Rare earth electrolysis anode slag negative pressure continuous collection and waste heat recycling system

Abstract

The invention relates to the technical field of rare earth electrolysis, in particular to a rare earth electrolysis anode slag negative pressure continuous collecting and waste heat recycling system which comprises an electrolytic furnace, an anode plate, a cathode bar and a fixing mechanism and further comprises a scraping assembly, a recycling assembly and a discharging groove. By arranging the scraping assembly, the anode slag is scraped off from the anode plate through rotation of the blades, surrounding electrolyte is guided by force generated by rotation of the scraping assembly to generate an upward flowing trend, the scraped anode slag is promoted to float upwards along with fluid, and therefore the recycling assembly can conveniently conduct vacuum adsorption and recycling on the anode slag; and on the other hand, the rotating blades can achieve a stirring effect to a certain extent, so that the melting and electrolysis of the raw materials are accelerated.

Description

Technical Field

[0001] This invention relates to the field of rare earth electrolysis technology, specifically to a system for continuous negative pressure collection and waste heat recovery of rare earth electrolysis anode slag. Background Technology

[0002] Rare earth metals, as metallic complexes formed by the combination of rare earth elements and other elements, have become an indispensable strategic resource for my country due to their superior magneto-optical and photoelectric properties. Currently, the main production method for rare earth metals is molten salt electrolysis. The core of this method lies in placing rare earth oxides and fluoride electrolytes in an electrolytic furnace, where an electric current induces electrochemical reactions at the cathode and anode of the furnace. During this process, precious rare earth metals are deposited at the cathode, while the anode produces anode gases including oxygen, carbon monoxide, carbon dioxide, and hydrogen fluoride.

[0003] However, traditional anode structures are mostly made of graphite or carbonaceous materials, which leads to the continuous formation of anode slag on the anode surface during electrolysis. This anode slag is mainly composed of carbon slag, fluorides, and metal oxides. This anode slag has extremely strong adhesion, and without external intervention, it will continuously accumulate and form a dense layer on the anode surface. The formation of this dense layer not only significantly reduces the effective conductive area of ​​the anode but also significantly increases the inter-electrode resistance, thus seriously affecting the normal progress of the electrolysis reaction. In addition, some of the detached anode slag will settle to the bottom of the electrolytic furnace and mix with the rare earth metal melt. This not only reduces the purity of the rare earth metals but also greatly increases the energy consumption of subsequent separation and purification processes.

[0004] To address the aforementioned problems, existing technologies commonly employ manual slag removal. However, this method has several drawbacks. First, the high-temperature environment near the electrolytic furnace poses a serious threat to the safety of workers, and manual processing is relatively inefficient. Second, the removed anode slag is often not processed promptly, leaving it exposed to the air for extended periods. This not only wastes heat but may also have adverse environmental impacts.

[0005] To address this, a system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a system for continuous negative pressure collection and waste heat recovery of rare earth electrolysis anode slag. This system solves the problem of anode slag adhering to the anode surface and affecting the normal progress of the electrolysis reaction. By scraping off the anode slag with a scraping component, the surrounding fluid is guided to carry the anode slag upward, preventing it from settling and mixing with the rare earth while facilitating the adsorption of the slag by the recovery component. Then, the recovery component uses negative pressure to adsorb the anode slag floating on the liquid surface and transfers the waste heat of the anode slag to the raw material about to fall, thereby preheating it and accelerating the reaction efficiency.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag includes an electrolytic furnace, an anode plate, a cathode rod, and a fixing mechanism. It also includes a scraping component, a recovery component, and a discharge trough. The scraping component is connected to the fixing mechanism, the recovery component is located on one side of the electrolytic furnace, and the discharge trough is connected to the upper side of the recovery component. The scraping component scrapes off the anode slag adhering to the anode plate and guides the fluid flow to cause the anode slag to float upwards. The recovery component extracts the floating anode slag and transfers its heat to the discharge trough.

