Quartz sand gradient heating acid leaching purification control method

Abstract

The invention is suitable for the technical field of quartz sand purification, and particularly relates to a quartz sand gradient heating acid leaching purification control method which comprises the following steps: in response to initial heating operation, obtaining initial purification information; generating an acidity-dissolution rate coupling sequence based on the initial purification information; based on the acidity-dissolution rate coupling sequence, determining first heat preservation time of a target temperature of a first stage; obtaining an impurity dissolution curve under the first heat preservation time; determining a second heating operation based on the impurity dissolution curve; and obtaining stage purification information of the second heating operation, and determining second heat preservation time of the target temperature of the second stage based on the stage purification information. According to the method, the heat preservation time and the heating rate are dynamically adjusted, and the problem that energy consumption is sharply increased due to excessive heating in traditional constant-temperature or fixed segmented heating is solved.

Description

Background Technology

[0001] Quartz sand, as an important industrial raw material, is widely used in high-end fields such as semiconductors, photovoltaics, optical glass, and precision casting. These fields have extremely high purity requirements for quartz sand, typically requiring an SiO2 content of 99.99% or even 99.999%. Therefore, purification processes are necessary to remove impurities such as iron, aluminum, calcium, and magnesium from the quartz sand. Acid leaching is one of the mainstream technologies for quartz sand purification. Its principle is to utilize the chemical reaction between acid and impurity minerals, converting soluble impurities into ionic states that enter the solution, and then achieving purification through solid-liquid separation. The commonly used temperature control methods in the acid leaching purification process of quartz sand are constant-temperature acid leaching or segmented temperature-increasing acid leaching. To improve the shortcomings of constant-temperature acid leaching, the industry has gradually adopted segmented temperature-increasing acid leaching technology, which divides the acid leaching process into multiple temperature stages.

[0002] In existing technologies, due to the differences in impurity content and distribution of different batches of quartz sand raw materials, the staged heating acid leaching may result in insufficient heat preservation in some stages, leading to incomplete dissolution of shallow impurities, or excessive heat preservation in a certain stage, causing energy waste and acid loss. This results in significant fluctuations in the purification effect of quartz sand and affects the purification quality of quartz sand. Summary of the Invention

[0003] This application provides a method for controlling the gradient heating acid leaching purification of quartz sand, which can solve the problem of large fluctuations in the purification effect of segmented heating acid leaching.

[0004] In a first aspect, embodiments of this application provide a method for controlling the gradient temperature rise acid leaching purification of quartz sand, including: In response to the initial heating operation, initial purification information is acquired; wherein, the initial heating operation is used to indicate the operation of the heating device heating to the target temperature of the first stage for the first time; Based on the initial purification information, an acidity-dissolution rate coupled sequence is generated; Based on the acidity-dissolution rate coupling sequence, the first holding time for the target temperature in the first stage is determined. Obtain the impurity dissolution curve under the first heat preservation time; The second heating operation is determined based on the impurity dissolution curve; wherein the second heating operation is used to indicate the heating rate at which the heating device heats from the target temperature of the first stage to the target temperature of the second stage; Acquire the stage purification information of the second heating operation, and determine the second holding time for the target temperature of the second stage based on the stage purification information; wherein the stage purification information is used to reflect the purification characteristics of the acid solution during the process of heating from the target temperature of the first stage to the target temperature of the second stage.

