A rapid solid-liquid separation device for calcified biomassized red mud
By installing a Venturi device and an electromagnetic induction coil on the outside of the slurry feed pipe and the spiral guide barrel, a rotating magnetic field eddy current is formed, which solves the problem of low solid-liquid separation efficiency of red mud in the existing technology, realizes rapid solid-liquid separation of red mud, and improves sedimentation separation efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NORTHEASTERN UNIV CHINA
- Filing Date
- 2023-07-20
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies offer limited improvement in the solid-liquid separation efficiency of red mud in the Bayer process, failing to fundamentally change the solid-liquid separation mechanism in red mud, resulting in poor sedimentation separation performance.
A rapid solid-liquid separation device for calcified biomass red mud is adopted. By installing a Venturi device on the slurry feed pipe and an electromagnetic induction coil outside the spiral guide barrel, a rotating magnetic field is generated, forming a downward vortex. This promotes the rapid entry of flocculant into the slurry and accelerates the sedimentation of red mud. Rapid solid-liquid separation is achieved by utilizing the coupling effect between the rotating magnetic field and the flocculant.
It significantly improves the solid-liquid separation speed of red mud, increasing the separation speed by 2 to 5 times, inhibiting secondary reactions of the slurry, and improving the sedimentation and separation efficiency in the alumina production process.
Smart Images
Figure CN117085374B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solid-liquid separation after bauxite leaching, and specifically relates to a rapid solid-liquid separation device for calcified biomass red mud. Background Technology
[0002] Aluminum is a pillar industry in my country's non-ferrous metals metallurgy sector. As of 2022, my country's primary aluminum production capacity reached over 36 million tons, and alumina production exceeded 80 million tons, accounting for more than 50% of global production. Currently, over 90% of my country's alumina is produced using the Bayer process, which involves converting alumina from bauxite into alumina products through processes such as leaching, sedimentation, decomposition, and calcination.
[0003] In the Bayer process, improving sedimentation separation efficiency has always been a research hotspot in related industries. For example, the patent application CN114452689A from Guizhou Guanglu Alumina Co., Ltd., entitled "A Sedimentation Tank for Red Mud Sedimentation in Alumina Production," comprises: a sedimentation tank body; a conical discharge port and a base at the bottom of the sedimentation tank body; the conical discharge port being fixedly connected to the sedimentation tank body; the conical discharge port being fixedly connected to the base via a support plate; a bracket, a limiting post, and a rotating pry bar on the base; the rotating pry bar being connected to a discharge device; a discharge hole at the bottom of the conical discharge port; a sliding groove on the support plate; the discharge device being slidably connected to the sliding groove; the rotating pry bar being rotatably connected to the bracket; and a limiting rod on the limiting post, which slidably engages with the limiting post via a limiting hole. Because this invention includes a discharge device and a rotating pry bar, the discharge hole can be easily cleared.
[0004] The patent CN114917630A, "A Novel Red Mud Settling Flocculant Addition Device," applied for by China Aluminum International Engineering Co., Ltd. and others, involves welding a flanged pipe opening to the top cover of the settling tank. A first straight pipe section of the same diameter as the pipe opening is welded to the lower end of the opening. This first straight pipe section is directly inserted below the surface of the clear liquid layer and / or welded to the settling tank's feed pipe. A flocculant straight pipe section is inserted inside the pipe opening, with its bottom extending to or slightly beyond the bottom of the first straight pipe section. The flocculant straight pipe section is connected to the main flocculant pipe via a connecting pipe. The advantages of this invention are: 1. There are no welding points between the flocculant straight pipe section inside the settling tank and the settling tank, making installation and disassembly convenient. 2. Replacing the flocculant addition pipe does not require emptying the settling tank. After alkali washing the pipe, the connecting pipe is removed, and the flocculant straight pipe section inserted inside the settling tank is pulled out for direct replacement, significantly saving maintenance time, reducing the labor intensity of maintenance personnel, and minimizing the impact on the operating indicators of the settling system.
