Slag adhering method suitable for furnace kiln adopting top-blown sinking smelting technology

Abstract

The invention discloses a slag adhering method suitable for a top-blown sinking smelting technology furnace. The slag adhering method specifically comprises the following steps: (1) early-stage slag adhering operation; (2) halfway material stopping and slag adhering operation; (3) after the smelting period, slag adhering operation is finished; and (4) heat preservation operation of the heat preservation burner. According to the method, rapid slag adhering to the furnace wall can be effectively achieved, the scouring force of a molten pool to a furnace lining and the risk that furnace bricks are flaked off are effectively reduced, and therefore the service life of the furnace bricks is prolonged, the operation period is prolonged, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of nonferrous metallurgy, and more particularly to a slagging method suitable for a top-blown sinking smelting furnace. Background Art

[0002] The top-blown submerged metallurgical furnace process is a molten pool submerged technology that integrates the entire oxidation, reduction, and volatilization process. It features a simple furnace structure, high operational flexibility, environmental friendliness, large material handling capacity, strong adaptability, low impurity requirements, and low energy consumption. However, it also has many technical imperfections, with short furnace life being its most significant drawback. Since its commissioning in 2012, the short furnace life of the top-blown submerged metallurgical furnace has been a major bottleneck restricting its production and driving up costs.

[0003] The top-blown submerged metallurgical furnace is a typical lance-operated, oxygen-enriched, immersion-type, strong-oxidizing furnace. Large quantities of air and enriched oxygen are continuously injected into the molten pool via lances on the top of the furnace, causing the molten pool to churn constantly. The materials entering the furnace undergo a series of reactions under the thorough stirring of the lances. The strong stirring action of this process creates a strong scouring of the refractory bricks in the furnace lining. The highly oxidizing atmosphere generates a large amount of ferroferric oxide, which causes the temperature of the melt in the furnace to fluctuate rapidly. Therefore, a small amount of slag or brick spalling is unavoidable during normal smelting production, but generally does not affect production organization. If large-scale brick spalling occurs in the furnace, it increases the risk of the furnace shell burning through and a large amount of high-temperature melt overflowing, causing burns and fires from the high-temperature melt splashing. This makes slag discharge at the front of the furnace difficult, increases labor intensity, and poses environmental pollution risks such as harmful heavy metal fumes and continuous production costs. Therefore, when large areas of furnace bricks are peeling off in the furnace, it is necessary to stop the furnace and slag as soon as possible before smelting operations can be carried out. Different flexible slag methods need to be adopted according to the height and height of the peeling furnace bricks.

[0004] Therefore, how to develop a slagging method suitable for top-blown sinking smelting technology furnace to strengthen the slagging of the furnace wall is a problem that technicians in this field urgently need to solve. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a slag hanging method suitable for a top-blown sinking smelting technology furnace to solve the shortcomings of the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A slagging method applicable to a top-blown submerged smelting technology furnace comprises the following steps:

[0008] (1) Early slagging operation

[0009] Before feeding, use a probe to determine the starting molten pool, insert the spray gun into the molten pool to strengthen slagging, stop feeding for slagging operation, increase the air flow of the spray gun, add lump coal, control the furnace pressure to -5~5Pa, control the Fe / SiO2 ratio to 1.6~1.7 during the slagging period, and control the slag temperature to 1260~1300℃. Take advantage of the high melting point of magnetic iron to increase the magnetite content of the slag. The number of slagging times per furnace period should be no less than 3. After multiple slagging, check whether the slagging in the brick-dropping area is normal. If the slagging effect is poor, stop production and continue slagging.

[0010] The main chemical reaction of the process is: C+O2=CO2△H(standard condition)=-393.5kJ / mol

[0011] (2) Stopping the material and hanging slag during the process

[0012] Before discharging slag for the second time in front of the furnace, stop the material and carry out slagging operation midway. Use a probe to determine the height of the molten pool. At this time, the molten pool is relatively high. Lower the spray gun to the molten pool for multiple strengthening slagging. Increase the air flow of the spray gun and add lump coal. The furnace pressure is controlled at -5~5Pa. The Fe / SiO2 ratio is controlled at 1.6~1.7 during the slagging period and 1.5~1.6 during the copper making period. The slag temperature is controlled at 1260~1300℃. Taking advantage of the high melting point of magnetic iron, increase the magnetite content of the slag. The number of slagging times per furnace period is not less than 3. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging.

