Method for starting up a fluidized roaster for zinc smelting

Abstract

This invention discloses a method for starting up a fluidized bed roasting furnace for zinc smelting, comprising: a) preheating the furnace to 250-350°C using firewood or charcoal; b) preheating the furnace body to 600-750°C by injecting natural gas and air into the furnace using a spray gun, and then stopping the spray gun; c) after the furnace body cools to 50-200°C, throwing zinc calcined sand into the fluidized bed roasting furnace as a base material; d) heating the furnace body in at least two stages to bring the furnace body temperature to 800-900°C; e) adding zinc sulfide concentrate into the furnace, maintaining the temperature at 800-900°C, gradually withdrawing the spray guns, leaving 1-2 spray guns, and continuing to add zinc sulfide concentrate; f) after the furnace body temperature stabilizes at 850-950°C, withdrawing the spray guns, and the start-up process is complete. The method of the present invention effectively improves fuel utilization, increases thermal efficiency, reduces energy consumption, reduces carbon emissions, reduces equipment maintenance and start-up costs, reduces SO2 concentration and waste acid production in flue gas, and is energy-saving and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of zinc smelting technology, specifically relating to a start-up method for a fluidized bed roasting furnace in zinc smelting. Background Technology

[0002] Zinc is one of the important metallic raw materials for national economic development. With social progress and human development, zinc is widely used in industries such as automobiles, construction, home appliances, shipbuilding, light industry, machinery, and batteries, mainly in the form of galvanized zinc, zinc-based alloys, and zinc oxide. Currently, it ranks second only to copper and aluminum in non-ferrous metal consumption.

[0003] Zinc smelting primarily utilizes hydrometallurgical processes, accounting for approximately 90% of total zinc production. The main hydrometallurgical zinc refining process consists of fluidized bed roasting of zinc concentrate, roasted sand leaching, leaching solution purification, electrowinning of the purified solution, and ingot casting. Fluidized bed roasting of zinc concentrate is the first and most crucial step in hydrometallurgical zinc refining. It ensures that the vast majority of zinc sulfide in the zinc concentrate is converted into zinc oxide and a small amount of sulfate, while simultaneously removing impurities such as arsenic and antimony to the greatest extent possible. Sulfur is converted into sulfur dioxide, which is then used to produce acid in the flue gas.

[0004] Currently, fluidized bed roasting of zinc concentrate is mainly carried out using large-scale fluidized bed roasting furnaces. The start-up technology of large-scale fluidized bed roasting furnaces is the key to ensuring smooth operation of the furnace and producing qualified roasted sand. The traditional start-up method mainly uses oil guns to inject diesel fuel for heating. This method will cause the following problems: (1) Diesel fuel is a liquid. When the injected diesel fuel comes into contact with oxygen in the combustion air, it is a liquid-gas reaction. The contact is insufficient, the combustion is incomplete, and the thermal efficiency is low; (2) In order to make the diesel fuel burn more completely, the industry often uses high-pressure air to atomize the diesel fuel at the nozzle. However, this also increases the equipment cost and the difficulty of operation; (3) Incomplete combustion of diesel fuel will enter the dust collection system, especially the electrostatic precipitator. The incompletely burned diesel fuel will stick to the surface of the electrostatic precipitator system, which will seriously reduce the efficiency of the electrostatic precipitator and even cause equipment failure; (4) The diesel fuel has a high sulfur content, which will produce sulfur dioxide, corrode the equipment, and increase the cost of equipment maintenance and flue gas treatment; (5) The high sulfur content of diesel fuel will produce a lot of SO2 gas when burned. After acid production, a large amount of waste acid will be produced, which cannot be sold directly, increasing the treatment cost. Summary of the Invention

[0005] This invention is based on the inventor's discovery and understanding of the following facts and problems: In the related technology, Chinese patent application No. 202011026019.5 discloses a method for igniting and starting a fluidized bed combustion furnace. This method uses coal as fuel for heating, which will cause the following problems: (1) Coal is a solid. When coal comes into contact with oxygen in the air, it is a solid-gas reaction. There is only surface contact, which is insufficient, resulting in incomplete combustion and low thermal efficiency; (2) When the fluidized bed uses coal for heating, the heating is uneven, the operation is difficult, and the operating environment is poor; (3) Using coal as fuel for heating increases the content of dust, suspended matter, particulate matter, etc. in the flue gas, which increases the burden and difficulty of subsequent dust collection system and increases energy consumption; (4) The sulfur content in coal is high, which will produce sulfur dioxide, corrode equipment, and increase the cost of equipment maintenance and flue gas treatment; (5) The use of coal increases carbon emissions due to incomplete combustion and low thermal efficiency.