[0005] The technical solutions described in this application embodiment have at least the following technical effects: The quartz sand gradient heating acid leaching purification control method provided in this application obtains initial purification information by responding to the initial heating operation used to indicate the first heating of the heating device to the target temperature of the first stage; then, based on the initial purification information, an acidity-dissolution rate coupling sequence is generated, which can capture the correlation between acid characteristics and impurity dissolution in real time; furthermore, based on the acidity-dissolution rate coupling sequence, the first holding time of the target temperature of the first stage is determined, so that the purification time of the initial purification stage is closely matched with the actual purification process, effectively reducing control deviations caused by factors such as raw material batch differences and acid concentration fluctuations; then, the first holding time is obtained. The impurity dissolution curve is obtained at a specific temperature and time. Based on the impurity dissolution curve, a second heating operation is determined to indicate the heating rate of the heating device from the target temperature of the first stage to the target temperature of the second stage. This allows for the selection of an appropriate rate based on the intensity of the reaction during the holding process, matching the reaction progress while preventing acid decomposition or local overheating. Finally, stage purification information is obtained for the second heating operation, which reflects the purification characteristics of the acid during the process of heating from the target temperature of the first stage to the target temperature of the second stage. Based on the stage purification information, the second holding time for the target temperature of the second stage is determined, which can specifically promote the dissolution of deep impurities. This method reduces the surge in energy consumption caused by overheating in traditional constant temperature or fixed segmented heating by dynamically adjusting the holding time and heating rate. At the same time, precise holding control reduces unnecessary volatilization and loss of acid at high temperatures. Through the synergistic control of gradient heating and precise holding, the temperature change is matched with the dissolution pattern of impurities, reducing the damage to the crystal structure of quartz sand caused by sudden temperature rises and falls or sustained high temperatures. This effectively ensures the stability of the physical properties of quartz sand and ultimately achieves a significant improvement in the purity of quartz sand, meeting the demand for high-purity quartz sand in high-end fields.

[0006] Secondly, embodiments of this application provide a quartz sand gradient heating acid leaching purification control system, comprising: The first acquisition module is used to acquire initial purification information in response to the initial heating operation; wherein, the initial heating operation is used to indicate the operation of the heating device to heat to the target temperature of the first stage for the first time; A generation module is used to generate an acidity-dissolution rate coupled sequence based on the initial purification information; The first determining module is used to determine the first holding time of the target temperature in the first stage based on the acidity-dissolution rate coupling sequence. The second acquisition module is used to acquire the impurity dissolution curve under the first heat preservation time; The second determining module is used to determine a second heating operation based on the impurity dissolution curve; wherein the second heating operation is used to indicate the heating rate of the heating device from the target temperature of the first stage to the target temperature of the second stage; The third determining module is used to acquire the stage purification information of the second heating operation, and determine the second holding time of the target temperature of the second stage based on the stage purification information; wherein, the stage purification information is used to reflect the purification characteristics of the acid solution during the process of heating from the target temperature of the first stage to the target temperature of the second stage.

[0007] Thirdly, embodiments of this application provide a gradient temperature acid leaching purification device for quartz sand, including a heating device, an acidity monitoring device, and a control device. The control device is electrically connected to the heating device and the acidity monitoring device. The control device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method described in any one of the first aspects above.

[0008] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any one of the first aspects above.

[0009] Fifthly, embodiments of this application provide a computer program product that, when running on a quartz sand gradient heating acid leaching purification device, causes the quartz sand gradient heating acid leaching purification device to execute the quartz sand gradient heating acid leaching purification control method described in any one of the first aspects.

[0010] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic flowchart of the gradient temperature rise acid leaching purification control method for quartz sand provided in the embodiments of this application; Figure 2 This is a schematic diagram of the quartz sand gradient heating acid leaching purification control system provided in the embodiments of this application; Figure 3This is a schematic diagram of the control device of the quartz sand gradient heating acid leaching purification equipment provided in the embodiments of this application. Detailed Implementation

[0013] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0014] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0015] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0016] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determination" or "if the described condition or event is detected" may be interpreted, depending on the context, as "once determination," "in response to determination," "once the described condition or event is detected," or "in response to the detection of the described condition or event."

