Method for accelerating molten pool making speed of bottom blowing furnace by using oxygen lance

Abstract

The invention discloses a method for accelerating the molten pool making speed of a bottom-blowing furnace by using an oxygen lance, which comprises the following steps: S1, determining the opening condition of the oxygen lance according to the hearth structure of the bottom-blowing furnace and the position of cold matte; s2, the oxygen flow for opening the oxygen lance is precisely controlled, and the oxygen flow is made to be matched with the requirement for combustion of natural gas in the furnace; s3, the oxygen lance is protected through an oxygen lance protection sleeve; s4, the melting condition of the cold matte in the furnace is monitored in real time, and the opening condition of an oxygen lance is adjusted; and S5, monitoring the liquid level height of the molten pool through the measuring rod until the molten pool is constructed. According to the method, the molten pool making time of a traditional bottom blowing furnace is shortened from 24-36 hours to 12-15 hours through centralized oxygen supply and accurate heating of the oxygen lance, the production progress is rapidly recovered, the shutdown period is remarkably shortened, and the production efficiency is greatly improved; meanwhile, the consumption of natural gas is reduced, and the energy consumption and cost are reduced; and through the compressed air protection device, the service life of the oxygen lance is effectively prolonged, and the equipment loss is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of copper smelting in a bottom blowing furnace, and specifically relates to a method for accelerating the speed of forming a molten pool in a bottom blowing furnace by utilizing an oxygen lance. Background Art

[0002] Bottom-blown furnace copper smelting technology is an efficient copper smelting process, which is widely used in the field of copper smelting. After running for 1 to 3 years, the bottom-blown furnace needs to be shut down for regular maintenance due to the burning of refractory materials and damage to auxiliary equipment. After the maintenance is completed, the first task of resuming production is to rebuild the molten pool, that is, to melt the cold copper matte in the furnace to a certain liquid level to meet the normal production needs of subsequent feeding.

[0003] At present, the method of making a molten pool by smelting copper in a bottom-blown furnace mainly relies on the main burner and the auxiliary burner to inject natural gas into the furnace, and the high temperature generated by the combustion melts the cold copper matte. The main and auxiliary burners are set above the furnace body, and the cold copper matte in the furnace is heated by injecting natural gas and burning to generate high temperature. The cold copper matte mainly absorbs heat through heat conduction and convection to complete melting. The operator gradually melts the cold copper matte to form a liquid molten pool by adjusting the flow rate and combustion intensity of the natural gas.

[0004] Melting by natural gas combustion is the core technology method of traditional bottom-blown furnace to make molten pool, and it is also the key process step to achieve rapid resumption of production after maintenance. However, the disadvantages of this method are:

[0005] 1. Low thermal efficiency: Since the main and auxiliary burners are set at a higher position, the cold copper matte at the bottom of the furnace is difficult to directly receive heat, the heat conduction efficiency is low, and the melting speed is slow.

[0006] 2. High natural gas consumption: In order to maintain sufficiently high temperature for long-term heating, a large amount of natural gas is required to be continuously supplied, resulting in excessive energy consumption and increased costs.

[0007] 3. High time cost: It usually takes 24-36 hours to complete the molten pool making process, which is time-consuming. It not only affects the company's production resumption progress, but also prolongs the shutdown cycle and restricts production efficiency. Summary of the invention

[0008] The object of the present invention is to provide a method for accelerating the molten pool forming speed of a bottom blowing furnace by using an oxygen lance with high thermal efficiency and low natural gas consumption.

[0009] The method provided by the present invention for accelerating the speed of forming a molten pool in a bottom blowing furnace by using an oxygen lance comprises the following steps:

[0010] S1. Determine the opening status of the oxygen lance according to the bottom blowing furnace structure and the position of the cold copper matte;

[0011] S2. Accurately control the oxygen flow rate of the oxygen lance to match the demand for natural gas combustion in the furnace;

[0012] S3. Protect the oxygen lance through an oxygen lance protective cover;

[0013] S4. Real-time monitoring of the melting of the cold copper matte in the furnace and adjustment of the opening of the oxygen lance;

[0014] S5. Monitor the liquid level of the molten pool by measuring the rod until the molten pool is completed.