[0013] The main chemical reaction of the process is: C+O2=CO2△H(standard condition)=-393.5kJ / mol

[0014] (3) Slag hanging operation at the end of smelting period

[0015] At the end of copper making, use a probe to determine the height of the molten pool. Taking advantage of the high melting point of the molten pool, lower the spray gun into the molten pool for multiple strengthening slagging, increase the air flow of the spray gun, add lump coal, control the furnace pressure to -5~-10Pa, control the Fe / SiO2 ratio to 1.6~1.7 during the slagging period, control the Fe / SiO2 ratio to 1.5~1.7 during the copper making period, control the slag temperature to 1240~1280℃, and the melt discharge temperature to 1210~1240℃. Taking advantage of the high melting point of magnetic iron, increase the magnetite content of the slag. The number of slagging times per furnace period is no less than 3. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, continue to slagging multiple times.

[0016] The main chemical reaction of the process is: C+O2=CO2△H(standard condition)=-393.5kJ / mol

[0017] (4) Insulation burner insulation operation

[0018] After copper making is completed, the slag and melt are discharged and the spray gun is replaced. At this time, a diesel burner is used to keep the entire furnace and melt warm. The return oil pressure is controlled at 0.8-0.9 MPa and the furnace pressure is controlled at -2-5 Pa. The insulation effect of the furnace is observed on site at the top feed port to prevent thermal vibration from causing the furnace bricks to continue to fall.

[0019] The main chemical reactions in the process are: 2C 16 H 34 +49O2=CO2+34H2O△H(standard conditions)=-435.7kJ / mol.

[0020] Furthermore, in the above step (1), the spray gun is inserted into the area 200-300 mm above the molten pool or 200-300 mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the timing of stopping the feeding is 30-40 minutes, and the feeding amount is 30-40 tons; the air flow rate of the spray gun is 13000-19000 Nm 3 / h.

[0021] Furthermore, in the above step (1), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1.5-2 t / h, and a fuel coefficient of 6600-7500 Nm 3 / t, the excess air coefficient is 100% to 120%.

[0022] A further beneficial effect of the above method is that the heat generated by the combustion of lump coal is used to increase the slag temperature.

[0023] Furthermore, in the above step (2), the timing of stopping the material is when the total feed amount is 130-150t; the molten pool height is determined to be 2000mm by a probe rod; the spray gun is lowered to the area 200-300mm above the molten pool or 200-300mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the spray gun air flow rate is 13000-19000Nm 3 / h.

[0024] Furthermore, in the above step (2), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1.5-2 t / h, and a fuel coefficient of 6600-7500 Nm 3 / t, the excess air coefficient is 100% to 120%.

[0025] A further beneficial effect of the above method is that the heat generated by the combustion of lump coal is used to increase the slag temperature.

[0026] Furthermore, in the above step (2), the magnetite content of the slag is 42%.

[0027] A further beneficial effect of adopting the above-mentioned method is that the method of stopping the material and hanging slag midway of the present invention, by adding a small amount of lump coal and blowing in a large flow of lance air, makes the lump coal fully burn, increases the magnet content of the slag, utilizes the high melting point of magnetic iron, enhances the hanging slag effect, and reduces the risk of magnetic iron being reduced.

[0028] Furthermore, in the above step (3), the molten pool height is determined to be 2200mm by using a probe rod; the spray gun is lowered to the area 200-300mm above the molten pool or 200-300mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the spray gun air flow rate is 20000Nm 3 / h, enter C2 mode, set C2 air volume to 13000~15000Nm 3 / h.

[0029] Furthermore, in the above step (3), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1-1.5 t / h, and a fuel coefficient of 7500 Nm 3 / t, the excess air coefficient is 50%.

[0030] A further beneficial effect of the above method is that the heat generated by the combustion of lump coal is used to increase the slag temperature.

[0031] Furthermore, in the above step (3), the magnetite content of the slag is 36%.

[0032] A further beneficial effect of the above-mentioned method is that the slagging operation method at the end of the smelting period of the present invention utilizes the characteristics of high viscosity and large slag splashing of the high and low temperature slag in the molten pool to repeatedly strengthen the slagging of the furnace wall, thereby avoiding the risk of the slag on the furnace wall being melted by high temperature.

