Molten aluminum detection equipment and method

Abstract

The invention discloses molten aluminum detection equipment and a method, the molten aluminum detection equipment is used for detecting to-be-detected molten aluminum sampled from an electrolytic cell, and the molten aluminum detection equipment comprises a container for accommodating the to-be-detected molten aluminum sampled from the electrolytic cell; the probe comprises a first shell as well as a laser device and a spectrograph which are arranged in the inner space of the first shell, pulse laser emitted by the laser device is incident into the container, so that the molten aluminum to be detected in the container generates plasma emission light, and the spectrograph is used for collecting the plasma emission light; the gas purging device is communicated with the internal space of the first shell; the controller is used for controlling the gas purging device to provide clean gas for the internal space of the first shell in the process that the probe detects the to-be-detected molten aluminum in the container, and the clean gas is used for replacing gas in the internal space and enabling the internal space to keep positive pressure. The technical problem that the detection period of the content of the elements in the molten aluminum is long is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic cells, and in particular relates to an aluminum liquid detection device and method. Background Art

[0002] During the production of molten aluminum in electrolytic cells, it is usually necessary to test the content of elements such as iron (Fe) and silicon (Si). If the content of elements such as iron and silicon fluctuates greatly, immediate intervention and adjustment are required to ensure that product quality meets the requirements.

[0003] The current industry-wide method for testing elemental content in molten aluminum is primarily offline sampling and testing. This involves manually collecting samples from the hot molten aluminum, cooling and preparing them, and then sending them to a laboratory for composition determination using a direct-reading spark spectrometer or chemical analysis methods. This traditional approach has numerous drawbacks, including a long testing cycle. Specifically, the process from sampling, cooling, and sample preparation to analytical results often takes 2-5 days, resulting in poor timeliness. This makes it difficult to accurately reflect transient changes in the raw aluminum liquid's composition, hindering real-time guidance for adjustments in electrolytic aluminum production and compromising product quality. Therefore, the long testing cycle for elemental content in molten aluminum is a pressing technical issue that needs to be addressed. Summary of the Invention

[0004] The embodiments of the present invention provide an aluminum liquid detection device and method, which solve the technical problem of a long detection period for the content of elements in the aluminum liquid.

[0005] In a first aspect, an embodiment of the present invention provides an aluminum liquid detection device for detecting aluminum liquid to be detected sampled from an electrolytic cell, the aluminum liquid detection device comprising: a container for accommodating the aluminum liquid to be detected sampled from the electrolytic cell; a probe comprising a first shell and a laser and a spectrometer arranged in an internal space of the first shell, wherein pulsed laser emitted by the laser is incident on the container to cause the aluminum liquid to be detected in the container to generate plasma emission light, and the spectrometer collects the plasma emission light; a gas purge device connected to the internal space of the first shell; and a controller electrically connected to the laser, the spectrometer, and the gas purge device, wherein the controller is configured to: during the process of the probe detecting the aluminum liquid to be detected in the container, control the gas purge device to provide a clean gas to the internal space of the first shell, wherein the clean gas is used to replace the gas in the internal space and maintain a positive pressure in the internal space.

[0006] In combination with the first aspect of the present invention, in some embodiments, the first shell includes: a light transceiver part, in which the laser and the spectrometer are arranged; a light guiding part, which is protruded relative to the light transceiver part, is connected to the light transceiver part, and is arranged opposite to the container; wherein the pulsed laser emitted by the laser passes through the light guiding part and is emitted into the container, and the spectrometer collects the plasma emission light returned through the light guiding part.

[0007] In combination with the first aspect of the present invention, in some embodiments, an air inlet and an air outlet are provided on the first shell; the gas purging device includes: a gas filter, the air outlet of the gas filter is connected to the air inlet of the first shell; an air pump, the air outlet of the air pump is connected to the air inlet of the gas filter; an air compressor, the air outlet of the air compressor is connected to the air inlet of the air pump; a one-way valve, the air inlet of the one-way valve is connected to the air outlet of the first shell, and the air outlet of the one-way valve is connected to the air inlet of the air pump.

[0008] In combination with the first aspect of the present invention, in some embodiments, it further includes: a base; a support rod, one end of which is arranged on the base, and the first shell is arranged on the other end of the support rod; a moving device, movably arranged on the support rod, and the container is fixedly arranged on the moving device, and the moving device moves relative to the support rod, driving the container to change the distance relative to the laser and the spectrometer.

[0009] In combination with the first aspect of the present invention, in some embodiments, it also includes: a magnetic field strength sensor, electrically connected to the controller, for detecting the ambient magnetic field strength of the surrounding environment where the laser is located; the controller is also used to: obtain the ambient magnetic field strength detected by the magnetic field strength sensor; if the ambient magnetic field strength is greater than a preset intensity threshold, control the laser to be powered off.

