Electro-fused recrystallized magnesite-chrome brick salt leaching drying process

Abstract

The present application belongs to the technical field of fused recrystallized magnesite-chrome brick production, in particular to a fused recrystallized magnesite-chrome brick salt immersion and drying process. The following scheme is proposed, including the following steps: step one, place the sintered brick blank with residual heat into the work station, and perform vacuum extraction treatment after sealing the work station; step two, inject a preheated salt solution into the vacuum pretreated work station, establish a directional circulating flow field for dynamic pressure impregnation, and simultaneously perform ultrasonic monitoring and fluid dynamic slip ring monitoring, and generate process state evaluation information based on the fused data. The present application integrates vacuum pretreatment, dynamic pressure impregnation, intelligent drying and controllable cooling in an intelligent work station, improves the filling efficiency of large pores and complex pores, and ensures the excellence and stability of the product through the combined monitoring method, achieving simultaneous improvement of product quality, production efficiency and energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of electrofused rebonded magnesia-chrome brick production technology, and in particular to a salt immersion and drying process for electrofused rebonded magnesia-chrome bricks. Background Technology

[0002] The RH vacuum refining furnace is an indispensable and important smelting equipment in the metallurgical industry for ladle refining. Electrofused rebonded magnesia-chrome bricks are commonly used refractory materials in the RH vacuum refining furnace. The production process of electrofused rebonded magnesia-chrome bricks generally includes batching, molding, sintering and salt immersion drying.

[0003] As a key post-processing step, the salt immersion and drying process is still in a rudimentary stage. The existing technology mainly adopts the static atmospheric pressure immersion method. After sintering, the brick blanks need to be cooled, transported to an independent salt immersion tank, soaked for a long time, taken out and drained, and then transferred to the drying kiln. The immersion effect on the brick blanks is prone to uneven immersion, which affects their use. Summary of the Invention

[0004] Based on the technical problems in the background art, the present invention proposes a salt immersion and drying process for electrofused and recombined magnesia-chrome bricks.

[0005] The present invention proposes a salt immersion and drying process for electrofused rebonded magnesia-chrome bricks, comprising the following steps:

[0006] Step 1: Place the sintered brick blank with residual heat into the work station, seal the work station, and then perform vacuum treatment.

[0007] The temperature of the sintered brick blank with residual heat is 300℃ to 450℃, and the vacuum degree target for vacuuming is -0.06MPa to -0.08MPa.

[0008] Step 2: Inject preheated salt solution into the vacuum pretreatment station to establish a directional circulating flow field for dynamic pressure impregnation, and simultaneously perform ultrasonic monitoring and fluid dynamic slip ring monitoring. Generate process status assessment information based on the fused data.

[0009] The method for establishing a directional circulating flow field is as follows: the salt solution enters through the liquid inlet distributors distributed on the left and right sides at the bottom of the workstation, flows from bottom to top through the flow channel between the side of the brick blank and the inner wall of the workstation, and finally exits through the liquid outlet located in the middle of the top to form a closed loop.

[0010] Ultrasonic monitoring specifically involves transmitting and receiving signals through an array of ultrasonic probes, analyzing the changes in the propagation velocity and amplitude attenuation coefficient of ultrasonic waves within the brick blank, and mapping the information on the salt saturation and effective penetration depth of local areas inside the brick blank.

[0011] Fluid dynamic slip ring monitoring specifically involves: symmetrically installing slip rings in the horizontal flow channels on both sides of the brick blank within the work station; the slip rings are connected to the side wall of the work station via springs and can move horizontally towards the brick blank; by measuring the displacement of the slip rings caused by the impact of the horizontal liquid flow, the instantaneous intensity of the horizontal permeation flow towards the brick blank is reflected; the slip ring displacement is the largest in the initial stage of impregnation and shows a monotonically decreasing trend as the pores of the brick blank are filled and the permeation resistance increases.

[0012] Based on fused data, process status assessment information is generated, specifically including: calculating the overall process comprehensive index, which integrates the average salt saturation of the brick blank, the average effective penetration depth, and the degree of decay of the average slip ring displacement relative to its initial value; calculating the process consistency health index, which assesses the process health status by comparing the symmetry of saturation, penetration depth, and slip ring displacement on the left and right sides of the brick blank; indicating that impregnation is complete when the overall process comprehensive index reaches the preset target value; and issuing an early warning when the process consistency health index continues to be lower than the set threshold.