[0009] Preferably, the scraping assembly includes a mounting shaft, a connecting frame, and blades. The mounting shaft is connected to a fixing mechanism, the connecting frame is connected to the mounting shaft, and a plurality of blades are connected to the connecting frame and are staggered at different height positions.

[0010] Preferably, the blade is arc-shaped, and its height gradually increases from the front to the rear in the forward direction.

[0011] Preferably, the recovery assembly includes a processing tank, a negative pressure pipeline, and a suction head. The processing tank is located on one side of the electrolytic furnace, the negative pressure pipeline is connected to the processing tank, and the suction head is connected to the end of the negative pressure pipeline near the electrolyte. The suction head is located in the inner circle formed by multiple anode plates, and the opening at the bottom of the suction head is above the liquid surface. An inclined filter plate is laid in the middle of the suction head, which divides the suction head into an adsorption chamber at the top and a storage chamber at the bottom. A miniature water pump for draining the liquid is installed in the storage chamber.

[0012] Preferably, the rear sidewall of the suction head has an opening at the liquid storage chamber, and a slidable sealing plate is provided on the opening to control the opening or closing of the opening.

[0013] Preferably, the wall thickness of the negative pressure pipe on the upper side is less than that of the pipe wall at other locations, and the upper wall of the negative pressure pipe is made of a material with high thermal conductivity.

[0014] Preferably, the material discharge trough is located on the upper side of the negative pressure pipe, the bottom surface of the material discharge trough is made of a high thermal conductivity material, and the length of the material discharge trough is greater than the length of the negative pressure pipe.

[0015] Preferably, the surface of the material discharge trough is provided with multiple raised strips, the raised strips are inverted "V" shape, and multiple rows of raised strips are distributed alternately.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. This invention uses a scraping assembly to scrape the anode slag off the anode plate by rotating blades. The force generated by the rotation guides the surrounding electrolyte to flow upward, causing the scraped anode slag to float upward with the fluid. This facilitates the negative pressure adsorption and recovery of the anode slag by the recovery assembly, thus preventing excessive anode slag accumulation on the anode plate from affecting the normal reaction. On the other hand, the rotating blades can also play a stirring role to a certain extent, thereby accelerating the melting and electrolysis of the raw materials.

[0018] 2. This invention uses the negative pressure generated by the recovery component to remove the anode slag floating on the liquid surface, thereby ensuring the normal progress of the reaction. At the same time, placing the suction head above the liquid surface can also extract the anode gas generated during the reaction, thus avoiding harmful gases from affecting the surrounding working environment. On the other hand, by placing the negative pressure pipe together with the material discharge trough, the residual heat of the anode slag can be quickly transferred to the raw material about to enter the electrolysis furnace, thereby preheating it and enabling it to melt faster when it falls into the electrolysis furnace, thus accelerating the reaction efficiency.

[0019] 3. Through the ingenious design of the filter plate and sealing plate, the present invention enables the anode slag and electrolyte to be separated under pressure. Furthermore, through the setting of a micro water pump, the filtered electrolyte can be discharged into the electrolytic furnace in real time or intermittently, thereby achieving full utilization of the electrolyte. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal component installation positions after the electrolytic furnace of the present invention has been partially cut open;

[0022] Figure 3 This is a schematic diagram of the scraping component of the present invention;

[0023] Figure 4 This is a schematic diagram of the negative pressure pipeline wall thickness of the present invention;

[0024] Figure 5 for Figure 4 View from the center F direction;

[0025] Figure 6This is a schematic diagram of the material discharge trough of the present invention.

