Red mud waste heat recovery and utilization device
By designing a red mud waste heat recovery and utilization device and using a shell-and-tube heat exchanger for counter-current convection heat exchange, the problem of unutilized red mud slurry waste heat was solved, the uniformity of red mud filtrate and the cleaning quality of smelting equipment were improved, and energy and water resources were saved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGXI GUANGTOU LINGANG IND CO LTD
- Filing Date
- 2025-07-02
- Publication Date
- 2026-07-31
AI Technical Summary
In the bauxite smelting process, the residual heat of the red mud slurry is not effectively recovered and utilized, resulting in the waste of energy and water resources. Furthermore, the temperature and composition of the red mud filtrate are uneven, affecting the cleaning quality of the smelting equipment.
A red mud waste heat recovery and utilization device is designed, including a red mud mixing tank, a heat exchanger, a red mud slurry storage tank and a filtrate tank. The red mud slurry is made uniform by a stirring structure, and the heat exchange is carried out by a shell-and-tube heat exchanger to realize the heat transfer between the red mud slurry and the filtrate, thereby improving the temperature and composition uniformity of the filtrate.
This technology enables efficient recovery and utilization of waste heat from red mud, improves the cleaning quality of smelting equipment and water conservation, enhances the washing effect of red mud filtrate, and reduces energy consumption.
Smart Images
Figure CN224580784U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to bauxite smelting and processing, and more particularly to a device for recovering and utilizing waste heat from red mud. Background Technology
[0002] In bauxite smelting, alumina is extracted using the Bayer process or sintering process. The remaining solid waste is red mud, the main component of which is Fe2O3 (iron oxide). The red mud and washing liquid generated by the washing equipment are produced at approximately 90°C or higher.
[0003] For every ton of alumina produced, 1-2 tons of red mud are generated, and the amount of red mud slurry exceeds 2.5 tons. Due to the large flow rate and high temperature of the discharged red mud and washing liquid, energy is wasted to a great extent. Utility Model Content
[0004] The present invention aims to solve at least one of the aforementioned technical problems by providing a red mud waste heat recovery and utilization device, which recovers and utilizes the waste heat of red mud slurry for heat exchange with red mud filtrate, and cleans red mud with the red mud filtrate at a higher temperature, thereby improving the cleaning quality of smelting equipment and saving heat energy and water resources.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A red mud waste heat recovery and utilization device includes a red mud mixing tank, a heat exchanger, a red mud slurry storage tank, and a filtrate tank. The red mud mixing tank is equipped with a stirring structure and is used to receive red mud and washing liquid discharged from a sedimentation and washing system, and also to mix the red mud and washing liquid into raw red mud slurry. The input end of the main flow channel of the heat exchanger is used to receive the raw red mud slurry. The red mud slurry storage tank is connected to the output end of the main flow channel to receive the red mud slurry after heat utilization. The red mud slurry storage tank is used to provide the red mud slurry after heat utilization to a filter press. The filtrate tank is used to receive the red mud filtrate squeezed out by the filter press, and also to supply the red mud filtrate to the input end of the secondary flow channel of the heat exchanger. The output end of the secondary flow channel is used to supply the red mud filtrate after heat absorption to the sedimentation and washing system.
[0007] Compared with the prior art, the beneficial effects of this application include: the red mud is stirred into a red mud slurry with more uniform temperature and composition, which facilitates the full and effective absorption of the red mud waste heat by the filtrate, saves energy by utilizing the red mud waste heat, and the resulting higher temperature filtrate is reused for precipitation and washing in smelting equipment, etc., which softens and dissolves the precipitate better during washing, improves the washing effect, and saves water resources.
[0008] As an improvement to the above technical solution, the heat exchanger is a shell-and-tube heat exchanger, which has a straight tube side and a shell side surrounding the tube side. The tube side is used for flowing red mud slurry, and the shell side is used for flowing red mud filtrate.
[0009] As an improvement to the above technical solution, the tube side and the shell side are used for counter-current convection.
[0010] As an improvement to the above technical solution, the shell-and-tube heat exchanger includes a core tube and a shell tube. The shell tube is assembled from two detachable jackets, the ends of which together hold the end of the core tube. The inner wall of the shell tube and the outer wall of the core tube together define the shell side.
[0011] As an improvement to the above technical solution, both jackets are provided with multiple annular fan-shaped baffles spaced apart along the axial direction, with the baffles extending into the shell side, and the baffles of the two jackets are staggered.
[0012] As an improvement to the above technical solution, the jacket is provided with connecting ears, so that the two jackets are spliced together in the form of flanges, and the outer wall of the jacket is provided with an insulation layer covering the connecting ears.
[0013] As an improvement to the above technical solution, the tube is detachably inserted with a metal flow divider, which includes a core rod and at least two fan blades spaced apart circumferentially along the core rod, thereby dividing the tube into at least two sub-channels.
