High-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system and process

Abstract

The invention discloses a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system and process. Comprising a liquid slag tank, a first-stage wet cooling rolling crushing device, a second-stage closed dry cooling crushing device, a transfer slag tank for transferring steel slag between the first-stage wet cooling rolling crushing device and the second-stage closed dry cooling crushing device, a third-stage continuous conveying and atomizing cooling efficient digestion device, a cooling water closed circulating device and a control device, different cooling and crushing devices and processes are adopted according to mineral decomposition and lattice transformation characteristics of the steel slag in different stages, an original tank-type pressure hot disintegration device is not needed, consumption of cooling water is effectively reduced, the crushing efficiency of the steel slag is greatly improved, the material grade of the crushed steel slag is small, and the service life of the steel slag is prolonged. The conversion rate of digestion of f-CaO in the steel slag is improved, and conditions are created for realizing waste heat recovery of the steel slag.

Description

Technical Field

[0001] The present invention relates to the technical field of steel slag treatment, and in particular to a system and process for high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion. Background Art

[0002] Currently, the waste heat of steel slag is not efficiently recovered, and its mineral resource value is not fully utilized due to the limitations of steel slag processing technology. With the exception of the air quenching granulation process, which does not use water, all other existing steel slag processing processes use water spray cooling and crushing throughout the entire process. The tank-type pressurized hot-steaming process is carried out in a state of steel slag accumulation. Due to the lack of mechanical power to form the tumbling, collision, and crushing, the steel slag particle size is relatively large during the processing process. Although it is in full contact with water, the conversion rate of the f-CaO digestion reaction in the steel slag is low due to the small specific area of ​​the steel slag material. In addition, the residual f-CaO content in the batch is very unstable, which greatly affects the comprehensive utilization rate of the steel slag.

[0003] Among them, GB / T29514-2018 "Technical Specifications for Steel Slag Treatment Process" requires that "the particle size of steel slag after tank-type hot stuffing treatment is ≤20mm, accounting for more than 70%"; GB / T51387-2019 "Technical Standards for Steel Slag Treatment and Comprehensive Utilization" requires that "the content of particle size less than 20mm in steel slag after hot stuffing should be greater than 60%", and during operation, it is required that "steel slag be treated by pressurized hot stuffing, and high-temperature steel slag above 500 degrees shall not be sent into a pressurized hot stuffing tank for hot stuffing."

[0004] Chinese patent CN102230036A discloses a method for treating molten steel slag waste heat with pressurized hot stuffing, which combines roller crushing with pressurized hot stuffing to treat the slag. The description of the slag temperature and particle size is as follows: Roller crushing involves spraying water mist on the surface of the molten steel slag in a slag pretreatment chamber to cool it, followed by roller crushing to a specific temperature and particle size of 200-800°C and 300 mm or less. Chinese patent CN207362265U discloses a vertical pressurized hot stuffing device for converter slag, which also uses a pressurized hot stuffing process to treat the slag. The pressurized hot stuffing process demonstrates the following results: the entire converter slag vertical pressurized hot stuffing treatment cycle is only 1.5 to 2 hours, the slag pulverization rate (<20 mm) after hot stuffing is above 70%, and the free calcium oxide content of the stabilized slag is less than 3%.

[0005] It can be seen that in the current steel slag process, the particle size of the steel slag material in the f-CaO digestion reaction process of the steel slag treated by the pressurized hot stuffing process is relatively large, and the pressurized hot stuffing process has staged requirements for the steel slag temperature, which limits the pressurized hot stuffing time. The cooling water consumption in the entire treatment process is relatively large, and the conversion rate of the f-CaO digestion reaction in the steel slag is low. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system and process, which can solve the problems of large cooling water consumption, large steel slag material grade and low steel slag digestion conversion rate in the steel slag treatment process mentioned in the background technology.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0008] A high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system comprises a liquid slag tank, a first-level wet cooling roller crushing device, a second-level closed dry cooling, crushing device, a transfer slag tank for transferring steel slag between the first-level wet cooling roller crushing device and the second-level closed dry cooling, crushing device, a third-level continuous conveying and atomizing cooling efficient digestion device, a cooling water closed circulation device, and a control device; the liquid slag tank is arranged above the inlet of the first-level wet cooling roller crushing device, the steel slag temperature control device is arranged below the first-level wet cooling roller crushing device, the cooling water closed circulation device is connected to the second-level closed dry cooling, crushing device, and the third-level continuous conveying and atomizing cooling efficient digestion device is arranged below the discharge port of the second-level closed dry cooling, crushing device; the first-level wet cooling roller crushing device, the second-level closed dry cooling, crushing device, the third-level continuous conveying and atomizing cooling efficient digestion device, and the cooling water closed circulation device are electrically connected to the control device respectively.

