Flux circulating type smelting method for magnesium or magnesium alloy

Abstract

The invention discloses a flux circulating type smelting method for magnesium or magnesium alloy, which is characterized in that flux at the bottom of a molten pool is extracted to the surface of the molten pool and then enters the molten pool to realize vertical circulating type smelting treatment of the flux, and the flux is extracted to a space above the surface of the molten pool to be independently filtered; and the filtered flux downwards flows back to the surface of the molten pool to be circularly smelted. In conclusion, the flux refining impurities can be treated on line to achieve continuous smelting production of magnesium or magnesium alloy, and the continuous smelting device has the advantages of being high in impurity filtering effect, good in smelting efficiency and precision, environmentally friendly, continuous and intelligent.

Description

Technical Field

[0001] The present invention relates to the technical field of metal smelting and metallurgy, and in particular to a flux circulation smelting method for magnesium or magnesium alloy. Background Art

[0002] Magnesium and its alloys occupy a crucial position in the global manufacturing industry, thanks to their unique lightweight, high strength, excellent electromagnetic shielding, and corrosion resistance. They are increasingly used in high-tech fields such as aerospace, lightweight automotive, consumer electronics, and medical devices. According to the International Magnesium Association, the global magnesium alloy market is expected to exceed US$60 billion in 2022, with a compound annual growth rate of 8.3%. However, the magnesium smelting industry faces a series of severe challenges in its pursuit of efficient production.

[0003] During the magnesium smelting process, companies often use large doses of flux to refine raw magnesium, as it contains a large amount of impurities. This often results in a large amount of sediment in the refining furnace. The main components of the common raw magnesium sediment in actual industrial production are residual flux and impurities in the raw magnesium. This residual flux component has great commercial recovery value. However, there is currently no efficient and feasible method or approach for the recycling and reuse of raw magnesium sediment.

[0004] Furthermore, magnesium smelting companies currently primarily add flux, stir the reaction, and then allow the mixture to settle before casting. This intermittent, manual operation of stirring and settling is not only labor-intensive for operators and inefficient, but also fails to meet modern industry's demand for high-purity and high-quality products. Therefore, the magnesium smelting industry requires green, continuous, and intelligent raw magnesium flux refining technology.

[0005] In response to the aforementioned issues with conventional flux refining, a number of flux-free purification methods for magnesium and magnesium alloy melts have been proposed, primarily including natural sedimentation, sublimation refining, electrolytic refining, vacuum purification, ultrasonic purification, gas buoyancy, and filtration purification. However, conventional flux-free refining methods (ZL2009100489939 and ZL021362017) are currently difficult to effectively remove from raw magnesium, as it contains a large amount of impurities. Furthermore, they present key technical challenges such as corrosion of plant equipment, environmental pollution, unstable refining results, and the inability to operate continuously.

[0006] Patent ZL201410192585.1 previously disclosed a continuous flux smelting method and apparatus for magnesium and magnesium alloys. This invention utilizes an internal flux-refining pump to draw high-temperature melt from the upper portion of the melt pool and flux from the bottom of the crucible. The pump forcibly stirs and mixes the high-temperature melt with refining gas before ejecting it from the outlet. This achieves a combined refining of the melt and gas while simultaneously driving macroscopic circulation convection within the crucible, promoting melting of the incoming charge and ensuring uniform temperature and quality within the crucible. A flux circulation and purification pump draws slag-containing flux from the bottom of the crucible to the upper surface of the melt pool. After filtration and separation of the slag, the flux is distributed by gravity onto the surface of the crucible, providing flame retardancy. The slag then settles to the bottom of the crucible along with the incoming charge. These functions are performed simultaneously and uninterruptedly under a sealed furnace lid, enabling efficient, green, and continuous flux smelting of magnesium and magnesium alloys.

[0007] However, this patent still has the following defects: 1. The melt circulation treatment device on the left side of the crucible simultaneously sucks the melt and flux from the top and bottom of the molten pool and then sprays them out from the middle of the molten pool, while the flux and slag treatment device structure on the right side sucks the flux from the bottom of the molten pool and then flows out from the top of the molten pool. The two will interfere with and affect each other. 2. The flux and slag treatment device structure directly draws the bottom flux to the upper surface of the molten pool for filtration. The inner side of the filter device is directly connected to the molten pool. When the filter device is clogged by reacting impurities, the extracted flux will flow directly from the inner side of the filter device back to the molten pool, failing to achieve the filtering effect, resulting in poor recycling and refining effects and poor flux recycling utilization. 3. There is no corresponding detection and control means for the suction and filtration of the flux. Operation and control are performed manually based on experience or a fixed time program. This makes it difficult to achieve precise control of the flux suction and filtration, which is not conducive to improving the smelting efficiency and effect.

