Method for discharging high-temperature melt in top-blown furnace

Abstract

The invention discloses a method for discharging high-temperature melt in a top-blown furnace, and belongs to the technical field of non-ferrous metal smelting. The method specifically comprises the following steps: (1) preparing for feeding before blowing out; (2) discharging slag at regular intervals; (3) discharging crude copper; (4) quickly heating residual slag; (5) discharging residual residues; and (6) stepped cooling. According to the method, the thickness of the slag crust of the furnace wall can be reduced to the minimum limit, molten copper and slag in the furnace can be safely, rapidly and completely emptied, favorable conditions are created for subsequent overhaul, and the safe, environment-friendly, efficient and economical furnace shutdown effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of nonferrous metal smelting, and more particularly to a method for discharging high-temperature melt in a top-blown furnace. Background Art

[0002] In the nonferrous metallurgy industry, refractory bricks need to be replaced during furnace shutdowns and overhauls. Top-blown furnaces (such as top-blown oxygen converters and top-blown oxygen-enriched melting furnaces) are core equipment in the metallurgical industry, and the methods used to perform these maintenance procedures directly impact production efficiency and safety.

[0003] The traditional shutdown and maintenance method results in a large amount of residual melt in the furnace, low maintenance efficiency, and time-consuming and labor-intensive inspection. Residual melt or combustible gas in the furnace may cause explosions, increasing safety and environmental risks. The cooling time is relatively long, and natural cooling requires several days, affecting production continuity. Rapid cooling can easily cause cracks in the furnace body and shorten the furnace life.

[0004] Therefore, how to safely and quickly discharge the high-temperature melt in the top-blown furnace is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, an object of the present invention is to provide a method for discharging a high-temperature melt in a top-blown furnace to address the deficiencies in the prior art.

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

[0007] A method for discharging a high-temperature melt in a top-blown furnace comprises the following steps:

[0008] (1) Preparation for charging before shutdown

[0009] Before the top-blown furnace is shut down, copper matte is produced;

[0010] (2) Regular discharge of slag

[0011] After the copper making period is over, the spray gun is replaced, during which the heat preservation operation is carried out, the slag is discharged, the spray gun is lowered to stir the molten pool, and the slag is continued to be discharged;

[0012] (3) Discharge of crude copper

[0013] Use a spray gun to carry out insulation work and discharge the crude copper after reaching the standard;

[0014] (4) Rapid heating of the remaining slag

[0015] When the blister copper is discharged, the lump coal is transported to the top-blown furnace, the remaining melt is stirred at a low gun position, and oxygen-enriched air is continuously blown in using a lance to quickly heat and clean the furnace.

[0016] (5) Discharge of residual residue

[0017] Discharge the remaining residue in the furnace and perform heat preservation during the process;

[0018] (6) Step-by-step cooling

[0019] The furnace body is slowly cooled down in steps. After it drops to 450℃, it is kept at a constant temperature for 2 to 3 hours. After it drops to 350℃, it is kept at a constant temperature for 1 to 2 hours. After it drops to 200℃, it is stopped from being kept warm and cooled naturally.

[0020] Furthermore, in the above step (1), the main components of the copper matte are, by mass percentage, Cu 61%-65%, S 14%-15%, Fe 6%-8%, SiO2 0.6%-0.7%, CaO 0.2%-0.3%, MgO 0.2%-0.4%, Al2O3 0.08%-0.1%, ZnO 0.5%-0.6% and Pb 1%-1.3%; preferably, Cu 65%, S 13.8%, Fe 6.2%, SiO2 0.65%, CaO 0.2%, MgO 0.3%, Al2O3 0.1%, ZnO 0.5% and Pb 1.2%.

[0021] A further beneficial effect of adopting the above method is that high-grade copper matte production is put into production at a high limit organization, the thickness of the crude copper layer is increased, and the thickness of the remaining slag layer can be reduced when the slag mouth position is fixed; the high-grade copper matte is put into production, the slag volume is reduced, and the slag discharge time is shortened.