[0006] Chinese patent application CN202022367836.9 discloses a flue gas scrubbing device for the start-up of a fluidized bed roasting furnace. This technical solution relates to a device for treating flue gas during the start-up process of a fluidized bed roasting furnace. Traditional fluidized bed roasting furnaces use diesel heating for start-up, which increases the difficulty of flue gas treatment and necessitates the addition of a corresponding flue gas treatment system. This technical solution also fully demonstrates the problems existing in the traditional start-up process of fluidized bed roasting furnaces.

[0007] Chinese patent application CN201811459709.2 discloses a method for starting and firing a fluidized bed furnace. This technical solution uses an oil gun to inject diesel fuel for heating, which has the following problems: (1) Diesel fuel is a liquid. When the injected diesel fuel comes into contact with oxygen in the injected air, it is a liquid-gas reaction. The contact is insufficient, the combustion is incomplete, and the thermal efficiency is low. (2) In order to make the diesel fuel burn more completely, the industry often uses a method of adding high-pressure air to the diesel fuel nozzle for atomization. However, this also increases the equipment cost and the difficulty of operation. (3) Incomplete combustion of diesel fuel will enter the dust collection system, especially the electrostatic precipitator. The incompletely burned diesel fuel will stick to the surface of the electrostatic precipitator system, which will seriously reduce the efficiency of the electrostatic precipitator and even cause equipment failure. (4) The diesel fuel has a high sulfur content, which will produce sulfur dioxide, corrode the equipment, and increase the cost of equipment maintenance and flue gas treatment. (5) The combustion of diesel fuel produces a lot of SO2 gas. After acid production, a large amount of waste acid is produced. It can only be treated as waste acid and cannot be sold directly, which increases the treatment cost.

[0008] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a start-up method for a fluidized bed roasting furnace in zinc smelting. By using natural gas as the heat source for the fluidized bed roasting furnace, it effectively improves fuel utilization, increases thermal efficiency, reduces carbon emissions, lowers flue gas treatment costs, and increases the purity of the product sulfuric acid, thus achieving comprehensive utilization of sulfur.

[0009] The furnace start-up method for a fluidized bed roasting furnace in zinc smelting according to an embodiment of the present invention includes:

[0010] a. Preheat the fluidized bed roasting furnace to 250-350℃ using firewood or charcoal;

[0011] b. Use a natural gas torch to inject natural gas and air to preheat the furnace body to 600-750°C, then stop the torch;

[0012] c. After the furnace body cools to 50-200°C, zinc roasted sand is thrown into the fluidized bed roasting furnace to lay the bottom material;

[0013] d. The furnace body is heated in at least two stages by gradually adding natural gas injection guns, so that the furnace body temperature reaches 800-900℃;

[0014] e. Add zinc sulfide concentrate into the furnace, maintain the furnace temperature at 800-900℃, gradually withdraw the natural gas nozzles, leave 1-2 natural gas nozzles, and continue to add zinc sulfide concentrate.

[0015] f. After the furnace body temperature is maintained at a stable production stage of 850-950℃, remove all natural gas nozzles, and the furnace start-up process is completed.