[0010] In combination with the first aspect of the present invention, in some embodiments, the materials of the optical transceiver, the second shell of the laser, and the third shell of the spectrometer are all magnetic metals; the material of the light guide part is quartz glass; the container is a crucible, the thickness of the crucible is 1 mm to 9 mm, and the outer wall of the crucible is covered with a ceramic fiber insulation layer.

[0011] In combination with the first aspect of the present invention, in some embodiments, the controller is further used to: control the laser to emit pulsed laser, wherein the pulsed laser is incident on the container so that the aluminum liquid to be detected in the container generates the plasma emission light; control the spectrometer to collect the plasma emission light to obtain first spectral data; and process the first spectral data to obtain the content of the target element in the aluminum liquid to be detected.

[0012] In combination with the first aspect of the present invention, in some embodiments, the controller is further used to: preprocess the first spectral data to obtain second spectral data, wherein the preprocessing includes denoising and smoothing; perform spectral analysis on the second spectral data to obtain a first spectral intensity of the target element in the aluminum liquid to be detected; and determine the content of the target element based on the first spectral intensity.

[0013] In combination with the first aspect of the present invention, in some embodiments, the controller is also used to: obtain the spectral intensity of the aluminum element in the aluminum liquid to be detected; correct the first spectral intensity based on the spectral intensity of the aluminum element to obtain the second spectral intensity of the target element; input the second spectral intensity of the target element into a preset content prediction model to obtain the content of the target element, and the content prediction model is obtained by training a machine learning model based on multiple groups of training samples, and each group of training samples includes the historical spectral intensity and historical content of the target element in the aluminum liquid generated during the historical production of aluminum liquid.

[0014] In a second aspect, an embodiment of the present invention provides a method for detecting molten aluminum, which is applied to a controller of an molten aluminum detection device as described in any one of the first aspects, the method comprising: controlling the gas purge device to provide clean gas to the internal space of the first shell; controlling the laser to emit pulsed laser, wherein the pulsed laser is incident on the container so that the molten aluminum to be detected in the container generates the plasma emission light; controlling the spectrometer to collect the plasma emission light to obtain first spectral data; and processing the first spectral data to obtain the content of the target element in the molten aluminum to be detected.

[0015] The one or more technical solutions provided by the embodiments of the present invention achieve at least the following technical effects or advantages: An embodiment of the present invention provides a molten aluminum detection device for detecting molten aluminum sampled from an electrolytic cell. The molten aluminum detection device includes: a container for containing the molten aluminum sampled from the electrolytic cell; a probe comprising a first housing and a laser and a spectrometer disposed within the interior of the first housing. The laser emits pulsed laser light that is incident on the container, causing the molten aluminum to generate plasma emission light within the container, which is collected by the spectrometer. A gas purge device communicates with the interior of the first housing. A controller is electrically connected to the laser, the spectrometer, and the gas purge device. The controller is configured to control the gas purge device to supply a clean gas to the interior of the first housing while the probe is detecting the molten aluminum within the container. The clean gas is used to displace the gas within the interior and maintain a positive pressure within the interior. It should be noted that after the spectrometer collects the plasma emission light, the content of each element in the molten aluminum can be quickly determined based on the information collected by the spectrometer. This means that the probe can perform real-time detection of the molten aluminum and thereby obtain its composition in real time, avoiding manual offline sampling and testing, thereby improving the timeliness of molten aluminum detection. Therefore, the detection cycle of the element content in the aluminum liquid is shortened.

[0016] Furthermore, the gas purge device maintains a positive pressure within the first housing, preventing corrosive gases from entering the probe and, consequently, corroding the optical path within the probe. This improves the accuracy of elemental content detection in the molten aluminum. Furthermore, the clean gas displaces the gas in the internal space, improving its cleanliness and preventing smoke and dust from affecting the optical path, further enhancing the accuracy of elemental content detection in the molten aluminum. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of an aluminum liquid detection device in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the gas purge device; Figure 3 Schematic diagram of a probe in a fixed position in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] In the present invention, descriptions such as "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions of various embodiments may be combined with each other, but this must be based on the fact that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0021] Figure 1 Schematic diagram of aluminum liquid detection equipment in an embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides an aluminum liquid detection device for detecting aluminum liquid to be detected sampled from an electrolytic cell. The aluminum liquid detection device includes: a container 10 for accommodating the aluminum liquid to be detected sampled from the electrolytic cell; a probe 20, wherein the probe 20 includes a first shell 210 and a laser 220 and a spectrometer 230 disposed in the interior space of the first shell 210, wherein pulsed laser light emitted by the laser 220 is incident on the container 10 to cause the aluminum liquid to be detected in the container 10 to generate plasma emission light, and the spectrometer 230 collects the plasma emission light; a gas purge device 30 in communication with the interior space of the first shell 210; and a controller electrically connected to the laser 220, the spectrometer 230, and the gas purge device 30. The controller is configured to control the gas purge device 30 to supply a clean gas to the interior space of the first shell 210 during the process of the probe 20 detecting the aluminum liquid to be detected in the container 10. The clean gas is used to replace the gas in the interior space and maintain a positive pressure in the interior space.

