Copper residue waste heat recovery system and waste heat recovery method thereof

Abstract

The present application belongs to the technical field of comprehensive utilization of slag waste heat recovery, and particularly relates to a copper slag waste heat recovery system and a waste heat recovery method thereof. The system comprises a slag package, a granulation bin is arranged at the slag outlet of the slag package, a spray gun is arranged in the granulation bin, and a rotating cup device is arranged on the spray gun; the outlet of the granulation bin is connected with a boiler, the boiler is connected with a waste heat boiler and a pyrolysis gasifier, the boiler is connected with the waste heat boiler and the pyrolysis gasifier; the waste heat boiler is connected with a power generation equipment, low-pressure steam generated after power generation of the power generation equipment is used for heating and heating of a user heat accumulator, and condensed water generated by heating and heating of the user heat accumulator enters the boiler; first hot air in the granulation bin enters the waste heat boiler, and superheated steam generated by the boiler enters the power generation equipment. The present application adopts a granulation method combining gas quenching and centrifugation, and high-temperature gas and superheated steam at different temperatures are obtained through air and water cooling in different environments, and are applied to the pyrolysis gasifier and the waste heat boiler, so that efficient utilization of copper slag waste heat is realized.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization technology of slag waste heat recovery, specifically relating to a copper slag waste heat recovery system and a waste heat recovery method. Background Technology

[0002] Pyrometallurgical copper smelting is a process that produces electrolytic copper from copper sulfide concentrate through matte smelting, blowing, pyrometallurgical refining, and electrolytic refining. High-temperature copper slag mainly refers to the slag produced during matte smelting, copper matte blowing, and crude copper refining. This copper slag is mainly composed of fir olivine, magnetite, copper sulfide, metallic copper, and some gangue, with iron and copper contents of approximately 40% and 2%–8%, respectively.

[0003] The pyrometallurgical copper smelting process generates approximately 2.2 tons of copper slag per ton of copper produced. The slag exits the furnace at a temperature of about 1200℃–1300℃, and each ton of slag contains approximately 1.13 GJ of heat. However, currently, the high-temperature waste heat from the copper slag in pyrometallurgical copper smelting plants is largely not recovered and utilized. The recovery and utilization of high-temperature copper slag waste heat can not only reduce energy consumption in copper smelting production but also reduce pollutant emissions, alleviating environmental pressure and playing a crucial role in energy conservation and emission reduction for enterprises. Further in-depth research is needed on high-temperature copper slag waste heat recovery and utilization technology.

[0004] The current copper slag treatment process uses a slow cooling method with slag bags. The main purpose of this method is to allow the copper slag to form a better crystal structure during the cooling process, which facilitates better copper recovery in subsequent mineral processing. However, the slow cooling process with slag bags makes it difficult to utilize the residual heat of the high-temperature copper slag. This not only results in a large waste of residual heat, but also causes the evaporation of spray wastewater to form salt scale that adheres to the pipes and slag bags, leading to severe corrosion and wear, significantly reducing cooling efficiency, interfering with production, and increasing the difficulty of subsequent copper slag resource utilization. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a copper slag waste heat recovery system and method. It achieves effective integration and connection between the recyclable energy processing system and the production system. The granulation bin employs a combination of gas quenching and centrifugal granulation, characterized by high operational safety and high recovery rate. Through cooling with air and water in different environments, high-temperature gases and superheated steam at varying temperatures are obtained, specifically applied to the pyrolysis gasification furnace and waste heat boiler. This not only solves the serious problem of resource waste but also effectively realizes the efficient utilization of copper slag waste heat. After waste heat recovery by this system, the original high-temperature copper slag at approximately 1200℃~1400℃ is transformed into low-temperature slag particles at approximately 80℃~150℃, demonstrating significant waste heat recovery and facilitating subsequent flotation processes.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0007] One of the objectives of this invention is to provide a copper slag waste heat recovery system, including a slag bag, a granulation chamber provided at the slag outlet of the slag bag, a spray gun provided below the slag outlet and inside the granulation chamber, and a rotating cup device provided on the spray gun. The rotating cup device is used to centrifuge, crush and granulate the copper slag, while the spray gun is used to air cool and granulate the copper slag, and heat exchange to form the first hot air.

