting event from a dust agglomerate in a converter as defined in claim 1, wherein: The flow control in step 2) is 12000-15000 Nm 3 / h.

3. The method of preventing an explosion venting event from a dust agglomerate in a converter as defined in claim 1, wherein: In the step 3), the nitrogen is used to blow the flue for 1-2 minutes after the iron feeding and stirring are completed.

4. The method of preventing an explosion venting event from a dust agglomerate in a converter as defined in claim 1, wherein: By using the method, no positive pressure is generated.

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