[0005] The aforementioned disclosed technical solutions aim to improve the sedimentation and separation effect by modifying the internal structure of the sedimentation tank to facilitate the unblocking of the discharge holes or by optimizing the flocculant addition structure. Red mud sedimentation is a solid-liquid separation process, but it does not fundamentally change the solid-liquid separation method in red mud from the perspective of improving gas-solid separation efficiency. Therefore, the improvement effect on red mud sedimentation and separation is limited. Summary of the Invention
[0006] The purpose of this invention is to provide a rapid solid-liquid separation device for calcified biomass red mud. The device includes: a stirring shaft, a slurry feed pipe, a venturi device, a settling tank, a clear liquid overflow tank, a spiral guide barrel, an electromagnetic induction coil, a sludge rake, and an underflow outlet. The slurry feed pipe is located at the top of the settling tank, with its inlet horizontally connected to the tangential direction of the spiral guide barrel. A Venturi device is installed on the slurry feed pipe, with multiple flocculant inlets installed at the narrowest part of the Venturi device. The spiral guide barrel is located inside the settling tank and fixed to the upper part of the settling tank by a fixing device. The spiral guide barrel has downward spiral patterns inside. An electromagnetic induction coil is installed on the outside of the spiral guide barrel. The stirring shaft extends into the settling tank, and its bottom is connected to a sludge scraper via a connecting rod. By driving the sludge scraper to rotate, the red mud is forced to leave the settling tank from the bottom outlet. The clear liquid overflow tank is connected to the top of the settling tank and is equipped with a wedge-shaped baffle. The clear liquid is discharged from the top of the settling tank through the clear liquid overflow tank.
[0007] The above-mentioned rapid solid-liquid separation device for calcified biomass red mud includes:
[0008] The device processes transformed red mud treated using calcification biomass technology, and the iron-bearing phase in the red mud is a magnetic iron-bearing phase.
[0009] A Venturi device is installed in the slurry feed pipe. Multiple flocculant inlets are installed in the narrow part of the Venturi device. The suction generated by the slurry flowing through the Venturi tube promotes the flocculant to enter the slurry quickly.
[0010] The spiral guide tank is equipped with a rotating magnetic mechanism on the outside. The rotating magnetic field generated by the electromagnetic induction coil drives the magnetic iron-containing phase in the red mud to rotate, forming a downward vortex to improve the settling effect. The settling speed is 2 to 5 times higher than that of conventional red mud settling tanks. The electromagnetic induction coil is composed of multiple energized coils and generates a rotating magnetic field through an AC power supply.
[0011] The spiral guide tube has downward spiral patterns inside. The slurry enters the spiral guide tube horizontally along the tangential direction from the slurry feed pipe and flows downward along the spiral pattern inside the tube (e.g., Figure 2 The spiral guide barrel has a deep conical structure, which promotes the agglomeration of red mud solids in the slurry into large particles, thus accelerating the red mud settling effect.
[0012] The eddy current effect generated by the electromagnetic induction coil can quickly entrain the flocculant into the red mud slurry. The coupling effect of the rotating magnetic field with the flocculant and the spin flow accelerates the solid-liquid separation of the red mud slurry. The solid-liquid separation speed is 2 to 5 times higher than that of conventional red mud settling tanks, and the secondary reaction of the slurry is suppressed.
[0013] The magnetic field generated by the electromagnetic induction coil is an eddy current magnetic field with a magnetic field strength of 80-300 mT. The eddy current direction is downward rotation. By adjusting the electromagnetic field strength, the calcified biomass inside the guide tank is driven to rotate as it dissolves into the slurry. The rotation speed range is 20-200 rpm.
[0014] Compared with existing sedimentation separation processes, the advantages of this invention are:
[0015] (1) The slurry feed pipe of the red mud rapid solid-liquid separation device is a Venturi structure. Multiple flocculant inlets are installed at the narrow part of the Venturi pipe. The slurry flows through the Venturi device and generates suction, which prompts the flocculant to enter the slurry quickly.
[0016] (2) The spiral guide barrel of the red mud rapid solid-liquid separation device is equipped with a rotating magnetic mechanism. The rotating magnetic field generated by the electromagnetic induction coil drives the magnetic iron-containing phase in the red mud to rotate, forming a downward vortex to enhance the settling effect. The coupling effect of the rotating magnetic field with flocculant and self-spinning flow accelerates the rapid solid-liquid separation of red mud slurry. The solid-liquid separation speed is 2 to 5 times higher than that of conventional red mud settling tank, and the secondary reaction of slurry is suppressed.
[0017] (3) The eddy current effect generated by the electromagnetic induction coil of the red mud rapid solid-liquid separation device can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is increased by 2 to 5 times compared with the conventional red mud settling tank, thus inhibiting the secondary reaction of the slurry.