[0008] The outlet of the granulation bin is connected to a fixed bed boiler, which is connected to a waste heat boiler and a pyrolysis gasification furnace. The fixed bed boiler is used to exchange heat with the copper slag, and then generate a second hot air.

[0009] The waste heat boiler is connected to a power generation device. First hot air and second hot air enter the waste heat boiler to exchange heat with the waste heat boiler to form first superheated steam. The first superheated steam enters the power generation device to generate electricity.

[0010] The low-pressure steam generated by the power generation equipment is used to heat the user's heat storage tank. The condensate generated by the user's heat storage tank enters the fixed bed boiler and is used to exchange heat with the copper slag to generate second superheated steam. The second superheated steam enters the power generation equipment and is used to generate electricity.

[0011] The copper slag in the slag bag is circulated through a granulation bin, a fixed-bed boiler, and a waste heat boiler to achieve waste heat recovery from the copper slag.

[0012] Preferably, in the above-mentioned copper slag waste heat recovery system, the spray gun is a gas spray gun, one end of the gas spray gun is connected to an air compressor through a first air pipe, and a first solenoid valve is provided on the first air pipe.

[0013] Preferably, in the above-mentioned copper slag waste heat recovery system, the fixed bed boiler adopts two heat exchange methods: water cooling and air cooling. The air cooling method involves connecting an air compressor through an air pipe, which supplies cold air into the fixed bed boiler, where it exchanges heat to form a second type of hot air. The water cooling method involves the condensate generated by the user's heat storage device for heating entering the fixed bed boiler through a drain pipe, where it exchanges heat to form a second type of superheated steam.

[0014] Preferably, in the above-mentioned copper slag waste heat recovery system, the granulation bin is provided with an exhaust port, the exhaust port is connected to the waste heat boiler through a first hot air exhaust pipe, the waste heat boiler is connected to the power generation equipment through a second hot air exhaust pipe, and a second solenoid valve is provided on the first hot air exhaust pipe.

[0015] Preferably, in the above-mentioned copper slag waste heat recovery system, the fixed bed boiler is provided with a third hot air exhaust pipe, the third hot air exhaust pipe is connected to the first hot air exhaust pipe, and a third solenoid valve is provided on the third hot air exhaust pipe.

[0016] Preferably, in the above-mentioned copper slag waste heat recovery system, the three hot air exhaust pipes are connected to a connecting pipe, the connecting pipe is connected to a pyrolysis gasification furnace, the second hot air enters the pyrolysis gasification furnace for pyrolysis reaction, the connecting pipe is equipped with a fourth solenoid valve, the pyrolysis gasification furnace is equipped with a first exhaust pipe, and the first exhaust pipe is connected to the three hot air exhaust pipes.

[0017] Preferably, in the above-mentioned copper slag waste heat recovery system, the fixed bed boiler is provided with a superheated steam discharge pipe, the superheated steam discharge pipe is connected to the power generation equipment, and a fifth solenoid valve is provided on the superheated steam discharge pipe.

[0018] Preferably, in the above-mentioned copper slag waste heat recovery system, the outlet of the fixed-bed boiler is connected to a flotation recovery device.

[0019] The second objective of this invention is to provide a method for recovering waste heat from copper slag using the aforementioned copper slag waste heat recovery system, comprising the following steps:

[0020] The copper slag in the slag bag is discharged through the slag outlet into the granulation bin. At this time, the temperature of the copper slag is 1200℃~1400℃. The copper slag enters the rotating cup device, which centrifuges, crushes and granulates the copper slag. At the same time, the copper slag is further crushed, granulated and heat-exchanged by the cold air of the spray gun. It falls into the bottom of the granulation bin and is cooled to 1000℃~1100℃ before entering the fixed bed boiler.

[0021] The cold air from the spray gun cools and exchanges heat with the copper slag, forming the first hot air that enters the waste heat boiler.

[0022] After the fixed-bed boiler exchanges heat with the copper slag, the resulting second hot air at 600℃~800℃ enters the waste heat boiler and the pyrolysis gasification furnace. At the same time, the condensate generated by the user's heat storage device for heating enters the fixed-bed boiler to exchange heat with the copper slag, generating second superheated steam, which then enters the power generation equipment.

