Liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method

Abstract

The invention discloses a liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method. The system comprises a heat exchanger, a flue gas purification chamber, a hydraulic machine and a buffer device connected with the hydraulic machine. An outlet of the buffer device is connected with a slag flowing groove, one end, far away from the buffer device, of the slag flowing groove is provided with a blowing plate, a granulating bin with a conveying platform is arranged below the blowing plate, an output end of the conveying platform is connected with an inlet of the roller kiln, and an outlet of the roller kiln is provided with a screening machine; the roller kiln comprises a heating section and a cooling section which are used for crystallizing granulated slag; the buffer device is provided with an air outlet pipe and a hot air conveying pipe which are connected with the heat exchanger, the flue gas purification chamber is connected with the heat exchanger and the roller kiln through the hot air conveying pipe, waste heat recycling is achieved, and the slag utilization rate is increased.

Description

Technical Field

[0001] The present application relates to a liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method, belonging to the field of metallurgical slag technology. Background Art

[0002] With the rapid development of my country's metallurgical industry, the production processes of the metallurgical industry and its related industries discharge a large amount of slag. How to achieve efficient, high-value and green utilization of slag is a common problem in the metallurgical industry. In the field of metallurgical slag treatment, existing technologies generally face technical bottlenecks such as low waste heat recovery rate and insufficient product added value. The traditional water quenching method uses high-pressure water flow to quench slag above 1400°C. Although it can form glassy particles for cement raw materials, it has technical defects such as large water resource consumption, unrecovered sensible heat of high-temperature slag, and generation of toxic gases during the cooling process. The wind quenching method uses high-speed airflow to crush liquid slag to achieve granulation. Although it reduces water resource consumption and pollution emissions compared to the water quenching method, the current process still needs to configure a circulating water cooling system to implement secondary cooling of the granulated slag, resulting in a double waste of water resources and waste heat, and the resulting product has a single mineral phase structure and a limited scope of application.

[0003] The patent with publication number CN 118028549 A discloses a high-temperature liquid slag air quenching granulation and waste heat efficient recovery system. During the granulation and blowing process of this method, the air in the water-cooled granulation bin exchanges heat with the water-cooled wall to achieve slag waste heat resource recovery. The patent with publication number CN 214529097 U discloses a high-temperature liquid dilute slag air quenching granulation and waste heat recovery system. The phase change heat storage rod absorbs the heat of the high-temperature flue gas and undergoes phase change to emit heat to ensure the temperature inside the device. Currently, slag furnace slag needs to be forced to cool after air quenching granulation, and its products are mostly used as cement admixtures, which limits the use scenarios of granulated slag. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies in the prior art and provide a liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method to improve the utilization rate of slag and expand the scope of use of granulated slag.

[0005] To achieve the above objectives, this application is implemented using the following technical solutions: In a first aspect, the present application provides a liquid slag air quenching granulation and waste heat circulation crystallization processing system, comprising: a heat exchanger, a flue gas purification chamber, a hydraulic press, and a buffer device connected to the hydraulic press; The outlet of the buffer device is connected to a slag trough; a blowing plate is provided at one end of the slag trough away from the buffer device, a granulation bin with a conveying platform is provided below the blowing plate, the output end of the conveying platform is connected to the inlet of the roller kiln, and a screening machine is provided at the outlet of the roller kiln; The roller kiln includes a heating section and a cooling section for crystallizing the granulated slag; the buffer device is provided with an outlet pipe and a hot air conveying pipe connected to the heat exchanger; the flue gas purification chamber is connected to the heat exchanger and the roller kiln through the hot air conveying pipe to realize the recycling of waste heat.

[0006] In combination with the first aspect, further, the blowing plate is provided with a nozzle connected to an air compressor for blowing the liquid slag into granulated slag; the shape of the nozzle includes any one of circular, rectangular and triangular.

[0007] Furthermore, a plurality of slag flow troughs are provided at the output end of the buffer device to perform multi-stage diversion of the high-temperature molten slag; and 3-6 diversion pipes are provided in the slag flow troughs.

[0008] Furthermore, the shape of the slag trough is any one or more of a semi-open C-shape, a closed circle and a rectangle; the shape of the blowing plate includes a rectangle or an arc.

[0009] Furthermore, the length of the slag trough is 0.5m-2m, and the inlet diameter of the slag trough is 30mm-50mm.