[0008] Therefore, any solution that can realize online treatment of flux impurities to achieve continuous production, and can better improve impurity filtration efficiency, and enhance smelting efficiency and precision, becomes a technical problem that needs to be further considered and solved by those skilled in the art. Summary of the Invention

[0009] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a flux circulation smelting method for magnesium or magnesium alloys that can perform online treatment of flux impurities to achieve continuous production, with higher impurity filtering effect, better smelting efficiency and precision.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions: A flux circulation smelting method for magnesium or magnesium alloys, wherein the flux is extracted from the bottom of the molten pool to the surface of the molten pool and then enters the molten pool to achieve a top-down circulation smelting treatment of the flux. The method is characterized in that the flux is extracted to a space above the surface of the molten pool for independent filtration, and then the filtered flux flows downward back to the surface of the molten pool for circulation smelting.

[0011] In this way, in this method, by extracting the flux to the space above the surface of the molten pool for independent filtration, the reaction impurities can be completely filtered out, and then the clean flux can be returned to the molten pool for continued smelting. This method of allowing the flux to flow three-dimensionally for smelting better allows the flux and the molten liquid to fully contact. The flux flowing back to the molten pool has a good flame retardant effect on the surface, and is also convenient for contact and reaction with new furnace charges, thereby improving smelting efficiency. Compared with conventional stirring smelting and the method in the inventor's prior patent, the flux is independently filtered to completely remove impurities before flowing into the molten pool for circulation, avoiding impurities from entering the secondary circulation and affecting the smelting effect, and better improving the smelting accuracy.

[0012] Furthermore, during smelting, the depth of the flux layer deposited at the bottom of the molten pool is detected in real time. When the depth of the flux layer increases and reaches the maximum depth threshold, the bottom flux is extracted and filtered; when the depth of the flux layer decreases and reaches the minimum depth threshold, the molten pool is replenished with flux; when the depth of the flux layer increases again and reaches the maximum depth threshold, the replenishment of the flux is stopped and the cycle continues.

[0013] In this way, the extraction and replenishment of flux can be better controlled, and the continuity of the entire smelting process can be better guaranteed.

[0014] Furthermore, the present method is implemented by a smelting device for magnesium or magnesium alloys, which comprises a furnace, an electric heating device is arranged in the furnace wall, a feeding port is arranged at the upper end of the furnace, one side of the upper end of the furnace inner cavity is raised upward as a whole to form a filtering area higher than the molten pool of the furnace, the lower end of the inner cavity of the filtering area and the upper end of the inner cavity of the furnace are directly connected, a vertical flux extraction channel is arranged on one side of the inner cavity of the filtering area and extends downward to the bottom of the inner cavity of the furnace, a flux extraction pump is also arranged on the flux extraction channel, a flux outlet is arranged on the inner side of the upper end of the flux extraction channel, a slag filter module is arranged in the filter area below the flux outlet, and a slag outlet is also arranged at the upper end of the filter area above the slag filter module.

[0015] When the smelting device is used in this way, raw materials are added from the feeding port and heated and melted, and then flux is added for smelting. The flux and the slag generated by the reaction fall to the lower end of the furnace cavity, and are then extracted from the flux extraction channel to the filtration area by the flux extraction pump. The slag is filtered by the slag filtration module. After filtering, the flux falls back to the upper surface of the molten pool, which can better shield the contact between the melt surface and the air, and also facilitate the direct contact and reaction of the newly added raw materials with the flux. While reacting with the raw materials, the flux, mixed with the reaction product slag, gradually descends to the lower layer of the molten pool and circulates in sequence, realizing the circulation and mixing of the flux in the molten pool and achieving refining, and simultaneously completing the cleaning of the slag. This prevents slag impurities from circulating in the molten pool and affecting the smelting effect, and better improves the smelting accuracy and efficiency.

[0016] Furthermore, a feeding port cover is correspondingly installed on the feeding port, and a slag outlet cover is correspondingly installed on the slag outlet.

[0017] In this way, it is convenient to achieve sealing during the smelting process and prevent harmful gases from overflowing and affecting environmental hygiene.

[0018] Furthermore, a raw material baffle is provided at a lower middle position of the inner cavity of the furnace, directly below the feeding port, and a plurality of through holes penetrating from top to bottom are opened on the raw material baffle.

[0019] In this way, the newly added raw materials fall above the raw material baffle and are in the middle of the molten pool where the temperature is higher, which can better complete the melting and smelting, while also avoiding the impact of the raw materials falling to the bottom of the molten pool on the flux circulation.

[0020] Furthermore, the furnace is also provided with a liquid outlet channel, the inlet of the liquid outlet channel is located in the upper middle part of the molten pool away from the side of the flux extraction channel, and a liquid outlet pump is also provided on the liquid outlet channel.