[0014] As an improvement to the above technical solution, one end of the tube is detachably connected to a first end cap, and the end of the tube and the first end cap together clamp one end of the diverter.
[0015] As an improvement to the above technical solution, the fan blade is provided with a second extrusion slit, and two adjacent sub-channels are connected through the second extrusion slit. Attached Figure Description
[0016] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:
[0017] Figure 1 This is a flowchart of the red mud waste heat recovery and utilization device according to an embodiment of the present invention;
[0018] Figure 2 for Figure 1 A schematic diagram of the shell-and-tube heat exchanger structure of the red mud waste heat recovery and utilization device is shown.
[0019] Figure 3 for Figure 2 An exploded view of a shell-and-tube heat exchanger is shown.
[0020] Figure 4 for Figure 2 The image shows a frontal sectional view of the shell-and-tube heat exchanger, with the flow divider hidden.
[0021] The accompanying drawings are only one specific embodiment of this utility model, and the form and structure of this specific embodiment should not limit the extension of other embodiments.
[0022] Red mud mixing tank 100, stirring structure 110, stirring paddle 111, mixing motor 112;
[0023] The shell-and-tube heat exchanger consists of a core tube 210, a tube side 211, a jacket 220, a shell side 221, a baffle plate 222, a connecting lug 223, a first end cover 230, a second end cover 240, a flow divider 250, a core rod 251, a fan blade 252, and a second extrusion slit 253.
[0024] Red mud slurry storage tank 300;
[0025] Filtration tank 400;
[0026] Filter press 500. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0028] Reference Figure 1 This utility model provides a red mud waste heat recovery and utilization device, including a red mud mixing tank 100, a heat exchanger, a red mud slurry storage tank 300, and a filtrate tank 400. The red mud mixing tank 100 is equipped with a stirring structure 110. The red mud mixing tank 100 is used to receive the red mud and washing liquid discharged from the sedimentation and washing system, and also to mix the red mud and washing liquid into the original red mud slurry. The input end of the main flow channel of the heat exchanger is used to receive the original red mud slurry. The red mud slurry storage tank 300 is connected to the output end of the main flow channel to receive the red mud slurry after heat utilization. The red mud slurry storage tank 300 is used to provide the red mud slurry after heat utilization to the filter press 500. The filtrate tank 400 is used to receive the red mud filtrate squeezed out by the filter press 500, and also to supply the red mud filtrate to the input end of the secondary flow channel of the heat exchanger. The output end of the secondary flow channel is used to supply the red mud filtrate after heat absorption to the sedimentation and washing system.
[0029] Understandably, referring to Figure 1 The stirring structure 110 includes a stirring paddle 111 and a mixing motor 112, such as a hydraulic motor or an electric motor, which is connected to the stirring paddle 111 for transmission. In some configurations, the stirring paddle 111 is configured with a specific shape, such as a multi-blade type or a spiral type.
[0030] In practice, when the diameter of the red mud mixing tank 100 and the red mud slurry storage tank 300 is ≤2m, these tanks are generally equipped with a top cover, and the stirring paddle 111 and the mixing motor 112 are installed on the top cover; when the diameter of the tank is ≥2m, the tank is generally equipped with a bridge frame, and the stirring paddle 111 and the mixing motor 112 are installed on the bridge frame.
[0031] The outer perimeter walls of the red mud mixing tank 100 and the red mud slurry storage tank 300 are provided with a thermal insulation layer, such as a foam plastic layer or a honeycomb structure sheet.
[0032] Red mud mixing tank 100 and red mud slurry storage tank 300 are turbid liquid tanks, see reference. Figure 1 These types of tanks are generally designed with a conical bottom, with a sludge discharge port located at the lowest point of the conical bottom.
[0033] The red mud mixing tank 100 mixes the red mud and washing liquid into a uniform red mud slurry, ensuring a relatively uniform temperature and composition. The red mud mixing tank 100 pre-stores a certain amount of the original red mud slurry to ensure a continuous and stable supply of this slurry to the heat exchanger, ensuring a relatively uniform temperature and composition. The filtrate flowing in the secondary channel stably absorbs the waste heat from the red mud, improving the efficiency of waste heat utilization. Furthermore, the external discharge pump connected to the red mud mixing tank 100 operates stably.
[0034] For the pumping of red mud, diaphragm pumps (a common tool) and mud pumps are preferred, i.e. Figure 1 The external drainage pumps P1 and P2 shown are diaphragm pumps or mud pumps, etc.
[0035] The operation process of this utility model can be as follows: A. Open pump P1 and valve F2, close pump P2, valve F1 and valve F3, filter press 500 first filters a portion of the original red mud slurry, so that the filtrate tank 400 pre-stores red mud filtrate.