[0022] Furthermore, in the above step (1), during the operation of producing copper matte, the Fe / SiO2 ratio during the slag-making period is controlled at 1.1-1.8, the CaO content in the slag is controlled at 3%-7%, the slag temperature is controlled at 1270-1310°C, and the high-flow air flow of the spray gun is 13000-21000m 3 / h; preferably, the slag-making period Fe / SiO2 is 1.6, the CaO in the slag is 4.2%, the slag temperature is 1300 ℃, the spray gun has a large flow rate of 16500m 3 / h.

[0023] Furthermore, in the above step (1), during the operation of producing copper matte, the Fe / SiO2 ratio during the copper making period is controlled at 1.0-2.0, the slag temperature is controlled at 1250-1290°C, and the high flow air of the spray gun is 10000-26000m 3 / h; preferably, the copper making period Fe / SiO2 is 1.5, the slag temperature is 1250 ° C, and the spray gun has a large flow rate of 24000m 3 / h.

[0024] A further beneficial effect of adopting the above method is that the slag has good fluidity and the slag discharge efficiency of the process is improved.

[0025] Furthermore, in the above step (1), during the operation of feeding and producing copper matte, the slag is controlled to contain Cu≤18%, CO<1500ppm, and the pressure at the front end of the spray gun is controlled at 60-80kPa throughout the entire process; preferably, the slag is controlled to contain Cu at 16%, CO<300ppm, and the pressure at the front end of the spray gun is 70kPa throughout the entire process.

[0026] A further beneficial effect of the above method is that the slag shape and temperature are reasonably controlled during the slag making period and the copper making period, which greatly improves the slag tapping efficiency.

[0027] Furthermore, in the above step (4), the lump coal is anthracite with a fixed carbon content of ≥65%, a particle size of 5-15 mm, an input rate of 2-3 t / h, and a fuel coefficient of 6000-7500 Nm 3 / t, coal surplus coefficient 80% to 120%; preferably, the lump coal is anthracite with a fixed carbon content of 65%, a particle size of 8mm, an input rate of 3t / h, and a fuel coefficient of 7500Nm 3 / t, coal surplus coefficient 90%.

[0028] Furthermore, in the above step (4), the oxygen concentration of the oxygen-enriched air is 30% to 40%, and the flow rate is 10,000 to 15,000 m 3 / h; preferably, the oxygen concentration of the oxygen-enriched air is 32%, and the flow rate is 13000m 3 / h.

[0029] A further beneficial effect of the above method is that the use of oxygen enrichment can achieve rapid heating of the slag.

[0030] Furthermore, in the above step (4), the furnace pressure is controlled to be -1 to -5 Pa, and CO is controlled to be less than 1500 ppm throughout the entire process until the slag temperature reaches 1350 to 1370°C; preferably, the furnace pressure is controlled to be -2 Pa, and CO is controlled to be less than 300 ppm throughout the entire process until the slag temperature rises to 1370°C.

[0031] A further beneficial effect of the above method is that the use of high-temperature melt to wash the furnace reduces the thickness of the furnace wall slag to a minimum, improves maintenance efficiency, and reduces operating costs.

[0032] Furthermore, in the above step (5), the spray gun is completely lifted out of the molten pool, and a diesel burner is used for heat preservation operation, with a fuel consumption of 400-600 kg / h; the diesel is 0# national standard diesel, and the diesel fuel coefficient is 10-12 Nm 3 / kg.

[0033] Furthermore, in the above step (5), the furnace pressure is maintained at -1 to +2 Pa, the blister copper temperature is controlled at 1200 to 1250° C., the target blister copper grade Cu is ≥ 97.2%, and the copper matte is ≤ 0.5%.

[0034] Furthermore, in the above step (6), the temperature is lowered to 450°C and kept constant for 2 hours, lowered to 350°C and kept constant for 2 hours, and then lowered to 200°C and stopped keeping the temperature.

[0035] A further beneficial effect of adopting the above is that a scientific cooling method is formulated to maximize the service life of the furnace body.

[0036] 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:

[0037] 1. The present invention can safely and quickly discharge and completely drain the high-temperature melt in the furnace, thereby improving maintenance efficiency and reducing the risk of furnace damage, thereby achieving a safe, environmentally friendly, efficient and economical furnace shutdown effect, making up for the shortcomings of the copper matte blowing process system of the top-blown furnace, and improving production efficiency and safety.