[0009] The above-mentioned high-temperature steel slag graded cooling crushing and f-CaO efficient digestion system has a steel slag temperature control device provided at the lower part of the first-level wet cooling roller crushing device, and the output end of the steel slag temperature control device is connected to the input end of the control device.

[0010] In the above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system, a conveying weight control device is provided above the feed inlet of the secondary closed dry cooling and crushing device, and the conveying weight control device is electrically connected to the control device.

[0011] The above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system, the two-level closed dry cooling and crushing device includes a drum cooler, the drum cooler cylinder adopts a membrane wall structure, and a spiral stirring compound crushing assembly is arranged inside the drum cooler cylinder; the spiral stirring compound crushing assembly includes a guide plate and a special-shaped stirring rod arranged on the water-cooling tube in the membrane wall structure, and the guide plate and the special-shaped stirring rod are arranged at intervals; the guide plate is distributed in a spiral structure along the discharge direction of the cylinder, the guide plate is a straight plate structure and the radial height of the guide plate is arranged in three stages in a gradually increasing trend along the discharge direction; the special-shaped stirring rod is arranged in the front half area of ​​the drum feed side, and includes a base and a rod head; the rod head located at the front feeding section inside the drum is a spherical rod head, and the rod head located at the rear feeding section inside the drum is a cylindrical rod head.

[0012] The above-mentioned high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system, the three-stage continuous conveying and atomizing cooling efficient digestion device includes a buffer bin, a drum feeder, an aerosol spray gun, a humidifying spray gun, and a belt conveyor; a material door is provided at the bottom of the buffer bin, and the controlled end of the material door is connected to the output end of the control device, the drum feeder is arranged below the buffer bin, and the belt conveyor is arranged below the drum feeder; a downward-inclined bar screen is provided on the outside of the drum feeder, and the aerosol spray gun is respectively provided above and below the bar screen; the humidifying spray gun is provided above the belt conveyor; a material surface detection device is provided on the top of the buffer bin, and the output end of the material surface detection device is connected to the input end of the control device; a steel slag temperature detection device is provided above the discharge end of the belt conveyor, and the output end of the steel slag temperature detection device is connected to the input end of the control device.

[0013] A high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process is implemented based on a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system according to any one of claims 1 to 5. The process flow is as follows: S1. Primary cooling and crushing of slag: Pour the liquid slag in the liquid slag tank into the primary wet cooling roller crushing device for preliminary cooling and crushing. The temperature of the slag is monitored in real time by the slag temperature control device. When the slag temperature is cooled to an appropriate range, the next step is carried out. S2, slag transfer: the processed solid slag is transferred to the top of the secondary closed dry cooling crushing device through the transfer slag tank; S3, Secondary Cooling and Crushing of Slag: The transfer slag tank feeds the solid slag into a secondary closed dry cooling and crushing device, where large slag particles are crushed into fine particles. The slag is also cooled by a closed cooling water circulation device, and its waste heat is recycled. The crushed fine slag is then stored in a buffer bin in a tertiary continuous conveying and atomizing cooling high-efficiency digestion device. S4. Slag atomization, cooling and digestion: When the material level detection device detects that the material level in the buffer bin has reached a certain height range, the fine slag particles are fed into the drum feeder through the material gate. The material output from the drum feeder forms a material curtain of a certain width and falls onto the bar screen. At the same time, the aerosol spray gun sprays water on the particles on the bar screen to fully react with the water, thereby accelerating the efficient digestion of f-CaO in the slag particles. S5. Slag cooling: After being screened by the bar screen, the large pieces of slag are separated from the fine particles and fall on the surface of the belt conveyor. The humidifying spray gun is opened later to cool the slag again.