[0023] The combustible gas generated by the pyrolysis gasification furnace and the second hot air generated after the copper slag is exchanged by the fixed bed boiler heat the water in the waste heat boiler to form the first superheated steam, which enters the power generation equipment. The power generation equipment generates electricity through the first and second superheated steam and provides electricity to users. The low-pressure steam generated after the power generation equipment generates electricity is used to heat the user's heat storage tank for heating. The condensate generated from heating enters the fixed bed boiler for heat exchange and generates the second superheated steam, forming a heat exchange cycle.

[0024] A fixed-bed boiler cools copper slag to 80℃~150℃ through heat exchange before discharging it for flotation, thereby realizing the recovery of waste heat from the copper slag and the resource utilization of copper slag.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] This invention proposes a copper slag waste heat recovery system, realizing the effective integration and connection between the recyclable energy processing system and the production system. The granulation bin adopts a granulation method combining gas quenching and centrifugation, featuring high operational safety and high recovery rate. Through cooling with air and water in different environments, high-temperature gases and superheated steam at different temperatures are obtained, which are specifically applied to the pyrolysis gasification furnace and waste heat boiler. This not only solves the serious problem of resource waste but also effectively realizes the efficient utilization of copper slag waste heat. After waste heat recovery by this system, the original high-temperature copper slag at approximately 1200℃~1400℃ is transformed into low-temperature slag particles at approximately 80℃~150℃, demonstrating a significant waste heat recovery effect and providing convenience for subsequent flotation processes. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the copper slag waste heat recovery system of the present invention.

[0028] 1-Slag bag, 2-Slag outlet, 3-Granulation bin, 4-Spray gun, 5-Rotating cup device, 6-Fixed bed boiler, 7-Air compressor, 8-Waste heat boiler, 9-Pyrolysis gasification furnace, 10-Power generation equipment, V1-First solenoid valve, V2-Second solenoid valve, V3-Third solenoid valve, V4-Fourth solenoid valve, V5-Fifth solenoid valve, V6-Sixth solenoid valve, V7-Seventh solenoid valve, V8-Eighth solenoid valve, V9-Ninth solenoid valve. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that the technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Certain terms are used in this invention to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This invention does not distinguish components based on differences in terminology, but rather on differences in function. As used throughout the specification and claims, "comprising" is an open-ended term and should be understood as "including but not limited to".

[0031] The current copper slag treatment process uses a slow cooling method with slag bags. The main purpose of this method is to allow the copper slag to form a better crystal structure during the cooling process, which facilitates better copper recovery in subsequent mineral processing. However, the slow cooling process with slag bags makes it difficult to utilize the residual heat of the high-temperature copper slag. This not only results in a large waste of residual heat, but also causes the evaporation of spray wastewater to form salt scale that adheres to the pipes and slag bags, leading to severe corrosion and wear, significantly reducing cooling efficiency, interfering with production, and increasing the difficulty of subsequent copper slag resource utilization.

[0032] To address the above problems, this invention provides a copper slag waste heat recovery system, such as... Figure 1 As shown, the system includes a slag bag 1, a granulation chamber 3 located below the slag outlet 2 of the slag bag 1, and a spray gun 4 located inside the granulation chamber 3. The spray gun 4 is equipped with a rotating cup device 5, which is used for centrifugation, crushing, and granulation of the copper slag. Simultaneously, the spray gun 4 is used for air cooling and granulation of the copper slag, generating a first hot air through heat exchange. The outlet of the granulation chamber 3 is connected to a fixed-bed boiler 6, which is connected to a waste heat boiler 8 and a pyrolysis gasification furnace 9. The fixed-bed boiler 6 generates a second hot air after heat exchange with the copper slag. The waste heat boiler 8 is connected to a power generation device 10, which generates a second hot air. The second hot air enters the waste heat boiler 8 to exchange heat with the waste heat boiler 8 and form the first superheated steam. The first superheated steam enters the power generation equipment 10 and is used to generate electricity. The low-pressure steam generated by the power generation equipment 10 is used to heat the user's heat storage tank. The condensate generated by the user's heat storage tank enters the fixed bed boiler 6 and is used to exchange heat with the copper slag to generate the second superheated steam. The second superheated steam enters the power generation equipment 10 and is used to generate electricity. The copper slag in the slag bag 1 is circulated through the granulation bin 3, the fixed bed boiler 6 and the waste heat boiler 8 to achieve the recovery of copper slag waste heat.