[0021] In this way, it is convenient to rely on the liquid discharge pump to extract the liquid for casting. At the same time, the liquid discharge channel is located away from the flux extraction channel, which can minimize the content of mixed flux in the liquid discharge and improve the accuracy of the melt. In specific implementation, because this method removes slag during the flux circulation process, so that the melt no longer contains slag, when the flux content in the melt is not required to be high or the residual flux can be further processed in the tundish later, the liquid discharge operation can be directly performed while continuing to circulate the flux for smelting in the later stage of smelting. New raw materials can be added while discharging or after discharging, truly realizing continuous circulation smelting and greatly improving the smelting rate. Of course, after the refining is completed, the flux circulation can also be stopped for a period of time before discharging to better ensure the accuracy of the melt.

[0022] Furthermore, the liquid outlet pump blade device is located at the inlet of the liquid outlet channel, and the liquid outlet pump motor is located on the outer upper end surface of the furnace.

[0023] This will better protect the discharge pump motor and extend its service life.

[0024] Furthermore, the pump blade mechanism of the flux extraction pump is located at the lower end port of the flux extraction channel, and the motor of the flux extraction pump is located on the outer surface of the upper end of the filtration area.

[0025] This will better protect the motor of the flux extraction pump and extend its service life.

[0026] Furthermore, the slag filtration module includes a filter basket arranged along the cross section of the filter area, a filter net is provided at the lower end of the filter basket, and the lower end of the filter basket is placed on a limit block mounted on the inner wall of the filter area, and the slag outlet can be set for the filter basket to pass through.

[0027] In this way, when the slag needs to be cleaned, the slag outlet can be opened, and the filter basket can be taken out upward as a whole to clean the slag, which greatly facilitates the cleaning and removal of the slag.

[0028] Furthermore, the filter screen is configured as multiple layers with meshes gradually decreasing downwards, and the filter screens above the bottom layer are detachable.

[0029] In this way, better filtration of the slag can be achieved.

[0030] Furthermore, a vibrator is provided on the inner wall of the filter area of the filter basket installation area.

[0031] This is because the high-temperature molten flux and melt are both very viscous, making them difficult to pass through the filter mesh. Therefore, after installing a vibrator, it can provide vibration when filtering the slag, allowing the flux to flow through the filter better and faster, preventing the slag from quickly clogging the filter and affecting the flux's reflux rate, thereby reducing melting efficiency.

[0032] Furthermore, a filter area liquid level monitoring sensor is provided on the inner wall of the filter area. The filter area liquid level monitoring sensor is connected to the controller, and the controller is connected to the alarm device and the motor of the flux extraction pump.

[0033] In this way, when the flux is circulating and filtering, the slag gradually increases in the filter basket, the filter screen gradually becomes clogged, and the liquid level in the filter area gradually rises. When the liquid level monitoring sensor in the filter area detects that the liquid level exceeds the warning line, the controller can control the motor of the flux extraction pump to stop running first, and at the same time control the alarm device to sound an alarm, notifying the staff to clean up the slag. Therefore, the safety of the filtration is greatly guaranteed.

[0034] Furthermore, the filtration zone liquid level monitoring sensor is a contact probe, mounted on the sidewall of the filtration zone cavity facing away from the flux extraction channel, above the flux outlet. When the liquid level rises to the contact probe's location, the probe collects a signal and transmits it to the controller for control. This simplifies the structure, and compared to hydraulic pressure detection, the probe does not need to be exposed to high melt temperatures for extended periods, significantly extending its service life.

[0035] Furthermore, a flux compensation port is provided on the side wall of the filter area below the filter basket installation area, and the flux compensation port is connected to a flux compensation channel outwardly and upwardly.

[0036] In this way, it is convenient to add flux compensation into the furnace through the flux compensation channel and the flux compensation port when needed.

[0037] Furthermore, a baffle extending obliquely downward is provided at the upper end of the flux compensation port, which can better prevent the flux liquid flowing out of the filter basket from overflowing from the flux compensation port.

[0038] Furthermore, the bottom surface of the inner cavity of the furnace is tilted downward toward the side where the flux extraction channel is located.

[0039] This makes it easier for the flux layer that sinks to the bottom of the furnace cavity and the slag contained therein to move to the side where the flux extraction channel is located and be extracted upward, thereby achieving better circulation.

[0040] Furthermore, a bottom flux layer monitoring device is provided in the furnace. The bottom flux layer monitoring device is used to detect and monitor the depth of the flux layer deposited at the bottom of the molten pool and is connected to the controller. A flux addition control module is provided in the controller. When it is detected that the depth of the flux layer reaches the maximum depth threshold, the flux addition control module controls the flux extraction pump to start working to extract and circulate the bottom flux. When it is detected that the depth of the flux layer reaches the minimum depth threshold, the flux addition control module controls the display to issue a flux addition requirement warning.