[0022] It should be noted that the clean gas can refer to air or an inert gas that has been filtered of soot and impurities. Furthermore, the process of the probe 20 detecting the aluminum liquid in the container 10 includes the laser 220 emitting a pulsed laser and the spectrometer 230 collecting the plasma-emitted light. The temperature range of the aluminum liquid to be detected is 700°C to 1000°C.

[0023] refer to Figure 1 and Figure 2 As shown, Figure 2 for Figure 1Schematic diagram of the gas purge device, the first shell 210 may include: an optical transceiver 2110, a laser 220 and a spectrometer 230 are arranged in the optical transceiver 2110; a light guiding part 2120 is protruded relative to the optical transceiver 2110, is connected to the optical transceiver 2110, and is arranged opposite to the container 10; wherein, the pulsed laser emitted by the laser 220 passes through the light guiding part 2120 and is emitted into the container, and the spectrometer 230 collects the plasma emission light returned through the light guiding part 2120.

[0024] It should be noted that the first housing 210 can include only the optical transceiver 2110. However, this would result in low molten aluminum detection accuracy. The reasons are explained in detail below: Both the laser 220 and the spectrometer 230 need to maintain a certain distance from the molten aluminum, that is, the optical transceiver 2110 needs to maintain a certain distance from the molten aluminum. Furthermore, due to the presence of dust in the molten aluminum environment, the pulsed laser and plasma light passing through the area between the optical transceiver 2110 and the molten aluminum will be affected by the long-distance dust interference, thereby reducing the accuracy of molten aluminum detection. Therefore, in this embodiment of the present invention, the first housing 210 is limited to including the optical transceiver 2110 and the light guide 2120. The interior of the light guide 2120 can be a hollow cavity without any other devices. Furthermore, because the gas purge device 30 can provide clean gas, the internal cavity of the light guide 2120 is filled with clean gas, preventing the pulsed laser and plasma light from being affected by long-distance dust interference, thereby improving the accuracy of molten aluminum detection.

[0025] refer to Figure 2 As shown, the first shell 210 is provided with an air inlet and an air outlet; the gas purge device 30 may include: a gas filter 310, the air outlet of the gas filter 310 is connected to the air inlet of the first shell 210; an air pump 320, the air outlet of the air pump 320 is connected to the air inlet of the gas filter 310; an air compressor 330, the air outlet of the air compressor 330 is connected to the air inlet of the air pump 320; a one-way valve 340, the air inlet of the one-way valve 340 is connected to the air outlet of the first shell 210, and the air outlet of the one-way valve 340 is connected to the air inlet of the air pump 320.

[0026] It should be noted that the various components within the gas purge device 30 can be connected via a gas pipeline. The gas purge device 30 and the first housing 210 can also be connected via a gas pipeline. For example, the air compressor 330 and the air pump 320 can be connected via a gas pipeline. The air inlet and outlet of the first housing 210 can be both located in the optical transceiver 2110 or both located in the optical guide 2120. During gas purge, the gas flow path can be sequentially through the air compressor 330, the air pump 320, the gas filter 310, the interior space of the first housing 210, the one-way valve 340, and the air pump 320. Furthermore, when the gas pressure within the interior space of the first housing 210 is high, the one-way valve 340 opens, allowing gas to flow from the one-way valve 340 to the air pump 320. When the gas pressure within the interior space of the first housing 210 is low, the one-way valve 340 closes, preventing gas from flowing from the one-way valve 340 to the air pump 320. The following describes the functional implementation of one-way valve 340: One-way valve 340 may include a spring-loaded check valve. One-way valve 340 automatically opens and closes in response to fluid pressure differentials via a mechanical spring. The spring-loaded check valve opens when the positive pressure exceeds the spring preload. Gas filter 310 may be a HEPA filter circulating air system with a three-stage filter capable of filtering corrosive gases such as hydrogen fluoride.

[0027] It should be noted that the probe 20 can be handheld or fixed in position. The following describes the case where the probe 20 is fixed in position: refer to Figure 3 As shown, Figure 3 Schematic diagram of a fixed-position probe in an embodiment of the present invention. The aluminum liquid detection device may further include: a base 40; a support rod 50, one end of which is provided on the base 40, and the first shell 210 is provided on the other end of the support rod 50; a moving device 60, which is movably provided on the support rod 50, and the container 10 is fixedly provided on the moving device 60. The moving device 60 moves relative to the support rod 50, driving the container 10 to change the distance relative to the laser 220 and the spectrometer 230.

[0028] In some embodiments, the controller is further configured to: before the probe 20 detects the aluminum liquid to be detected in the container 10 , control the movement device 60 to move so that the container 10 is located at a target position.