[0033] The spray gun 4 surrounds the outside of the rotating cup device 5. Both the spray gun 4 and the rotating cup device 5 are located directly below the slag outlet 2. When the copper slag enters the granulation chamber 3 through the slag outlet 2, the copper slag enters the rotating cup device 5, which centrifuges, crushes and granulates the copper slag flowing in from the slag outlet 2. At the same time, the spray gun 4 air-cools the copper slag and further crushes and granulates it. The cold air is heated by the copper slag to form the first hot air, which is discharged from the granulation chamber into the waste heat boiler 8.

[0034] The cold air from the spray gun 4 further crushes, granulates, and exchanges heat with the copper slag, falling to the bottom of the granulation chamber 3 and being discharged into the fixed-bed boiler 6. The fixed-bed boiler 6 exchanges heat with the copper slag using both air cooling and water cooling methods. The second hot air generated by air cooling enters the waste heat boiler 8 and the pyrolysis gasification furnace 9, while the first superheated steam generated by water cooling enters the power generation equipment 10. Simultaneously, the pyrolysis gasification furnace 9 produces combustible gas after reaction, which can be further recovered and reused. The hot air generated by the combustible gas enters the waste heat boiler 8 for heat exchange and reuse. The electrical energy generated by the power generation equipment 10 is transmitted to users via wires to provide them with electricity. The low-pressure steam generated after the power generation equipment 10 generates electricity is used to heat the user's heat storage tank. The condensate generated by the user's heat storage tank enters the fixed-bed boiler 6 and is used to exchange heat with the copper slag. This system can realize a high-temperature copper slag waste heat recovery system that integrates the recyclable energy processing system with the production system, has high operational safety, and a high recovery rate.

[0035] This invention proposes a copper slag waste heat recovery system, realizing the integration and effective connection between the recyclable energy processing system and the production system. The granulation bin adopts a granulation method combining gas quenching and centrifugation, featuring high operational safety and high recovery rate. By cooling with air and water in different environments, high-temperature gases and superheated steam at different temperatures are obtained, which are specifically applied to pyrolysis gasification furnaces and waste heat boilers. This not only solves the serious problem of resource waste but also effectively realizes the efficient utilization of copper slag waste heat.

[0036] The following specific examples will provide further explanation.

[0037] Example

[0038] This invention provides a copper slag waste heat recovery system, such as... Figure 1As shown, the system includes a slag bag 1, a granulation chamber 3 located below the slag outlet 2 of the slag bag 1, and a spray gun 4 located inside the granulation chamber 3. The spray gun 4 is equipped with a rotating cup device 5, which is used for centrifugation, crushing, and granulation of the copper slag. Simultaneously, the spray gun 4 is used for air cooling and granulation of the copper slag, generating a first hot air through heat exchange. The outlet of the granulation chamber 3 is connected to a fixed-bed boiler 6, which is connected to a waste heat boiler 8 and a pyrolysis gasification furnace 9. The fixed-bed boiler 6 generates a second hot air after heat exchange with the copper slag. The waste heat boiler 8 is connected to a power generation device 10, which generates a second hot air. The second hot air enters the waste heat boiler 8 to exchange heat with the waste heat boiler 8 and form the first superheated steam. The first superheated steam enters the power generation equipment 10 and is used to generate electricity. The low-pressure steam generated by the power generation equipment 10 is used to heat the user's heat storage tank. The condensate generated by the user's heat storage tank enters the fixed bed boiler 6 and is used to exchange heat with the copper slag to generate the second superheated steam. The second superheated steam enters the power generation equipment 10 and is used to generate electricity. The copper slag in the slag bag 1 is circulated through the granulation bin 3, the fixed bed boiler 6 and the waste heat boiler 8 to achieve the recovery of copper slag waste heat.

[0039] The granulation bin 3 is made of high-temperature and corrosion-resistant materials, and its top is equipped with a slag inlet to receive high-temperature copper slag from the smelting process. Inside the granulation bin, near the slag inlet, a rotating cup device and one or more rows of gas spray guns are installed to ensure that the high-temperature copper slag is cooled and granulated by the centrifugal force of the rotating cup and the impact of high-speed airflow after entering the granulation bin. The bottom of the granulation bin has a slag outlet, and through a suitable tilt angle and vibration device, the granulated copper slag is smoothly discharged.