[0015] Step S1 is specifically as follows: using a non-contact temperature sensor to monitor the distribution of cold copper matte in the furnace in real time; the sensor detects the temperature distribution of cold copper matte in the furnace through infrared thermal radiation; combining with the bottom blowing furnace observation hole, a comprehensive judgment is made on the spatial distribution and relative density area of ​​cold copper matte to determine the key areas that need to be heated; using the oxygen gun positioning system, the oxygen gun corresponding to the cold copper matte distribution area is selected, and adjusted through a mechanical adjustment device to ensure that the oxygen injection accurately acts on the area with the densest cold copper matte; the oxygen guns in the areas not covered by the cold copper matte remain closed; according to the melting demand of the cold copper matte area, the oxygen guns in the corresponding areas are gradually opened, and the oxygen guns in non-key areas are closed in real time.

[0016] Step S2 is specifically as follows: according to the current state of the molten pool, the initial flow rate of oxygen in the oxygen lance is set, and the flow rate range is dynamically adjusted to meet the heat demand in the furnace; the temperature distribution in the furnace is monitored by a temperature sensor: when the molten pool temperature is lower than 1200°C, the oxygen flow rate is gradually increased to increase the thermal intensity of the combustion reaction; when the local temperature is higher than 1400°C or the combustion is incomplete, the oxygen flow rate is reduced.

[0017] Step S3 is specifically as follows: the oxygen gun protective cover is made of a high temperature resistant and corrosion resistant composite material, and an insulating layer is arranged inside; a plurality of compressed air inlets are arranged on the outer shell of the oxygen gun protective cover, and compressed air is introduced to form a uniform annular wind curtain; the compressed air pressure is 3-6kg.

[0018] Step S4 is specifically as follows: observing the melting progress of the cold copper matte in real time through the bottom blowing furnace observation hole; analyzing the heat distribution of the molten pool in combination with the temperature sensor data; adjusting the opening and closing strategy of the oxygen gun, and adjusting the oxygen flow rate accordingly to ensure that the melting process continues to be efficient.

[0019] Step S5 is specifically as follows: the measuring rod has a three-section structure, including a measuring section, an adjusting section and an operating section: the measuring section is 600 mm long, the operating section is 4800 mm long, the adjusting section is a rigid hinge, and the angle can be adjusted from 120° to 150°; the measuring rod is made of a high-temperature resistant and corrosion-resistant high-chromium alloy, with a hollow interior and an inner diameter of 15 mm, which can be used to introduce cooling gas; an anti-adhesion coating is sprayed on the surface of the measuring rod; when using the measuring rod, slowly insert the measuring section of the measuring rod into the molten pool, and when the measuring section contacts the liquid surface, the color of the thermal coating changes; after being inserted into the molten pool and touching the bottom, stay for 10 to 20 seconds, and slowly extract the measuring rod, and the scale corresponding to the color difference on the measuring section is the liquid level; when the liquid level reaches the molten pool requirement standard, gradually close the oxygen gun and reduce the natural gas combustion intensity at the same time.

[0020] The beneficial effects of the present invention are:

[0021] Through centralized oxygen supply and precise heating through the oxygen lance, the time for making a molten pool in a traditional bottom-blown furnace is shortened from 24-36 hours to 12-15 hours, quickly resuming production progress, significantly shortening the downtime period, and greatly improving production efficiency; at the same time, the use of natural gas is reduced, reducing energy consumption and costs; finally, the precise positioning and flow regulation of the oxygen lance improves operational flexibility, and the compressed air protection device effectively extends the service life of the oxygen lance and reduces equipment loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technical solutions. Obviously, the described embodiments are only part of the embodiments, not all of the embodiments. 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.

[0024] like Figure 1 As shown, the method disclosed in this embodiment of using an oxygen lance to accelerate the speed of forming a molten pool in a bottom blowing furnace comprises the following specific steps:

[0025] S1. Determine the opening status of the oxygen lance according to the bottom blowing furnace structure and the position of the cold copper matte. The specific steps are as follows:

[0026] Use non-contact temperature sensors to monitor the distribution of cold copper matte in the furnace in real time. The sensor detects the temperature distribution of cold copper matte in the furnace through infrared thermal radiation to avoid interference with the measurement due to melt splashing.