[0026] In the diagram: 1. Electrolytic furnace; 2. Anode plate; 3. Cathode rod; 4. Fixing mechanism; 5. Scraping assembly; 501. Mounting shaft; 502. Connecting frame; 503. Blade; 6. Recycling assembly; 601. Processing box; 602. Negative pressure pipeline; 603. Suction head; 604. Filter plate; 605. Micro water pump; 606. Sealing plate; 7. Material discharge chute; 8. Raised strip. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1 to 6 This invention provides a system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag, the technical solution of which is as follows:

[0029] For details, please refer to Figure 1 , Figure 2 and Figure 3 A system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag includes an electrolytic furnace 1, an anode plate 2, a cathode rod 3, and a fixing mechanism 4. The anode plate 2 is made of graphite material, and an anode pressure plate is fixed on the anode plate 2, which fixes the anode plate 2 to the electrolytic furnace 1. The fixing mechanism 4 is located on one side of the electrolytic furnace 1 and is used to fix the cathode rod 3 and suspend the cathode rod 3 in the center of the electrolytic furnace 1. The fixing mechanism 4 has a lifting function, which can remove the cathode rod 3 from the electrolytic furnace 1 after the reaction is completed, making the operation convenient.

[0030] It also includes a scraping component 5, a recycling component 6, and a material discharge chute 7. The scraping component 5 is connected to the fixing mechanism 4. All parts of the scraping component 5 are made of silicon carbide, a ceramic material that can be used at a high temperature of 1500 degrees Celsius and has good corrosion resistance and insulation. The scraping component 5 includes a mounting shaft 501, a connecting frame 502, and blades 503. The mounting shaft 501 is connected to the lower side of the fixing mechanism 4, and a drive motor is set at the corresponding position above it. The drive motor drives the mounting shaft 501 to rotate. In addition, the mounting shaft 501 is sleeved on the part of the cathode rod 3 above the electrolyte surface, which can effectively prevent the corrosion generated during the reaction from adhering to its surface and causing the necking phenomenon, thus effectively improving the service life of the cathode rod 3.

[0031] The connecting frame 502 is connected to the mounting shaft 501, and multiple blades 503 are connected to the connecting frame 502. The side of the blades 503 away from the connecting frame 502 can be in contact with the surface of the anode plate 2. When they rotate with the mounting shaft 501, they can scrape off the anode slag adhering to the surface of the anode plate 2. Since the main function of the blades 503 is to scrape off the anode slag on the anode plate 2, the rotation frequency does not need to be too fast, so as not to excessively agitate the electrolyte and affect the sedimentation of the precipitated rare earth metals. The blades 503 are arc-shaped, and their height gradually increases from the front to the rear in the forward direction. On the one hand, this can reduce the resistance when they move. On the other hand, when they move forward in the rotation direction, they can guide the surrounding fluid to flow upward along their surface. Since the main component of the anode slag is unreacted... Rare earth oxides, carbides, and impurities are in a semi-molten state at high temperatures, and their density is only slightly greater than that of the molten electrolyte. Although they tend to sink when not affected by external forces, they will float above the liquid surface for a certain period of time when affected by the rising fluid and the rising anode gas. The carbonaceous components in the anode slag may react with the electrolyte to produce gases such as carbon dioxide. These gases will adhere to the surface of the anode slag, increasing its buoyancy. Since the density of the anode slag itself is similar to that of the electrolyte, it can float under the external force of the bubbles, thus floating above the liquid surface. This allows the recovery component 6 to easily adsorb these anode slags and avoid the waste of resources and efficiency caused by extracting a large amount of electrolyte and then filtering it.

[0032] Multiple blades 503 are staggered at different heights, enabling them to fully scrape off the anode slag adhering to the anode plate 2. In addition, the blades 503 are distributed at different heights within the electrolytic furnace 1, allowing them to stir the electrolyte at different heights within the electrolytic furnace 1. This not only enables the continuously falling raw materials to dissolve quickly but also accelerates the electrolysis efficiency.