[0033] Furthermore, in the above step (4), the diesel is 0# national standard diesel, and the air-oil ratio ignition coefficient is 10-13Nm 3 / kg, the excess air ignition coefficient is 1.0~1.5Nm 3 / kg, the combustion air flow rate is 7000~8500Nm 3 / h, fuel consumption is 500-600kg / h.

[0034] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. The present invention makes full use of the characteristics of different molten pool heights and different slag splashing heights of top-blown submerged metallurgical furnaces to carry out all-round slagging on the furnace wall. The lance is raised to the surface of the molten pool or above the molten pool, and an appropriate amount of lump coal is added. The furnace wall is frequently slagging with high-speed and high-flow lance air, and the furnace chamber maintains a slight positive pressure during the insulation period.

[0036] 2. The present invention has formed a set of "one hanging, two stabilizations and four constant" operation methods. One hanging is to perform slag hanging operation, two stabilizations are to stabilize the composition of materials entering the furnace and the slag type, and four constants are to control the constant amount of materials, constant flow, constant temperature of the melt and constant molten pool.

[0037] 3. Through the implementation of the slagging method of the present invention, the slagging effect of the lining of the top-blown sunken metallurgical furnace is significantly improved. The slag of 30 to 50 mm can be attached to the peeling part of the furnace bricks, which basically solves the problem that the lining of the top-blown sunken metallurgical furnace cannot be slaged.

[0038] 4. Through the implementation of the slagging method of the present invention, the average slagging on the furnace wall of the top-blown submerged metallurgical furnace is increased from the previous 100 mm to more than 200 mm, effectively reducing the risk of the furnace steel shell burning through and a large amount of high-temperature melt overflowing, causing high-temperature melt splashing and burns, and causing fire.

[0039] 5. The powerful multiple slag hanging method of the present invention effectively protects the furnace bricks, prevents the risk of furnace bricks peeling and collapsing, and realizes a new operation method of using slag to resist slag and protecting bricks with slag.

[0040] 6. The method of the present invention can effectively achieve rapid slagging of the furnace wall, effectively reduce the scouring force of the molten pool on the furnace lining and the risk of flaking of furnace bricks, thereby extending the service life of furnace bricks, improving the operation cycle and reducing production costs.

[0041] 7. Controlling the slag temperature, iron-silicon ratio, lance air volume and lance position at different stages are key control parameters of the present invention. The control parameters and operating steps involved in the present invention can be flexibly adjusted according to the degree and height of furnace brick spalling, and can be widely promoted and applied to the same or similar metallurgical furnaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the structure of a top-blown sunken metallurgical furnace;

[0043] Among them, 1-furnace body, 2-diesel burner, 3-charging system, 4-coal bunker, 5-furnace top feeding port, 6-spray gun, 7-detection rod;

[0044] Figure 2 This is a process flow chart for the slagging method of a top-blown sinking smelting technology furnace. DETAILED DESCRIPTION

[0045] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0046] Example 1

[0047] Take the Φ5×16m top-blown sunken metallurgical furnace (blister copper smelting process) as an example. Figure 1 As shown, the furnace comprises a furnace body 1, a feeding system 3, and a lump coal bunker 4. The top of the furnace body 1 is provided with a furnace top feeding port 5, a lance 6, a diesel burner 2, and a probe 7, from left to right. The lump coal bunker 4 is connected to the furnace top feeding port 5 via the feeding system 3. Due to a process failure, the furnace bricks of a top-blown sunken metallurgical furnace peeled off approximately 9,000 mm from the furnace bottom, resulting in a furnace shutdown and slagging.

[0048] The slagging method is applicable to top-blown sinking smelting technology furnaces, such as Figure 2 As shown, the specific steps include:

[0049] (1) Early slagging operation

[0050] Before feeding, use the probe 7 to determine the starting molten pool, insert the spray gun 6 to the area 200mm above the molten pool to strengthen the slag hanging. The position of the spray gun 6 can be flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. When the feeding time is 30min and the feeding amount is 30t, stop the feeding and carry out the slag hanging operation. Increase the air flow of the spray gun 6 to 13000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.5t / h, and a fuel coefficient of 6600Nm 3 / t, the excess air coefficient is 100%, the furnace pressure is controlled at -5Pa, the Fe / SiO2 in the slagging stage is controlled at 1.6, the slag temperature is controlled at 1260℃, and the high melting point of magnetic iron is used to increase the magnet content of the slag. Slagging is carried out 3 times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging;