[0029] It should be noted that the target position can be the position of container 10 such that the aluminum liquid surface is located at the corresponding position of the laser focus. After the mobile device 60 is provided, the position of container 10 can be adjusted to accurately inject the laser into the aluminum liquid, avoiding optical path deviation. This allows for better control of laser emission and plasma emission light collection, thereby improving the accuracy of element content detection in the aluminum liquid. It should be noted that the base 40 can be a cart. In the electrolytic cell application scenario, the aluminum liquid detection equipment can be more conveniently moved, improving the convenience of aluminum liquid detection.

[0030] In some embodiments, the aluminum liquid detection equipment may further include: a control cabinet 80, which is arranged on the base 40, and the controller is arranged inside the control cabinet 80; a display screen 90, which is electrically connected to the controller, and the bottom of the display screen 90 is fixedly arranged on the top of the control cabinet 80; a sampling tool 91, which is used to take out the aluminum liquid to be detected from the electrolytic cell; a cross bar 70, which is arranged on the support bar 50, and the cross bar 70 is provided with a storage hole, and the storage hole of the cross bar 70 is used to place the sampling tool 91.

[0031] It should be noted that the gas purge device 30 can be fixedly mounted on the outer wall of the first shell 210 , on the support rod 50 , on the base 40 , or inside the control cabinet 80 .

[0032] In some embodiments, the aluminum liquid detection device may further include: a magnetic field strength sensor electrically connected to the controller, for detecting the ambient magnetic field strength of the environment surrounding the laser 220; the controller is further configured to: obtain the ambient magnetic field strength detected by the magnetic field strength sensor; and control the laser 220 to be powered off if the ambient magnetic field strength is greater than a preset strength threshold.

[0033] It should be noted that the magnetic field strength sensor is located near the laser 220. Specifically, the magnetic field strength sensor can be installed on the base 40 or inside the control cabinet 80. When the ambient magnetic field intensity is too strong, it interferes with the laser 220, potentially leading to unstable laser output, reduced beam quality, and decreased laser efficiency. Therefore, if the ambient magnetic field intensity exceeds a preset intensity threshold, the laser 220 is powered off and no further aluminum liquid testing is performed. This avoids obtaining abnormal data due to pulsed laser anomalies, thereby preventing incorrect elemental content and improving the accuracy of elemental content detection in the aluminum liquid.

[0034] In some embodiments, the materials of the optical transceiver 2110, the second shell of the laser 220, and the third shell of the spectrometer 230 are all magnetic metals; the material of the light guide 2120 is quartz glass; the container 10 is a crucible, the thickness of the crucible is 1 mm to 9 mm, and the outer wall of the crucible is covered with a ceramic fiber insulation layer.

[0035] It should be noted that "magnetic metal" refers to metals that are easily magnetized, typically with high magnetic permeability, and can produce a significant magnetization effect under the influence of an external magnetic field. Common magnetic metals include iron, silicon steel, stainless steel, and nickel-iron alloys. When the optical transceiver 2110, the second housing of the laser 220, and the third housing of the spectrometer 230 are all made of magnetic metal, electromagnetic interference can be reduced to a certain extent, ensuring long-term reliable operation in the strong magnetic field surrounding the electrolytic cell. This also ensures accurate emission of the pulsed laser and accurate collection of the plasma emission light, enabling reliable first spectrum data to be obtained, thereby improving the accuracy of elemental content detection in the molten aluminum. The light guide 2120 is made of quartz glass, which is resistant to high temperatures, corrosion, aluminum adhesion, and thermal shock. It can operate directly in close proximity to molten aluminum, thereby ensuring the proper operation of the molten aluminum testing equipment. The crucible features a thin-walled design and is covered with a highly effective thermal insulation layer. The crucible's low heat capacity and thermal insulation design ensure that the molten aluminum remains liquid throughout the measurement process, preventing rapid condensation that could affect measurement accuracy.

[0036] In some embodiments, the controller is further used to: control the laser 220 to emit a pulsed laser, wherein the pulsed laser is incident into the container 10 so that the aluminum liquid to be detected in the container 10 generates plasma emission light; control the spectrometer 230 to collect the plasma emission light to obtain first spectral data; and process the first spectral data to obtain the content of the target element in the aluminum liquid to be detected.

[0037] In some embodiments, the controller is further configured to: control the spectrometer 230 to collect light emitted by the plasma to obtain a light signal; and control the spectrometer 230 to convert the light signal into first spectrum data.

[0038] In some embodiments, the controller is further used to: preprocess the first spectral data to obtain second spectral data, the preprocessing including denoising and smoothing; perform spectral analysis on the second spectral data to obtain a first spectral intensity of the target element in the aluminum liquid to be detected; and determine the content of the target element based on the first spectral intensity.

[0039] It should be noted that the target element may be iron (Fe), silicon (Si) and other elements.

[0040] In some embodiments, the controller is also used to: obtain the spectral intensity of the aluminum element in the aluminum liquid to be detected; correct the first spectral intensity based on the spectral intensity of the aluminum element to obtain a second spectral intensity of the target element; input the second spectral intensity of the target element into a preset content prediction model to obtain the content of the target element, and the content prediction model is obtained by training a machine learning model based on multiple groups of training samples, and each group of training samples includes the historical spectral intensity and historical content of the target element in the aluminum liquid generated during the historical production of aluminum liquid.