[0027] Combined with the observation hole of the bottom blowing furnace, a comprehensive judgment is made on the spatial distribution and relative density area of ​​the cold copper matte to determine the key areas that need to be heated.

[0028] Use the oxygen lance positioning system to select the oxygen lance corresponding to the distribution area of ​​cold copper matte, and fine-tune it through the mechanical adjustment device to ensure that the oxygen injection is precisely applied to the area with the densest cold copper matte. The oxygen lance in the area not covered by cold copper matte remains closed to avoid oxygen waste.

[0029] According to the melting requirements of the cold copper matte area, the oxygen guns in the corresponding area are gradually opened, and the oxygen guns in non-key areas are closed in real time. By opening the oxygen guns one by one, the heat concentration in the target area is controlled to prevent overheating or local temperature out of control.

[0030] S2. Accurately control the oxygen flow rate of the oxygen gun to match the demand for natural gas combustion in the furnace. The specific steps are as follows:

[0031] According to the current state of the molten pool, the initial flow rate of oxygen in the oxygen lance is set, and the flow range is dynamically adjusted to meet the heat demand in the furnace.

[0032] Monitor the temperature distribution in the furnace through temperature sensors:

[0033] When the molten pool temperature is lower than 1200°C, gradually increase the oxygen flow rate to enhance the thermal intensity of the combustion reaction;

[0034] When the local temperature is higher than 1400℃ or the combustion is incomplete, reduce the oxygen flow rate to prevent local overheating.

[0035] By adjusting the ratio of oxygen to natural gas, the combustion reaction is ensured to be complete to achieve the best heating effect.

[0036] S3. Protect the oxygen lance through the oxygen lance protective cover. The specific steps are as follows:

[0037] The oxygen lance protective cover is made of high temperature resistant and corrosion resistant composite material, with an internal heat insulation layer to reduce the temperature of the oxygen lance nozzle and extend its service life.

[0038] A plurality of compressed air inlets are arranged on the outer shell of the oxygen lance protective cover, and compressed air is introduced to form a uniform annular wind curtain to isolate high-temperature smoke and melt splashes.

[0039] According to the temperature environment in the furnace, adjust the compressed air pressure to 3-6kg, which can effectively isolate the high temperature without affecting the thermal balance in the furnace.

[0040] S4. Real-time monitoring of the melting of the cold copper matte in the furnace and adjustment of the opening of the oxygen lance. The specific steps are as follows:

[0041] Through the bottom-blowing furnace observation hole, the melting progress of cold copper matte is observed in real time; combined with the temperature sensor data, the heat distribution of the molten pool is analyzed. The opening and closing strategies of the oxygen lance are adjusted, and the oxygen flow rate is adjusted accordingly to ensure that the melting process is continuously efficient; ensure that the combustion reaction of oxygen and natural gas is complete, and maintain the efficiency and stability of the melting process.

[0042] S5. Monitor the liquid level of the molten pool by measuring the rod until the molten pool is completed. The specific steps are as follows:

[0043] The measuring rod is a three-section structure, including the measuring section, the adjusting section and the operating section: the measuring section is 600mm long, the operating section is 4800mm long, the adjusting section is a rigid hinge, and the angle can be adjusted from 120° to 150°. The measuring rod is made of a high-temperature resistant and corrosion-resistant high-chromium alloy, with a hollow interior and an inner diameter of 15mm. Cooling gas can be introduced to reduce the rod temperature and extend its service life; the surface of the measuring rod is sprayed with an anti-adhesion coating (such as an aluminum oxide coating) to reduce melt adhesion.

[0044] When using a measuring rod, slowly insert the measuring section of the measuring rod into the molten pool. When the measuring section touches the liquid surface, the color of the thermosensitive coating changes. After inserting into the molten pool and touching the bottom, stay for 10 to 20 seconds and slowly withdraw the measuring rod. The scale corresponding to the color difference on the measuring section is the liquid level.

[0045] When the liquid level reaches the molten pool requirement standard, the oxygen lance is gradually closed, and the natural gas combustion intensity is reduced to enter a stable production stage.