[0014] In the above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process, in step S1, the hydraulic steel slag is cooled by cold water spraying to convert it into solid steel slag, and the solid steel slag is crushed by a crushing component. The temperature of the processed steel slag is 800-900°C, the particle size of the processed steel slag is less than 300mm, and the particle size of less than 80mm accounts for more than 80%.

[0015] In the above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process, in step S3, large-particle steel slag is crushed by a drum slag cooler with a spiral stirring composite crushing component. The temperature of the processed steel slag is 300-200°C, and the proportion of particle size less than 8mm is greater than 90%.

[0016] In the above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process, in step S4, the direction of the aerosol spray gun nozzle is matched with the falling position of the material curtain, and the water spray volume of the aerosol spray gun is adjusted to match the steel slag temperature in the buffer bin and the rotation speed of the drum feeder, so that the fine-particle steel slag is cooled again. After cooling, the steel slag temperature is 100-200°C.

[0017] In the above-mentioned high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process, in step S5, the speed of the belt conveyor is adjusted to maintain the thickness of the material layer on the belt at 30 to 50 mm, which facilitates the cooling of the steel slag by the humidifying spray gun. The temperature of the steel slag at the discharge end of the belt conveyor is 50-100°C. The temperature of the discharged steel slag is detected by the slag temperature detection device at the discharge end to adjust the water spray volume of the humidifying spray gun.

[0018] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is as follows.

[0019] The present invention provides a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system and process. Different cooling and crushing devices and processes are adopted according to the mineral decomposition and lattice transformation characteristics of the steel slag at different stages. The original tank-type pressurized hot stuffing device does not need to be used, which effectively reduces the consumption of cooling water and greatly improves the crushing efficiency of the steel slag. The material grade of the crushed steel slag is smaller, the conversion rate of f-CaO digestion in the steel slag is improved, and conditions are created for realizing the recovery of steel slag waste heat.

[0020] Specifically, the liquid steel slag is first converted into solid high-temperature steel slag through a first-stage wet cooling roller crushing device, and the steel slag is initially cooled and crushed. The steel slag is then further cooled and crushed through a second-stage closed dry cooling crushing device to obtain fine-grained low-temperature steel slag. This operation uses a membrane wall structure to cool the steel slag, effectively absorbing the waste heat in the steel slag. The steel slag is then fully reacted with water through a three-stage continuous conveying and atomizing cooling high-efficiency digestion device to accelerate the digestion of f-CaO in the steel slag and improve the steel slag conversion rate. The steel slag material grade after the three-stage treatment is much lower than the steel slag material grade after the current pressurized hot stuffing process. The multi-stage cooling treatment can ultimately reduce the steel slag temperature to 50-100°C. Since the steel slag is crushed to obtain fine-grained steel slag in the second-stage closed dry cooling crushing device, it is easy for the steel slag to fully react with water to accelerate the digestion of f-CaO in the steel slag, greatly improving the batch homogeneity of the residual f-CaO component in the steel slag, and increasing the conversion rate of the steel slag digestion reaction and the comprehensive utilization rate of the steel slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a specific process flow chart of the present invention; Figure 2 This is a schematic diagram of the specific structure of the front section of the internal feeding of the drum slag cooler of the present invention; Figure 3 This is a schematic diagram of the specific structure of the rear section of the internal feeding of the drum slag cooler of the present invention; Figure 4 This is a schematic diagram of the specific structure of the three-stage continuous conveying and atomization cooling high-efficiency digestion device described in the present invention.

[0022] Among them: 1. Liquid slag tank, 2. First-stage wet cooling roller crushing device, 3. Steel slag temperature control device, 4. Transfer slag tank, 5. Conveying weight control device, 6. Second-stage closed dry cooling crushing device, 7. Third-stage continuous conveying and atomizing cooling high-efficiency digestion device, 8. Cooling water closed circulation device, 9. Water cooling pipe, 10. Guide plate, 11. Base, 12. Spherical rod head, 13. Cylindrical rod head, 14. Material surface detection device, 15. Buffer bin, 16. Material door, 17. Drum feeder, 18. Aerosol spray gun, 19. Screen, 20. Humidification spray gun, 21. Steel slag temperature detection device, 22. Belt conveyor. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] A high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system, such as Figures 1 to 4 As shown, it includes a liquid slag tank 1, a first-level wet cooling roller crushing device 2, a steel slag temperature control device 3, a transfer slag tank 4, a conveying weight control device 5, a second-level closed dry cooling crushing device 6, a third-level continuous conveying and atomizing cooling high-efficiency digestion device 7, a cooling water closed circulation device 8, and a control device.