[0051] (2) Stopping the material and hanging slag during the process

[0052] Before the second slag discharge in front of the furnace and when the total feed volume is 130t, the feed is stopped and slag is added. The molten pool height is determined to be 2000mm by the probe rod 7. At this time, the molten pool is relatively high. The spray gun 6 is lowered to the area 200mm above the molten pool to strengthen the slag addition several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 17000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.5t / h, and a fuel coefficient of 6600Nm 3 / t, the excess air coefficient is 100%, the furnace pressure is controlled at -5Pa, the Fe / SiO2 ratio is controlled at 1.6 during the slagging period, the Fe / SiO2 ratio is controlled at 1.5 during the copper making period, the slag temperature is controlled at 1260℃, and the magnetite content of the slag is increased to 42% by taking advantage of the high melting point of magnetic iron. Slag is added three times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging for three more times. If the slagging effect is good, resume feeding;

[0053] (3) Slag hanging operation at the end of smelting period

[0054] At the end of copper making, the detection rod 7 is used to determine that the molten pool height is 2200mm. Taking advantage of the high melting point of the molten pool, the spray gun 6 is lowered to the area 200mm above the molten pool to strengthen the slag hanging several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 20000Nm 3 / h, enter C2 mode, set C2 air volume to 13000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1t / h, and a fuel coefficient of 7500Nm 3 / t, the excess air coefficient is 50%, the furnace pressure is controlled at -5Pa, the Fe / SiO2 ratio is controlled at 1.6 during the slagging period, and the Fe / SiO2 ratio is controlled at 1.5 during the copper making period, the slag temperature is controlled at 1240℃, the melt discharge temperature is 1210℃, and the magnetite content of the slag is increased to 36% by taking advantage of the high melting point of magnetic iron. Slag is added three times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, continue to add slag multiple times;

[0055] (4) Insulation burner insulation operation

[0056] After copper making is completed, the slag is discharged, the melt is discharged and the spray gun 6 is replaced. At this time, the diesel burner 2 is used to keep the entire furnace and melt warm. The diesel is 0# national standard diesel, and the air-oil ratio ignition coefficient is 10Nm 3 / kg, the excess air ignition coefficient is 1.0Nm 3 / kg, the combustion air flow rate is 7000Nm 3 / h, oil consumption is 500kg / h, return oil pressure is controlled at 0.8Mpa, furnace pressure is controlled at -2Pa, and the insulation effect in the furnace is observed on-site at the furnace top feed port 5 to avoid thermal vibration causing the furnace bricks to continue falling.

[0057] After implementing the above solution, the average slag thickness of the top-blown submerged metallurgical furnace bricks at approximately 9,000 mm from the furnace bottom can reach 200-300 mm. As the number of slag removal operations increases, the maximum slag thickness can reach 400 mm, enabling rapid slag removal of the furnace walls. The resulting slag effectively protects the furnace bricks from direct contact with the melt, forming a protective layer that effectively reduces the impact of the molten pool on the furnace lining and the risk of brick flaking. This can extend the operating cycle by 6-8 months, saving over 1.5 million yuan in production costs.

[0058] Example 2

[0059] Take the Φ5×16m top-blown sunken metallurgical furnace (blister copper smelting process) as an example. Figure 1 As shown, the furnace comprises a furnace body 1, a feeding system 3, and a lump coal bunker 4. The top of the furnace body 1 is provided with a furnace top feeding port 5, a lance 6, a diesel burner 2, and a probe 7, from left to right. The lump coal bunker 4 is connected to the furnace top feeding port 5 via the feeding system 3. A process failure caused the furnace bricks of a top-blown sunken metallurgical furnace to peel off approximately 12,000 meters from the furnace bottom, resulting in a furnace shutdown and slagging.