[0036] Step A can be omitted, meaning that the red mud filtrate buffered in step A can be replaced with water.
[0037] B. After the filtrate tank 400 buffers a certain amount of red mud filtrate squeezed out by the filter press 500, for example, when the liquid level in the filtrate tank 400 is ≥25%, refer to... Figures 1 to 4 V 22 The liquid-to-solid supply channel of the filtrate tank 400 to the heat exchanger is referenced. Figures 1 to 4 V 11 The main channel of the heat exchanger is supplied with raw red mud slurry;
[0038] C. The liquid in the secondary channel absorbs the heat energy of the original red mud slurry in the main channel, as shown in the reference. Figures 1 to 4 V 12 After heat utilization, the red mud slurry is discharged into the red mud slurry storage tank 300, as per reference. Figures 1 to 4 V 23 The heated liquid is then supplied to the sedimentation and washing system.
[0039] D. The red mud slurry storage tank 300 supplies the heat-utilized red mud slurry to the filter press 500, and the filter press 500 supplies the filtrate squeezed out of the red mud slurry to the filtrate tank 400.
[0040] Repeat B, C, and D in a loop.
[0041] Compared with the prior art, the beneficial effects of this application include: the red mud is stirred into a red mud slurry with more uniform temperature and composition, which facilitates the full and effective absorption of the red mud waste heat by the filtrate, saves energy by utilizing the red mud waste heat, and the resulting higher temperature filtrate is reused for precipitation and washing in smelting equipment, etc., which softens and dissolves the precipitate better during washing, improves the washing effect, and saves water resources.
[0042] Reference Figures 1 to 4 Ideally, the heat exchanger is a shell-and-tube heat exchanger 200, which has a straight-through tube side 211 and a shell side 221 surrounding the tube side 211. The tube side 211 serves as the main flow channel for the flow of red mud slurry, while the shell side 221 serves as a secondary flow channel for the flow of red mud filtrate. Therefore, the tube side 211 is easier to clean and can be cleaned quickly using a long scraper or a long straight brush, allowing the red mud slurry to flow through the easier-to-clean and maintain tube side 211.
[0043] Reference Figure 1 , Figure 4 The tube side 211 is the central channel (inner flow channel) of the shell-and-tube heat exchanger 200; the shell side 221 is the outer flow channel of the shell-and-tube heat exchanger 200, which surrounds the central flow channel. The tube side 211 is made of metal, and even the shell side 221 is made of metal and is integrally formed with the shell side 221, for example, by welding them together.
[0044] Reference Figures 1 to 4 Ideally, tube side 211 and shell side 221 are designed for counter-current convection, see reference. Figures 1 to 4 The original red mud slurry flows from left to right in the tube side 211, and the filtrate flows from right to left in the shell side 221. The filtrate absorbs the heat from the tube side 211 and the original red mud slurry.
[0045] Reference Figure 2 , Figure 3 In some embodiments of this utility model, the shell-and-tube heat exchanger 200 includes a core tube 210 and a shell. The shell is detachably assembled from two jackets 220, the ends of which together hold the end of the core tube 210. The inner wall of the shell and the outer wall of the core tube 210 together define the shell side 221. In this utility model, the shell side 221 is also relatively easy to clean.
[0046] Reference Figure 3 , Figure 4In some embodiments of this utility model, both jackets 220 are provided with multiple annular fan-shaped baffles 222 spaced apart along the axial direction. The baffles 222 extend into the shell side 221, and the baffles 222 of the two jackets 220 are staggered. Therefore, referring to... Figure 3 and Figure 4 When the filtrate in the shell side 221 flows from right to left, the filtrate path is wavy, allowing the red mud filtrate to absorb heat from the tube side 211 more quickly and fully during the flow homogenization process. In addition, the baffle plate 222 also serves as a reinforcing rib of the jacket 220, giving the jacket 220 higher strength and enabling it to withstand higher hydraulic pressure.
[0047] On the other hand, refer to Figure 2 , Figure 3 When assembling the core tube 210 and the two jackets 220, sealant can be applied first, and then screws can be used for connection. When disassembling and reassembling the core tube 210 and the two jackets 220, the old sealant should be removed first, and then new sealant should be applied.
[0048] To prevent the two jackets 220 from rotating relative to the core tube 210, a positioning structure, such as a positioning protrusion and a positioning notch (positioning recess), is connected between the jackets 220 and the core tube 210.
[0049] In some configurations, the baffle plate 222 abuts against the outer wall of the core tube 210.
[0050] In some embodiments of this utility model, a first squeezing slit is provided between the outer wall of the core tube 210 and the baffle plate 222. Therefore, in the shell side 221, the red mud filtrate mainly flows in a wave-shaped baffle and turbulent manner, and a small part accelerates and flows along the outer wall of the core tube 210 through the first squeezing slit, which intensifies the rolling and temperature equalization of the red mud filtrate in the shell side 221.