[0025] The liquid slag tank 1 is connected to the first-level wet cooling roller crushing device 2 and is used to transport liquid high-temperature steel slag to the first-level wet cooling roller crushing device. Specifically, the liquid slag tank 1 is transported by an overhead crane, and after being tilted, the liquid steel slag is poured into the first-level wet cooling roller crushing device 2.

[0026] The first-stage wet cooling roller crushing device 2 is used to pre-treat the liquid steel slag to achieve preliminary cooling and crushing of the steel slag. The controlled end of the first-stage wet cooling roller crushing device 2 is connected to the output end of the control device.

[0027] The first-stage wet cooling roller crushing device 2 includes a spray cooler and a crushing assembly. The spray cooler is used to cool the liquid slag to form solid high-temperature slag, which facilitates the crushing assembly to perform preliminary crushing on the cooled solid slag.

[0028] The slag temperature control device 3 is arranged at the lower part of the first-stage wet cooling roller crushing device 2 and is used to control the temperature of the processed slag. The output end of the slag temperature control device 3 is connected to the input end of the control device.

[0029] Specifically, the slag temperature control device 3 is an infrared temperature sensor for measuring the temperature of the slag. The steel slag is spray-cooled by the first-level wet cooling roller crushing device 2, and the infrared temperature sensor is used to measure the temperature of the steel slag to ensure that the liquid steel slag is converted into solid high-temperature steel slag after being processed by the first-level wet cooling roller crushing device 2. The temperature of the treated high-temperature steel slag is controlled at 800-900°C, the particle size of the treated steel slag is less than 300mm, and the particle size less than 80mm accounts for more than 80%.

[0030] The transfer slag pot 4 is arranged between the first-level wet cooling roller crushing device 2 and the second-level closed dry cooling crushing device 6. The transfer slag pot 4 mainly transfers the steel slag that has been preliminarily processed by the first-level wet cooling roller crushing device 2 to the second-level closed dry cooling crushing device 6 through the overhead crane for further processing.

[0031] The conveying weight control device 5 is arranged above the feeding port of the secondary closed dry cooling crushing device 6. The conveying weight control device 5 includes a vibrating feeder. A weight sensor is provided on the vibrating feeder. The controlled end of the vibrating feeder is connected to the controlled end of the control device, and the output end of the weight sensor is connected to the input end of the control device.

[0032] Specifically, the material weight data is collected in real time through the weight sensor and transmitted to the control device. The control device compares the actual weight with the preset value, calculates the feeding speed or amplitude that needs to be adjusted through the algorithm, and dynamically adjusts the vibration frequency or motor speed to accurately control the feeding amount.

[0033] The secondary closed dry cooling crushing device 6 includes a drum slag cooler, the drum slag cooler cylinder adopts a membrane wall structure, and a spiral stirring composite crushing component is arranged inside the drum slag cooler cylinder.

[0034] The cooling water closed circulation device 8 is connected to the membrane wall structure and is used to cool the slag inside the drum.

[0035] The spiral stirring compound crushing assembly includes a guide plate 10 and a special-shaped stirring rod arranged on the water-cooling tube 9 in the membrane wall structure. The guide plate 10 and the special-shaped stirring rod are arranged at intervals. The guide plate 10 is distributed in a spiral structure along the discharge direction of the cylinder. The guide plate 10 is a straight plate structure, and its height changes in three stages along the discharge direction, gradually increasing to achieve turning and advancing of the slag.

[0036] The special-shaped stirring rod is set in the front half area of ​​the drum feed side, including a base 11 and a rod head. The rod head is detachably connected to the top of the base for easy replacement. The base 11 is a trapezoidal structure and is fixedly connected to the water cooling pipe parallel to the drum axis.