[0017] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0018] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0019] Currently, the commonly used temperature control methods in the acid leaching purification process of quartz sand are mainly isothermal acid leaching or simple segmented temperature-increasing acid leaching. Isothermal acid leaching refers to maintaining a single constant temperature throughout the entire acid leaching process. This method is simple to operate, but it has significant drawbacks: different impurity minerals have significantly different reactivity with the acid solution; at low temperatures, some insoluble impurities react slowly, leading to low purification efficiency; while high temperatures can accelerate the reaction rate, they can easily cause the acid solution to evaporate too quickly, resulting in a surge in energy consumption, and may also cause damage to the quartz sand lattice, affecting product quality. To improve the shortcomings of isothermal acid leaching, the industry has gradually adopted segmented temperature-increasing acid leaching technology, which divides the acid leaching process into multiple temperature stages. However, the temperature control of existing segmented temperature-increasing methods largely relies on empirical settings and lacks dynamic response to real-time purification characteristics during the acid leaching process. For example, the target temperature, heating rate, and holding time for each stage are usually fixed in advance based on historical experimental data, and cannot be adjusted according to the dynamic changes in key parameters such as acidity changes and impurity dissolution rates during the actual acid leaching process.

[0020] Specifically, after the initial heating to the target temperature for the first stage, existing methods often directly adopt a fixed holding time, without considering the differences in impurity content and distribution among different batches of quartz sand raw materials, as well as the impact of fluctuations in the initial concentration of acid on the impurity leaching process. This may result in insufficient holding time, leading to incomplete leaching of shallow impurities, or excessive holding time, causing energy waste and acid loss. Furthermore, in subsequent heating stages, existing methods often use a constant heating rate, which can easily lead to problems such as excessively rapid heating causing localized overheating and acid decomposition, or excessively slow heating prolonging the overall process cycle. In addition, the setting of holding time at the target temperature in subsequent stages lacks quantitative calculation basis combined with purification information from each stage during the heating process, making it difficult to accurately control the leaching effect of deep impurities.

[0021] To address the aforementioned issues, this application provides a method for controlling the gradient heating acid leaching purification of quartz sand. In this method, initial purification information is obtained by responding to an initial heating operation that indicates the heating device's first heating to the target temperature of the first stage. Then, based on this initial purification information, an acidity-dissolution rate coupling sequence is generated, enabling real-time capture of the correlation between acid characteristics and impurity dissolution. Next, based on the acidity-dissolution rate coupling sequence, the first holding time for the target temperature of the first stage is determined, ensuring a deep match between the purification time of the initial purification stage and the actual purification process, effectively reducing control deviations caused by factors such as raw material batch differences and acid concentration fluctuations. Then, an impurity dissolution curve is obtained under the first holding time. Based on the impurity dissolution curve, a second heating operation is determined to indicate the heating rate from the target temperature of the first stage to the target temperature of the second stage. This allows for the selection of an appropriate rate based on the reaction intensity during the holding process, matching the reaction process while preventing acid decomposition or localized overheating. Finally, stage purification information reflecting the purification characteristics of the acid during the process of heating from the target temperature of the first stage to the target temperature of the second stage is obtained for the second heating operation. Based on this stage purification information, the second holding time for the target temperature of the second stage is determined, thus enabling targeted promotion of deep impurity dissolution. This method reduces the surge in energy consumption caused by overheating in traditional constant temperature or fixed segmented heating by dynamically adjusting the holding time and heating rate. At the same time, precise holding control reduces unnecessary volatilization and loss of acid at high temperatures. Through the synergistic control of gradient heating and precise holding, the temperature change is matched with the dissolution pattern of impurities, reducing the damage to the crystal structure of quartz sand caused by sudden temperature rises and falls or sustained high temperatures. This effectively ensures the stability of the physical properties of quartz sand and ultimately achieves a significant improvement in the purity of quartz sand, meeting the demand for high-purity quartz sand in high-end fields.

[0022] The quartz sand gradient heating acid leaching purification control method provided in this application embodiment can be applied to quartz sand gradient heating acid leaching purification equipment. In this case, the quartz sand gradient heating acid leaching purification equipment is the executing subject of the quartz sand gradient heating acid leaching purification control method provided in this application embodiment. This application embodiment does not impose any restrictions on the specific type of quartz sand gradient heating acid leaching purification equipment.