[0016] The advantages and technical effects of the start-up method for a fluidized bed roasting furnace in zinc smelting according to embodiments of the present invention are as follows: 1. In this embodiment, natural gas is injected into the furnace through a natural gas lance to provide heat for the start-up process. Natural gas, being a gas, comes into full contact with oxygen in the injected air, resulting in complete combustion and high thermal efficiency. Compared to using diesel fuel, this method reduces the need for a diesel atomization system, simplifies the injection equipment, lowers equipment costs, and offers simple operation and high thermal utilization. 2. In this embodiment, the furnace body is preheated to 600–750°C for a baking operation, which removes moisture from the bricks of the newly constructed roasting furnace. The furnace body is then cooled to 50–200°C to allow for the mechanical and manual addition of bottom material (low-sulfur zinc roasting sand) into the furnace for production start-up and heat storage, ensuring the safety of the conveying equipment and personnel. 3. In this embodiment, the start-up of the fluidized bed roasting furnace for zinc smelting is achieved by controlling the temperature to maintain the bottom material in a solid state. Since the bottom material laid in the roasting furnace is... Low-sulfur zinc calcined sand after high-temperature roasting cannot achieve self-heating equilibrium. Natural gas is injected through a natural gas torch to raise the temperature of the furnace and calcined sand to over 800°C. Then, zinc sulfide concentrate is added to the furnace to gradually achieve a self-heating reaction. 4. The method in this embodiment has minimal impact on the dust collection system, especially the electrostatic precipitator, reducing maintenance costs. 5. In this embodiment, natural gas is used for heating. Natural gas has a low sulfur content and high combustibility, resulting in low sulfur dioxide levels in the flue gas. The combustion products do not damage operating equipment at high temperatures, reducing equipment corrosion and lowering equipment maintenance and flue gas treatment costs. 6. The method in this embodiment can reduce the production of waste acid. 7. The method in this embodiment has high thermal efficiency and low energy consumption. Compared with diesel / pulverized coal heating, energy consumption can be reduced by 10-15%, SO2 production can be reduced by more than 40%, and equipment maintenance and start-up costs can be reduced by 30-40%.

[0017] In some embodiments, the hearth area of ​​the fluidized bed roasting furnace is ≥75m². 2 .

[0018] In some embodiments, in step a, the preheating time using firewood or charcoal is 25-75 hours.

[0019] In some embodiments, there are 3-6 natural gas injection guns, evenly distributed radially along the fluidized bed roasting furnace.

[0020] In some embodiments, in step b, the preheating time of the natural gas injection gun is 48-200 hours, the injected natural gas pressure is 20-100 kPa, and the natural gas flow rate is 50-600 Nm³. 3 / h, air pressure 5~10kPa, air flow rate 1000~7000Nm 3 / h.

[0021] In some embodiments, in step c, the thickness of the base material is 650-850 mm.

[0022] In some embodiments, step d involves heating the furnace body in four stages by successively adding natural gas lances. Specifically: the first stage of heating is performed using one natural gas lance, with the temperature reaching 300–450°C, followed by starting the blower to turn the material over and then shutting it off; the second stage of heating is performed using two to three natural gas lances, with the temperature reaching 500–600°C, followed by starting the blower again to turn the material over and then shutting it off; the third stage of heating is performed using three to four natural gas lances, with the temperature reaching 650–750°C, followed by starting the blower to maintain the fluidization of the zinc calcined sand in the fluidized furnace; and the fourth stage of heating is performed using four to six natural gas lances, with the temperature reaching 800–900°C.

[0023] In some embodiments, in step d, the pressure of the natural gas injected by the natural gas nozzle is 15–120 kPa, and the natural gas flow rate is 30–800 Nm³. 3 / h, air pressure 3~15kPa, air flow rate 800~8000Nm 3 / h.

[0024] In some embodiments, during step d, in the first stage of heating, the blower is started to turn the material 1-2 times, with each turning time lasting 1-10 minutes; in the second stage of heating, the blower is started to turn the material 2-3 times, with each turning time lasting 2-8 minutes; in the third stage of heating, the blower pressure maintaining the zinc concentrate in a fluidized state is 8-15 kPa, and the blower volume is 15000-50000 Nm³. 3 / h.

[0025] In some embodiments, in step e, 1-2 natural gas nozzles are removed each time; in step f, during the stable production stage, the blower pressure is 10-20 kPa and the blower volume is 45000-120000 Nm³. 3 / h. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The furnace start-up method for a fluidized bed roasting furnace in zinc smelting according to an embodiment of the present invention includes:

[0028] a. Preheat the fluidized bed roasting furnace to 250-350℃ using firewood or charcoal;

[0029] b. Use a natural gas torch to inject natural gas and air to preheat the furnace body to 600-750°C, then stop the torch;

[0030] c. After the furnace body cools to 50-200°C, zinc roasted sand is thrown into the fluidized bed roasting furnace to lay the bottom material;

[0031] d. The furnace body is heated in at least two stages by gradually adding natural gas injection guns, so that the furnace body temperature reaches 800-900℃;

[0032] e. Add zinc sulfide concentrate into the furnace, maintain the furnace temperature at 800-900℃, gradually withdraw the natural gas nozzles, leave 1-2 natural gas nozzles, and continue to add zinc sulfide concentrate.