[0018] (4) The red mud rapid solid-liquid separation device realizes rapid solid-liquid separation of bauxite leaching slurry, which greatly improves the efficiency of the sedimentation separation process in the alumina production process. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of a rapid solid-liquid separation device for red mud. In the diagram, 1-stirring shaft, 2-slurry feed pipe, 3-Venturi device, 4-sedimentation tank, 5-clear liquid overflow tank, 6-spiral guide barrel, 7-electromagnetic induction coil, 8-sludge rake, and 9-underflow outlet.
[0020] Figure 2 A schematic diagram showing the tangential direction of the leached red mud slurry entering the spiral guide tube. Detailed Implementation
[0021] In the embodiments of the present invention, the red mud produced by converting the iron-bearing phase in the red mud leached by the Bayer process into a magnetic iron-bearing phase is produced using the calcification biomass conversion technology.
[0022] The method of the present invention is not limited to processing this type of red mud; any raw material with alumina and iron oxide as the main components can be processed by this device.
[0023] Example 1
[0024] A device for rapid solid-liquid separation of red mud converted from calcified biomass, such as... Figure 1 As shown, it consists of the following nine parts: a stirring shaft 1, a slurry feed pipe 2, a Venturi device 3, a settling tank 4, a clear liquid overflow tank 5, a spiral guide tube 6, an electromagnetic induction coil 7, a sludge scraper 8, and an underflow outlet 9. The slurry feed pipe 2 is located at the top of the settling tank 4, with its inlet horizontally connected tangentially to the spiral guide tube 6. A Venturi device 3 is installed on the slurry feed pipe 2, with multiple flocculant inlets installed at the narrowest part of the Venturi device 3. The slurry flowing through the Venturi tube generates suction, prompting the flocculant to quickly enter the slurry. The spiral guide tube 6 is located inside the settling tank 4 and fixed to the upper part of the settling tank 4 by a fixing device. The spiral guide tube 6 has a deep conical structure with downward spiral patterns inside. An electromagnetic induction coil 7 is installed on the outside of the spiral guide tube 6. The electromagnetic induction coil 7 consists of three energized coils. It generates a rotating magnetic field through an AC power supply. The generated rotating magnetic field drives the magnetic iron-containing phase in the slurry to rotate, forming a downward eddy current, thereby improving the settling effect. The stirring shaft 1 is inserted into the settling tank 4. The bottom of the stirring shaft is connected to the sludge rake 8 through a connecting rod. By driving the sludge rake 8 to rotate at a low speed, the red mud leaves the settling tank from the bottom outlet 9. The clear liquid overflow tank 5 is connected to the top of the settling tank 4. The clear liquid overflow tank is equipped with a wedge-shaped baffle. The clear liquid is discharged from the top of the settling tank 4 through the clear liquid overflow tank 5.
[0025] The aforementioned apparatus is used to process the red mud produced after converting the iron-bearing phase in the dissolved red mud into a magnetic iron-bearing phase using the calcified biomass conversion technology. The magnetic field strength is 80 mT, the eddy current direction is downward rotation, and the rotational speed of the magnetic field is 100 pm.
[0026] The solid-liquid separation speed is increased by 2 times compared to conventional red mud settling tanks, and secondary reactions of the slurry are suppressed; at the same time, the eddy current generated by the rotating magnetic field can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is increased by 2 times compared to conventional red mud settling tanks.
[0027] Example 2
[0028] The apparatus described in Example 1 is used to process the red mud produced after converting the iron-bearing phase in the dissolved red mud into a magnetic iron-bearing phase using the biomass conversion technology. The magnetic field generated by the electromagnetic induction coil 7 is an eddy current magnetic field with a magnetic field strength of 100 mT, the eddy current direction is downward rotation, and the rotational speed of the rotating magnetic field is 200 pm.
[0029] The solid-liquid separation speed is 5 times faster than that of conventional red mud settling tanks, and the secondary reaction of the slurry is suppressed; at the same time, the eddy current generated by the rotating magnetic field can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is 5 times faster than that of conventional red mud settling tanks.
[0030] Example 3
[0031] The red mud produced by converting the iron-bearing phase in the dissolved red mud into a magnetic iron-bearing phase using the apparatus of Example 1 was processed; the magnetic field strength generated by the electromagnetic induction coil 7 was 200 mT, the eddy current direction was downward rotation, and the rotation speed of the rotating magnetic field was 150 pm.