[0041] This allows for better monitoring and control of the timing of starting the flux extraction cycle and adding flux. When the flux layer at the bottom of the furnace accumulates to a certain depth, the flux extraction and filtration cycle is started. Once the flux gradually decreases to a certain level, a prompt is given to add flux. This ensures better controllability and stability of flux circulation smelting.

[0042] Furthermore, the bottom flux layer monitoring device includes two sets of relative resistance detection devices that are staggered up and down, and the relative resistance detection device includes a pair of vertically arranged detection probes with horizontal symmetrical intervals and fixed intervals. The detection probes are made of metal material and are wrapped with high-temperature resistant insulating sleeves. The lower ends of the detection probes have probes exposed from the high-temperature resistant insulating sleeves. The upper ends of the two detection probes are connected to a resistance tester and connected to a power supply to form a resistance detection circuit. The resistance tester is used to realize the resistance size detection between the probes at the lower ends of the two detection probes and communicate with the controller; the specifications of the two sets of relative resistance detection devices are consistent and the two probes of one set are horizontally spaced at the upper limit height position of the flux layer, and the two probes of the other set are horizontally spaced at the lower limit height position of the flux layer.

[0043] This is because the flux layer at the bottom of the molten pool is mainly composed of flux components such as magnesium chloride and potassium chloride, mixed with a large amount of slag. Its specific gravity is relatively large and it will gradually sink to the bottom of the molten pool, while the molten melt (magnesium liquid or magnesium alloy melt) has a lighter specific gravity and will float above the flux layer to form a layer. Due to the different compositions of the flux layer and the melt layer, different resistances will be formed between two conductive probes at the same distance. The resistance of the melt part will be smaller than that of the flux part. Therefore, the above device can detect the resistance between two pairs of probes at different heights, with the same spacing and specifications, in real time. When the upper pair of probes detects a stable lower value (range) and the lower pair detects a stable higher value (range), it means that the upper surface of the flux layer is now within the safe zone between the upper and lower pairs of probes. When the upper pair of probes detects that the resistance between the probes gradually increases and falls within the detection range of the lower probes, it means that the flux layer is gradually increasing and reaching this height. At this time, the upward extraction of flux from the flux layer can be controlled, and the addition of flux can be controlled to stop. When the lower pair of probes detects that the resistance between the probes gradually decreases and falls within the detection range of the upper probes, it means that the flux layer is gradually decreasing and reaching this height. At this time, the addition of flux to the furnace can be controlled. This cycle achieves the effect of dynamic monitoring and control of flux addition, better ensuring the stability and efficiency of the smelting process.

[0044] Furthermore, the high temperature resistant insulating sleeve is a ceramic sleeve, which can better resist high temperature and provide insulation.

[0045] Furthermore, the resistance detection device also includes a height control slider, and the two detection probes are symmetrically fixed on the height control slider. The height control slider can be slid up and down and clamped on a vertical slide rail vertically arranged on the inner wall of the furnace. A screw hole is vertically penetrated on the height control slider, and a screw is screwed into the screw hole. The screw is connected to the height control motor located above.

[0046] In this way, the height control slider forms a screw-nut transmission mechanism through the screw hole and the screw rod. The height control motor drives the screw rod to rotate, which can drive the height control slider to slide up and down along the vertical slide rail, thereby adjusting the detection height position of the pair of probes below the resistance detection device up and down. This allows the height range of the flux layer to be adjusted up and down quickly and conveniently when needed.

[0047] Furthermore, the height-controlling slider and the screw are located above the molten pool liquid level, which can better extend the service life.

[0048] Furthermore, the probe is a tungsten needle probe, which has better electrical conductivity and high temperature resistance.

[0049] Taking raw magnesium smelting as an example, when the present invention is used for raw magnesium smelting, after raw magnesium and initial flux are put into equipment, raw magnesium forms a sediment at the bottom of the furnace body under the action of the initial flux and fully standing. Its main components are residual flux and impurity components in the raw magnesium. Subsequently, the bottom flux layer height state is monitored in real time by a bottom flux layer monitoring device, the sediment is sucked, and the sediment after suction is subjected to a series of filtration and separation treatments. A certain amount of flux supplementary components are then added through a flux compensation port to form a recycled flux, and the added raw magnesium is refined by the recycled flux. After a series of treatments, the magnesium liquid is transported to the magnesium liquid pouring port by a magnesium liquid transport pump for pouring. The whole process realizes that the flux recycling process has the characteristics of greening, continuity, and intelligence.

[0050] In summary, the present invention can perform online treatment of flux refining impurities to achieve continuous smelting production of magnesium or magnesium alloys, and has the advantages of high impurity filtering effect, good smelting efficiency and precision, and green, continuous and intelligent. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a schematic structural diagram of a magnesium and magnesium alloy smelting device used in the optimal embodiment of the present invention.

[0052] Figure 2 for Figure 1 An enlarged schematic diagram of the local structure of a separate filtration area.