[0046] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for accelerating the speed of forming a molten pool in a bottom blowing furnace by using an oxygen lance, characterized in that: The following steps are involved: S1. Determine the opening status of the oxygen lance according to the bottom blowing furnace structure and the position of the cold copper matte; S2. Accurately control the oxygen flow rate of the oxygen lance to match the demand for natural gas combustion in the furnace; S3. Protect the oxygen lance through an oxygen lance protective cover; S4. Real-time monitoring of the melting of the cold copper matte in the furnace and adjustment of the opening of the oxygen lance; S5. Monitor the liquid level of the molten pool by measuring the rod until the molten pool is completed.

2. The method for accelerating the molten pool formation speed of a bottom blowing furnace using an oxygen lance as claimed in claim 1, characterized in that: Step S1 is specifically as follows: Use non-contact temperature sensors to monitor the distribution of cold copper matte in the furnace in real time; the sensor detects the temperature distribution of cold copper matte in the furnace through infrared thermal radiation; combined with the bottom blowing furnace observation hole, make a comprehensive judgment on the spatial distribution and relative density area of ​​cold copper matte to determine the key areas that need to be heated; use the oxygen gun positioning system to select the oxygen gun corresponding to the cold copper matte distribution area, and adjust it through the mechanical adjustment device to ensure that the oxygen injection acts accurately on the area with the densest cold copper matte; the oxygen gun in the area not covered by cold copper matte remains closed; according to the melting demand of the cold copper matte area, the oxygen gun in the corresponding area is gradually opened, and the oxygen gun in the non-key area is closed in real time.

3. The method for accelerating the molten pool formation speed of a bottom blowing furnace by using an oxygen lance as claimed in claim 1, characterized in that: Step S2 is specifically as follows: According to the current state of the molten pool, the initial flow rate of oxygen in the oxygen lance is set, and the flow rate range is dynamically adjusted to meet the heat demand in the furnace; the temperature distribution in the furnace is monitored by a temperature sensor: when the molten pool temperature is lower than 1200℃, the oxygen flow rate is gradually increased to enhance the thermal intensity of the combustion reaction; when the local temperature is higher than 1400℃ or the combustion is incomplete, the oxygen flow rate is reduced.

4. The method for accelerating the molten pool formation speed of a bottom blowing furnace by using an oxygen lance as claimed in claim 1, characterized in that: Step S3 is specifically as follows: The oxygen gun protective cover is made of high temperature resistant and corrosion resistant composite material, with an internal heat insulation layer; multiple compressed air inlets are arranged on the outer shell of the oxygen gun protective cover to introduce compressed air to form a uniform annular wind curtain; the compressed air pressure is 3-6kg.

5. The method for accelerating the molten pool formation speed of a bottom blowing furnace by using an oxygen lance as claimed in claim 1, characterized in that: Step S4 is specifically as follows: Through the observation hole of the bottom blowing furnace, the melting progress of the cold copper matte can be observed in real time; combined with the temperature sensor data, the heat distribution of the molten pool can be analyzed; the opening and closing strategy of the oxygen gun can be adjusted, and the oxygen flow rate can be adjusted accordingly to ensure that the melting process continues to be efficient.

6. The method for accelerating the molten pool formation speed of a bottom blowing furnace by using an oxygen lance as claimed in claim 1, characterized in that: Step S5 is specifically as follows: The measuring rod is a three-section structure, including the measuring section, the adjusting section and the operating section. The measuring section is 600mm long, the operating section is 4800mm long, the adjusting section is a rigid hinge, and the angle can be adjusted from 120° to 150°. The measuring rod is made of a high-temperature resistant and corrosion-resistant high-chromium alloy, with a hollow interior and an inner diameter of 15mm, which can be used to introduce cooling gas. The surface of the measuring rod is sprayed with an anti-adhesion coating. When using the measuring rod, slowly insert the measuring section of the measuring rod into the molten pool. When the measuring section touches the liquid surface, the color of the thermosensitive coating changes. After inserting into the molten pool and touching the bottom, stay for 10 to 20 seconds, and slowly withdraw the measuring rod. The scale corresponding to the color difference on the measuring section is the liquid level. When the liquid level reaches the molten pool requirement standard, the oxygen lance is gradually closed and the natural gas combustion intensity is reduced.

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