[0040] The fixed-bed boiler 6 serves as the system's heat exchange equipment. Its slag inlet is connected to the slag outlet of the granulation bin 3, receiving copper slag that has been gas-quenched, cooled, and granulated. The fixed-bed boiler 6 has an efficient heat exchange surface inside to absorb residual heat from the copper slag. The boiler has one hot gas output end and one cold gas input end. The cold gas input end is located at the bottom of the fixed-bed boiler 6 to ensure sufficient heat exchange. The hot gas output end is directly connected to the waste heat boiler 8 and the pyrolysis gasification furnace 9 to transfer high-temperature hot gas for recycling and improving energy efficiency. In addition, the fixed-bed boiler 6 also has a steam output end connected to the generator set 5 for power generation.

[0041] Waste heat boiler 8 receives high-temperature hot air from granulation bin 3 and fixed-bed boiler 6, and converts the heat energy in the hot air into steam through internal heat exchange tube bundles. The design of waste heat boiler 8 should fully consider thermal efficiency to ensure that as much heat energy as possible is converted into steam. The steam output end of waste heat boiler 8 is connected to generator set 5 to provide power for power generation.

[0042] The pyrolysis gasification furnace 7, as an advanced thermochemical conversion device, is integrated into the entire waste heat recovery system. This device utilizes a high-temperature heat source to pyrolyze and gasify organic matter or specific materials to generate combustible gases or other high-value-added products.

[0043] Generator set 10 employs a steam turbine or steam turbine-generator combined cycle system, receiving steam from waste heat boiler 8 and fixed-bed boiler 6 to drive the generator to generate electricity. The selection of generator set 10 should be optimized based on the overall thermal efficiency and power demand of the system.

[0044] In one specific embodiment, the spray gun 4 is a gas spray gun, one end of which is connected to an air compressor 7 via a first air pipe. A first solenoid valve V1 is provided on the first air pipe. The flow rate of cold air entering the spray gun 4 can be adjusted by the first solenoid valve V1, thereby controlling the particle size of the further crushed particles and the temperature of heat exchange. The granulation chamber 3 adopts a granulation method combining air quenching and centrifugation, which has the characteristics of high operational safety and high recovery rate.

[0045] In one specific embodiment, the rotating cup device 5 includes a granulator. The rotating cup device 5 centrifuges, crushes, and granulates the copper slag flowing in from the slag outlet 2. When the molten slag flows from the top into the center of the high-speed rotating granulator inside the rotating cup device 5 and spreads on the surface of the granulator to form a liquid film, as the granulator rotates, the molten slag liquid film gradually moves towards the edge of the granulator under the action of centrifugal force, the speed gradually increases, and the thickness of the liquid film gradually decreases. When the molten slag moves to the outer edge of the granulator, the granulator wall no longer has a restraining effect on it. At this time, the molten slag is broken under the influence of centrifugal force, surface tension, and gas-liquid interaction, and finally forms fine droplets. At the same time, the spray gun 4 air-cools and further crushes and granulates the copper slag. The cold air is heated by the copper slag to form the first hot air and is discharged from the granulation chamber into the waste heat boiler 8.

[0046] In one specific embodiment, the fixed-bed boiler 6 employs both water cooling and air cooling. Air cooling is achieved by connecting an air compressor 7 via an air pipe, which supplies cold air into the fixed-bed boiler 6, where it exchanges heat to form hot air. Water cooling involves condensate from the user's heat storage device entering the fixed-bed boiler 6 via a drain pipe, where it exchanges heat to form superheated steam. A seventh solenoid valve V7 is installed on the air pipe, and an eighth solenoid valve V8 is installed on the drain pipe. In addition to providing cold air to the spray gun 4, the air compressor 7 also provides cold air to the fixed bed boiler 6 through the air pipe. The flow rate of the cold air in the air pipe is controlled by the seventh solenoid valve V7, thereby controlling the air-cooled heat exchange flow rate of the fixed bed boiler 6. Water cooling is achieved by the condensate generated by the user's heat storage device for heating entering the fixed bed boiler 6 through the drain pipe. After the condensate exchanges heat with the fixed bed boiler 6, the fixed bed boiler 6 is equipped with a second superheated steam discharge pipe, which is connected to the power generation equipment 10. The fixed bed boiler 6 generates second superheated steam by exchanging heat with the copper slag. The second superheated steam is discharged into the power generation equipment 10 through the superheated steam discharge pipe. The superheated steam discharge pipe is equipped with a fifth solenoid valve V5, which is used to control the flow rate of the superheated steam in the superheated steam discharge pipe.