[0013] Step 3: After impregnation, recover the brine and switch the same workstation to drying mode to perform drying operations based on the measured liquid absorption.

[0014] Based on the total liquid absorption of the brick blank calculated from the ultrasonic monitoring data at the end of impregnation, a customized segmented drying curve is generated and executed; during the drying process, the stability of the ultrasonic velocity inside the brick blank is continuously monitored, and the rate of change of the velocity is lower than the set threshold is used as the criterion for determining whether drying is complete.

[0015] Step 4: After drying, perform controlled cooling to cool the brick blanks to a safe unloading temperature and remove them, while keeping the workstation in a residual heat state.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. In this invention, vacuum pretreatment, dynamic pressure impregnation, intelligent drying and controllable cooling are highly integrated into a single intelligent workstation. The vacuum pretreatment and residual heat of the brick blank are used to reduce the flow resistance of salt solution penetration, improve the filling efficiency of large and complex pores, and ensure the superiority and stability of the product through a combination of internal and external monitoring methods, thereby achieving simultaneous improvement in product quality, production efficiency and energy efficiency. Attached Figure Description

[0018] Figure 1 This is an overall flow chart of the salt immersion and drying process for electrofused rebonded magnesia-chrome bricks proposed in this invention;

[0019] Figure 2 This is a flowchart of a dual-modal sensing and evaluation system for an electrofused and rebonded magnesia-chrome brick salt immersion and drying process proposed in this invention.

[0020] Figure 3This is a schematic diagram of the overall structure of a closed station in the electrofused and salt-drying process for magnesia-chrome bricks proposed in this invention.

[0021] Figure 4 This is a schematic diagram of the support platform structure in the closed station of the electrofused and rebonded magnesia-chrome brick salt immersion and drying process proposed in this invention.

[0022] Figure 5 This is a schematic diagram of the sealed cover structure in the sealed station of the electrofused and salt-drying process of magnesia-chrome bricks proposed in this invention.

[0023] Figure 6 This is a schematic cross-sectional view of the sealed working station in the salt immersion and drying process of electrofused and rebonded magnesia-chrome bricks proposed in this invention.

[0024] In the diagram: 1. Support platform, 101. Annular groove, 2. Brick blank, 3. Sealed cover, 4. Hydraulic lifting rod, 5. Inlet pipe, 6. Outlet pipe, 7. Slide rod, 8. Slip ring, 801. Guide vane, 9. Spring, 10. Ultrasonic probe, 11. Vacuum tube, 12. Drain pipe. Detailed Implementation

[0025] Example 1: Refer to Figures 1-2 A process for salt immersion and drying of electrofused and rebonded magnesia-chrome bricks includes the following steps:

[0026] Step 1: Loading, sealing and vacuum pretreatment of brick blanks: The sintered brick blanks with residual heat are placed into the integrated intelligent station, sealed and then vacuumed to create an initial pressure difference for subsequent pressure impregnation.

[0027] The specific method is as follows:

[0028] 1. Brick loading and station sealing: The robotic arm quickly transfers the bricks, which have been sintered in the tunnel kiln and are in the temperature range of 300℃ to 450℃, to the central support platform of the integrated station. The cover plate of the station with a high-temperature sealing structure is closed and locked to ensure that the station can be strictly sealed during pressurized impregnation and negative pressure drying. The residual heat of the bricks is used to significantly reduce the viscosity of the subsequent impregnation salt solution, improve its fluidity and permeability, realize the thermal energy coupling between processes, and save energy from the source.

[0029] 2. Vacuum Pretreatment Stage: Close all pipeline valves, start the vacuum pump unit connected to the workstation, and perform vacuuming operation on the internal space of the sealed workstation. The vacuum level is controlled between -0.06MPa and -0.08MPa. The vacuuming time is set according to the volume of the workstation and the total volume of the brick blank, usually 3 to 8 minutes. By applying negative pressure to the external environment of the brick blank, the gas pressure in its internal pores is higher than that of the external environment, especially for pores with good connectivity. Under the pressure difference, the gas escapes outward. This is equivalent to pre-emptively creating space for the subsequent entry of salt solution and establishing an initial pressure gradient direction from the inside to the outside. This can effectively reduce the resistance of salt solution entering large pores in the early stage of impregnation, which is conducive to promoting the early filling of large-sized pores and complex pore networks by salt solution, and improving the overall impregnation efficiency and depth.