[0051] Reference Figure 2 , Figure 3 In some embodiments of this utility model, the jacket 220 is provided with connecting ears 223, so that the two jackets 220 are spliced together in the form of flanges. The outer wall of the jacket 220 is provided with an insulation layer covering the connecting ears 223, and the connection between the two jackets 220 has a good insulation effect.
[0052] Reference Figure 3In some embodiments of this utility model, the tube side 211 is detachably inserted with a metal flow divider 250, thus ensuring convenient cleaning and maintenance of the tube side 211. The flow divider 250 divides the tube side 211 into multiple rows. The flow divider 250 includes a core rod 251 and at least two fan blades 252 spaced circumferentially along the core rod 251, dividing the tube side 211 into at least two sub-channels. The metal flow divider 250 absorbs heat quickly and has heat dissipation holes, increasing the heat exchange area and improving the temperature uniformity of the red mud slurry within the tube side 211, allowing the heat within the tube side 211 to be absorbed more effectively and completely. The outer periphery of the metal flow divider 250 contacts the peripheral wall of the tube side 211, further accelerating the transfer of heat from the tube side 211 to the shell side 221.
[0053] Reference Figure 3 The flow divider 250 is equipped with four fan blades 252, which divide the tube 211 into four sub-flow channels.
[0054] Reference Figures 2 to 4 In some embodiments of this utility model, one end of the tube 211 is detachably connected to a first end cap 230, and the other end of the tube 211 is detachably connected to a second end cap 240. The end of the tube 211 and the first end cap 230 together clamp one end of the diverter 250.
[0055] Reference Figure 3 , Figure 4 The end cap corresponding to the left end of the shell side 221 is the first end cap 230, and the left end of the diverter 250 is provided with a flange for being clamped by the shell side 221 and the first end cap 230.
[0056] Reference Figure 3 In some embodiments of this utility model, the fan blade 252 is provided with a second extrusion slit 253, and two adjacent sub-channels are connected through the second extrusion slit 253, which intensifies the red mud slurry turbulence in each sub-channel.
[0057] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the scope of the technical solution of this utility model.
Claims
1. A red mud waste heat recovery device, characterized by, include: A red mud mixing tank with a stirring structure is used to receive red mud and washing liquid discharged from the sedimentation and washing system, and to mix the red mud and washing liquid into a raw red mud slurry. The heat exchanger, whose main flow channel inlet is used to receive the original red mud slurry; A red mud slurry storage tank is connected to the output end of the main channel. The red mud slurry storage tank is used to provide the filter press with red mud slurry after heat utilization. The filtrate tank is used to receive the red mud filtrate squeezed out by the filter press, and also to supply the red mud filtrate to the input end of the heat exchanger's secondary flow channel. The output end of the secondary flow channel is used to supply the heat-absorbing red mud filtrate to the sedimentation and washing system.
2. The red mud waste heat recovery and utilization device according to claim 1, characterized in that, The heat exchanger is a shell-and-tube heat exchanger, which has a straight tube side and a shell side surrounding the tube side. The tube side is used for flowing red mud slurry, and the shell side is used for flowing red mud filtrate.
3. The red mud waste heat recovery and utilization device according to claim 2, characterized in that, The tube side and the shell side are used for counter-current convection.
4. The red mud waste heat recovery and utilization device according to claim 2, characterized in that, The shell-and-tube heat exchanger includes a core tube and a shell tube. The shell tube is assembled from two detachable jackets. The ends of the two jackets together hold the end of the core tube. The inner wall of the shell tube and the outer wall of the core tube together define the shell side.
5. The red mud waste heat recovery device according to claim 4, characterized in that, Both jackets are provided with multiple annular fan-shaped baffles spaced apart along the axial direction. The baffles extend into the shell side, and the baffles of the two jackets are staggered.
6. The red mud waste heat recovery device according to claim 4, characterized in that, The jacket is provided with connecting lugs, so that two jackets are spliced together in the form of flanges, and the outer wall of the jacket is provided with an insulation layer covering the connecting lugs.
7. The red mud waste heat recovery device according to any one of claims 2 to 6, characterized in that, The tube is detachably inserted with a metal flow divider, which includes a core rod and at least two fan blades spaced circumferentially along the core rod, thereby dividing the tube into at least two sub-channels.
8. The red mud waste heat recovery and utilization device according to claim 7, characterized in that, One end of the tube is detachably connected to a first end cap, and the end of the tube and the first end cap together clamp one end of the diverter.
9. The red mud waste heat recovery and utilization device according to claim 7, characterized in that, The fan blade is provided with a second extrusion slit, and two adjacent sub-channels are connected through the second extrusion slit.