[0047] In one specific embodiment, the granulation chamber 3 is provided with an exhaust port, which is connected to the waste heat boiler 8 through a first hot air exhaust pipe. The waste heat boiler 8 is connected to the power generation equipment 10 through a second hot air exhaust pipe. A second solenoid valve V2 is provided on the first hot air exhaust pipe. When cold air enters the granulation chamber 3 through the spray gun 4, i.e., during the air cooling and further crushing and granulation of the copper slag, the cold air and the copper slag exchange heat. The crushed and granulated copper slag falls to the bottom of the granulation chamber 3. The exhaust port is located on the upper wall of the granulation chamber 3. The first hot air generated by the heat exchange enters the second hot air exhaust pipe through the exhaust port. The flow rate of the first hot air discharged into the waste heat boiler 8 is controlled by the solenoid valve V2. The first hot air heats the waste heat boiler 8, and the waste heat boiler 8 transfers heat to water to generate steam. After steam-water separation, the steam enters the superheater for reheating to become first superheated steam, which is discharged into the power generation equipment 10 through the second hot air exhaust pipe. A sixth solenoid valve V6 is provided on the second hot air exhaust pipe to control the flow rate of the first superheated steam in the second hot air exhaust pipe. The first superheated steam generated by the water-heat exchange in the waste heat boiler 8 is saturated steam. The power generation equipment 10 is a steam power generation equipment. The first superheated steam converts thermal energy into mechanical energy through a steam turbine, which in turn drives the generator to rotate and generate electrical energy. The low-pressure steam generated after the power generation equipment 10 generates electricity is discharged into the user's heat storage tank through a low-pressure steam pipe for heating the user's heat storage tank. A ninth solenoid valve V9 is installed on the low-pressure steam pipe, which is used to control the flow rate of the low-pressure steam.

[0048] In one specific embodiment, the fixed-bed boiler 6 is provided with a third hot air exhaust pipe, which is connected to a first hot air exhaust pipe. A third solenoid valve V3 is provided on the third hot air exhaust pipe. The third hot air exhaust pipe is connected to a connecting pipe, which is connected to a pyrolysis gasification furnace 9. Second hot air enters the pyrolysis gasification furnace 9 for pyrolysis reaction. A fourth solenoid valve V4 is provided on the connecting pipe. The pyrolysis gasification furnace 9 is provided with a first exhaust pipe, which is connected to the three hot air exhaust pipes. The third hot air exhaust pipe is located on the upper wall of the fixed bed boiler 6. The outlet end of the third hot air exhaust pipe is connected to the first hot air exhaust pipe. The third hot air exhaust pipe is equipped with a third solenoid valve V3, which is used to control the flow rate of hot air discharged into the waste heat boiler 8 through the third hot air exhaust pipe. The third hot air exhaust pipe is connected to the pyrolysis gasification furnace 9 through a connecting pipe. The first hot air is discharged into the pyrolysis gasification furnace 9 through the connecting pipe. After the reaction, the pyrolysis gasification furnace can produce combustible gas that can be further recycled. The generated hot air can enter the third hot air exhaust pipe through the exhaust pipe and then be discharged into the waste heat boiler 8 for use. The connecting pipe is equipped with a fourth solenoid valve V4, which controls the flow rate of the first hot air entering the pyrolysis gasification furnace 9.

[0049] In one specific embodiment, the outlet of the fixed-bed boiler 6 is connected to a flotation recovery device 11. The flotation recovery device 11 is designed to receive and process the slag particles discharged from the fixed-bed boiler 6. Utilizing the flotation principle, the flotation recovery device 11 effectively separates valuable minerals from gangue minerals by adding specific flotation agents and adjusting conditions such as the pH value of the slurry, thereby achieving the recovery of valuable metals. During the flotation process, valuable minerals separate from gangue minerals due to differences in their surface physicochemical properties, forming a concentrate froth layer. After collection, dewatering, and other post-processing steps, a concentrate product containing high-grade valuable metals can be obtained, while the remaining tailings can be further processed or safely disposed of.