[0037] The rod head is made of heat-resistant and wear-resistant cast steel. The rod head located at the front feeding section inside the drum is a spherical rod head 12, and the rod head located at the rear feeding section inside the drum is a cylindrical rod head 13. The steel slag is stirred by the special-shaped stirring rod, which achieves efficient crushing of the steel slag and avoids material jamming.

[0038] The secondary closed dry cooling crushing device 6 adopts a drum slag cooler to perform rotary cooling of the steel slag, and a spiral stirring composite crushing assembly consisting of a spirally arranged guide plate 10 and a special-shaped stirring rod is arranged in the drum. The drum speed is frequency-controlled and interlocked with the slag feeding amount and the slag discharge temperature to complete the crushing of the steel slag to obtain fine-grained low-temperature steel slag. The temperature of the processed fine-grained low-temperature steel slag is 200-300℃, of which the particle size of the steel slag less than 8mm accounts for more than 90%.

[0039] The three-stage continuous conveying and atomizing cooling high-efficiency digestion device 7 is arranged below the discharge port of the two-stage closed dry cooling crushing device 6, and is used to receive the fine-particle low-temperature steel slag after the two-stage treatment.

[0040] The three-stage continuous conveying and atomization cooling high-efficiency digestion device 7 includes a buffer bin 15, a drum feeder 17, an aerosol spray gun 18, a humidifying spray gun 20, and a belt conveyor 22. A material gate 16 is provided at the bottom of the buffer bin 15, and the controlled end of the material gate 16 is connected to the output end of the control device. The drum feeder 17 is arranged below the buffer bin 15, and the belt conveyor 22 is arranged below the drum feeder 17.

[0041] A material level detection device 14 is provided on the top of the buffer bin 15 , and an output end of the material level detection device 14 is connected to an input end of the control device for detecting the height of the material in the buffer bin 15 .

[0042] A downwardly inclined bar screen 19 is provided on the outside of the drum feeder 17. Aerosol spray guns 18 are respectively provided above and below the bar screen 19 to cool the material falling onto the bar screen. At the same time, the aerosol spray gun is used to fully mix the material with water to accelerate the digestion of the material. In this process, the temperature of the slag is cooled to 100-200°C.

[0043] Two moistening spray guns 20 are arranged at intervals above the belt conveyor 22 for cooling the material again. The temperature of the cooled slag is cooled to 50-100°C after moistening and cooling the slag.

[0044] A slag temperature detection device 21 is provided above the discharging end of the belt conveyor 22 , and an output end of the slag temperature detection device 21 is connected to an input end of the control device.

[0045] The operating steps of the present invention are as follows: First, the liquid slag tank is transported by an overhead crane and the high-temperature liquid slag in the liquid slag tank 1 is poured into the first-level wet cooling roller crushing device 2 to cool the liquid slag to a solid state, and then the slag is preliminarily crushed by the crushing assembly.

[0046] The slag temperature control device 3 at the bottom of the first-level wet cooling roller crushing device 2 detects the temperature of the treated slag, and discharges the solid high-temperature slag into the transfer slag pot 4 when it reaches the appropriate temperature. The transfer slag pot 4 containing the solid high-temperature slag is transported to the top of the second-level closed dry cooling crushing device 6 by the overhead crane, and the treated solid high-temperature slag is transferred to the second-level closed dry cooling crushing device 6.

[0047] Then, the secondary closed dry cooling and crushing device 6 cools and crushes the steel slag again through the drum slag cooler to obtain fine-grained low-temperature steel slag.

[0048] Fine-grained low-temperature steel slag is transported to the inside of the buffer bin 15 and discharged into the drum feeder 17 through the material gate 16. After being processed by the drum feeder, the steel slag is output as a material curtain with a certain width, and then falls onto the bar screen to screen the large particles in the steel slag. At the same time, the air mist spray gun cools the fine-grained steel slag on the bar screen to fully mix the water and the material, accelerating the digestion of the material.

[0049] During this process, the material level in the buffer bin is monitored in real time by the material level detection device 14 so as to adjust the water spraying amount to match the slag temperature in the buffer bin and the drum feeder speed, thereby accelerating the cooling of the slag.