[0041] In some embodiments, the controller is further configured to: use the ratio of the first spectral intensity to the spectral intensity of the aluminum element as the second spectral intensity of the target element.

[0042] It should be noted that due to fluctuations in the plasma state, the spectral intensities of various elements in the molten aluminum can deviate from their true values. When these spectral intensities deviate from the true values, the determined elemental content is also inaccurate, leading to low test accuracy. To address this issue, considering that the spectral intensities of various elements in the molten aluminum have roughly the same fluctuation trends, the spectral intensity of aluminum is used as a standard value to correct the spectral intensity of the target element. This compensates for the impact of plasma state fluctuations on the measurement, thereby improving the accuracy of elemental content detection in the molten aluminum.

[0043] In some embodiments, the content prediction model can be pre-established through the following steps: obtaining multiple groups of training samples; inputting the historical spectral intensity of each group of samples in the multiple groups of training samples into the machine learning model to obtain the predicted content; inputting the predicted content and the historical content into the loss function to obtain the loss value; iteratively optimizing the machine learning model based on the loss value to obtain the content prediction model.

[0044] It should be noted that electrolytic aluminum, as an important raw material basic industry in my country, has an annual production capacity of more than 45 million tons, accounting for more than half of the world's total production capacity, and the large-scale electrolytic cell leads the world's technological progress. Such a large production capacity and super-large electrolytic cells exceeding 600KA require timely detection of impurities such as Fe and Si in the raw aluminum liquid during the electrolytic aluminum production process. First, it meets the raw aluminum liquid packaging or aluminum alloy ratio and improves product quality; second, it determines whether the bottom of the electrolytic cell is leaking to avoid major economic losses. However, the detection method currently commonly used in the industry is mainly offline sampling and testing, that is, manual sampling from high-temperature aluminum liquid, cooling and preparing the sample, and then sending it to the laboratory to use imported direct reading spark spectrometers to determine its raw aluminum composition. This traditional approach has many shortcomings: (1) Poor data timeliness: It often takes 2-5 days from sampling, cooling, sample preparation to issuing analysis results. It is difficult to reflect the instantaneous changes in the raw aluminum liquid composition in a timely manner and cannot guide electrolytic aluminum production in real time, especially aluminum alloy production. (2) Large quality fluctuations: Due to the lag in analysis results, the measured values may no longer represent the current melt composition, resulting in the inability to detect and correct fluctuations in impurity content and alloying element content in a timely manner. In addition, differences in sampling, sample preparation techniques, and cooling processes among different personnel can also cause large quality fluctuations. (3) Risk of furnace leakage: Due to the poor timeliness of detection data, workers are unable to timely grasp the increase in Fe and Si content caused by electrolytic cell leakage, and thus fail to deal with it in a timely manner, which will cause immeasurable economic losses and major safety accidents to the company.

[0045] It should be noted that the embodiment of the present invention uses laser 220 and spectrometer 230 to analyze molten aluminum. Its technical principle is LIBS (Laser Induced Breakdown Spectroscopy). LIBS has the advantages of requiring no complex sample preparation and enabling rapid multi-element detection. Once it can be stably operated on-site, it can quickly detect the composition of raw aluminum liquid. However, the complex environment of an aluminum smelting plant, especially large tanks exceeding 500kA, is characterized by strong magnetic fields, high temperatures, vibration, and dust. This poses significant challenges to the stable operation of LIBS equipment. Firstly, the working environment in an aluminum smelting plant is extremely harsh. Not only are temperatures high and dusty, but the operating current of the electrolytic cells can reach hundreds of thousands of amperes, generating strong magnetic fields of 1000 gauss (Gs) or even higher. This can severely interfere with delicate optical and electronic systems, causing spectrometer drift, signal distortion, and even electronic device failure. Secondly, the raw aluminum liquid itself experiences temperatures exceeding 900°C, exposing itself to issues such as high-temperature radiation, corrosion, oxidation, and vibration. This places extremely high demands on the tolerance and long-term stability of the measurement probe. In particular, the combination of high magnetic fields and high temperatures places stringent demands on the LIBS system's anti-interference design, structural material selection, electromagnetic compatibility, and heat dissipation and thermal insulation capabilities. Furthermore, the strong continuous spectrum and background interference of aluminum as the detection matrix can mask the characteristic spectral lines of trace impurity elements, resulting in insufficient detection sensitivity and inaccurate quantification. This makes it difficult to achieve high-sensitivity, low detection limits, and high repeatability for alloying elements such as Fe and Si in molten aluminum. Consequently, most existing LIBS systems remain at the laboratory or quasi-field industrial stage and are unable to meet the rapid detection requirements of my country's electrolytic aluminum production in extreme environments such as high-strength magnetic fields and high temperatures. Given the large-scale, high-intensity production of electrolytic aluminum in my country, there is an urgent need for a LIBS system for detecting raw aluminum with strong magnetic interference resistance (>400 Gs), high-temperature corrosion resistance, and real-time online analytical accuracy. This system can enable rapid detection of key elements such as Fe and Si in raw aluminum and optimize process control. Therefore, the present invention addresses these issues by improving the equipment and methods. For details, please refer to the above embodiments.