[0038] 2. The present invention can reduce the thickness of the furnace wall slag to a minimum, safely and quickly drain the copper liquid and slag in the furnace, create favorable conditions for subsequent maintenance, and achieve a safe, environmentally friendly, efficient and economical shutdown effect.

[0039] 3. The method of the present invention is applicable to the high-temperature melt emptying operations of most top-blown furnaces, which can significantly improve maintenance efficiency and reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of a top-blown furnace system involved in a method for discharging a high-temperature melt in a top-blown furnace;

[0041] Among them, 1-slag discharge port, 2-blister copper discharge port, 3-furnace body, 4-feeding port, 5-top charging machine, 6-lump coal bunker, 7-spray gun, 8-molten pool height measurement (sampling) device, 9-insulation burner, 10-rising flue;

[0042] Figure 2 This is a process flow chart for the discharge method of high-temperature melt in a top-blown furnace. DETAILED DESCRIPTION

[0043] 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.

[0044] Example 1

[0045] by Figure 1Taking the top-blown furnace system shown as an example, it includes a furnace body 3, a furnace top feeder 5 and a lump coal bunker 6; wherein, a slag discharge port 1 and a blister copper discharge port 2 are respectively provided on both sides of the bottom of the furnace body 3; a discharge port 4, a spray gun 7, a molten pool height measuring (sampling) device 8, an insulation burner 9 and an ascending flue 10 are respectively provided on the top of the furnace body 3 from left to right; the lump coal bunker 6 is connected to the discharge port 4 through the furnace top feeder 5.

[0046] Methods for discharging high temperature melt in top-blown furnaces, such as Figure 2 As shown, the specific steps include:

[0047] (1) Preparation for charging before shutdown

[0048] Before the top-blown furnace is shut down, it produces 250 tons of copper matte per batch.

[0049] The main components of copper matte are, by mass percentage, Cu 61%, S14.2%, Fe 6.9%, SiO20.67%, CaO 0.2%, MgO 0.2%, Al2O30.1%, ZnO 0.4% and Pb 1.5%;

[0050] Specifically, 60 t / h of copper matte, 4.5 t / h of SiO2, 2.2 t / h of CaO, and 2 t / h of lump coal were fed from the furnace top feeder 5, and the furnace pressure was maintained at -5 Pa. The lump coal was anthracite with a fixed carbon content of 65%, a particle size of 8 mm, and a smelting excess coefficient of 95%. The lance 7 was inserted into the molten pool 300 mm away from the white matte layer, and the concentration of the combustion-enriched oxygen introduced by the lance 7 was 38%.

[0051] After the molten pool height in the furnace is measured using the molten pool height measuring (sampling) device 8, when the molten pool height exceeds 2000mm, slag is regularly discharged from the slag discharge port 1 to ensure that the molten pool height in the furnace does not exceed 2000mm after the slag forming period. After testing and analysis, it was found that: the Fe / SiO2 in the slag forming period was 1.6, the CaO content in the slag was 4.5%, the slag temperature was 1300℃, and the maximum flow rate of the spray gun 7 was 16500m 3 / h; Fe / SiO2 in copper making period is 1.5, slag temperature is 1250℃, which makes slag have good fluidity and improves slag discharge efficiency. The spray gun has 7 large flow air of 24000m 3 / h, the slag Cu content is controlled to be 15.0%, CO < 300ppm during the whole process, and the pressure at the front end of the spray gun 7 is 70kPa;

[0052] When the total input of copper matte is 250t, stop the slag making period and immediately start the copper making period. 3 / h spray gun with 7 high flow air flow to oxidize and desulfurize white matte. After sampling and testing, Cu≥97.2% and copper matte≤0.5 are qualified and then the copper making period is stopped;

[0053] (2) Regular discharge of slag

[0054] After the copper-making period is over, the molten pool height is 1900 mm as measured by the molten pool height measuring (sampling) device 8. The old spray gun 7 is removed and replaced with a new one. During this period, a heat preservation burner 9 is used to maintain heat. The negative pressure in the furnace is controlled. The slag produced during the copper-making period is discharged from the slag discharge port 1 until it stops flowing. The spray gun 7 is lowered to stir the molten pool. The slag produced during the copper-making period is continuously discharged from the slag discharge port 1.