[0030] Step 2, Pressure Impregnation and Dual-Modal Sensing Integrated Assessment: After vacuum pretreatment, a salt solution is injected into the workstation and a circulation is established. During the dynamic impregnation process, ultrasonic and slip ring data are collected simultaneously, and comprehensive analysis and fusion calculations are performed to generate an intuitive process status assessment report and provide real-time prompts to the staff.

[0031] The specific method is as follows:

[0032] 1. Solution injection and circulation flow field establishment: The vacuum pump is stopped, and the work station is kept under a certain negative pressure. The magnesium salt solution of a specific concentration, which has been preheated to 60°C to 80°C in the storage tank, is injected into the work station under the drive of an external pump. The injection process can be controlled in stages. In the initial stage, the negative pressure of the work station is used for suction, and in the later stage, it is switched to pumping.

[0033] After the work station is filled with solution, a circulation pump is used to make the solution pass through the perforated plate liquid distributors distributed on the left and right sides at the bottom of the work station. The solution is evenly converted into countless fine and gentle jets and enters the work station. The liquid flows from bottom to top through the carefully designed narrow flow channel between the side of the brick blank and the inner wall of the work station, forming a surrounding flush and pressure penetration on the brick blank. Finally, the liquid converges in the top area of ​​the brick blank and is smoothly discharged from the top outlet, returning to the storage tank for temperature and concentration regulation, forming a closed loop.

[0034] Under the combined action of gravity and pumping force, a stable flow field naturally forms from both sides towards the center and from bottom to top within the workstation. This flow field not only provides uniform fluid pressure to promote penetration, but also continuously renews the solution boundary layer on the surface of the brick blank through fluid shear force, maintaining a high concentration difference driving force, and carrying away any trapped air bubbles through converging flow. Vacuum-assisted liquid filling combined with directional circulating pressure impregnation constitutes an enhanced impregnation process of first pumping and then pressing, and dynamic circulation, which effectively improves mass transfer efficiency and penetration uniformity compared to static soaking.

[0035] 2. Simultaneous monitoring by a dual-modal sensing system:

[0036] Ultrasonic monitoring system: The waterproof and corrosion-resistant ultrasonic probe array arranged in the top wall of the work station starts to work. The probe emits ultrasonic pulses at a fixed frequency and receives signals that penetrate the brick blank or are reflected back from the internal pores and interfaces of the brick blank; the main analysis is the propagation speed V of the ultrasonic longitudinal wave in the brick blank and the amplitude attenuation coefficient α of the center frequency of the received signal.

[0037] It should be noted that the density and acoustic impedance of the brine solution are much higher than those of air. Once the brine solution enters the pores, it replaces air, significantly altering the effective elastic modulus and density of the composite medium in the brick blank, leading to a systematic increase in the sound velocity V. Simultaneously, the numerous newly formed liquid-solid interfaces become strong sources of sound scattering, resulting in increased sound wave energy attenuation, i.e., an increase in α. Based on the acoustic characteristics-permeability database established through extensive prior experiments, a calibration model can be used to map the sound velocity increment ΔV and attenuation increment Δα measured at a specific location to the local apparent brine saturation at that location. and effective penetration depth index .

[0038] Slip ring displacement monitoring system: Two slip ring structures are symmetrically installed in the horizontal flow channel above the liquid distributor and on the side of the brick blank within the workstation. The slip rings are mounted on horizontal guide rails, with their movement direction horizontal towards the brick blank. The slip rings are connected to the side wall of the workstation via a corrosion-resistant alloy spring with a precise elastic coefficient. The spring preload keeps the slip rings initially positioned close to the outer wall of the flow channel. The flow-facing side of the slip ring, i.e., the side facing away from the brick blank, faces the horizontal flow direction. A magnet is embedded inside the slip ring, and a non-contact magnetostrictive displacement sensor is installed externally. The sensor measures in real time the displacement X of the slip ring towards the brick blank caused by the fluid thrust.

[0039] It should be noted that in the initial stage of impregnation: when the solution circulation is established and the liquid flow reaches the height of the slip ring from bottom to top, part of it turns into a horizontal flow towards the brick blank; at this time, the brick blank has the highest porosity and the lowest permeation resistance, and its suction capacity for the horizontal liquid flow is extremely strong. Therefore, the liquid flow velocity and flow rate of the horizontal liquid flow towards the brick blank are high. These high-speed and high-flow-rate liquid flows first impact the flow-facing surface of the slip ring head-on, applying a large hydrodynamic thrust towards the brick blank, forcing the slip ring to overcome the spring force and produce a large initial displacement. At this time, the slip ring displacement X is near its maximum value.