[0033] like Figure 4As shown, the recovery component 6 is located on one side of the electrolytic furnace 1 and is used to extract anode slag floating on the liquid surface through negative pressure adsorption. The recovery component 6 includes a processing tank 601, a negative pressure pipe 602, and a suction head 603. The processing tank 601 is located on one side of the electrolytic furnace 1 and has a negative pressure adsorption mechanism inside. The negative pressure adsorption mechanism can generate the negative pressure required to extract the anode slag. The negative pressure pipe 602 is connected to the processing tank 601 and is inclined downward. The suction head 603 is connected to the end of the negative pressure pipe 602 near the electrolyte. The suction head 603 is located in the inner circle formed by multiple anode plates 2, and the opening at the bottom of the suction head 603 is above the liquid surface, allowing it to be drawn by negative pressure. The negative pressure generated by the auxiliary mechanism extracts the anode slag on the liquid surface. By adjusting the power of the negative pressure adsorption mechanism, the anode slag floating on the liquid surface can be extracted as centrally as possible, thus avoiding the extraction of too much electrolyte. The suction head 603 is provided with an inclined filter plate 604 in the middle. The filter plate 604 divides the suction head 603 into an upper adsorption chamber and a lower storage chamber. A micro water pump 605 for draining is installed in the storage chamber. The filter plate 604 allows the electrolyte to be filtered into the storage chamber. The electrolyte is then pumped out by the micro water pump 605 and falls back into the electrolysis furnace 1. The anode slag that cannot pass through the filter plate 604 will continue to be pumped into the negative pressure pipe 602 along the filter plate 604. The inclined arrangement of the filter plate 604 is conducive to the rapid separation of anode slag and electrolyte.

[0034] like Figure 5 As shown, the rear side wall of the suction head 603 has an opening at the liquid storage chamber. A sliding sealing plate 606 is installed on the opening. The sealing plate 606 is used to control the opening or closing of the opening, thereby controlling the pressure in the liquid storage chamber. When the opening is closed, the liquid storage chamber is only open on one side of the filter plate 604. At this time, the liquid storage chamber is in a relatively closed area. The negative pressure has no effect on the electrolyte in the liquid storage chamber. The electrolyte can fall freely into the liquid storage chamber under the action of gravity and be temporarily stored. Later, the electrolyte will be pumped out by a micro water pump and discharged into the electrolysis furnace 1 to achieve pressurized separation of electrolyte and anode slag. If the filter plate 604 is blocked, the opening can be opened by moving the sealing plate 606. At this time, air will enter from the opening under the action of negative pressure and then pass through the filter plate 604 to unclog the filter plate 604. The cleaned anode slag will be adsorbed into the negative pressure pipe 602 by the negative pressure to achieve self-cleaning of the filter plate 604 and also to recover the residual anode slag on the filter plate 604. The sealing plate 606 can be driven by linear motion units such as electric push rods and cylinders.

[0035] The wall thickness of the upper part of the negative pressure pipe 602 is smaller than that of other parts of the pipe wall. The upper wall of the negative pressure pipe 602 is made of aluminum, which has a high thermal conductivity. Therefore, when the extracted anode slag enters the negative pressure pipe 602, the residual heat it carries can be easily conducted out through the upper wall of the negative pressure pipe 602, thus facilitating the timely utilization of the residual heat.

[0036] like Figure 2 and Figure 6 As shown, in the rare earth electrolysis process, the raw materials are usually not added to the electrolysis furnace 1 all at once, but are added continuously during the electrolysis process. This is because the rare earth electrolysis process needs to maintain the continuity and stability of the reaction in the electrolysis cell. Adding a large amount of raw materials at once may lead to incomplete reaction, slag settling at the bottom, and other problems, affecting product quality and production efficiency. Therefore, a feeding trough 7 is set up for continuous feeding. The feeding trough 7 is located on the upper side of the negative pressure pipe 602. The bottom surface of the feeding trough 7 is made of aluminum, which has a high thermal conductivity and can quickly conduct the heat transferred from the anode slag in the negative pressure pipe 602 and transfer the heat to the raw materials in the feeding trough 7, thereby fully preheating the raw materials so that they can melt quickly after falling into the electrolyte. In addition, the feeding trough 7 made of aluminum is low in cost, lightweight, easy to process, and easy to replace.