[0046] It should be noted that the mobile device 60 can be specifically divided into a transverse movement mechanism and a lifting mechanism. During detection, the transverse movement mechanism automatically moves the crucible to the detection position. After it is in place, the lifting mechanism lifts the crucible to the laser focus. The laser 220 emits a pulsed laser to excite the surface of the original aluminum liquid sample, generating plasma emission light. The spectrometer 230 collects the light signal and converts it into spectral data. Finally, data processing is performed to obtain the content of elements such as Fe and Si. When the element content exceeds the set range, an alarm can be issued in time to prompt the production personnel to adjust the process parameters. After the detection is completed, the lifting mechanism descends and the transverse movement mechanism is reset. The entire detection process from excitation to result output can be completed in no more than 80 seconds, which can meet the real-time detection requirements of the production site.

[0047] It should be noted that the probe can integrate both the laser emission and spectrum collection optical paths. A highly stable pulsed laser can be used as the excitation light source, preferably an Nd:YAG solid-state laser (e.g., a 1064 nm pulsed laser with a laser energy of 100 mJ), which can maintain stable output energy even in strong magnetic fields. Laser 220 is equipped with a special shielded housing and an anti-interference power supply to minimize the impact of the electrolytic cell's strong magnetic field and electromagnetic noise on the laser output. The high-energy laser pulses emitted by laser 220 are directed to the surface of the molten aluminum via an optical transmission system, generating a plasma spectral signal. Spectrometer 230 is specially designed to resist strong magnetic field interference, such as using a magnetically permeable material shielded housing. The operating wavelength of spectrometer 230 covers the characteristic spectral lines of Fe, Si, and other target elements, ensuring detection of major impurity elements in the molten aluminum. To reduce on-site electromagnetic noise, the spectral signal is transmitted via optical fiber, combining narrowband filtering and electronic filtering techniques to improve the signal-to-noise ratio. Spectrometer 230 can be a fiber-coupled UV-visible spectrometer with a detection range of 200–800 nm and a resolution better than 0.1 nm, capable of resolving the main characteristic spectral lines of Fe and Si. Probe 20 is made of high-temperature and corrosion-resistant materials, enabling direct access to molten aluminum. The overall structure of probe 20 can be designed for vibration resistance, and components that could introduce electromagnetic noise are shielded to ensure long-term reliable operation in the strong magnetic fields and vibration environments surrounding the electrolytic cell. The control system of this embodiment of the present invention can be further divided into a control circuit, a signal processing unit, a motor mechanism, and a data analysis software module. The control circuit is responsible for synchronizing the triggering of laser 220 with spectral data acquisition, enabling the acquisition of a set of spectra for each laser pulse. The control system is specifically designed for electromagnetic compatibility to address strong on-site magnetic interference. The circuit board and key chips are shielded and filtered to ensure reliable signal transmission and processing. The motor mechanism can include a motor controller and a driver. Position commands are sent by the traverse and lift motor controllers, and the corresponding drivers execute and provide feedback. The control system also features a built-in magnetic field sensor for real-time monitoring of ambient magnetic field strength. When the external magnetic field exceeds a preset threshold (e.g., 400 GS), it automatically issues a warning signal and shuts off the laser power supply to protect the equipment. The data analysis module processes and quantitatively calculates acquired spectral data in real time, including features like spectral line analysis, model optimization, and concentration calculation.

[0048] It should be noted that in the process of determining the content prediction model, the machine learning model can use a deep convolutional neural network (CNN). The network structure includes: input layer: receiving preprocessed spectral data (for example, wavelength range 200-900nm, resolution 0.1nm), convolution layer: 3 layers, using 32, 64, and 128 filters respectively, pooling layer: max pooling with a step size of 2, fully connected layer: 2 layers, the number of neurons is 256 and 128 respectively, output layer: corresponding to the content prediction of each element. The improved loss function used in network training can be as follows: Where: L mse is the mean square error loss, L smooth is the smoothing regularization term, α and β are weight coefficients, and L is the loss value.

[0049] An incremental learning algorithm based on gradient descent is used to continuously optimize the model. The update rule is: Among them, W t is the model parameter at time t, W t+1 is the model parameter at time t+1, is the learning rate, is the gradient of the loss function, (x t ,y t ) is the element content (Fe, Si) corresponding to the currently input spectral data. The analysis results can be displayed in real time through the human-machine interface and uploaded to the factory control system for production regulation.