[0033] f. After the furnace body temperature is maintained at a stable production stage of 850-950℃, remove all natural gas nozzles, and the furnace start-up process is completed.

[0034] The start-up method for a fluidized bed roasting furnace in zinc smelting according to this invention uses natural gas injection guns to heat the start-up process. Natural gas, being a gas, comes into full contact with oxygen in the injected air, resulting in complete combustion and high thermal efficiency. Compared to using diesel fuel, this method reduces the need for a diesel atomization system, simplifies the injection equipment, lowers equipment costs, and offers simple operation and high thermal utilization. In this embodiment, the furnace body is preheated to 600–750°C for a baking operation, removing moisture from the bricks of the newly constructed roasting furnace. The furnace body is then cooled to 50–200°C to allow for the mechanical and manual addition of bottom material (low-sulfur zinc roasted sand) for production start-up and heat storage, ensuring the safety of the conveying equipment and personnel. In this embodiment, the start-up of the fluidized bed roasting furnace for zinc smelting is performed by controlling the temperature to maintain the bottom material in a solid state. Since the bottom material in the roasting furnace is low-sulfur zinc roasted sand that has undergone high-temperature roasting, self-heating equilibrium cannot be achieved. The method employs natural gas injection via a natural gas torch to raise the temperature of the furnace body and roasted sand to over 800°C. Zinc sulfide concentrate is then added to the furnace to gradually achieve a self-heating reaction. This method has minimal impact on the dust collection system, especially the electrostatic precipitator, reducing maintenance costs. In this embodiment, natural gas is used for heating. Natural gas has a low sulfur content and high combustibility, resulting in low sulfur dioxide levels in the flue gas. The generated flue gas is directly connected to the acid conversion system, eliminating environmental pollution and the generation of waste acid. The combustion products do not damage operating equipment at high temperatures, reducing equipment corrosion and lowering maintenance and flue gas treatment costs. This method can reduce the production of waste acid. Furthermore, this method boasts high thermal efficiency and low energy consumption. Compared to diesel / pulverized coal heating, energy consumption can be reduced by 10-15%, SO2 production can be reduced by over 40%, and equipment maintenance and start-up costs can be reduced by 30-40%.

[0035] In some embodiments, the hearth area of ​​the fluidized bed roasting furnace is ≥75m². 2 The method described in this invention can be applied to large-scale fluidized bed roasting furnaces and has broad application prospects.

[0036] In some embodiments, in step a, the preheating time using firewood or charcoal is 25-75 hours. In the method of this embodiment, preheating with wood or charcoal effectively removes free water from the furnace.

[0037] In some embodiments, the number of natural gas injection guns is 3-6, evenly distributed radially along the fluidized bed roasting furnace. In this embodiment of the invention, a preferred number of injection guns is used to achieve staged heating of the furnace body and maintain stability during the start-up process.

[0038] In some embodiments, in step b, the preheating time of the natural gas injection gun is 48-200 hours, the injected natural gas pressure is 20-100 kPa, and the natural gas flow rate is 50-600 Nm³. 3 / h, air pressure 5~10kPa, air flow rate 1000~7000Nm 3 / h. In this embodiment of the invention, a natural gas spray gun is used to preheat the furnace body, which can effectively remove the bound water inside the furnace body.

[0039] In some embodiments, in step c, the thickness of the bottom material is 650-850 mm. In this embodiment of the invention, a preferred bottom material thickness ensures heat storage within the furnace and maintains stable furnace bottom blast pressure.