[0037] The length of the material discharge trough 7 is greater than the length of the negative pressure pipe 602, so that the raw material sliding down from the material discharge trough 7 can land near the middle of the electrolytic furnace 1, thereby keeping it away from the suction head 603 and avoiding the situation where the raw material is sucked away as soon as it falls into the electrolyte, thus causing waste of raw material.

[0038] The surface of the material feeding trough 7 is provided with multiple raised strips 8, which are inverted "V" shapes and are arranged in multiple rows. The raised strips 8 are also made of aluminum, making them integrally formed with the material feeding trough 7, which facilitates processing and increases the heat conduction area in the three-dimensional space, thereby ensuring that the raw material is fully preheated. On the other hand, the multiple rows of raised strips 8 can slow down the sliding speed of the raw material, allowing it to fully absorb the heat transferred from the anode slag, thus ensuring that it is fully preheated and increasing its melting speed after falling into the electrolyte. At the same time, slowing down its sliding speed can also prevent it from splashing large water droplets when falling into the electrolyte, thereby preventing the electrolyte from splashing onto the areas of the equipment exposed to the air and causing oxidation, corrosion, and other phenomena.

[0039] The specific working principle is as follows: First, the anode plate 2 and cathode rod 3 are fixed in a suitable position inside the electrolytic furnace 1. Then, electrolyte is placed in the electrolytic furnace 1 and heated to a molten state. The raw material is poured into the feeding trough 7 and continuously falls into the electrolyte at a certain rate. The scraping component 5 and the recovery component 6 are activated. By activating the scraping component 5, on the one hand, the scraping component 5 scrapes off the anode slag adhering to the anode plate 2 during the reaction. On the other hand, the rotation of the scraping component 5 plays a stirring role, thereby accelerating the reaction rate. Furthermore, its rotation guides the flow of the surrounding fluid, causing the scraped anode slag to float to the surface of the electrolyte, thus facilitating subsequent collection and processing. By activating the recovery component 6, on the one hand, the negative pressure generated by the component is used to remove the anode slag floating on the surface of the electrolyte. On the other hand, during the extraction process, the residual heat is used to preheat the raw material about to slide down in the feeding trough 7, so that it can melt quickly after falling into the electrolyte, thereby improving the electrolysis efficiency.

[0040] Specifically, during the electrolysis process, the raw materials and electrolyte will generate anode slag on the anode plate 2, which is composed of carbon slag, fluorides and metal oxides. This anode slag will adhere to the surface of the anode plate 2 and reduce the effective conductive area of ​​the anode plate 2. Therefore, the scraping component 5 is equipped with blades 503. The surface of the blades 503 away from the connecting frame 502 can be in contact with the anode plate 2. Therefore, when it rotates, it can scrape off the anode slag adhering to the anode plate 2. Since its shape is arc-shaped and its height gradually increases from the front to the rear in the forward direction, the electrolyte around the blades 503 will gradually flow upward along its surface during its movement, thereby driving the scraped anode slag to float. In addition, the carbonaceous components in the anode slag will also react with the electrolyte to generate gases such as carbon dioxide. These gases will adhere to the surface of the anode slag, increasing its buoyancy. Since the density of the anode slag itself is similar to that of the electrolyte, it can float under the external force of the bubbles, thus floating above the liquid surface, which facilitates subsequent adsorption treatment.

[0041] By generating negative pressure inside the processing tank 601, and using the negative pressure pipe 602 and suction head 603 to place the extraction position above the electrolyte surface, the anode slag floating on the electrolyte surface is extracted. In this process, a small amount of electrolyte will inevitably be extracted. When the anode slag and electrolyte enter the negative pressure pipe 602 from the suction head 603, due to the design of the filter plate 604, the electrolyte will pass through the filter plate 604 and enter the storage chamber, and be extracted by the micro water pump 605 and fall back into the electrolysis furnace 1. The anode slag that cannot pass through the filter plate 604 will continue to be drawn into the negative pressure pipe 602 along the filter plate 604.