[0060] The slagging method is applicable to top-blown sinking smelting technology furnaces, such as Figure 2 As shown, the specific steps include:

[0061] (1) Early slagging operation

[0062] Before feeding, use the probe 7 to determine the starting molten pool, insert the spray gun 6 to the area 300mm above the molten pool to strengthen the slag hanging. The position of the spray gun 6 can be flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. When the feeding time is 35min and the feeding amount is 35t, stop the feeding and carry out the slag hanging operation. Increase the air flow of the spray gun 6 to 15000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.8t / h, and a fuel coefficient of 7000Nm 3 / t, the excess air coefficient is 110%, the furnace pressure is controlled at 0Pa, the Fe / SiO2 in the slagging stage is controlled at 1.65, the slag temperature is controlled at 1280℃, and the high melting point of magnetic iron is used to increase the magnet content of the slag. Slagging is carried out 4 times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging;

[0063] (2) Stopping the material and hanging slag during the process

[0064] Before the second slag discharge in front of the furnace and when the total feed volume is 140t, the feed is stopped and slag is added. The molten pool height is determined to be 2000mm by the probe rod 7. At this time, the molten pool is relatively high. The spray gun 6 is lowered to the area 300mm above the molten pool to strengthen the slag addition several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 18000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.8t / h, and a fuel coefficient of 7000Nm 3 / t, the excess air coefficient is 110%, the furnace pressure is controlled at 0Pa, the Fe / SiO2 in the slagging stage is controlled at 1.65, the Fe / SiO2 in the copper making stage is controlled at 1.55, the slag temperature is controlled at 1280℃, and the magnetite content in the slag is increased to 42% by taking advantage of the high melting point of magnetic iron. The slag is added 4 times per furnace period. After multiple slagging, check whether the slagging in the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging for 4 more times. If the slagging effect is good, resume feeding.

[0065] (3) Slag hanging operation at the end of smelting period

[0066] At the end of copper making, the detection rod 7 is used to determine that the molten pool height is 2200mm. Taking advantage of the high melting point of the molten pool, the spray gun 6 is lowered to the area 300mm above the molten pool to strengthen the slag hanging several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 20000Nm 3 / h, enter C2 mode, set C2 air volume to 14000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.2t / h, and a fuel coefficient of 7500Nm 3 / t, the excess air coefficient is 50%, the furnace pressure is controlled at -8Pa, the Fe / SiO2 ratio is controlled at 1.65 during the slagging period, the Fe / SiO2 ratio is controlled at 1.55 during the copper making period, the slag temperature is controlled at 1260℃, the melt discharge temperature is 1220℃, and the magnetite content of the slag is increased to 36% by taking advantage of the high melting point of magnetic iron. Slag is added 4 times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, continue to add slag multiple times;

[0067] (4) Insulation burner insulation operation

[0068] After copper making is completed, the slag is discharged, the melt is discharged and the spray gun 6 is replaced. At this time, the diesel burner 2 is used to keep the entire furnace and melt warm. The diesel is 0# national standard diesel, and the air-oil ratio ignition coefficient is 12Nm 3 / kg, the excess air ignition coefficient is 1.2Nm 3 / kg, the combustion air flow rate is 8000Nm 3 / h, the oil consumption is 550kg / h, the return oil pressure is controlled at 0.85Mpa, the furnace pressure is controlled at 2Pa, and the insulation effect in the furnace is observed on-site at the furnace top feed port 5 to avoid thermal vibration causing the furnace bricks to continue falling.

[0069] After implementing the above solution, the average slag thickness of a top-blown submerged metallurgical furnace bricks at a height of approximately 12,000 mm from the furnace bottom can reach 150-200 mm. As the number of slag removal operations increases, the maximum slag thickness can reach 350 mm, enabling rapid slag removal of the furnace walls. The resulting slag effectively protects the furnace bricks from direct contact with the melt, forming a protective layer that effectively reduces the impact of the molten pool on the furnace lining and the risk of brick flaking. This can extend the operating cycle by 8-10 months, saving over 2 million RMB in production costs.

[0070] Example 3

[0071] Take the Φ5×16m top-blown sunken metallurgical furnace (blister copper smelting process) as an example. Figure 1 As shown, the furnace comprises a furnace body 1, a feeding system 3, and a lump coal bunker 4. The top of the furnace body 1 is provided with a furnace top feeding port 5, a lance 6, a diesel burner 2, and a probe 7, from left to right. The lump coal bunker 4 is connected to the furnace top feeding port 5 via the feeding system 3. A process failure caused the furnace bricks of a top-blown submerged metallurgical furnace to peel off approximately 14,000 mm from the furnace bottom, resulting in a furnace shutdown and slagging.