[0055] (3) Discharge of crude copper

[0056] After the slag layer is reduced to 300mm, the negative pressure of the furnace is controlled, and the heat preservation operation is performed using the spray gun 7 to maintain the furnace pressure at -1Pa. After sampling and testing, Cu ≥ 97.2% and copper matte ≤ 0.5 are qualified and then the crude copper is discharged. The crude copper temperature is controlled at 1240℃ until slag flows out of the crude copper discharge port 2, and the port is immediately blocked;

[0057] (4) Rapid heating of the remaining slag

[0058] After the discharge of blister copper is completed, the lance 7 is inserted into the remaining molten pool, the lump coal in the lump coal bin 6 is started, and is transported to the top-blown furnace through the furnace top feeder 5. Oxygen-enriched air is blown into the molten pool using the lance 7 to stir the temperature, and the furnace is continuously cleaned to reduce the thickness of the furnace wall slag to a minimum. The molten pool height measurement (sampling) device 8 is used to measure the molten pool height and observe the slag temperature. During this period, the lump coal is anthracite with a fixed carbon content of 65%, a particle size of 8mm, an input rate of 2.5t / h, and a fuel coefficient of 7500Nm 3 / t, the excess coal coefficient is 90%, the oxygen concentration of the injected combustion air is controlled at 32%, and the flow rate is 12000m 3 / h, oxygen flow rate is 2500m 3 / h, control the furnace pressure to -2Pa, and control CO<300ppm during the whole process;

[0059] (5) Discharge of residual residue

[0060] After the slag temperature rises to 1350°C, immediately open the crude copper discharge port 2 to quickly discharge the remaining slag in the furnace into the accident pit at the bottom of the furnace. During this period, after the spray gun 7 is cleaned, it is lifted and hoisted to the spray gun 7 placement area. Use the insulation burner 9 to perform insulation operation, control the negative pressure of the furnace, and plug the port after the slag liquid is drained;

[0061] (6) Step-by-step cooling

[0062] After the high-temperature melt in the furnace is emptied, a diesel insulation burner 9 is used for step-by-step cooling. The initial oil volume is 500 kg / h. The oil volume is increased or decreased based on the temperature of the thermocouple of the ascending flue 10 as the control benchmark to cool the furnace: after cooling to 450°C, keep the temperature constant for 2 hours; after cooling to 350°C, keep the temperature constant for 2 hours; after cooling to 200°C, extinguish the diesel insulation burner 9 to stop insulation and allow the furnace to cool naturally.

[0063] In actual production, it takes 1.2 hours to raise the slag temperature to 1350°C using traditional compressed air combustion, but only 0.3 hours using oxygen-enriched air combustion, which increases the heating efficiency by 75%. However, the heating limit of traditional compressed air combustion is 1350°C, making it difficult to further increase the slag temperature.

[0064] After the slag discharge port 1 was blocked, the residual molten pool in the furnace was measured to be 50 mm using the molten pool height measurement (sampling) device 8, and the slag thickness of the furnace wall was measured to be 100 mm using a tape measure. The cleaning speed of the 50 mm thick slag at the bottom of the furnace during maintenance was 0.5 m 2 / h, the furnace wall slag cleaning speed is 10t / h, and the slag density is 4.4g / cm 3 .

[0065] Taking a Φ5*16m top-blown furnace as an example, the slag area at the bottom of the furnace is: πr 2 =3.14*2.5*2.5=19.63m 2 , the residue cleaning time is: 19.63 / 0.5=39.25h, the total weight of the furnace wall slag is: m=ρv=3.14*2.5*2.5*16-3.14*2.4*2.4*16=108t, and the furnace wall slag cleaning time is: 108 / 10=10.8h.