[0050] The screened large slag material falls onto the belt conveyor 22 and is cooled again by the humidifying spray gun above the belt conveyor, and then discharged through the discharge end of the belt conveyor. The slag temperature detection device 21 at the discharge end of the belt conveyor will adjust the spray volume of the humidifying spray gun in real time according to the discharge temperature.

[0051] A high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process is based on a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system. The process flow is as follows: S1. Primary cooling and crushing of slag: The liquid slag in the liquid slag tank 1 is poured into the primary wet cooling roller crushing device 2 for preliminary cooling and crushing. The temperature of the slag is detected in real time by the slag temperature control device 3. When the slag temperature is cooled to an appropriate range, the next step is carried out.

[0052] In step S1, the hydraulic slag is cooled by spraying cold water to convert it into solid slag, and the solid slag is crushed by a crushing assembly. The temperature of the processed slag is 800-900°C, the particle size of the processed slag is less than 300mm, and the particle size less than 80mm accounts for more than 80%.

[0053] S2. Steel slag transfer: The processed solid steel slag is transferred to the top of the secondary closed dry cooling and crushing device 6 through the transfer slag tank 4.

[0054] S3. Secondary cooling and crushing of steel slag: The transfer slag tank 4 feeds the solid steel slag inside into the secondary closed dry cooling and crushing device 6, where the large particles of steel slag are crushed to obtain fine particles. At the same time, the steel slag is cooled by the cooling water closed circulation device 8, and the waste heat of the steel slag is recycled. The crushed fine particles of steel slag are stored in the buffer bin of the tertiary continuous conveying and atomizing cooling high-efficiency digestion device 7.

[0055] In step S3, the large-particle steel slag is crushed by a drum slag cooler with a spiral stirring composite crushing component. The temperature of the processed steel slag is 300-200°C, and the particle size less than 8mm accounts for more than 90%.

[0056] In step S3, the steel slag is continuously conveyed to the secondary closed dry cooling and crushing device through the conveying weight control device, and the feed weight is detected at the same time to adjust the speed of the drum slag cooler and the flow rate of the cooling water closed circulation device 8 to cool and crush the large pieces of high-temperature steel slag.

[0057] S4. Slag atomization, cooling and digestion: When the material level detection device 14 detects that the material level in the buffer bin 15 has reached a certain height range, the fine-grained slag is fed into the drum feeder 17 through the material gate 16. The material output by the drum feeder forms a material curtain of a certain width and falls onto the bar screen 19. At the same time, the aerosol spray gun sprays water on the particles on the bar screen 19 to allow the water to fully react with the particles, thereby accelerating the efficient digestion of f-CaO in the slag particles.

[0058] In step S4, the nozzle direction of the aerosol spray gun 18 is matched with the falling position of the material curtain. By adjusting the water spray volume of the aerosol spray gun 18 to match the slag temperature in the buffer bin 15 and the rotation speed of the drum feeder 17, the fine-grained slag is cooled again. After cooling, the slag temperature is 100-200°C.

[0059] S5. Slag cooling: After being screened by the bar screen 19, the large pieces of slag are separated from the fine particles and fall on the surface of the belt conveyor 22. The moistening spray gun 20 is opened with a delay to cool the slag again.

[0060] In step S5, the speed of the belt conveyor is adjusted to maintain the thickness of the material layer on the belt at 30-50 mm, which is convenient for the humidifying spray gun to cool the steel slag. The temperature of the steel slag at the discharge end of the belt conveyor is 50-100°C. The temperature of the discharged steel slag is detected by the discharge end slag temperature detection device 21 to adjust the water spraying amount of the humidifying spray gun.

[0061] The present invention provides a high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system. Different cooling and crushing devices and processes are adopted according to the mineral decomposition and lattice transformation characteristics of the steel slag at different stages. The original tank-type pressurized hot stuffing device does not need to be used, which effectively reduces the consumption of cooling water and greatly improves the crushing efficiency of the steel slag. The material grade of the crushed steel slag is smaller, the conversion rate of f-CaO digestion in the steel slag is improved, and conditions are created for realizing the recovery of steel slag waste heat.