[0042] When the anode slag enters the negative pressure pipe 602, because the upper wall of the negative pressure pipe 602 is thinner, the residual heat of the extracted anode slag can be easily conducted away through the upper wall of the negative pressure pipe 602. Above the negative pressure pipe 602 is the material discharge trough 7, which is made of aluminum with high thermal conductivity. Therefore, it can easily absorb the residual heat transferred from the anode slag and transfer the heat to the raw material in the material discharge trough 7, thereby preheating it fully. This facilitates the timely utilization of residual heat, allowing the raw material in the material discharge trough 7 to melt faster when it enters the electrolyte, thus accelerating the electrolysis efficiency.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag, comprising an electrolytic furnace (1), an anode plate (2), a cathode rod (3), and a fixing mechanism (4), characterized in that: It also includes a scraping component (5), a recycling component (6), and a discharge chute (7). The scraping component (5) is connected to the fixing mechanism (4), the recycling component (6) is located on one side of the electrolytic furnace (1), and the discharge chute (7) is connected to the upper side of the recycling component (6). The scraping component (5) scrapes off the anode slag adhering to the anode plate (2) and guides the fluid flow to make the anode slag float upward. The recycling component (6) extracts the floating anode slag and transfers its heat to the discharge chute (7).

2. The rare earth electrolytic anode slag negative pressure continuous collection and waste heat recovery system according to claim 1, characterized in that: The scraping assembly (5) includes a mounting shaft (501), a connecting frame (502), and blades (503). The mounting shaft (501) is connected to the fixing mechanism (4), the connecting frame (502) is connected to the mounting shaft (501), and a plurality of blades (503) are connected to the connecting frame (502). The plurality of blades (503) are staggered at different height positions.

3. The rare earth electrolytic anode slag negative pressure continuous collection and waste heat recovery system according to claim 2, characterized in that: The blade (503) is arc-shaped, and its height gradually increases from the front to the rear in the forward direction.

4. The rare earth electrolytic anode slag negative pressure continuous collection and waste heat recovery system according to claim 1, characterized in that: The recovery assembly (6) includes a processing tank (601), a negative pressure pipe (602), and a suction head (603). The processing tank (601) is located on one side of the electrolytic furnace (1). The negative pressure pipe (602) is connected to the processing tank (601). The suction head (603) is connected to the end of the negative pressure pipe (602) near the electrolyte. The suction head (603) is located in the inner circle of a circle formed by multiple anode plates (2), and the opening at the bottom of the suction head (603) is above the liquid surface. An inclined filter plate (604) is laid in the middle of the suction head (603). The filter plate (604) divides the suction head (603) into an adsorption chamber located above and a liquid storage chamber located below. A micro water pump (605) for draining liquid is installed in the liquid storage chamber.

5. The rare earth electrolytic anode slag negative pressure continuous collection and waste heat recovery system according to claim 4, characterized in that: The suction head (603) has an opening on its rear side wall at the liquid storage chamber position, and a sliding sealing plate (606) is provided on the opening. The sealing plate (606) is used to control the opening or closing of the opening.

6. The rare earth electrolytic anode slag negative pressure continuous collection and waste heat recovery system according to claim 4, characterized in that: The wall thickness of the upper side of the negative pressure pipe (602) is smaller than that of the wall thickness at other locations, and the upper wall of the negative pressure pipe (602) is made of a material with high thermal conductivity.

7. A system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag according to claim 6, characterized in that: The material discharge trough (7) is located on the upper side of the negative pressure pipe (602). The bottom surface of the material discharge trough (7) is made of a material with high thermal conductivity, and the length of the material discharge trough (7) is greater than the length of the negative pressure pipe (602).

8. A system for continuous negative pressure collection and waste heat recovery of rare earth electrolytic anode slag according to claim 7, characterized in that: The surface of the material discharge trough (7) is provided with multiple raised strips (8), the raised strips (8) are inverted "V" shape, and multiple rows of raised strips (8) are staggered.

Images