[0050] The method for recovering waste heat from copper slag using the aforementioned copper slag waste heat recovery system includes the following steps:

[0051] S1. The copper slag in the slag bag 1 is discharged through the slag outlet 2 and enters the granulation bin 3. At this time, the temperature of the copper slag is 120℃~1400℃. The copper slag enters the rotating cup device 5, which centrifugally granulates, crushes and pelletizes the copper slag. At the same time, it is further crushed and granulated by the cold air of the spray gun 4 and falls into the bottom of the granulation bin 3. It is cooled to 1000℃~1100℃ and enters the fixed bed boiler 6.

[0052] S2 and the cold air from the spray gun 4 cool and exchange heat with the copper slag, forming the first hot air that enters the waste heat boiler 8.

[0053] S3. After the fixed-bed boiler 6 exchanges heat with the copper slag, the second hot air generated after the heat exchange, at 600℃~800℃, enters the waste heat boiler 8 and the pyrolysis gasification furnace 9. At the same time, the condensate generated by the user's heat storage device for heating enters the fixed-bed boiler 6 to exchange heat with the copper slag, generating second superheated steam. The second superheated steam enters the power generation equipment 10.

[0054] S4. The combustible gas generated by the pyrolysis gasification furnace 9 and the second air generated after the copper slag is heated by the heat exchange of the fixed bed boiler 6 heat the water in the waste heat boiler 8 to form the first superheated steam, which enters the power generation equipment 10. The power generation equipment 10 generates electricity through the first and second superheated steam and provides electricity to users. At the same time, the low-pressure steam generated by the power generation equipment 10 is used to heat the user's heat storage tank for heating. The condensate generated by heating enters the fixed bed boiler 6 for heat exchange and generates the second superheated steam, forming a heat exchange cycle.

[0055] S5 and fixed-bed boiler 6 cool the copper slag to 80℃~150℃ through heat exchange before discharging it for flotation, realizing the recovery of waste heat from the copper slag and the resource utilization of the copper slag.

[0056] In summary, this invention provides a copper slag waste heat recovery system, achieving effective integration and connection between the recyclable energy processing system and the production system. The granulation bin employs a combination of gas quenching and centrifugal granulation, featuring high operational safety and high recovery rate. By cooling with air and water in different environments, high-temperature gases and superheated steam at varying temperatures are obtained, specifically applied to the pyrolysis gasification furnace and waste heat boiler. This not only solves the serious problem of resource waste but also effectively realizes the efficient utilization of copper slag waste heat. After waste heat recovery by this system, the original high-temperature copper slag at approximately 1200℃~1400℃ is transformed into low-temperature slag particles at approximately 80℃~150℃, demonstrating significant waste heat recovery and facilitating subsequent flotation processes.

[0057] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0058] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A copper slag waste heat recovery system, comprising a slag bag (1), characterized in that, A granulation chamber (3) is provided at the slag outlet (2) of the slag bag (1). A spray gun (4) is provided in the granulation chamber (3) below the slag outlet (2). A rotating cup device (5) is provided on the spray gun (4). The rotating cup device (5) is used to centrifuge, crush and granulate the copper slag. At the same time, the spray gun (4) is used to air cool and granulate the copper slag, and heat exchange forms the first hot air. The outlet of the granulation bin (3) is connected to a fixed bed boiler (6), which is connected to a waste heat boiler (8) and a pyrolysis gasification furnace (9). The fixed bed boiler (6) is used to exchange heat with copper slag and generate second hot air after the heat exchange. The waste heat boiler (8) is connected to a power generation device (10). First hot air and second hot air enter the waste heat boiler (8) to exchange heat with the waste heat boiler (8) to form superheated steam. The first superheated steam enters the power generation device (10) to generate electricity. The low-pressure steam generated by the power generation equipment (10) after power generation is used to heat the user's heat storage device. The condensate generated by the user's heat storage device enters the fixed bed boiler (6) and is used by the fixed bed boiler (6) to exchange heat with copper slag to generate second superheated steam. The second superheated steam enters the power generation equipment (10) and is used by the power generation equipment (10) to generate electricity. The copper slag in the slag bag (1) is circulated through the granulation bin (3), the fixed bed boiler (6) and the waste heat boiler (8) to realize the recovery of copper slag waste heat; The granulation chamber (3) is provided with an exhaust port, which is connected to the waste heat boiler (8) through a first hot air exhaust pipe. The waste heat boiler (8) is connected to the power generation equipment (10) through a second hot air exhaust pipe. A second solenoid valve (V2) is provided on the first hot air exhaust pipe. The fixed-bed boiler (6) is provided with a third hot air exhaust pipe, which is connected to the first hot air exhaust pipe, and a third solenoid valve (V3) is provided on the third hot air exhaust pipe. The three hot air exhaust pipes are connected to a connecting pipe, and the connecting pipe is connected to a pyrolysis gasification furnace (9). The second hot air enters the pyrolysis gasification furnace (9) for pyrolysis reaction. A fourth solenoid valve (V4) is provided on the connecting pipe. A first exhaust pipe is provided on the pyrolysis gasification furnace (9), and the first exhaust pipe is connected to the three hot air exhaust pipes.