[0040] In the middle and late stages of impregnation: As the salt solution continues to penetrate, the pores of the brick blank are filled, the penetration resistance continues to increase, and its ability to draw in horizontal liquid flow weakens; in order to maintain the total circulation flow of the system, more liquid flow chooses the vertical upward flow path with less resistance, which causes the liquid flow velocity and flow rate to decrease horizontally towards the brick blank. Therefore, the hydrodynamic thrust of the impact slip ring decreases, and under the action of the spring restoring force, the slip ring displacement X shows a monotonically decreasing trend from the initial maximum value.

[0041] Late impregnation stage: When the brick blank is close to saturation and the horizontal seepage flow almost stops, the flow velocity in the horizontal channel is extremely low, the slip ring is almost not subjected to horizontal thrust, and the displacement X decreases and stabilizes at a low value close to the initial installation position.

[0042] The slip ring displacement X is a direct reflection of the instantaneous intensity of the horizontal seepage flow. The larger the X value, the stronger the seepage capacity of the brick at that moment; the faster the X value decreases, the higher the seepage rate; when the X value stabilizes at a low value, it indicates that seepage is basically complete. The curve X(t) of the slip ring displacement X changing with time t is expected to be a monotonically decreasing curve starting from a high point.

[0043] 3. Data integration and analysis and status prompts: The control system synchronously collects and time-aligns data from the ultrasonic array and the slip rings on both sides at a frequency of several times per second.

[0044] Calculate the overall process composite index PI.

[0045] The calculation formula is: ;

[0046] in The average apparent salt saturation of the entire brick blank was calculated based on ultrasonic data. The average effective penetration depth index is calculated based on ultrasonic data for the entire brick blank. This represents the average displacement of the left and right slip rings. This represents the initial average slip ring displacement recorded at the start of this batch of impregnation, and signifies the maximum horizontal seepage flow intensity. These are weighting coefficients, all of which are positive, and usually a and b are dominant. Their specific values ​​are determined through process testing and calibration.

[0047] The PI value starts from a small base value and increases monotonically as impregnation proceeds. When the PI value approaches 1, it indicates that the interior of the brick has achieved high saturation and deep penetration, and the horizontal permeation flow has been significantly reduced, indicating that the impregnation has reached the ideal endpoint.

[0048] Consistency Health Index in Calculation Process ,

[0049] ;

[0050] in, and These represent the average saturation on the left and right sides of the brick blank, respectively. and These are the average penetration depth indices for the left and right sides of the brick blank, respectively. and These represent the displacements of the left and right slip rings, respectively. Any abnormal deviation in saturation, penetration depth, or slip ring displacement on either side will lead to an increase in the absolute value of the corresponding item, thereby reducing the CHI value. The closer the CHI value is to one, the healthier and more symmetrical the process is. When the CHI value is consistently below the set threshold, it indicates a significant problem with process consistency, such as poor unilateral penetration, flow channel blockage, or sensor malfunction.

[0051] Status indicators and visualization: A real-time trend chart showing the changes in the overall process composite index (PI) and the process consistency health index (CHI) over time, as well as the decreasing curve of the average slip ring displacement;

[0052] When the process consistency health index (CHI) remains below the warning threshold, the system will issue a yellow warning, prompting the operator to check for possible causes of unevenness; when the overall process comprehensive index (PI) reaches the preset target value, the system will issue a green completion prompt, suggesting that the impregnation process be terminated.

[0053] If the monitoring data shows extreme contradictions, such as a very low PI value but a sudden drop in the CHI value, or an abnormal decline curve in the average displacement of the slip ring, the system will issue a red alarm, indicating that there may be a sensor malfunction or a serious process abnormality.

[0054] The technical solution integrates ultrasonic monitoring of saturation, penetration depth, and slip ring displacement information reflecting the intensity of horizontal seepage flow. It can effectively monitor the brick impregnation process and promptly identify and alert staff to abnormal or uneven impregnation caused by malfunctions during the impregnation process.

[0055] Step 3: Salt solution recovery, station heat preservation and intelligent drying: After impregnation, the salt solution is efficiently recovered and the same station is converted to drying mode; before drying, the temperature in the station will be actively adjusted and maintained at a set value to achieve heat energy recycling, and then a drying program optimized based on impregnation result data is executed.