[0010] Furthermore, a tempering agent is provided inside the buffer device, which can receive and temper the liquid slag.

[0011] Furthermore, a filter cartridge is provided inside the flue gas purification chamber, and an ash discharge port is provided below the filter cartridge.

[0012] Furthermore, the roller kiln is provided with a driving motor for controlling the transmission rate of the conveying platform; and a plurality of spray gun ports are provided at the bottom of the side wall of the roller kiln.

[0013] In a second aspect, the present application provides a liquid slag air quenching granulation and waste heat circulation crystallization treatment method, based on the aforementioned liquid slag air quenching granulation and waste heat circulation crystallization treatment system, the method comprising: The liquid slag is injected into the buffer device and homogenized with the tempering agent in the buffer device; The liquid slag after homogenization is blown into granulated slag by high-pressure airflow and transported hot to the roller kiln; The granulated slag is kept warm and crystallized in the heating section of the roller kiln, and then cooled in the cooling section; The flue gas from the buffer device and granulation bin is collected and treated in the heat exchanger and flue gas purification chamber for waste heat recovery.

[0014] Furthermore, the temperature range of the heating section is 600°C-1000°C, and the heating time is 10min-120min; The cooling mode of the cooling section includes water cooling and / or natural air cooling, and the temperature of the granulated slag after cooling is lower than 180°C.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present application provides a liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method, which can obtain granulated slag products by tempering and spraying various types of slag as metallurgical solid waste, thereby effectively improving the utilization rate of slag. The flue gas generated in the buffer device is heat exchanged in the heat exchanger. At the same time, the hot air from the granulation injection process can be dust-removed and then enter the buffer device and roller kiln, effectively improving the heat utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a liquid slag air quenching granulation and waste heat circulation crystallization treatment system proposed in this application; Figure 2 Schematic diagrams of two structures of blowing plate and nozzle; Figure 3 This is a schematic diagram of the three-dimensional structure of the roller kiln and conveying platform; Figure 4 This is a top view of the roller kiln and conveying platform; Figure 5 is a structural diagram of the heat exchanger; Figure 6 It is a structural diagram of the flue gas purification chamber; Among them: 1. Slag bag; 2. Hydraulic press; 3. Buffer device; 4. Slag flow chute; 5. Blowing plate; 6. Compressed air pipeline; 7. Air compressor; 8. Granulation bin; 9. Conveying platform; 10. Roller kiln; 11. Screening machine; 12. Flue gas purification chamber; 13. Flue gas inlet; 14. Hot air conveying pipe; 15. Heat exchanger; 16. Exhaust pipe; 17. Nozzle; 18. Heating section; 19. Cooling section; 20. Cooling nozzle; 21. Drive motor; 22. Spray gun nozzle; 23. Steel pipe; 24. Filter cartridge; 25. Ash discharge port. DETAILED DESCRIPTION

[0017] The technical solution of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application.

[0018] Example 1:

[0019] like Figure 1As shown, this embodiment provides a liquid slag air quenching granulation and waste heat recycling crystallization treatment system, including a buffer device 3 with a tempering agent added. A hydraulic press 2 is provided on one side of the buffer device 3, and a slag ladle 1 is placed on the hydraulic press 2, specifically installed on the hydraulic press 2 by hoisting. The hydraulic press 2 is raised to tilt the slag ladle 1, and the slag flows into the buffer device 3. After the liquid slag is heated in the buffer device 3 and thoroughly mixed with the tempering agent, the tempered slag flows through different diversion pipes at the bottom of the buffer device 3 and flows through the slag flow trough 4 to the tail end.

[0020] In this embodiment, the temperature of the liquid slag after being heated in the buffer device is 1400° C.-1600° C., and the tempering agent is added in a range of 0-50%.

[0021] In this embodiment, the length of the slag flow trough 4 is 0.5m-2m, the diameter of the slag flow trough entrance is 30mm-50mm, and the number of the diversion pipes of the slag flow trough is 3-6.

[0022] A blowing plate 5 is provided below the tail end of the slag trough 4, and a nozzle 17 is provided on the blowing plate 5. The nozzle 17 is connected to the air compressor 7 through a compressed air pipe 6; the shape of the slag trough 4 includes but is not limited to a semi-open C-type or closed circular, rectangular and other shapes.