[0050] It should be noted that the embodiments of the present invention, through their unique structural design and signal processing, achieve rapid and accurate detection of raw aluminum liquid composition, offering significant advantages over existing technologies. They offer fast detection speed and high real-time performance: A single composition analysis can be completed in less than 80 seconds, enabling near-real-time continuous detection and significantly reducing detection lag time. They also offer strong environmental adaptability and high reliability: The embodiments of the present invention can be applied on-site in aluminum electrolysis. Key components feature comprehensive magnetic field shielding and high-temperature, corrosion-resistant, shock-resistant, and dust-proof designs, enabling long-term stable operation in strong magnetic fields, high-temperature, and dusty environments. In particular, the introduction of magnetic field detection and automatic power-off protection ensures safe shutdown of the equipment in abnormally strong magnetic fields, improving system reliability. Simultaneous multi-element detection with real-time data feedback: LIBS technology can simultaneously obtain spectral information for multiple elements in a single laser excitation. Therefore, the embodiments of the present invention can simultaneously detect the contents of Fe, Si, and multiple other alloying elements, providing complete compositional information in a single test. Test results are displayed in real time via a software interface and can be transmitted online, facilitating production process control and enabling timely adjustments to raw material ratios or electrolysis process parameters based on composition fluctuations, thereby reducing product rejection rates.

[0051] It should be noted that the display screen can display the detection and analysis results in real time. The control cabinet houses the motor control module, water cooling control module, industrial computer, and battery module. The light guide provides isolation from aluminum molten splashes and high-temperature radiation. It should be noted that during spectral data processing, background correction is first performed to subtract the continuous radiation background from the plasma. Wavelet transforms are then used to de-noise and smooth the spectrum to highlight useful spectral line signals. Next, using a pre-stored database of elemental spectral lines, the software automatically detects the positions of characteristic spectral line peaks in the spectrum and calculates their peak intensities. For example, Fe has a characteristic spectral line around 273.7 nm, and Si has a characteristic spectral line around 251.6 nm. The software extracts these peak intensities from the processed spectra. To improve quantitative stability, the system selects a spectral line of aluminum (e.g., Al I 309.3 nm, with a similar excitation wavelength) as an internal standard. The intensity ratio of the Fe and Si characteristic lines to this internal standard is calculated to compensate for the effects of plasma state fluctuations on the measurement.

[0052] An embodiment of the present invention provides a molten aluminum detection device for detecting molten aluminum sampled from an electrolytic cell. The molten aluminum detection device includes: a container 10 for accommodating the molten aluminum sampled from the electrolytic cell; a probe 20 including a first housing 210 and a laser 220 and a spectrometer 230 disposed in an interior space of the first housing 210. Pulsed laser light emitted by the laser 220 is incident on the container 10, causing the molten aluminum to generate plasma emission light in the container 10. The spectrometer 230 collects the plasma emission light. A gas purge device 30 is communicated with the interior space of the first housing 210. A controller is electrically connected to the laser 220, the spectrometer 230, and the gas purge device 30. The controller is configured to control the gas purge device 30 to supply a clean gas to the interior space of the first housing 210 while the probe 20 is detecting the molten aluminum in the container 10. The clean gas is configured to displace gas in the interior space and maintain a positive pressure in the interior space. It should be noted that after spectrometer 230 collects the plasma emission light, the content of each element in the molten aluminum can be quickly determined based on the information collected by spectrometer 230. Specifically, probe 20 can perform real-time testing of the molten aluminum, thereby obtaining its composition in real time. This avoids manual offline sampling and testing, improving the timeliness of molten aluminum testing. Consequently, the detection cycle for elemental content in the molten aluminum is shortened. Furthermore, in the presence of corrosive gases in the molten aluminum environment, the gas purge device 30 maintains a positive pressure within the interior of the first housing 210, preventing corrosive gases from entering the interior of the probe 20 and, in turn, corroding the optical path within the probe 20. This improves the accuracy of elemental content detection in the molten aluminum. Furthermore, the clean gas displaces the gas in the internal space, thereby improving the cleanliness of the internal space and preventing smoke and dust from affecting the optical path, further improving the accuracy of elemental content detection in the molten aluminum.

[0053] Based on the same inventive concept, an embodiment of the present invention provides a method for detecting molten aluminum, which is applied to a controller of the molten aluminum detection equipment of any of the above embodiments. The method includes: controlling a gas purge device 30 to provide clean gas to the internal space of a first shell 210; controlling a laser 220 to emit a pulsed laser, wherein the pulsed laser is incident on a container 10 so as to cause the molten aluminum to be detected in the container 10 to generate plasma emission light; controlling a spectrometer 230 to collect the plasma emission light to obtain first spectral data; and processing the first spectral data to obtain the content of a target element in the molten aluminum to be detected.

[0054] It should be noted that, during the process of the probe 20 detecting the aluminum liquid to be detected in the container 10 , the gas purge device 30 may be controlled to provide clean gas to the inner space of the first shell 210 .

[0055] It should be understood that more implementation details of the aluminum liquid detection method in the embodiment of the present invention can be found in the aforementioned aluminum liquid detection equipment, and for the sake of brevity of the specification, they will not be repeated here.