[0023] For example, a gradient temperature acid leaching purification device for quartz sand may include a heating device, an acidity monitoring device, and a control device. The control device is electrically connected to the heating device and the acidity monitoring device. The heating device is used to heat and maintain the temperature of the material. For example, it can use electric heating, heat transfer oil heating, or steam heating; that is, the heating device can be an electric heating tube assembly, a heat transfer oil heating jacket, or a steam heating coil, but is not limited to these. The acidity monitoring device is used to monitor and control the concentration of the purification acid solution. For example, the acidity detection device may include an acidity sensor and a replenishment and adjustment component. The acidity sensor is used to detect the concentration of the acid solution in real time. For example, the acidity sensor can be a corrosion-resistant glass electrode pH sensor or an ion-selective electrode, directly immersed in the acid leaching reaction system, to collect the pH value or specific acid anion concentration signal of the acid solution in real time. The replenishment and adjustment component is used to replenish concentrated acid to regulate the concentration of the acid solution. For example, the replenishment and regulation assembly includes a concentrated acid storage tank, a metering pump, a solenoid valve, and a flow sensor. The concentrated acid storage tank is used to store the concentrated acid to be replenished; the metering pump is used to control the amount of acid replenished; the solenoid valve is installed in the pipeline between the metering pump and the acid leaching reaction vessel for quickly switching the acid replenishment circuit on and off; and the flow sensor monitors the acid flow rate in the acid replenishment pipeline in real time. The control device monitors and controls the entire process.

[0024] For example, the control device can be a PLC, microcontroller, mobile phone, tablet computer, laptop computer, ultra-mobile personal computer (UMPC), netbook, desktop computer, smart screen, smart TV and other terminal devices, Internet of Things terminal, computer, laptop computer, handheld communication device, handheld computing device, customer premises equipment (CPE) and / or other devices used for communication on wireless systems, as well as next-generation communication systems, such as mobile terminals in 5G networks or mobile terminals in future evolved Public Land Mobile Network (PLMN), etc.

[0025] To better understand the gradient temperature rise acid leaching purification control method for quartz sand provided in the embodiments of this application, the specific implementation process of the gradient temperature rise acid leaching purification control method for quartz sand provided in the embodiments of this application will be described by way of example below.

[0026] Figure 1 This illustration shows a schematic flowchart of the gradient temperature acid leaching purification control method for quartz sand provided in an embodiment of this application. The gradient temperature acid leaching purification control method for quartz sand includes: S100, in response to the initial heating operation, acquires initial purification information; wherein, the initial heating operation is used to indicate the operation of the heating device heating to the target temperature of the first stage for the first time.

[0027] It can be understood that initial purification information refers to the changes in acid parameters (initial concentration, acidity value, etc.) and quartz sand raw material parameters (particle size, specific surface area, etc.) in the acid leaching system during the initial heating process. Acid parameters can be obtained through an acidity sensor. Quartz sand raw material parameters can be obtained by acquiring images of the quartz sand using imaging equipment such as a camera, and then using particle morphology analysis algorithms to extract the contours of the segmented quartz sand particle images, obtaining characteristic parameters such as the circumcircle diameter and equivalent area diameter of the quartz sand particles.

[0028] S200, based on initial purification information, generates an acidity-dissolution rate coupled sequence.

[0029] It can be understood that the acidity-dissolution rate coupling sequence is a three-dimensional time-series data sequence that correlates dynamically collected acid parameters (acidity value, concentration, etc.) during the initial heating process with quartz sand raw material parameters (particle size distribution, specific surface area, etc.) through reaction kinetics. Dissolution rate refers to the amount of impurities in the quartz sand dissolved into the acid solution. The dissolution rate can be calculated by obtaining real-time acidity values ​​from an acidity sensor and converting them into real-time hydrogen ion concentration [H+]. + ] t Combined with the initial [H + Given the acid volume V and 0, calculate the cumulative acid consumption molar amount Δn (Δn = ([H + ]0-[H + ] t ()×V), and then based on the reaction of impurities with acids (e.g., in the initial stage of the reaction, to remove iron impurities, through the chemical formula Fe2O3 + 6H+), + =2Fe 3+ +3H₂O, meaning 1 mol Fe₂O₃ consumes 6 mol H₂O. + That is, the dissolution rate of impurities is obtained based on the concentration of hydrogen ions.