[0023] like Figure 2 As shown, the shape of the blowing plate 5 includes but is not limited to rectangular, circular arc and other shapes. The shape of the nozzle 17 includes but is not limited to circular, rectangular and other shapes. The distance between the blowing plate 5 and the nozzle 17 is 0.05m-0.5m, the nozzle diameter is 1mm-3mm, and the air compressor pressure is 0.2MPa-0.8MPa The tail end of the slag trough 4 is connected to one end of the granulation bin 8, and a conveying platform 9 is provided at the bottom of the granulation bin 8. During the falling process, the hot slag is broken into small droplets by the high-pressure air sprayed from the nozzle 17 and falls on the conveying platform 9 at the bottom of the granulation bin 10.

[0024] The other end of the conveying platform 9 is connected to the entrance of the roller kiln 10. Figure 4 Figure 1 shows a top view of the roller kiln and conveyor platform. The roller kiln 10 is divided into a heating section 18 and a cooling section 19. Cooling nozzles 20 are located above the cooling section 19. Hot granulated slag beads are transported through the conveyor platform 9 into the roller kiln 10. After being kept warm for a period of time in the heating section 18, they are rapidly cooled in the cooling section 19 by spraying water from the cooling nozzles 20, or by natural air cooling.

[0025] The outlet of the roller kiln 10 is connected to a screening machine 11 , and the granulated slag is screened by the screening machine 11 into products of different sizes after cooling.

[0026] like Figure 3Figure 1 is a schematic diagram of the three-dimensional structure of the roller kiln and the conveying platform. The side wall of the roller kiln 10 is provided with a drive motor 21 to control the transmission rate of the conveying platform 9. The bottom of the roller kiln side wall 10 is also provided with a plurality of spray gun ports 22 to control the internal temperature of the roller kiln 10.

[0027] The buffer device 3 is connected to the heat exchanger 15 through the hot air delivery pipe 14 and the air outlet pipe 16. Figure 5 FIG. 1 is a schematic diagram of the heat exchanger structure. A steel pipe 23 with a radius of 50 mm to 200 mm is provided in the heat exchanger 15. The hot gas in the buffer device 3 exchanges heat with the steel pipe 23 in the heat exchanger and is then discharged.

[0028] The top of the granulation bin 8 is connected to the flue gas purification chamber 12 through the flue gas inlet 13. Figure 6 FIG. 1 is a schematic diagram of the structure of the flue gas purification chamber. A filter cartridge 24 is provided in the flue gas purification chamber 12, and an ash discharge port 25 is provided below the filter cartridge 24. Dust-laden flue gas is filtered by the filter cartridge, and the dust falls into the ash discharge port 25 after being shaken.

[0029] The flue gas purification chamber 12 is connected to the heat exchanger 15 and the roller kiln 12 via a hot air duct 14. The hot flue gas ejected from the nozzle 17 passes through the dust removal process in the flue gas purification chamber 12 and then enters the buffer device 3 or the roller kiln 8 through the hot air duct 14, thereby recovering and reusing the heat energy of the flue gas during the production process.

[0030] Example 2:

[0031] Based on the liquid slag air quenching granulation and waste heat circulation crystallization treatment system provided in Example 1, this embodiment provides a liquid slag air quenching granulation and waste heat circulation crystallization treatment method, including: The liquid slag is injected into the buffer device 3 and homogenized with the tempering agent in the buffer device 3; The liquid slag after homogenization is blown into granulated slag by high-pressure airflow and transported hot to the roller kiln 10; The granulated slag is kept warm and crystallized in the heating section 18 of the roller kiln 10 and then cooled in the cooling section 19; The flue gas from the buffer device 3 and the granulation bin 8 is collected and processed in the heat exchanger 15 and the flue gas purification chamber 12 for waste heat recovery.

[0032] The specific steps are as follows: The liquid slag discharged from the blast furnace or electric furnace is stored in the slag bag 1. The slag bag 1 is hoisted and installed on the hydraulic press 2. The slag enters the buffer device 3 through the pouring action of the hydraulic press 2; The slag is heated and homogenized in the buffer device 3 with the tempering agent added, and then flows into the slag trough 4 through the opening on the bottom side of the buffer device 3. Subsequently, when the slag falls at the tail end of the slag trough 4, it is blown into granulated slag by the high-pressure gas sprayed from the nozzle, and falls onto the conveying platform 9 at the bottom of the granulation bin 8, and is transported forward to the roller kiln 10 in the form of hot charging and hot delivery.