[0056] The foregoing description is merely an embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A molten aluminum detection device, characterized in that: Used to detect aluminum liquid to be tested sampled from the electrolytic cell, the aluminum liquid testing equipment includes: A container for containing aluminum liquid to be tested sampled from the electrolytic cell; A probe comprising a first housing and a laser and a spectrometer disposed in an interior space of the first housing, wherein pulsed laser light emitted by the laser is incident on the container to cause the aluminum liquid to be detected in the container to generate plasma emission light, and the spectrometer collects the plasma emission light; a gas purge device, communicating with the interior space of the first shell; A controller is electrically connected to the laser, the spectrometer, and the gas purge device, wherein the controller is used to control the gas purge device to provide a clean gas to the internal space of the first shell during the process of the probe detecting the aluminum liquid to be detected in the container, wherein the clean gas is used to replace the gas in the internal space and maintain a positive pressure in the internal space.

2. The aluminum liquid detection equipment according to claim 1, characterized in that: The first housing includes: an optical transceiver unit, wherein the laser and the spectrometer are arranged in the optical transceiver unit; The light guide portion is protruding relative to the light transceiver portion, is connected to the light transceiver portion, and is arranged opposite to the container; wherein the pulsed laser emitted by the laser passes through the light guide portion and is emitted into the container, and the spectrometer collects the plasma emission light returned through the light guide portion.

3. The aluminum liquid detection equipment according to claim 1, characterized in that: The first shell is provided with an air inlet and an air outlet; the gas purge device comprises: a gas filter, wherein the gas outlet of the gas filter is connected to the gas inlet of the first shell; an air pump, wherein an air outlet of the air pump is connected to an air inlet of the gas filter; an air compressor, wherein an air outlet of the air compressor is connected to an air inlet of the air pump; A one-way valve, wherein the air inlet of the one-way valve is communicated with the air outlet of the first shell, and the air outlet of the one-way valve is communicated with the air inlet of the air pump.

4. The aluminum liquid detection equipment according to claim 1, characterized in that: Also includes: base; A support rod, one end of which is disposed on the base, and the first shell is disposed on the other end of the support rod; The moving device is movably arranged on the support rod, and the container is fixedly arranged on the moving device. The moving device moves relative to the support rod, driving the container to change the distance relative to the laser and the spectrometer.

5. The aluminum liquid detection equipment according to claim 1, characterized in that: Also includes: A magnetic field intensity sensor, electrically connected to the controller, for detecting the intensity of the ambient magnetic field in the surrounding environment of the laser; The controller is further configured to: obtain the ambient magnetic field intensity detected by the magnetic field intensity sensor; and control the laser to be powered off if the ambient magnetic field intensity is greater than a preset intensity threshold.

6. The aluminum liquid detection equipment according to claim 2, characterized in that: The optical transceiver, the second housing of the laser, and the third housing of the spectrometer are all made of magnetic conductive metal; The material of the light guide part is quartz glass; The container is a crucible, the thickness of the crucible is 1 mm to 9 mm, and the outer wall of the crucible is covered with a ceramic fiber insulation layer.

7. The aluminum liquid detection equipment according to any one of claims 1 to 6, characterized in that: The controller is also used to: controlling the laser to emit pulsed laser light, wherein the pulsed laser light is incident on the container so that the aluminum liquid to be detected in the container generates the plasma emission light; controlling the spectrometer to collect the plasma emitted light to obtain first spectrum data; The first spectral data is processed to obtain the content of the target element in the aluminum liquid to be detected.

8. The aluminum liquid detection equipment according to claim 7, characterized in that: The controller is also used to: Preprocessing the first spectral data to obtain second spectral data, wherein the preprocessing includes denoising and smoothing; performing spectral analysis on the second spectral data to obtain a first spectral intensity of the target element in the aluminum liquid to be detected; The content of the target element is determined based on the first spectrum intensity.

9. The aluminum liquid detection equipment according to claim 8, characterized in that: The controller is also used to: Obtaining the spectral intensity of the aluminum element in the aluminum liquid to be detected; Correcting the first spectral intensity based on the spectral intensity of the aluminum element to obtain a second spectral intensity of the target element; The second spectral intensity of the target element is input into a preset content prediction model to obtain the content of the target element. The content prediction model is obtained by training a machine learning model based on multiple groups of training samples, and each group of training samples includes the historical spectral intensity and historical content of the target element in the aluminum liquid generated during the historical production of aluminum liquid.

10. A method for detecting molten aluminum, applied to the controller of the molten aluminum detection device according to any one of claims 1 to 9, characterized in that: The method comprises: controlling the gas purge device to provide clean gas to the interior space of the first shell; controlling the laser to emit pulsed laser light, wherein the pulsed laser light is incident on the container so that the aluminum liquid to be detected in the container generates the plasma emission light; controlling the spectrometer to collect the plasma emitted light to obtain first spectrum data; The first spectral data is processed to obtain the content of the target element in the aluminum liquid to be detected.

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