[0053] Figure 3 for Figure 1 Schematic diagram of a separate relative resistance detection device.

[0054] Figure 4 for Figure 1 Circuit diagram of a separate relative resistance detection device.

[0055] Figure 5 In order to implement the verification by taking the original magnesium smelting as an example, a data chart of the filtering effect of the slag filtration module of the smelting device is provided.

[0056] Figure 6 In order to implement the verification by taking the original magnesium smelting as an example, the refining effect data chart of the slag filtration module of the smelting device and then adding flux for circulation refining is shown. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below with reference to specific embodiments.

[0058] Optimal embodiment: A flux circulation smelting method for magnesium or magnesium alloys, which realizes up and down circulation smelting of the flux by extracting the flux from the bottom of the molten pool to the surface of the molten pool and then re-entering the molten pool. The characteristic of the method is that the flux is extracted to the space above the surface of the molten pool for independent filtration, and then the filtered flux flows downward back to the surface of the molten pool for circulation smelting.

[0059] In this way, in this method, by extracting the flux to the space above the surface of the molten pool for independent filtration, the reaction impurities can be completely filtered out, and then the clean flux can be returned to the molten pool for continued smelting. This method of allowing the flux to flow three-dimensionally for smelting better allows the flux and the molten liquid to fully contact. The flux flowing back to the molten pool has a good flame retardant effect on the surface, and is also convenient for contact and reaction with new furnace charges, thereby improving smelting efficiency. Compared with conventional stirring smelting and the method in the inventor's prior patent, the flux is independently filtered to completely remove impurities before flowing into the molten pool for circulation, avoiding impurities from entering the secondary circulation and affecting the smelting effect, and better improving the smelting accuracy.

[0060] In this embodiment, the depth of the flux layer deposited at the bottom of the molten pool is detected in real time during smelting. When the depth of the flux layer increases and reaches the maximum depth threshold, the bottom flux is extracted and filtered; when the depth of the flux layer decreases and reaches the minimum depth threshold, the molten pool is replenished with flux; when the depth of the flux layer increases again and reaches the maximum depth threshold, the replenishment of flux is stopped and the cycle continues.

[0061] In this way, the extraction and replenishment of flux can be better controlled, and the continuity of the entire smelting process can be better guaranteed.

[0062] In this embodiment, the method is implemented by a magnesium or magnesium alloy smelting device, see Figure 1-4The smelting device for magnesium and magnesium alloys includes a furnace 1, an electric heating device (not shown in the figure) is provided in the furnace wall, a feeding port 2 is provided at the upper end of the furnace, one side of the upper end of the furnace cavity is raised upward as a whole to form a filtering area 3 that is higher than the molten pool of the furnace, the lower end of the inner cavity of the filtering area 3 is directly connected to the upper end of the inner cavity of the furnace, a vertical flux extraction channel 4 is provided on one side of the inner cavity of the filtering area and extends downward to the bottom of the inner cavity of the furnace, a flux extraction pump 10 is also provided on the flux extraction channel 4, a flux outlet 5 is provided on the inner side of the upper end of the flux extraction channel, a slag filter module is provided in the filter area below the flux outlet 5, and a slag outlet 6 is also provided at the upper end of the filter area above the slag filter module.

[0063] When the smelting device is used in this way, raw materials are added from the feeding port and heated and melted, and then flux is added for smelting. The flux and the slag generated by the reaction fall to the lower end of the furnace cavity, and are then extracted from the flux extraction channel to the filtration area by the flux extraction pump. The slag is filtered by the slag filtration module. After filtering, the flux falls back to the upper surface of the molten pool, which can better shield the contact between the melt surface and the air, and also facilitate the direct contact and reaction of the newly added raw materials with the flux. While reacting with the raw materials, the flux, mixed with the reaction product slag, gradually descends to the lower layer of the molten pool and circulates in sequence, realizing the circulation and mixing of the flux in the molten pool and achieving refining, and simultaneously completing the cleaning of the slag. This prevents slag impurities from circulating in the molten pool and affecting the smelting effect, and better improves the smelting accuracy and efficiency.

[0064] Among them, a feeding port cover is correspondingly installed on the feeding port 2, and a slag outlet cover is correspondingly installed on the slag outlet 6.

[0065] In this way, it is convenient to achieve sealing during the smelting process and prevent harmful gases from overflowing and affecting environmental hygiene.

[0066] A raw material baffle 7 is provided at the lower middle portion of the furnace cavity, directly below the feeding port, and a plurality of through holes are provided on the raw material baffle 7 which penetrate the raw material baffle 7 from top to bottom.

[0067] In this way, the newly added raw materials fall above the raw material baffle and are in the middle of the molten pool where the temperature is higher, which can better complete the melting and smelting, while also avoiding the impact of the raw materials falling to the bottom of the molten pool on the flux circulation.