[0033] The granulated slag is kept warm and crystallized in the heating section 18 of the roller kiln 10. After crystallization, it is water-cooled or naturally cooled in the cooling section 19 before being sent to the screening machine 11. After screening, it is transported by vehicle. Simultaneously, the flue gas in the buffer device 3 is discharged from the outlet pipe 16 through the heat exchanger 15 after sufficient heat exchange. Meanwhile, the flue gas from the granulation injection process enters the flue gas purification chamber 12 through the flue gas inlet 13, where it is dust-removed. It is then transported through the hot air duct and heat exchanger to the buffer device 3 and the roller kiln 10.

[0034] In this embodiment, the temperature of the heating section is 600°C-1000°C, and the heating time is 10min-120min; the cooling methods of the cooling section include but are not limited to water cooling and natural air cooling, and the temperature of the granulated slag after cooling is lower than 180°C.

[0035] In summary, the present application provides a liquid slag air quenching granulation and waste heat circulation crystallization treatment system and method, which realizes the air quenching granulation of liquid slag and achieves efficient utilization of thermal energy in the entire process through the flue gas purifier and heat exchanger; and expands the scope of use of granulated products through the crystallization treatment of the roller kiln and the particle size screening of the screening machine.

[0036] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A liquid slag air quenching granulation and waste heat circulation crystallization treatment system, characterized in that: include: A heat exchanger (15), a flue gas purification chamber (12), a hydraulic press (2), and a buffer device (3) connected to the hydraulic press (2); The outlet of the buffer device (3) is connected to a slag trough (4); a blowing plate (5) is provided at one end of the slag trough (4) away from the buffer device (3); a granulation bin (8) with a conveying platform (9) is provided below the blowing plate (5); the output end of the conveying platform (9) is connected to the inlet of a roller kiln (10); and a screening machine (11) is provided at the outlet of the roller kiln (10); The roller kiln (10) comprises a heating section (18) and a cooling section (19); the buffer device (3) is provided with an air outlet pipe (16) and a hot air delivery pipe (14) connected to the heat exchanger (15); the flue gas purification chamber (12) is connected to the heat exchanger (15) and the roller kiln (10) via the hot air delivery pipe (14).

2. The system according to claim 1, wherein: The blowing plate (5) is provided with a nozzle (17) connected to the air compressor (7); the shape of the nozzle includes any one of a circle, a rectangle and a triangle.

3. The processing system according to claim 1, wherein: The output end of the buffer device (3) is provided with a plurality of slag flow troughs (4) for performing multi-stage diversion of the high-temperature molten slag; 3-6 diversion pipes are provided in the slag flow troughs (4).

4. The processing system according to claim 3, characterized in that The shape of the slag trough is any one or more of a semi-open C-type, a closed circular type and a rectangular type; the shape of the blowing plate (5) includes a rectangular type or an arc type.

5. The processing system according to claim 1, wherein: The length of the slag trough (4) is 0.5m-2m, and the inlet diameter of the slag trough (4) is 30mm-50mm.

6. The processing system according to claim 1, wherein: The buffer device (3) is provided with a tempering agent inside, which can receive and temper the liquid slag.

7. The processing system according to claim 1, wherein: A filter cartridge (24) is provided inside the flue gas purification chamber (12), and an ash discharge port (25) is provided below the filter cartridge 24.

8. The processing system according to claim 1, wherein: The roller kiln (10) is provided with a driving motor (21) for controlling the transmission rate of the conveying platform (9); and a plurality of spray gun ports (22) are provided at the bottom of the side wall (10) of the roller kiln.

9. A method for treating liquid slag by air quenching granulation and waste heat circulation crystallization, characterized in that: Based on the processing system according to claim 1, the method comprises: injecting the liquid slag into the buffer device (3) and homogenizing it with the tempering agent in the buffer device (3); The liquid slag after homogenization is blown into granulated slag by high-pressure airflow and transported hot to a roller kiln (10); The granulated slag is kept warm and crystallized in a heating section (18) of a roller kiln (10), and then cooled in a cooling section (19); The flue gas from the buffer device (3) and the granulation bin (8) is collected and processed in the heat exchanger (15) and the flue gas purification chamber (12) for waste heat recovery.

10. The processing method according to claim 9, characterized in that: The temperature range of the heating section (18) is 600°C-1000°C, and the heating time is 10min-120min; The cooling method of the cooling section (19) includes water cooling and / or natural air cooling, and the temperature of the granulated slag after cooling is lower than 180°C.

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