[0030] S300, based on the acidity-dissolution rate coupling sequence, determines the first holding time for the target temperature in the first stage.

[0031] It can be understood that the first holding time is the duration for which the quartz sand maintains the acid leaching reaction at the target temperature in the first stage. The core purpose is to maximize the dissolution of easily soluble impurities in the corresponding stage within this temperature range. For example, a key change sequence can be extracted based on the acidity-dissolution rate coupling sequence. This key change sequence can be used as a reference analysis stage to analyze the acid leaching situation in the key change sequence, indirectly reflecting the amount of impurities that need to be dissolved in this stage, thereby determining the first holding time at the target temperature of the first stage. Alternatively, the initial acidity A0 (e.g., pH=1.8) can be used as the acidity value when the temperature is raised to the target temperature of the first stage, and the real-time acidity A0 can be recorded per unit time thereafter. tCalculate the cumulative acid consumption rate η, and then, based on historical data, set the first-stage acid consumption rate threshold η_max (e.g., η_max = 35%). That is, when the acid consumption reaches 35% of the initial amount, the easily soluble impurities in this stage have been basically dissolved. Then, find the time t when the acid consumption rate reaches η_max from the acidity-dissolution rate coupling sequence. a Simultaneously record the dissolution rate Ra at this point. If Ra ≥ R_target, directly use t... a As the first holding time; if Ra < R_target, calculate the additional acid consumption rate Δη = (R_target - Ra) / (Rmax - R0) × (η_max - η0) (Rmax is the maximum dissolution rate in this stage), and then calculate the additional holding time Δt. The final holding time = t a +Δt, etc., but not limited to these.

[0032] In one possible implementation, in step S300, determining the first holding time for the target temperature of the first stage based on the acidity-dissolution rate coupling sequence includes: S310, based on the acidity-dissolution rate coupled sequence, extracts key change sequences.

[0033] It can be understood that the key change sequence is a core segment extracted from the complete acidity-dissolution rate coupling sequence, focusing on the critical reaction stages of efficient acid consumption and rapid dissolution of impurities during the heating process. For example, based on the acidity-dissolution rate coupling sequence, the acidity change rate and dissolution rate change rate can be calculated, then the inflection point of dissolution rate change can be determined based on the dissolution rate change rate, and the key change sequence can be extracted based on the acidity change rate and dissolution rate change inflection point. Alternatively, a Pearson correlation coefficient r between the acidity change and dissolution rate change within each window can be calculated using a preset unit time (e.g., 5 minutes) as a sliding window (the closer r is to 1, the stronger the correlation), forming a window-correlation coefficient sequence. Then, a correlation threshold r_threshold (e.g., 0.8) can be set, and windows with r ≥ r_threshold are determined as strongly correlated windows. Continuous strongly correlated windows are then merged into a data cluster. Finally, the length (including the time span) and average correlation coefficient of each data cluster are calculated, and the data cluster with the longest length and the largest average r value is selected. The corresponding original coupling sequence segment is the key change sequence, and so on, but not limited to these methods.

[0034] In one possible implementation, in step S310, based on the acidity-dissolution rate coupling sequence, key change sequences are extracted, including: S311, based on the acidity-dissolution rate coupled sequence, calculates the rate of change of acidity and the rate of change of dissolution rate between adjacent data points.