[0068] The melting furnace 1 is further provided with a liquid outlet channel 8 , the entrance of which is located in the upper middle part of the molten pool away from the side of the flux extraction channel. A liquid outlet pump 9 is also provided on the liquid outlet channel 8 .

[0069] In this way, it is convenient to rely on the liquid discharge pump to extract the liquid for casting. At the same time, the liquid discharge channel is located away from the flux extraction channel, which can minimize the content of mixed flux in the liquid discharge and improve the accuracy of the melt. In specific implementation, because this method removes slag during the flux circulation process, so that the melt no longer contains slag, when the flux content in the melt is not required to be high or the residual flux can be further processed in the tundish later, the liquid discharge operation can be directly performed while continuing to circulate the flux for smelting in the later stage of smelting. New raw materials can be added while discharging or after discharging, truly realizing continuous circulation smelting and greatly improving the smelting rate. Of course, after the refining is completed, the flux circulation can also be stopped for a period of time before discharging to better ensure the accuracy of the melt.

[0070] Among them, the pump blade device of the liquid discharge pump 9 is located at the entrance of the liquid discharge channel, and the liquid discharge pump motor is located on the outer upper end surface of the furnace.

[0071] This will better protect the discharge pump motor and extend its service life.

[0072] The pump blade mechanism of the flux extraction pump 10 is located at the lower end port of the flux extraction channel, and the motor of the flux extraction pump 10 is located on the outer surface of the upper end of the filter area.

[0073] This will better protect the motor of the flux extraction pump and extend its service life.

[0074] Among them, the slag filtration module includes a filter basket 11 arranged along the cross section of the filter area, a filter net 12 is provided at the lower end of the filter basket 11, and the lower end of the filter basket is placed on a limit block mounted on the inner wall of the filter area, and the slag outlet can be set for the filter basket to pass through.

[0075] In this way, when the slag needs to be cleaned, the slag outlet can be opened, and the filter basket can be taken out upward as a whole to clean the slag, which greatly facilitates the cleaning and removal of the slag.

[0076] The filter screen 12 is provided as a plurality of layers with meshes gradually decreasing downwards, and the filter screens above the bottom layer are detachable.

[0077] In this way, better filtration of the slag can be achieved.

[0078] A vibrator 13 is further provided on the inner wall of the filter area of the filter basket installation area.

[0079] This is because the high-temperature molten flux and melt are both very viscous, making them difficult to pass through the filter mesh. Therefore, after installing a vibrator, it can provide vibration when filtering the slag, allowing the flux to flow through the filter better and faster, preventing the slag from quickly clogging the filter and affecting the flux's reflux rate, thereby reducing melting efficiency.

[0080] A filter area liquid level monitoring sensor 14 is also provided on the inner wall of the filter area. The filter area liquid level monitoring sensor 14 is connected to a controller 15 , and the controller 15 is connected to an alarm device and a motor of a flux extraction pump.

[0081] In this way, when the flux is circulating and filtering, the slag gradually increases in the filter basket, the filter screen gradually becomes clogged, and the liquid level in the filter area gradually rises. When the liquid level monitoring sensor in the filter area detects that the liquid level exceeds the warning line, the controller can control the motor of the flux extraction pump to stop running first, and at the same time control the alarm device to sound an alarm, notifying the staff to clean up the slag. Therefore, the safety of the filtration is greatly guaranteed.

[0082] The filtration zone liquid level monitoring sensor 14 is a contact probe, mounted on the sidewall of the filtration zone cavity facing away from the flux extraction channel, above the flux outlet. When the liquid level reaches the contact probe, the probe collects a signal and transmits it to the controller for control. This simplifies the structure, and compared to hydraulic pressure detection, the probe does not need to be exposed to high melt temperatures for extended periods, significantly extending its service life.

[0083] A flux compensation port 16 is further provided on the side wall of the filter area below the filter basket installation area, and the flux compensation port is connected to a flux compensation channel upward and outward.

[0084] In this way, it is convenient to add flux compensation into the furnace through the flux compensation channel and the flux compensation port when needed.

[0085] A baffle extending obliquely downward is provided at the upper end of the flux compensation port 16, which can better prevent the flux liquid flowing out of the filter basket from overflowing from the flux compensation port.

[0086] The bottom surface of the inner cavity of the furnace is tilted downward toward the side where the flux extraction channel is located.

[0087] This makes it easier for the flux layer that sinks to the bottom of the furnace cavity and the slag contained therein to move to the side where the flux extraction channel is located and be extracted upward, thereby achieving better circulation.

[0088] Among them, a bottom flux layer monitoring device is also provided in the furnace. The bottom flux layer monitoring device is used to detect and monitor the depth of the flux layer deposited at the bottom of the molten pool and is connected to the controller. A flux addition control module is provided in the controller 15. When it is detected that the depth of the flux layer reaches the maximum depth threshold, the flux addition control module controls the flux extraction pump to start working and extract the bottom flux in a cycle. When it is detected that the depth of the flux layer reaches the minimum depth threshold, the flux addition control module controls the display to issue a flux addition demand warning.