[0066] Example 2

[0067] by Figure 1 Taking the top-blown furnace system shown as an example, it includes a furnace body 3, a furnace top feeder 5 and a lump coal bunker 6; wherein, a slag discharge port 1 and a blister copper discharge port 2 are respectively provided on both sides of the bottom of the furnace body 3; a discharge port 4, a spray gun 7, a molten pool height measuring (sampling) device 8, an insulation burner 9 and an ascending flue 10 are respectively provided on the top of the furnace body 3 from left to right; the lump coal bunker 6 is connected to the discharge port 4 through the furnace top feeder 5.

[0068] Methods for discharging high temperature melt in top-blown furnaces, such as Figure 2 As shown, the specific steps include:

[0069] (1) Preparation for charging before shutdown

[0070] Before the top-blown furnace is shut down, it produces 250 tons of copper matte per batch.

[0071] The main components of copper matte are, by mass percentage, Cu 63%, S13.8%, Fe 6.0%, SiO20.62%, CaO 0.17%, MgO 0.2%, Al2O30.1%, ZnO 0.4% and Pb 1.2%;

[0072] Specifically, 60 t / h of copper matte, 4 t / h of SiO2, 2 t / h of CaO, and 2.3 t / h of lump coal were fed from the furnace top feeder 5, and the furnace pressure was maintained at -5 Pa. The lump coal was anthracite with a fixed carbon content of 65%, a particle size of 8 mm, and a smelting excess coefficient of 95%. The lance 7 was inserted into the molten pool 300 mm away from the white matte layer, and the concentration of the combustion-enriched oxygen injected by the lance 7 was 40%.

[0073] After the molten pool height in the furnace is measured using the molten pool height measuring (sampling) device 8, when the molten pool height exceeds 2000mm, slag is regularly discharged from the slag discharge port 1 to ensure that the molten pool height in the furnace does not exceed 2000mm after the slag forming period. After testing and analysis, it was found that: the Fe / SiO2 in the slag forming period was 1.55, the CaO content in the slag was 4.0%, the slag temperature was 1290°C, and the maximum flow rate of the spray gun 7 was 16500m 3 / h; Fe / SiO2 in copper making period is 1.47, slag temperature is 1260℃, which makes slag have good fluidity and improves slag discharge efficiency. The spray gun has 7 large flow air of 24000m 3 / h, the slag Cu content is controlled to be 15.7%, CO<300ppm during the whole process, and the pressure at the front end of the spray gun 7 is 70kPa;

[0074] When the total input of copper matte is 250t, stop the slag making period and immediately start the copper making period. 3 / h spray gun with 7 high flow air flow to oxidize and desulfurize white matte. After sampling and testing, Cu≥97.2% and copper matte≤0.5 are qualified and then the copper making period is stopped;

[0075] (2) Regular discharge of slag

[0076] After the copper-making period is over, the molten pool height is 1800 mm as measured by the molten pool height measuring (sampling) device 8. The old spray gun 7 is removed and replaced with a new one. During this period, a heat preservation burner 9 is used to maintain heat. The negative pressure in the furnace is controlled. The slag produced during the copper-making period is discharged from the slag discharge port 1 until it stops flowing. The spray gun 7 is lowered to stir the molten pool. The slag produced during the copper-making period is continuously discharged from the slag discharge port 1.

[0077] (3) Discharge of crude copper

[0078] After the slag layer is reduced to 250mm, the negative pressure of the furnace is controlled, and the heat preservation operation is performed using the spray gun 7 to maintain the furnace pressure at -1Pa. After sampling and testing, Cu ≥ 97.2% and copper matte ≤ 0.5 are qualified and then the crude copper is discharged. The crude copper temperature is controlled at 1230℃ until slag flows from the crude copper discharge port 2, and the port is immediately blocked;

[0079] (4) Rapid heating of the remaining slag

[0080] After the discharge of blister copper is completed, the lance 7 is inserted into the remaining molten pool, the lump coal in the lump coal bin 6 is started, and is transported to the top-blown furnace through the furnace top feeder 5. Oxygen-enriched air is blown into the molten pool using the lance 7 to stir and heat the molten pool. The furnace is continuously cleaned to reduce the thickness of the furnace wall slag to a minimum. The molten pool height measurement (sampling) device 8 is used to measure the molten pool height and observe the slag temperature. During this period, the lump coal is anthracite with a fixed carbon content of 65%, a particle size of 8mm, an input rate of 3t / h, and a fuel coefficient of 7500Nm 3 / t, the excess coal coefficient is 90%, the oxygen concentration of the injected combustion air is controlled at 32%, and the flow rate is 13000m 3 / h, oxygen flow rate is 3000m 3 / h, control the furnace pressure to -2Pa, and control CO<300ppm during the whole process;