2. The copper slag waste heat recovery system according to claim 1, characterized in that, The spray gun (4) is a gas spray gun. One end of the gas spray gun is connected to an air compressor (7) through a first air pipe. A first solenoid valve (V1) is provided on the first air pipe.

3. The copper slag waste heat recovery system according to claim 1, characterized in that, The fixed-bed boiler (6) adopts two heat exchange methods: water cooling and air cooling. Air cooling is achieved by connecting an air compressor (7) through an air pipe. The air compressor (7) provides cold air into the fixed-bed boiler (6), which then exchanges heat with the fixed-bed boiler (6) to form second hot air. Water cooling is achieved by the condensate generated by the user's heat storage device for heating entering the fixed-bed boiler (6) through a drain pipe, which then exchanges heat with the fixed-bed boiler (6) to form second superheated steam.

4. The copper slag waste heat recovery system according to claim 1, characterized in that, The fixed-bed boiler (6) is equipped with a superheated steam discharge pipe, which is connected to the power generation equipment (10). A fifth solenoid valve (V5) is installed on the superheated steam discharge pipe.

5. The copper slag waste heat recovery system according to claim 1, characterized in that, The outlet of the fixed-bed boiler (6) is connected to a flotation recovery device (11).

6. A method for recovering waste heat from copper slag using the copper slag waste heat recovery system according to any one of claims 1-5, characterized in that, Includes the following steps: The copper slag in the slag bag (1) is discharged through the slag outlet (2) and enters the granulation bin (3). At this time, the temperature of the copper slag is 1200℃~1400℃. The copper slag enters the rotating cup device (5). The rotating cup device (5) centrifuges, crushes and granulates the copper slag. At the same time, the cold air from the spray gun (4) further crushes, granulates and exchanges heat on the copper slag. Then it falls into the bottom of the granulation bin (3) and is cooled to 1000℃~1100℃ before entering the fixed bed boiler (6). The cold air from the spray gun (4) cools and heats the copper slag, forming the first hot air that enters the waste heat boiler (8); After the fixed bed boiler (6) exchanges heat with the copper slag, the second hot air generated after the heat exchange is 600℃~800℃ and enters the waste heat boiler (8) and the pyrolysis gasification furnace (9). At the same time, the condensate generated by the user's heat storage device for heating enters the fixed bed boiler (6) to exchange heat with the copper slag and generate second superheated steam. The second superheated steam enters the power generation equipment (10). The combustible gas generated by the pyrolysis gasifier (9) and the second hot air generated after the copper slag is exchanged by the fixed bed boiler (6) heat the water in the waste heat boiler (8) to form the first superheated steam which enters the power generation equipment (10). The power generation equipment (10) generates electricity through the first and second superheated steam and provides electricity to users. The low-pressure steam generated after the power generation equipment (10) generates electricity is used to heat the user's heat storage tank. The condensate generated by the heating enters the fixed bed boiler (6) for heat exchange and generates the second superheated steam, forming a heat exchange cycle. The fixed-bed boiler (6) cools the copper slag to 80℃~150℃ through heat exchange and discharges it for flotation process, so as to realize the recovery of copper slag waste heat and the resource utilization of copper slag.

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