[0089] This allows for better monitoring and control of the timing of starting the flux extraction cycle and adding flux. When the flux layer at the bottom of the furnace accumulates to a certain depth, the flux extraction and filtration cycle is started. Once the flux gradually decreases to a certain level, a prompt is given to add flux. This ensures better controllability and stability of flux circulation smelting.

[0090] The bottom flux layer monitoring device includes two sets of relative resistance detection devices, each staggered vertically. These devices comprise a pair of horizontally symmetrical, vertically spaced detection probes 17, each made of metal and coated with a high-temperature-resistant insulating sleeve 18. The lower ends of the probes have probes 19 exposed from the sleeve. The upper ends of the two probes are connected to a resistance tester 20 and a power supply 21, forming a resistance detection circuit. The resistance tester is used to detect the resistance between the probes at the lower ends of the two probes and communicates with a controller. The two sets of relative resistance detection devices are of identical specifications, with the two probes of one set horizontally spaced at the upper limit of the flux layer and the two probes of the other set horizontally spaced at the lower limit of the flux layer. During implementation, a control switch 22 and a protective resistor 23 are also connected in series in the resistance detection circuit.

[0091] This is because the flux layer at the bottom of the molten pool is mainly composed of flux components such as magnesium chloride and potassium chloride, mixed with a large amount of slag. Its specific gravity is relatively large and it will gradually sink to the bottom of the molten pool, while the molten melt (magnesium liquid or magnesium alloy melt) has a lighter specific gravity and will float above the flux layer to form a layer. Due to the different compositions of the flux layer and the melt layer, different resistances will be formed between two conductive probes at the same distance. The resistance of the melt part will be smaller than that of the flux part. Therefore, the above device can detect the resistance between two pairs of probes at different heights, with the same spacing and specifications, in real time. When the upper pair of probes detects a stable lower value (range) and the lower pair detects a stable higher value (range), it means that the upper surface of the flux layer is now within the safe zone between the upper and lower pairs of probes. When the upper pair of probes detects that the resistance between the probes gradually increases and falls within the detection range of the lower probes, it means that the flux layer is gradually increasing and reaching this height. At this time, the upward extraction of flux from the flux layer can be controlled, and the addition of flux can be controlled to stop. When the lower pair of probes detects that the resistance between the probes gradually decreases and falls within the detection range of the upper probes, it means that the flux layer is gradually decreasing and reaching this height. At this time, the addition of flux to the furnace can be controlled. This cycle achieves the effect of dynamic monitoring and control of flux addition, better ensuring the stability and efficiency of the smelting process.

[0092] The high temperature resistant insulating sleeve 18 is a ceramic sleeve, which can better resist high temperature and provide insulation.

[0093] Among them, the resistance detection device also includes a height control slider 25, and the two detection probes 17 are symmetrically fixed on the height control slider 25. The height control slider 25 can be slid up and down and clamped on a vertical slide rail 26 vertically arranged on the inner wall of the furnace. A screw hole is vertically penetrated on the height control slider, and a screw 27 is screwed into the screw hole. The screw 27 is connected to the height control motor 28 located above.

[0094] In this way, the height control slider forms a screw-nut transmission mechanism through the screw hole and the screw rod. The height control motor drives the screw rod to rotate, which can drive the height control slider to slide up and down along the vertical slide rail, thereby adjusting the detection height position of the pair of probes below the resistance detection device up and down. This allows the height range of the flux layer to be adjusted up and down quickly and conveniently when needed.

[0095] The height control slider 25 and the screw 27 are located above the molten pool liquid level, which can better extend the service life.

[0096] The probe 19 is a tungsten needle probe, which has better electrical conductivity and high temperature resistance.

[0097] In order to better verify the effect of the present invention, based on the above embodiments, the applicant further implemented and tested the present invention by taking raw magnesium smelting as an example. When the scheme of the present invention is used for raw magnesium smelting, after the raw magnesium and the initial flux are put into the equipment, the raw magnesium forms a precipitate at the bottom of the furnace body under the action of the initial flux and is fully allowed to stand. The main components are residual flux and impurity components in the raw magnesium. Subsequently, the bottom flux layer monitoring device monitors the height state of the bottom flux liquid layer in real time, and the precipitate is sucked. The sucked precipitate is subjected to a series of filtration and separation treatments, and then a certain amount of flux supplementary components are added through the flux compensation port to form a recycled flux, and the added raw magnesium is refined by the recycled flux. After a series of treatments, the magnesium liquid is transported to the magnesium liquid pouring port for pouring by a magnesium liquid transport pump. The whole process realizes that the flux recycling process has the characteristics of green, continuous and intelligent. Then, through the quantitative analysis of the physical phase by XRD, the filtration separation device can separate about 85% of the impurities and residual flux components in the precipitate. The filtration separation effect data is as follows: Figure 5 As shown in the chart, a certain amount of flux is added to supplement the ingredients to form a recycled flux. The refining effect data is as follows Figure 6 As shown in the chart, the refining effect meets the actual production needs.