[0081] (5) Discharge of residual residue

[0082] After the slag temperature rises to 1360°C, immediately open the crude copper discharge port 2 to quickly discharge the remaining slag in the furnace into the accident pit at the bottom of the furnace. During this period, after the spray gun 7 is cleaned, it is lifted and hoisted to the spray gun 7 placement area. Use the insulation burner 9 to perform insulation operation, control the negative pressure of the furnace, and plug the port after the slag liquid is drained;

[0083] (6) Step-by-step cooling

[0084] After the high-temperature melt in the furnace is emptied, a diesel insulation burner 9 is used for step-by-step cooling. The initial oil volume is 500 kg / h. The oil volume is increased or decreased based on the temperature of the thermocouple of the ascending flue 10 as the control benchmark to cool the furnace: after cooling to 450°C, keep the temperature constant for 2 hours; after cooling to 350°C, keep the temperature constant for 2 hours; after cooling to 200°C, extinguish the diesel insulation burner 9 to stop insulation and allow the furnace to cool naturally.

[0085] In actual production, it takes 1.2 hours to raise the slag temperature to 1350°C using traditional compressed air combustion, and 0.4 hours to raise the temperature to 1360°C using oxygen-enriched air combustion, which improves the heating efficiency by 67%.

[0086] After the slag discharge port 1 was blocked, the molten pool height measuring (sampling) device 8 was used to measure the residual molten pool in the furnace to be 25mm and the slag thickness of the furnace wall to be 50mm. The cleaning speed of the 25mm thick slag at the bottom of the furnace during maintenance was 1m 2 / h, the furnace wall slag cleaning speed is 10t / h, and the slag density is 4.4g / cm 3 .

[0087] Taking a Φ5*16m top-blown furnace as an example, the slag area at the bottom of the furnace is: πr 2 =3.14*2.5*2.5=19.63m 2 , the residue cleaning time is: 3.14*2.5*2.5 / 1=19.63h, the total weight of the furnace wall slag is: m=ρv=3.14*2.5*2.5*16-3.14*2.45*2.45*16=55t, the time for cleaning the furnace wall slag is: [3.14*16*(2.5 2 -2.45 2 )*4.4] / 10=5.5h.

[0088] Example 3

[0089] by Figure 1 Taking the top-blown furnace system shown as an example, it includes a furnace body 3, a furnace top feeder 5 and a lump coal bunker 6; wherein, a slag discharge port 1 and a blister copper discharge port 2 are respectively provided on both sides of the bottom of the furnace body 3; a discharge port 4, a spray gun 7, a molten pool height measuring (sampling) device 8, an insulation burner 9 and an ascending flue 10 are respectively provided on the top of the furnace body 3 from left to right; the lump coal bunker 6 is connected to the discharge port 4 through the furnace top feeder 5.

[0090] Methods for discharging high temperature melt in top-blown furnaces, such as Figure 2 As shown, the specific steps include:

[0091] (1) Preparation for charging before shutdown

[0092] Before the top-blown furnace is shut down, it produces 250 tons of copper matte per batch.

[0093] The main components of copper matte are, by mass percentage, Cu 65%, S13.2%, Fe 5.6%, SiO20.65%, CaO 0.2%, MgO 0.3%, Al2O30.1%, ZnO 0.5% and Pb 1.2%;

[0094] Specifically, 60 t / h of copper matte, 4 t / h of SiO2, 2 t / h of CaO, and 2 t / h of lump coal are fed from the furnace top feeder 5, and the furnace pressure is maintained at -5 Pa. The lump coal is anthracite with a fixed carbon content of 65%, a particle size of 8 mm, and a smelting excess coefficient of 95%. The lance 7 is inserted into the molten pool 300 mm away from the white matte layer, and the concentration of the combustion-enriched oxygen injected by the lance 7 is 40%.