[0062] Specifically, the liquid steel slag is first converted into solid high-temperature steel slag through a first-stage wet cooling roller crushing device, and the steel slag is initially cooled and crushed. The steel slag is then further cooled and crushed through a second-stage closed dry cooling crushing device to obtain fine-grained low-temperature steel slag. This operation uses a membrane wall structure to cool the steel slag, effectively absorbing the waste heat in the steel slag. The steel slag is then fully reacted with water through a three-stage continuous conveying and atomizing cooling high-efficiency digestion device to accelerate the digestion of f-CaO in the steel slag and improve the steel slag conversion rate. The steel slag material grade after the three-stage treatment is much lower than the steel slag material grade after the current pressurized hot stuffing process. The multi-stage cooling treatment can ultimately reduce the steel slag temperature to 50-100°C. Since the steel slag is crushed to obtain fine-grained steel slag in the second-stage closed dry cooling crushing device, it is easy for the steel slag to fully react with water to accelerate the digestion of f-CaO in the steel slag, greatly improving the batch homogeneity of the residual f-CaO component in the steel slag, and increasing the conversion rate of the steel slag digestion reaction and the comprehensive utilization rate of the steel slag.

Claims

1. A high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system, characterized by: The invention comprises a liquid slag tank (1), a first-stage wet cooling roller crushing device (2), a second-stage closed dry cooling crushing device (6), a transfer slag tank (4) for transferring steel slag between the first-stage wet cooling roller crushing device (2) and the second-stage closed dry cooling crushing device (6), a three-stage continuous conveying and atomizing cooling high-efficiency digestion device (7), a cooling water closed circulation device (8), and a control device; the liquid slag tank (1) is arranged above the feed port of the first-stage wet cooling roller crushing device (2), and the steel slag temperature control device (3) is arranged above the feed port of the first-stage wet cooling roller crushing device (2). The first-stage wet cooling roller crushing device (2) is arranged at the lower part of the second-stage closed dry cooling crushing device (6), the cooling water closed circulation device (8) is connected to the second-stage closed dry cooling crushing device (6), and the third-stage continuous conveying and atomizing cooling high-efficiency digestion device (7) is arranged below the discharge port of the second-stage closed dry cooling crushing device (6); the first-stage wet cooling roller crushing device (2), the second-stage closed dry cooling crushing device (6), the third-stage continuous conveying and atomizing cooling high-efficiency digestion device (7), and the cooling water closed circulation device (8) are electrically connected to the control device respectively.

2. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system according to claim 1, characterized in that: A slag temperature control device (3) is provided at the lower part of the first-stage wet cooling roller crushing device (2), and the output end of the slag temperature control device (3) is connected to the input end of the control device.

3. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system according to claim 1, characterized in that: A conveying weight control device (5) is provided above the feed port of the secondary closed dry cooling crushing device (6), and the conveying weight control device (5) is electrically connected to the control device.

4. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system according to claim 1, characterized in that: The secondary closed dry cooling crushing device (6) includes a drum slag cooler, the drum slag cooler cylinder adopts a membrane wall structure, and a spiral stirring composite crushing component is arranged inside the drum slag cooler cylinder; the spiral stirring composite crushing component includes a guide plate (10) and a special-shaped stirring rod arranged on a water cooling pipe (9) in the membrane wall structure, and the guide plate (10) and the special-shaped stirring rod are arranged at intervals; the guide plate (10) is distributed in a spiral structure along the discharge direction of the cylinder, the guide plate (10) is a straight plate structure, and the radial height of the guide plate (10) is arranged in three stages along the discharge direction in a gradually increasing trend; the special-shaped stirring rod is arranged in the front half area of ​​the drum feeding side, and includes a base (11) and a rod head; the rod head located in the front feeding section inside the drum is a spherical rod head (12), and the rod head located in the rear feeding section inside the drum is a cylindrical rod head (13).

5. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion system according to claim 1, characterized in that: The three-stage continuous conveying and atomization cooling high-efficiency digestion device (7) comprises a buffer bin (15), a drum feeder (17), an aerosol spray gun (18), a humidifying spray gun (20), and a belt conveyor (22); a material door (16) is provided at the bottom of the buffer bin (15), a controlled end of the material door (16) is connected to an output end of a control device, the drum feeder (17) is provided below the buffer bin (15), and the belt conveyor (22) is provided below the drum feeder (17); a material door (16) is provided on the outside of the drum feeder (17). A bar screen (19) is arranged to be tilted downward, and an aerosol spray gun (18) is respectively arranged above and below the bar screen (19); the humidifying spray gun (20) is arranged above the belt conveyor (22); a material surface detection device (14) is arranged on the top of the buffer bin (15), and the output end of the material surface detection device (14) is connected to the input end of the control device; a steel slag temperature detection device (21) is arranged above the discharge end of the belt conveyor (22), and the output end of the steel slag temperature detection device (21) is connected to the input end of the control device.

6. A high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion process, the process being implemented based on the high-temperature steel slag graded cooling and crushing and f-CaO efficient digestion system according to any one of claims 1 to 5, characterized in that: The process flow is as follows: S1, primary cooling and crushing of slag: pouring the liquid slag in the liquid slag tank (1) into the primary wet cooling roller crushing device (2) for preliminary cooling and crushing, and detecting the temperature of the slag in real time through the slag temperature control device (3). When the temperature of the slag is cooled to a suitable range, the next step is carried out; S2, slag transfer: the treated solid slag is transferred to the top of the secondary closed dry cooling crushing device (6) through the transfer slag tank (4); S3, secondary cooling and crushing of steel slag: The transfer slag tank (4) sends the solid steel slag inside to the secondary closed dry cooling and crushing device (6), crushing the large particles of steel slag into fine particles of steel slag, and at the same time cooling the steel slag through the cooling water closed circulation device (8), and recycling the waste heat of the steel slag. The crushed fine particles of steel slag enter the buffer bin of the tertiary continuous conveying and atomization cooling high-efficiency digestion device (7) for storage; S4, steel slag atomization cooling digestion: When the material surface detection device (14) detects that the material surface of the buffer bin (15) reaches a certain height range, the fine steel slag particles are fed into the drum feeder (17) from the material gate (16), and the material output from the drum feeder forms a material curtain of a certain width and falls onto the bar screen (19). At the same time, the aerosol spray gun sprays water on the particles on the bar screen (19), so that the water and the particles fully react, thereby accelerating the efficient digestion of f-CaO in the steel slag particles; S5, slag cooling: After being screened by the bar screen (19), the large pieces of steel slag are separated from the fine particles of steel slag and fall on the surface of the belt conveyor (22). The moistening spray gun (20) is opened with a delay to cool the steel slag again.

7. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion process according to claim 6, characterized in that: In step S1, the hydraulic slag is cooled by spraying cold water to convert it into solid slag, and the solid slag is crushed by a crushing assembly. The temperature of the processed slag is 800-900°C, the particle size of the processed slag is less than 300mm, and the particle size less than 80mm accounts for more than 80%.

8. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion process according to claim 6, characterized in that: In step S3, the large-particle steel slag is crushed by a drum slag cooler with a spiral stirring composite crushing component. The temperature of the processed steel slag is 300-200°C, and the particle size less than 8mm accounts for more than 90%.

9. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion process according to claim 6, characterized in that: In step S4, the nozzle direction of the aerosol spray gun (18) is matched with the falling position of the material curtain, and the water spraying amount of the aerosol spray gun (18) is adjusted to match the temperature of the steel slag in the buffer bin (15) and the rotation speed of the drum feeder (17), so that the fine-grained steel slag is cooled again, and the temperature of the steel slag after cooling is 100-200°C.

10. The high-temperature steel slag graded cooling, crushing and f-CaO efficient digestion process according to claim 6, characterized in that: In step S5, the speed of the belt conveyor is adjusted so that the thickness of the material layer on the belt is maintained at 30 to 50 mm, so that the humidifying spray gun can cool the steel slag. The temperature of the steel slag at the discharge end of the belt conveyor is 50 to 100°C. The temperature of the discharged steel slag is detected by the slag temperature detection device (21) at the discharge end so as to adjust the water spraying amount of the humidifying spray gun.

Images