[0056] The specific method is as follows:

[0057] 1. Salt solution recovery and station emptying: When the operator judges that impregnation is complete based on the overall status prompt, or the system gives a completion suggestion based on the preset overall progress index (PI) threshold, the liquid drainage program is started manually or automatically; the circulation pump is turned off, and the quick drain valve at the bottom of the station is opened to drain most of the salt solution back to the storage tank by gravity and position difference; then, the compressed air purging valve is opened to introduce a stream of filtered, preheated low-pressure dry air into the station for about 30-60 seconds. This process aims to purge the residual liquid film on the surface of the brick blank and the inner wall of the complex flow channel, and discharge it through the top outlet to ensure that the inside of the station becomes a basically dry gaseous environment.

[0058] 2. Workstation heat preservation and drying preparation: After purging, the hot air circulation system operates at low power to precisely adjust and stabilize the temperature of the air inside the workstation within the set range of 150℃ to 180℃; this can significantly reduce the rapid thermal shock caused by the brick blanks coming into contact with the cold wall, which is beneficial to protecting the brick blank structure and making the initial cooling curve of the brick blanks smoother.

[0059] 3. Intelligent drying execution: After the heat retention reaches the set temperature, the system officially enters the drying mode. The control system automatically calls the embedded heat and mass transfer model based on the final ultrasonic data at the end of impregnation and the geometric parameters of the brick blank, and generates an optimal multi-segment drying temperature-time-wind speed curve. This curve usually includes a low-temperature preheating section, a constant-speed drying section, and a decreasing-speed drying section.

[0060] During this stage, the ultrasonic system continues to operate, but the monitoring focus shifts from saturation to the stable value of the sound velocity V. As moisture evaporates and salt crystallizes out in an ideal form, the acoustic characteristics inside the brick gradually tend towards a new stable state. When the rate of change of the sound velocity value in the core area of ​​the brick is lower than a minimum threshold over multiple consecutive sampling cycles, the system determines that drying is complete and issues a prompt. Customized drying based on measured liquid absorption achieves precise energy supply and avoids over-drying or under-drying.

[0061] Step 4, Controlled Cooling and Unloading: After drying, the brick blanks are cooled to a safe unloading temperature through programmed controlled cooling, while retaining some residual heat at the workstation to prepare for the next cycle.

[0062] The specific method is as follows:

[0063] 1. Programmed cooling: Upon receiving the drying completion notification, the system shuts down the heater; controls the cooling fan to run at an adjustable low speed, and may introduce filtered room temperature air to reduce the temperature inside the workstation at a controllable rate, and purposefully cools the brick blank temperature to the range of 120℃ to 150℃.

[0064] 2. Unloading and Station Preparation: When the temperature reaches the set unloading temperature, cooling stops. The operator or automatic control system unlocks and opens the station cover. The robotic arm reaches in and removes the fully processed brick blanks, transferring them to the finished product storage area or inspection station. At this time, the temperature of the internal cavity, support frame, and other components of the station is still significantly higher than room temperature, awaiting the loading of the next high-temperature brick blank. Retaining the residual heat of the station maximizes the utilization of heat energy in the continuous production cycle. When the next high-temperature brick blank enters, it will face a warm environment, greatly reducing the initial heat loss of the brick blank, stabilizing the starting point of the process, and saving energy.

[0065] Example 2: Refer to Figures 1-6Based on Example 1, for ease of understanding, a closed workstation model structure was constructed, including a support platform 1 and a closed cover 3 connected by a hydraulic lifting rod 4. The support platform 1 is provided with an annular groove 101 with a top opening. After the closed cover 3 is lowered, it contacts the bottom of the annular groove 101 and the outer wall of the closed cover 3 fits against the inner wall of the outer ring of the annular groove 101. The middle position at the top of the support platform 1 is used to place the brick blank 2.

[0066] In this invention, an inlet pipe 5 is connected to the middle position of both sides of the bottom inner wall of the annular groove 101, a drain pipe 12 is connected to one end of the bottom of the annular groove 101, an outlet pipe 6 is connected to the center position of the top of the sealing cover 3, and a vacuum pipe 11 is also connected to the top of the sealing cover 3. Solenoid valves are provided on the inlet pipe 5, the drain pipe 12, the outlet pipe 6 and the vacuum pipe 11.

[0067] In this invention, the vacuum tube 11 is connected to a vacuum pump for evacuating the sealed chamber; the inlet tube 5 is connected to a liquid pump and a gas pump respectively through a connector and multiple pipes, so that the inlet tube 5 can allow liquid to enter during the impregnation process and gas to enter during the drying process; the outlet tube 6 is also connected through a connector and pipes respectively, so that liquid can be extracted from the outlet tube 6 during the impregnation process and gas can be discharged from the outlet tube 6 during the drying process.