[0095] After the molten pool height in the furnace is measured using the molten pool height measuring (sampling) device 8, when the molten pool height exceeds 2000mm, slag is regularly discharged from the slag discharge port 1 to ensure that the molten pool height in the furnace does not exceed 2000mm after the slag forming period. After testing and analysis, it was found that: the Fe / SiO2 in the slag forming period was 1.6, the CaO content in the slag was 4.2%, the slag temperature was 1300℃, and the maximum flow rate of the spray gun 7 was 16500m 3 / h; Fe / SiO2 in copper making period is 1.5, slag temperature is 1250℃, which makes slag have good fluidity and improves slag discharge efficiency. The spray gun has 7 large flow air of 24000m 3 / h, the slag Cu content is controlled to be 16%, CO < 300ppm during the whole process, and the pressure at the front end of the spray gun 7 is 70kPa;

[0096] When the total input of copper matte reaches 250t, the slagging phase is stopped and the copper making phase is immediately started. The white copper matte is oxidized and desulfurized using a 25000m3 / h spray gun with a large air flow of 7.0%. After sampling and testing, the Cu content is ≥97.2% and the copper matte content is ≤0.5, which is qualified, and the copper making phase is stopped.

[0097] (2) Regular discharge of slag

[0098] After the copper-making period is over, the molten pool height is 1700 mm as measured by the molten pool height measuring (sampling) device 8. The old spray gun 7 is removed and replaced with a new one. During this period, a heat preservation burner 9 is used to maintain heat. The negative pressure in the furnace is controlled. The slag produced during the copper-making period is discharged from the slag discharge port 1 until it stops flowing. The spray gun 7 is lowered to stir the molten pool. The slag produced during the copper-making period is continuously discharged from the slag discharge port 1.

[0099] (3) Discharge of crude copper

[0100] After the slag layer is reduced to 200mm, the negative pressure of the furnace is controlled, and the heat preservation operation is performed using the spray gun 7 to maintain the furnace pressure at -1Pa. After sampling and testing, Cu ≥ 97.2% and copper matte ≤ 0.5 are qualified and then the crude copper is discharged. The crude copper temperature is controlled at 1220℃ until slag flows out of the crude copper discharge port 2, and the port is immediately blocked;

[0101] (4) Rapid heating of the remaining slag

[0102] After the discharge of blister copper is completed, the lance 7 is inserted into the remaining molten pool, the lump coal in the lump coal bin 6 is started, and is transported to the top-blown furnace through the furnace top feeder 5. Oxygen-enriched air is blown into the molten pool using the lance 7 to stir and heat the molten pool. The furnace is continuously cleaned to reduce the thickness of the furnace wall slag to a minimum. The molten pool height measurement (sampling) device 8 is used to measure the molten pool height and observe the slag temperature. During this period, the lump coal is anthracite with a fixed carbon content of 65%, a particle size of 8mm, an input rate of 3t / h, and a fuel coefficient of 7500Nm 3 / t, the excess coal coefficient is 90%, the oxygen concentration of the injected combustion air is controlled at 32%, and the flow rate is 13000m 3 / h, oxygen flow rate is 3000m 3 / h, control the furnace pressure to -2Pa, and control CO<300ppm during the whole process;

[0103] (5) Discharge of residual residue

[0104] After the slag temperature rises to 1370°C, immediately open the crude copper discharge port 2 to quickly discharge the remaining slag in the furnace into the accident pit at the bottom of the furnace. During this period, after the spray gun 7 is cleaned, it is lifted and hoisted to the spray gun 7 placement area. Use the insulation burner 9 to perform insulation operation, control the negative pressure of the furnace, and plug the port after the slag liquid is drained;

[0105] (6) Step-by-step cooling

[0106] After the high-temperature melt in the furnace is emptied, a diesel insulation burner 9 is used for step-by-step cooling. The initial oil volume is 500 kg / h. The oil volume is increased or decreased based on the temperature of the thermocouple of the ascending flue 10 as the control benchmark to cool the furnace: after cooling to 450°C, keep the temperature constant for 2 hours; after cooling to 350°C, keep the temperature constant for 2 hours; after cooling to 200°C, extinguish the diesel insulation burner 9 to stop insulation and allow the furnace to cool naturally.