[0040] In some embodiments, step d involves heating the furnace body in four stages by successively adding natural gas nozzles. Specifically: The first stage of heating is performed using one natural gas nozzle, reaching a temperature of 300–450°C. A blower is then started to turn the material over and subsequently shut off. Preferably, the blower is started 1–2 times, with each turning lasting 1–10 minutes. The second stage of heating is performed using 2–3 natural gas nozzles, reaching a temperature of 500–600°C. The blower is started again to turn the material over and subsequently shut off. Preferably, the blower is started 2–3 times, with each turning lasting 2–8 minutes. The third stage of heating is performed using 3–4 natural gas nozzles, reaching a temperature of 650–750°C. A blower is then started to maintain the fluidization of the zinc roasted ore in the fluidized furnace. Preferably, the blower pressure maintaining the fluidized zinc concentrate is 8–15 kPa, and the blower volume is 15,000–50,000 Nm³. 3 / h; The fourth stage of heating is performed using 4 to 6 natural gas injection nozzles, with the heating temperature reaching 800 to 900°C. More preferably, during each stage of heating, the natural gas pressure injected into each nozzle is 15 to 120 kPa, and the natural gas flow rate is 30 to 800 Nm³. 3 / h, air pressure 3~15kPa, air flow rate 800~8000Nm 3 / h. In this embodiment of the invention, a four-stage heating process is preferably adopted for the furnace body. This ensures that the heating operation of the roasting furnace is carried out uniformly according to a reasonable temperature gradient, and that the furnace body brickwork and outer shell support are heated slowly and evenly. This allows for the effective and uniform release of thermal expansion force, which is beneficial to the operation of the equipment. In this embodiment of the invention, the flow rate, pressure, and air flow rate of each natural gas burner are optimized. These parameters can be controlled online and can be precisely controlled according to the trend of furnace temperature rise and flame length. This ensures that the roasting furnace heats up stably and orderly while reducing natural gas consumption to a low level. In this embodiment of the invention, roasted sand is used as the furnace bottom material. On the one hand, this ensures that the overall furnace bed pressure is relatively uniform and stable. On the other hand, the enthalpy of roasted sand is used for heat storage. Roasted sand has very strong heat and mass transfer when fluidized, but its heat transfer effect is poor when stationary. In this embodiment of the invention, a blower is used to turn the material during the stage heating process, which can make the roasted sand on the entire furnace bed heated evenly and achieve the purpose of effective heat storage.

[0041] In some embodiments, in step e, 1-2 natural gas nozzles are removed each time; in step f, during the stable production stage, the blower pressure is 10-20 kPa and the blower volume is 45000-120000 Nm³. 3 / h. In this embodiment of the invention, as production stabilizes, the natural gas nozzles are withdrawn sequentially, effectively maintaining the stability of the furnace body and completing the start-up process.

[0042] The present invention will now be described in detail with reference to the embodiments.

[0043] Example 1 75m 2 Start-up of a large fluidized bed roasting furnace

[0044] (1) Check and ensure that the furnace charge required for start-up is sufficient and that the furnace charge storage is sufficient for 20 days; check and test the relevant equipment and procedures for start-up to ensure that the equipment operates normally and the procedures run smoothly.

[0045] (2) Use firewood or charcoal to preheat the fluidized roasting furnace to 250°C for 36 hours to remove free water from the furnace body;

[0046] (3) Three natural gas injection lances were used for furnace start-up. The natural gas injection lances were evenly arranged radially along the large fluidized bed roasting furnace. The injected natural gas pressure was 20 kPa, and the natural gas flow rate was 100 Nm³. 3 / h, air pressure: 5kPa, air flow rate: 1200Nm 3 / h; gradually increase the number of natural gas injection guns to preheat the fluidized bed roasting furnace to 700℃ for 80h to remove the bound water inside the furnace;

[0047] (4) Stop the gun and wait for the fluidized bed roasting furnace to cool down to about 100°C. Then, use a throwing machine to throw the zinc roasting sand into the fluidized bed to lay the bottom material. The zinc roasting sand particle size is 0.5-3mm and the bottom material thickness is 650mm.

[0048] (5) The first stage of heating is carried out using one natural gas nozzle. The natural gas pressure injected into the nozzle is 20 kPa, and the natural gas flow rate is 100 Nm³. 3 / h, air pressure: 5kPa, air flow rate: 1200Nm 3 / h, heat the temperature to 450℃, start the blower to turn the material once, turn the material over for 2 minutes and then turn it off;

[0049] (6) Use two natural gas nozzles for the second stage of heating. The gas volume and pressure of the natural gas nozzles are the same as in the first stage. The heating temperature is 600℃. Then, start the blower again to turn the material once. Turn the material over for 3 minutes and then turn it off.