Claims

1. A flux circulation smelting method for magnesium or magnesium alloys, wherein the flux at the bottom of the molten pool is drawn to the surface of the molten pool and then re-entered into the molten pool to achieve a top-down circulation smelting process of the flux, characterized in that: The flux is extracted into the space above the surface of the molten pool for independent filtration, and then the filtered flux flows down back to the surface of the molten pool for circulation smelting.

2. The flux circulation smelting method for magnesium or magnesium alloy according to claim 1, characterized in that: During smelting, the depth of the flux layer deposited at the bottom of the molten pool is detected in real time. When the depth of the flux layer increases and reaches the maximum depth threshold, the bottom flux is extracted and filtered; when the depth of the flux layer decreases and reaches the minimum depth threshold, the molten pool is replenished with flux; when the depth of the flux layer increases again and reaches the maximum depth threshold, the replenishment of flux is stopped and the cycle continues.

3. The flux circulation smelting method for magnesium or magnesium alloy according to claim 1, characterized in that: The present method is implemented by a smelting device for magnesium or magnesium alloys, which comprises a furnace, a heating device provided in the furnace wall, a feeding port provided at the upper end of the furnace, one side of the upper end of the furnace inner cavity protruding upward as a whole to form a filtering area higher than the furnace molten pool, the lower end of the filtering area inner cavity and the upper end of the furnace inner cavity are directly connected, a vertical flux extraction channel is provided on one side of the filtering area inner cavity and extends downward to the bottom of the furnace inner cavity, a flux extraction pump is also provided on the flux extraction channel, a flux outlet is provided on the inner side of the upper end of the flux extraction channel, a slag filter module is provided in the filter area below the flux outlet, and a slag outlet is also provided at the upper end of the filter area above the slag filter module.

4. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: A feeding port cover is correspondingly installed on the feeding port, and a slag outlet cover is correspondingly installed on the slag outlet.

5. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: A raw material baffle is provided at the lower middle portion of the furnace cavity, just below the feeding port, and a plurality of through holes penetrating from top to bottom are opened on the raw material baffle.

6. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: The furnace is also provided with a liquid outlet channel, the inlet of which is located in the upper middle part of the molten pool away from the side of the flux extraction channel, and a liquid outlet pump is also provided on the liquid outlet channel; The liquid outlet pump blade device is located at the inlet of the liquid outlet channel, and the liquid outlet pump motor is located on the outer upper end surface of the furnace.

7. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: The pump blade mechanism of the flux extraction pump is located at the lower end port of the flux extraction channel, and the motor of the flux extraction pump is located on the outer surface of the upper end of the filtering area.

8. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: The slag filtering module includes a filter basket arranged along the cross section of the filter area, a filter screen is arranged at the lower end of the filter basket, and the lower end of the filter basket is placed on a limit block mounted on the inner wall of the filter area, and the slag outlet is capable of allowing the filter basket to pass through; The filter screen is provided as multiple layers with meshes gradually decreasing downwards, and the filter screens above the bottom layer are detachable.

9. The flux circulation smelting method for magnesium or magnesium alloy according to claim 8, characterized in that: A vibrator is also provided on the inner wall of the filter area where the filter basket is installed; A filter area liquid level monitoring sensor is also provided on the inner cavity wall of the filter area. The filter area liquid level monitoring sensor is connected to the controller, and the controller is connected to the alarm device and the motor of the flux extraction pump. The liquid level monitoring sensor in the filtration area is a contact probe, which is installed on the side wall of the inner cavity of the filtration area away from the flux extraction channel and above the flux outlet position; A flux compensation port is also provided on the side wall of the filter area below the filter basket installation area, and the flux compensation port is connected to a flux compensation channel outward and upward; A baffle extending obliquely downward is provided at the upper end of the flux compensation port; The bottom surface of the inner cavity of the furnace is tilted downward toward the side where the flux extraction channel is located.

10. The flux circulation smelting method for magnesium or magnesium alloy according to claim 3, characterized in that: The furnace is also provided with a bottom flux layer monitoring device, which is used to detect and monitor the depth of the flux layer deposited at the bottom of the molten pool and is connected to the controller. The controller is provided with a flux addition control module. When it is detected that the depth of the flux layer reaches the maximum depth threshold, the flux addition control module controls the flux extraction pump to start working and extract the bottom flux in a cycle. When it is detected that the depth of the flux layer reaches the minimum depth threshold, the flux addition control module controls the display to issue a flux addition demand warning.

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