[0068] In this invention, ultrasonic probes 10 are arrayed on the top of the sealed cover 3; horizontally extending slide rods 7 are fixed on both sides of the sealed cover 3 at positions corresponding to the inlet pipe 5, and slide rings 8 are slidably connected to the slide rods 7. The slide rings 8 can only move horizontally on the slide rods 7. Multiple guide vanes 801 are installed on the outer wall of the slide rings 8 to impact the flowing liquid. A spring 9 is connected between the side of the slide rings 8 away from the brick blank 2 and the sealed cover 3; under normal conditions, the slide rings 8 are located above the inlet pipe 5 on the side closer to the brick blank 2; thus, the changes in liquid flow are sensed through the slide rings 8 during the liquid flow process, thereby ensuring the accuracy of monitoring.

[0069] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A salt impregnation and drying process for electrofused rebonded magnesia-chrome bricks, characterized in that, Includes the following steps: Step 1: Place the sintered brick blank with residual heat into the work station, seal the work station, and then perform vacuum treatment. Step 2: Inject preheated salt solution into the vacuum pretreatment station to establish a directional circulating flow field for dynamic pressure impregnation, and simultaneously perform ultrasonic monitoring and fluid dynamic slip ring monitoring. Generate process status assessment information based on the fused data. Ultrasonic monitoring specifically involves transmitting and receiving signals through an array of ultrasonic probes, analyzing the changes in the propagation velocity and amplitude attenuation coefficient of ultrasonic waves within the brick blank, and mapping the information on the salt saturation and effective penetration depth of local areas inside the brick blank. Fluid dynamic slip ring monitoring specifically involves: symmetrically installing slip rings in the horizontal flow channels on both sides of the brick blank within the work station; the slip rings are connected to the side wall of the work station via springs and can move horizontally toward the brick blank; by measuring the displacement of the slip rings caused by the impact of the horizontal liquid flow, the instantaneous intensity of the horizontal seepage flow toward the brick blank is reflected. The slip ring displacement is the largest in the initial stage of impregnation, and shows a monotonically decreasing trend as the pores of the brick blank are filled and the penetration resistance increases; Based on the fusion data, process status assessment information is generated, specifically including: calculating the overall process comprehensive index, which integrates the average salt saturation of the brick blank, the average effective penetration depth, and the degree of decay of the average slip ring displacement relative to its initial value. The process consistency health index is calculated by comparing the saturation, penetration depth and slip ring displacement symmetry on the left and right sides of the brick blank to assess the process health status. Step 3: After impregnation, recover the brine and switch the same workstation to drying mode to perform drying operations based on the measured liquid absorption. Step 4: After drying, perform controlled cooling to cool the brick blanks to a safe unloading temperature before removing them, and keep the workstation in a residual heat state.

2. The salt immersion and drying process for electrofused rebonded magnesia-chrome bricks according to claim 1, characterized in that, In step one, the temperature of the sintered brick blank with residual heat is 300℃ to 450℃, and the target vacuum degree of the vacuum treatment is -0.06MPa to -0.08MPa.

3. The salt immersion and drying process for electrofused rebonded magnesia-chrome bricks according to claim 1, characterized in that, In step two, the method for establishing a directional circulating flow field is as follows: the salt solution enters through the liquid inlet distributors distributed on the left and right sides at the bottom of the workstation, flows from bottom to top through the flow channel between the side of the brick blank and the inner wall of the workstation, and is finally discharged from the liquid outlet located in the middle of the top to form a closed loop.

4. A salt immersion and drying process for electrofused rebonded magnesia-chrome bricks according to any one of claims 1 to 3, characterized in that, When the overall process comprehensive index reaches the preset target value, the impregnation is indicated as complete; when the process consistency health index continues to be lower than the set threshold, an early warning is issued.

5. A salt immersion and drying process for electrofused rebonded magnesia-chrome bricks according to any one of claims 1 to 3, characterized in that, In step three, a customized segmented drying curve is generated and executed based on the total liquid absorption of the brick blank calculated from the ultrasonic monitoring data at the end of impregnation.

6. The salt immersion and drying process for electrofused rebonded magnesia-chrome bricks according to claim 5, characterized in that, During the drying process, the stability of the ultrasonic velocity inside the brick blank is continuously monitored, and the determination of drying completion is based on the rate of change of the sound velocity being lower than a set threshold.

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