[0050] (7) Three natural gas nozzles are used for the third stage of heating. The gas flow rate and pressure of the natural gas nozzles are the same as in the first stage. The heating temperature is raised to 800℃. The blower is started to maintain the fluidization of the zinc calcined sand in the fluidized furnace. The blower pressure is 8 kPa and the blower flow rate is 15000 Nm³. 3 / h;

[0051] (8) Use three natural gas torches for the fourth stage of heating. The gas volume and pressure of the natural gas torches are the same as in the first stage. Continue heating to raise the furnace temperature to 850°C and start feeding zinc sulfide concentrate using a throwing machine.

[0052] (9) Maintain the furnace temperature at around 850℃ for 1 hour, and remove the natural gas spray guns one by one.

[0053] (10) Keep one natural gas nozzle, and keep the nozzle pressure and flow rate the same as during the fourth stage of heating. Continue feeding until the furnace temperature is maintained at around 880°C and the production stage is reached. Then remove the natural gas nozzle.

[0054] After the furnace is started using the method described in this embodiment, the energy consumption is (0.74~0.78)×10 6MJ, the start-up cost is (78,000~80,000) yuan (natural gas price 3 yuan / Nm³). 3 The amount of sulfur brought in by natural gas is (115-120) kg.

[0055] In this embodiment, the fluidized bed roasting furnace is started up using conventional diesel heating, with an energy consumption of (0.85~0.88)×10 6 MJ has a start-up cost of (121,000~126,000) yuan (diesel price 6 yuan / liter), and the amount of sulfur carried in by diesel is (210~230) kg.

[0056] Compared with the traditional diesel-heated furnace start-up method, the furnace start-up method of this embodiment can reduce energy consumption by about 11-13%, reduce start-up costs by about 35-36%, and reduce SO2 production by about 45-48%.

[0057] Example 2 – 109m 2 Start-up of a large fluidized bed roasting furnace

[0058] (1) Check and ensure that the furnace charge required for start-up is sufficient and that the furnace charge storage is sufficient for 25 days; check and test the relevant equipment and procedures for start-up to ensure that the equipment operates normally and the procedures run smoothly.

[0059] (2) Use firewood or charcoal to preheat the fluidized roasting furnace to 300°C for 50 hours to remove free water from the furnace body;

[0060] (3) Four natural gas injection lances were used for furnace start-up. The natural gas injection lances were evenly arranged radially along the large fluidized bed roasting furnace. The injected natural gas pressure was 30 kPa and the natural gas flow rate was 300 Nm³. 3 / h, air pressure: 7kPa, air flow rate: 3500Nm 3 / h; gradually increase the number of natural gas injection guns to preheat the fluidized bed roasting furnace to 700℃ for 150h to remove the bound water inside the furnace.

[0061] (4) Stop the gun and wait for the fluidized bed roasting furnace to cool down to about 150°C. Then, use a throwing machine to throw the zinc roasting sand into the fluidized bed to lay the bottom material. The zinc roasting sand particle size is 0.5-3mm and the bottom material thickness is 700mm.

[0062] (5) The first stage of heating is carried out using one natural gas nozzle. The natural gas pressure injected into the nozzle is 30 kPa, and the natural gas flow rate is 300 Nm³. 3 / h, air pressure: 7kPa, air flow rate: 3500Nm 3 / h, heat the temperature to 400℃, start the blower to turn the material once, turn off the blower after 3 minutes of turning;

[0063] (6) Use two natural gas nozzles for the second stage of heating. The gas volume and pressure of the natural gas nozzles are the same as in the first stage. The heating temperature is 600℃. Then, start the blower again to turn the material over twice. Turn the material over for 5 minutes each time and then turn it off.

[0064] (7) Three natural gas nozzles are used for the third stage of heating. The gas flow rate and pressure of the natural gas nozzles are the same as in the first stage. The heating temperature is raised to 700℃. The blower is started to maintain the fluidization of the zinc calcined sand in the fluidized furnace. The blower pressure is 10 kPa and the blower flow rate is 30000 Nm³. 3 / h;

[0065] (8) Four natural gas torches were used for the fourth stage of heating. The gas volume and pressure of the natural gas torches were the same as in the first stage. Heating continued until the furnace temperature reached 850°C. The zinc sulfide concentrate was then fed into the furnace using a throwing machine.