[0107] In actual production, it takes 1.2 hours to raise the slag temperature to 1350°C using traditional compressed air combustion, and 0.5 hours to raise the temperature to 1370°C using oxygen-enriched air combustion, which improves the heating efficiency by 58%.

[0108] After the slag discharge port 1 is blocked, the molten pool height measuring (sampling) device 8 is used to measure that the residual molten pool in the furnace is 0 mm and the slag skin thickness of the furnace wall is 0 mm; the furnace bottom residue and the slag skin of the furnace wall do not need to be cleaned during maintenance.

[0109] 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 method for discharging high-temperature melt in a top-blown furnace, characterized in that: The specific steps include: (1) Preparation for charging before shutdown Before the top-blown furnace is shut down, copper matte is produced; (2) Regular discharge of slag After the copper making period is over, the spray gun is replaced, during which the heat preservation operation is carried out, the slag is discharged, the spray gun is lowered to stir the molten pool, and the slag is continued to be discharged; (3) Discharge of crude copper Use a spray gun to carry out insulation work and discharge the crude copper after reaching the standard; (4) Rapid heating of the remaining slag When the blister copper is discharged, the lump coal is transported to the top-blown furnace, the remaining melt is stirred at a low gun position, and oxygen-enriched air is continuously blown in using a lance to quickly heat and clean the furnace. (5) Discharge of residual residue Discharge the remaining residue in the furnace and perform heat preservation during the process; (6) Step-by-step cooling The furnace body is slowly cooled down in steps. After it drops to 450℃, it is kept at a constant temperature for 2 to 3 hours. After it drops to 350℃, it is kept at a constant temperature for 1 to 2 hours. After it drops to 200℃, it is stopped from being kept warm and cooled naturally.

2. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (1), the main components of the copper matte are, by mass percentage, Cu 62% to 65%, S 14% to 15%, Fe 6% to 8%, SiO2 0.6% to 0.7%, CaO 0.2% to 0.3%, MgO 0.2% to 0.4%, Al2O3 0.08% to 0.1%, ZnO 0.5% to 0.6% and Pb 1% to 1.3%.

3. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (1), during the operation of producing copper matte, the Fe / SiO2 ratio during the slag-making period is controlled at 1.1-1.8, the CaO content in the slag is controlled at 3%-7%, the slag temperature is controlled at 1270-1310°C, and the high-flow air flow of the spray gun is 13000-21000m 3 / h.

4. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (1), during the operation of producing copper matte, the Fe / SiO2 ratio during the copper making period is controlled at 1.0-2.0, the slag temperature is controlled at 1250-1290°C, and the high flow air of the spray gun is 10000-26000m 3 / h.

5. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (1), during the operation of producing copper matte by feeding materials, the slag is controlled to contain Cu≤18%, CO<1500ppm throughout the whole process, and the pressure at the front end of the spray gun is controlled at 60-80kPa.

6. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (4), the lump coal is anthracite with a fixed carbon content of ≥65%, a particle size of 5-15 mm, an input rate of 2-3 t / h, and a fuel coefficient of 6000-7500 Nm 3 / t, coal surplus coefficient 80% to 120%.

7. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (4), the oxygen-enriched air has an oxygen concentration of 30% to 40% and a flow rate of 10,000 to 15,000 m 3 / h.

8. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (4), the furnace pressure is controlled to be -1 to -5 Pa, and CO is controlled to be less than 1500 ppm throughout the entire process until the slag temperature reaches 1350 to 1370°C.

9. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (5), the spray gun is completely lifted out of the molten pool, and a diesel burner is used for heat preservation operation, with a fuel consumption of 400-600 kg / h; the diesel is 0# national standard diesel, and the diesel fuel coefficient is 10-12 Nm 3 / kg.

10. The method for discharging high-temperature melt in a top-blown furnace according to claim 1, characterized in that: In step (6), the temperature is lowered to 450°C and kept constant for 2 hours, lowered to 350°C and kept constant for 2 hours, and then lowered to 200°C and stopped keeping warm.

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