[0072] The slagging method is applicable to top-blown sinking smelting technology furnaces, such as Figure 2 As shown, the specific steps include:

[0073] (1) Early slagging operation

[0074] Before feeding, use the probe 7 to determine the starting molten pool, insert the spray gun 6 to the area 300mm below the molten pool to strengthen the slag hanging. The position of the spray gun 6 can be flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. When the feeding time is 40min and the feeding amount is 40t, stop the feeding and carry out the slag hanging operation. Increase the air flow of the spray gun 6 to 19000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 2t / h, and a fuel coefficient of 7500Nm 3 / t, the excess air coefficient is 120%, the furnace pressure is controlled at 5Pa, the Fe / SiO2 ratio in the slagging stage is controlled at 1.7, the slag temperature is controlled at 1300℃, and the high melting point of magnetic iron is used to increase the magnet content of the slag. Slag is added 5 times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging;

[0075] (2) Stopping the material and hanging slag during the process

[0076] Before the second slag discharge in front of the furnace and when the total feed volume is 150t, the feed is stopped and slag is added. The molten pool height is determined to be 2000mm by the probe rod 7. At this time, the molten pool is relatively high. The spray gun 6 is lowered to the area 300mm below the molten pool to strengthen the slag addition several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 19000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 2t / h, and a fuel coefficient of 7500Nm 3 / t, the excess air coefficient is 120%, the furnace pressure is controlled at 5Pa, the Fe / SiO2 ratio is controlled at 1.7 during the slagging period, the Fe / SiO2 ratio is controlled at 1.6 during the copper making period, the slag temperature is controlled at 1300℃, and the magnetite content of the slag is increased to 42% by taking advantage of the high melting point of magnetic iron. Slag is added 5 times per furnace period. After multiple slagging, check whether the slagging in the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging for 5 more times. If the slagging effect is good, resume feeding.

[0077] (3) Slag hanging operation at the end of smelting period

[0078] At the end of copper making, the detection rod 7 is used to determine that the molten pool height is 2200mm. Taking advantage of the high melting point of the molten pool, the spray gun 6 is lowered to the area 300mm below the molten pool to strengthen the slag hanging several times. The position of the spray gun 6 is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity. The air flow of the spray gun 6 is increased to 20000Nm 3 / h, enter C2 mode, set C2 air volume to 15000Nm 3 / h, adding anthracite with a fixed carbon content of ≥68%, a particle size of 5-15mm, a conveying speed of 1.5t / h, and a fuel coefficient of 7500Nm 3 / t, the excess air coefficient is 50%, the furnace pressure is controlled at -10Pa, the Fe / SiO2 ratio is controlled at 1.7 during the slagging period, the Fe / SiO2 ratio is controlled at 1.7 during the copper making period, the slag temperature is controlled at 1280℃, the melt discharge temperature is 1240℃, and the magnetite content of the slag is increased to 36% by taking advantage of the high melting point of magnetic iron. Slag is added 5 times per furnace period. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, continue to add slag multiple times;

[0079] (4) Insulation burner insulation operation

[0080] After copper making is completed, the slag is discharged, the melt is discharged and the spray gun 6 is replaced. At this time, the diesel burner 2 is used to keep the entire furnace and melt warm. The diesel is 0# national standard diesel, and the air-oil ratio ignition coefficient is 13Nm 3 / kg, the excess air ignition coefficient is 1.5Nm 3 / kg, the combustion air flow rate is 8500Nm 3 / h, the oil consumption is 600kg / h, the return oil pressure is controlled at 0.9Mpa, the furnace pressure is controlled at 5Pa, and the insulation effect in the furnace is observed on-site at the furnace top feed port 5 to avoid thermal vibration causing the furnace bricks to continue falling.

[0081] After implementing the above solution, the average slag thickness of a top-blown submerged metallurgical furnace bricks at a height of approximately 14,000 mm from the furnace bottom can reach 100-200 mm. As the number of slag removal operations increases, the maximum slag thickness can reach 350 mm, enabling rapid slag removal from the furnace walls. The resulting slag effectively protects the furnace bricks from direct contact with the melt, forming a protective layer that effectively reduces erosion of the furnace lining by the molten pool and the risk of brick flaking. This can extend the operating cycle by 9-12 months, saving over 2.5 million RMB in production costs.