[0066] (9) Maintain the furnace temperature at around 850℃ for 1 hour, and remove the natural gas spray guns one by one.

[0067] (10) Keep one natural gas nozzle, and keep the nozzle pressure and flow rate the same as during the fourth stage of heating. Continue feeding until the furnace temperature is maintained at around 880°C and the production stage is reached. Then remove the natural gas nozzle.

[0068] After the furnace is started using the method described in this embodiment, the energy consumption is (1.14~1.19)×10 6 MJ, the start-up cost is (120,000~125,000) yuan (natural gas price 3 yuan / Nm³). 3 The amount of sulfur brought in by natural gas is (180-190) kg.

[0069] In this embodiment, the fluidized bed roasting furnace is started up using conventional diesel heating, with an energy consumption of (1.28~1.35)×10. 6 MJ has a start-up cost of (182,000-190,000) yuan (diesel price 6 yuan / liter), and the amount of sulfur carried by diesel is (320-350) kg.

[0070] Compared with the traditional diesel-heated furnace start-up method, the furnace start-up method of this embodiment can reduce energy consumption by about 11-12%, reduce start-up costs by about 34-35%, and reduce SO2 production by about 43-45%.

[0071] Example 3 – 186m 2 Start-up of a large fluidized bed roasting furnace

[0072] (1) Check and ensure that the furnace charge required for start-up is sufficient and that the furnace charge storage is sufficient for 30 days; check and test the relevant equipment and procedures for start-up to ensure that the equipment operates normally and the procedures run smoothly.

[0073] (2) Use firewood or charcoal to preheat the fluidized roasting furnace to 300°C for 75 hours to remove free water from the furnace body;

[0074] (3) Six natural gas injection lances were used for furnace start-up. The natural gas injection lances were evenly arranged radially along the large fluidized bed roasting furnace. The injected natural gas pressure was 100 kPa, and the natural gas flow rate was 600 Nm³. 3 / h, air pressure: 10kPa, air flow rate: 7000Nm 3 / h; gradually increase the number of natural gas injection guns to preheat the fluidized bed roasting furnace to 700℃ for 180h to remove the bound water inside the furnace;

[0075] (4) Stop the gun and wait for the fluidized bed roasting furnace to cool down to about 150°C. Then, use a throwing machine to throw the zinc roasting sand into the fluidized bed to lay the bottom material. The zinc roasting sand particle size is 0.1-5mm and the bottom material thickness is 800mm.

[0076] (5) The first stage of heating is carried out using one natural gas nozzle. The natural gas pressure injected into the nozzle is 120 kPa, and the natural gas flow rate is 600 Nm³. 3 / h, air pressure: 10kPa, air flow rate: 7000Nm 3 / h, heat the temperature to 400℃, start the blower to turn the material twice, turn the material for 5 minutes each time and then turn it off;

[0077] (6) Use two natural gas nozzles for the second stage of heating. The gas volume and pressure of the natural gas nozzles are the same as in the first stage. The heating temperature is 600℃. Then start the blower again to turn the material over 3 times. Turn the material over for 8 minutes each time and then turn it off.

[0078] (7) Four natural gas nozzles were used for the third stage of heating. The gas flow rate and pressure of the natural gas nozzles were the same as in the first stage. The heating temperature was raised to 750℃. The blower was started to maintain the fluidization of the zinc calcined sand in the fluidized furnace. The blower pressure was 15 kPa and the blower flow rate was 50,000 Nm³. 3 / h;

[0079] (8) Six natural gas torches were used for the fourth stage of heating. The gas volume and pressure of the natural gas torches were the same as in the first stage. Heating continued until the furnace temperature reached 850°C. Zinc sulfide concentrate was then fed into the furnace using a throwing machine.

[0080] (9) Maintain the furnace temperature at around 850℃ for 2 hours, and remove the natural gas spray guns one by one;

[0081] (10) Keep 1-2 natural gas nozzles, and keep the nozzle pressure and flow rate the same as during the fourth stage of heating. Continue feeding materials until the furnace temperature is maintained at around 900℃ and the production stage is reached. Then remove the natural gas nozzles.

[0082] After the furnace is opened using the furnace opening method described in this embodiment, (2.0~2.06)×10 6 MJ, the start-up cost is (210,000~215,000) yuan (natural gas price 3 yuan / Nm³). 3 The amount of sulfur brought in by natural gas is (330-350) kg.