[0032] The solid-liquid separation speed is 3 times faster than that of conventional red mud settling tanks, and the secondary reaction of the slurry is suppressed. At the same time, the eddy current generated by the rotating magnetic field can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is 3 times faster than that of conventional red mud settling tanks.
[0033] Example 4
[0034] The apparatus of Example 1 is used to process the red mud produced after the iron-bearing phase in the dissolved red mud is converted into a magnetic iron-bearing phase using the biomass conversion technology. The magnetic field strength generated by the electromagnetic induction coil 7 is 30mT, the eddy current direction is downward rotation, and the rotation speed of the rotating magnetic field is 50pm.
[0035] The solid-liquid separation speed is twice that of conventional red mud settling tanks, and secondary reactions of the slurry are suppressed; at the same time, the eddy current generated by the rotating magnetic field can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is three times that of conventional red mud settling tanks.
[0036] Example 5
[0037] The red mud produced by converting the iron-bearing phase in the dissolved red mud into a magnetic iron-bearing phase using the apparatus of Example 1 was processed; the magnetic field strength generated by the electromagnetic induction coil 7 was 120 mT, the eddy current direction was downward rotation, and the rotation speed of the rotating magnetic field was 180 pm.
[0038] The solid-liquid separation speed is 4 times faster than that of conventional red mud settling tanks, and the secondary reaction of the slurry is suppressed. At the same time, the eddy current generated by the rotating magnetic field can quickly entrain the flocculant into the red mud slurry, and the solid-liquid mixing speed is 5 times faster than that of conventional red mud settling tanks.
Claims
1. A rapid solid-liquid separation device for calcified biomass red mud, characterized in that, include: The components include a stirring shaft (1), a slurry feed pipe (2), a venturi device (3), a settling tank (4), a clear liquid overflow tank (5), a spiral guide barrel (6), an electromagnetic induction coil (7), a sludge rake (8), and a bottom outlet (9). The slurry feed pipe (2) is located at the top of the settling tank (4), with its inlet horizontally connected to the tangential direction of the spiral guide barrel (6). A venturi device (3) is installed on the slurry feed pipe (2), and multiple flocculant inlets are installed at the narrowest part of the venturi device (3). The slurry flows through the venturi tube, generating suction that causes the flocculant to quickly enter the slurry. The spiral guide barrel (6) has a deep conical structure and is located inside the settling tank (4). It is fixed to the upper part of the settling tank (4) by a fixing device. The spiral guide barrel (6) has a spiral downward-facing structure inside. The slurry enters the spiral guide barrel (6) horizontally along the tangential direction from the slurry feed pipe (2) and flows downward along the spiral pattern inside the spiral guide barrel; an electromagnetic induction coil (7) composed of multiple energized coils is installed on the outside of the spiral guide barrel (6), which generates a rotating magnetic field through AC power. The generated rotating magnetic field drives the magnetic iron phase in the red mud to rotate, forming a downward eddy current to enhance the settling effect; the stirring shaft (1) is inserted into the settling tank (4), and the bottom of the stirring shaft is connected to the raking machine (8) through a connecting rod. By driving the raking machine (8) to rotate, the red mud is forced to leave the settling tank from the bottom outlet (9); the clear liquid overflow tank (5) is connected to the top of the settling tank (4), and the clear liquid overflow tank is equipped with a wedge-shaped baffle. The clear liquid is discharged from the top of the settling tank (4) through the clear liquid overflow tank (5).
2. The rapid solid-liquid separation device for calcified biomass red mud according to claim 1, characterized in that, The device processes transformed red mud treated using calcification biomass technology, and the iron-bearing phase in the red mud is a magnetic iron-bearing phase.
3. The rapid solid-liquid separation device for calcified biomass red mud according to claim 1, characterized in that, The magnetic field generated by the electromagnetic induction coil (7) is an eddy current magnetic field with a magnetic field strength of 80~300mT and the eddy current direction is downward rotation.
4. The rapid solid-liquid separation device for calcified biomass red mud according to claim 3, characterized in that, By adjusting the intensity of the electromagnetic field, the calcified biomass leaching slurry inside the guide tank is driven to rotate, with the rotation speed ranging from 20 to 200 rpm.