[0082] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A slagging method suitable for a top-blown submerged smelting furnace, characterized in that: The specific steps include: (1) Early slagging operation Before feeding, use a probe to determine the starting molten pool, insert the spray gun into the molten pool to strengthen slagging, stop feeding for slagging operation, increase the air flow of the spray gun, add lump coal, control the furnace pressure to -5~5Pa, control the Fe / SiO2 ratio to 1.6~1.7 during the slagging period, and control the slag temperature to 1260~1300℃. Take advantage of the high melting point of magnetic iron to increase the magnetite content of the slag. The number of slagging times per furnace period should be no less than 3. After multiple slagging, check whether the slagging in the brick-dropping area is normal. If the slagging effect is poor, stop production and continue slagging. (2) Stopping the material and hanging slag during the process Before discharging slag for the second time in front of the furnace, stop the material and carry out slagging operation midway. Use a probe to determine the height of the molten pool. At this time, the molten pool is relatively high. Lower the spray gun to the molten pool for multiple strengthening slagging. Increase the air flow of the spray gun and add lump coal. The furnace pressure is controlled at -5~5Pa. The Fe / SiO2 ratio is controlled at 1.6~1.7 during the slagging period and 1.5~1.6 during the copper making period. The slag temperature is controlled at 1260~1300℃. Taking advantage of the high melting point of magnetic iron, increase the magnetite content of the slag. The number of slagging times per furnace period is not less than 3. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, stop the production operation and continue slagging. (3) Slag hanging operation at the end of smelting period At the end of copper making, use a probe to determine the height of the molten pool. Taking advantage of the high melting point of the molten pool, lower the spray gun into the molten pool for multiple strengthening slagging, increase the air flow of the spray gun, add lump coal, control the furnace pressure to -5~-10Pa, control the Fe / SiO2 ratio to 1.6~1.7 during the slagging period, control the Fe / SiO2 ratio to 1.5~1.7 during the copper making period, control the slag temperature to 1240~1280℃, and the melt discharge temperature to 1210~1240℃. Taking advantage of the high melting point of magnetic iron, increase the magnetite content of the slag. The number of slagging times per furnace period is no less than 3. After multiple slagging, check whether the slagging of the brick-dropping area is normal. If the slagging effect is poor, continue to slagging multiple times. (4) Insulation burner insulation operation After copper making is completed, the slag and melt are discharged and the spray gun is replaced. At this time, a diesel burner is used to keep the entire furnace and melt warm. The return oil pressure is controlled at 0.8~0.9Mpa, and the furnace pressure is controlled at -2~5Pa. The insulation effect in the furnace is observed on-site at the furnace top feed port to avoid thermal vibration causing the furnace bricks to continue falling.

2. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (1), the spray gun is inserted into the area 200-300 mm above the molten pool or 200-300 mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the timing of stopping the feeding is 30-40 minutes, and the feeding amount is 30-40 tons; the air flow rate of the spray gun is 13000-19000 Nm 3 / h.

3. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (1), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1.5-2 t / h, and a fuel coefficient of 6600-7500 Nm 3 / t, the excess air coefficient is 100% to 120%.

4. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (2), the timing of stopping the material is when the total feed amount is 130-150t; the height of the molten pool is determined to be 2000mm by the probe rod; the spray gun is lowered to the area 200-300mm above the molten pool or 200-300mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the air flow rate of the spray gun is 13000-19000Nm 3 / h.

5. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (2), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1.5-2 t / h, and a fuel coefficient of 6600-7500 Nm 3 / t, the excess air coefficient is 100% to 120%.

6. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (2), the slag has a magnetite content of 42%.

7. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (3), the molten pool height is determined to be 2200mm by using a probe rod; the spray gun is lowered to an area 200-300mm above the molten pool or 200-300mm below the molten pool; the position of the spray gun is flexibly adjusted according to the molten pool height, furnace temperature and slag splashing intensity; the air flow rate of the spray gun is 20000Nm 3 / h, enter C2 mode, set C2 air volume to 13000~15000Nm 3 / h.

8. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (3), the lump coal is anthracite with a fixed carbon content of ≥68%, a particle size of 5-15 mm, a conveying speed of 1-1.5 t / h, and a fuel coefficient of 7500 Nm 3 / t, the excess air coefficient is 50%.

9. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (3), the slag has a magnetite content of 36%.

10. The slagging method for a top-blown submerged smelting furnace according to claim 1, characterized in that: In step (4), the diesel is 0# national standard diesel, and the air-oil ratio ignition coefficient is 10-13Nm 3 / kg, the excess air ignition coefficient is 1.0~1.5Nm 3 / kg, the combustion air flow rate is 7000~8500Nm 3 / h, fuel consumption is 500-600kg / h.

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