[0083] In this embodiment, the fluidized bed roasting furnace is started up using conventional diesel heating, with an energy consumption of (2.32~2.36)×10. 6 MJ has a start-up cost of (324,000~330,000) yuan (diesel price 6 yuan / liter), and the amount of sulfur carried in by diesel is (580~610) kg.

[0084] Compared with the traditional diesel-powered furnace start-up method, the furnace start-up method of this embodiment can reduce energy consumption by about 12-13%, reduce start-up costs by about 34-35%, and reduce SO2 production by about 42-43%.

[0085] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for starting up a fluidized roaster for zinc smelting, characterized in that, include: a. Preheat the fluidized bed roasting furnace to 250~350℃ using firewood or charcoal; b. Use a natural gas torch to inject natural gas and air to preheat the furnace body to 600~750℃, then stop the torch; c. After the furnace body cools to 50~200℃, zinc roasted sand is thrown into the fluidized roasting furnace to lay the bottom material; d. The furnace body is heated in at least two stages by gradually adding natural gas injection guns, so that the furnace body temperature reaches 800-900℃; e. Add zinc sulfide concentrate into the furnace, maintain the furnace temperature at 800-900℃, gradually withdraw the natural gas nozzles, leave 1-2 natural gas nozzles, and continue to add zinc sulfide concentrate. f. After the furnace body temperature is maintained at a stable production stage of 850~950℃, all natural gas nozzles are removed, and the furnace start-up process is completed. In step d, the furnace body is heated in four stages by successively adding natural gas torches. Specifically: the first stage of heating is performed using one natural gas torch, with the temperature reaching 300-450℃, followed by starting the blower to turn the material over and then shutting it off; the second stage of heating is performed using two to three natural gas torches, with the temperature reaching 500-600℃, followed by starting the blower again to turn the material over and then shutting it off; the third stage of heating is performed using three to four natural gas torches, with the temperature reaching 650-750℃, followed by starting the blower to maintain the fluidization of the zinc roasted sand in the fluidized bed roasting furnace; the fourth stage of heating is performed using four to six natural gas torches, with the temperature reaching 800-900℃. The furnace bed area of ​​the fluidized bed roasting furnace is ≥75m². 2 .

2. The start-up method for a fluidized roaster for zinc smelting according to claim 1, characterized by, In step a, the preheating time using firewood or charcoal is 25-75 hours.

3. The method for starting up a fluidized bed roasting furnace for zinc smelting according to claim 1, characterized in that, The natural gas injection guns are 3-6 in number and are evenly distributed radially along the fluidized bed roasting furnace.

4. The method for starting up a fluidized bed roasting furnace for zinc smelting according to claim 1, characterized in that, In step b, the preheating time of the natural gas injection gun is 48-200 hours, the injected natural gas pressure is 20-100 kPa, and the natural gas flow rate is 50-600 Nm³. 3 / h, air pressure 5~10kPa, air flow rate 1000~7000Nm 3 / h.

5. The start-up method for a fluidized roaster for zinc smelting according to claim 1, characterized by, In step c, the thickness of the base material is 650-850mm.

6. The method for starting up a fluidized bed roasting furnace for zinc smelting according to claim 1, characterized in that, In step d, the pressure of the natural gas injected by the natural gas nozzle is 15~120 kPa, and the flow rate is 30~800 Nm³. 3 / h, air pressure 3~15kPa, air flow rate 800~8000Nm 3 / h.

7. The method for starting up a fluidized bed roasting furnace for zinc smelting according to claim 1, characterized in that, In step d, during the first stage of heating, the blower is started to turn the material 1-2 times, with each turning time lasting 1-10 minutes; during the second stage of heating, the blower is started to turn the material 2-3 times, with each turning time lasting 2-8 minutes; during the third stage of heating, the blower pressure maintaining the zinc concentrate in a fluidized state is 8-15 kPa, and the blower volume is 15000-50000 Nm³. 3 / h.

8. The method for starting up a fluidized bed roasting furnace for zinc smelting according to claim 1, characterized in that, In step e, 1-2 natural gas nozzles are removed each time; in step f, during the stable production stage, the blower pressure is 10-20 kPa and the blower volume is 45000-120000 Nm³. 3 / h.