[0035] It is understandable that the acidity change rate reflects the rate at which the acidity of the solution is consumed per unit time. The dissolution rate change rate reflects the efficiency of impurity dissolution per unit time. Because pH exhibits a non-linear relationship and cannot directly reflect the true change in acid reactivity, the acidity change rate can be calculated based on hydrogen ion concentration, i.e., the formula is: ΔA n = (A n+1 -A n ) / Δt, where A n+1 Let A be the hydrogen ion concentration at the (n+1)th data point. n Let be the hydrogen ion concentration at the nth data point. Since the acid is continuously consumed by impurities during the reaction, the hydrogen ion concentration gradually decreases. Therefore, the acidity change rate is usually negative; the larger the absolute value, the faster the acid is consumed and the more vigorous the reaction. For example, the acidity change rate ΔA at the above data point is ΔA = (0.105 - 0.12) / 1 = -0.015 mol / (L·min), and the absolute value of 0.015 mol / (L·min) represents the acid consumption rate during that time period. The formula for calculating the dissolution rate change rate (ΔR / Δt) is: ΔR n = (R n+1 -R n ) / Δt, where R n+1 R represents the dissolution rate at the (n+1)th data point. n Let be the dissolution rate at the nth data point. The dissolution rate gradually increases as the reaction proceeds, so the rate of change of dissolution rate is usually positive; the larger the value, the faster the impurities dissolve. For example, the rate of change of dissolution rate at the above data point is ΔR = (28% - 25%) / 1 = 3% / min, which means that the impurity dissolution rate increased by 3 percentage points within that minute.

[0036] S312, determine the inflection point of dissolution rate change based on the dissolution rate change rate.

[0037] It is understandable that the inflection point of dissolution rate change is a critical time point in the acid leaching reaction where the efficiency of impurity dissolution changes fundamentally shifts, specifically manifested as a change in the dissolution rate change rate from a slow increase to a rapid increase. The dissolution rate change rate sequence can be iterated point by point in chronological order to find the time point that first satisfies the condition that "the dissolution rate change rate of three consecutive data points is greater than the slow increase threshold, and the change rate of the subsequent data point increases by ≥50% compared to the previous one." This time point is the potential inflection point. For example, if the dissolution rate change sequence is 0.9% / min, 1.1% / min, 1.3% / min (all ≤1.4% / min, slowly increasing), 2.1% / min (>1.4% / min, an increase of 61.5% compared to before), 3.2% / min (an increase of 52.4% compared to before), and 4.0% / min (an increase of 25% compared to before), then the starting point where three consecutive values ​​exceed the threshold and meet the growth rate requirement (the timestamp t=13min corresponding to 2.1% / min) is the inflection point. In addition, the validity of the inflection point can be further confirmed: when the dissolution rate enters the rapid increase stage, the acid consumption rate will inevitably accelerate synchronously. If the acidity change rate (the rate of decrease in hydrogen ion concentration) increases from ≤0.01mol / (L・min) to ≥0.015mol / (L・min) before and after the time point corresponding to the potential inflection point, and two consecutive data points remain at a high level, it indicates that the acid consumption and dissolution efficiency increase trends are consistent, and the inflection point is valid. Otherwise, the inflection point is invalid and needs to be searched again.

[0038] S313, extracting key change sequences based on the inflection points of acidity change rate and dissolution rate change.

[0039] For example, the acidity abrupt change time point where the first acidity change rate exceeds a preset threshold can be determined based on the acidity change rate. Then, the corresponding dissolution rate easing time point can be determined based on the dissolution rate change inflection point. Finally, the time period corresponding to the acidity abrupt change time point and the dissolution rate easing time point can be extracted into the acidity-dissolution rate coupling sequence and identified as the key change sequence. Alternatively, based on the acidity change rate sequence, the time point where the absolute value of the acidity change rate of three consecutive data points is greater than the preset acidity threshold and the increase of the subsequent data point is greater than that of the previous one can be found as the acidity change inflection point. Then, the dissolution rate change inflection point is compared with the acidity change inflection point. If the time difference between the two is less than a preset time (strong synergistic reaction), the acidity change inflection point is taken as the starting point and the end time when the dissolution rate change rate remains above 80% of the peak value after the dissolution rate change inflection point is taken as the ending point. The coupling sequence fragment within the time interval is extracted as the key change sequence in this way, and so on, but not limited to these.

[0040] This setup, by calculating dual change rates and identifying dissolution inflection points to extract key change sequences, captures the activation state of acid reaction activity through acidity change rate and defines the turning point of reaction efficiency by dissolution rate change inflection point. This allows the key change sequences to fully reflect the strong correlation and coupling characteristics between acid consumption and impurity dissolution, significantly improving the targeting and efficiency of subsequent first holding time calculations.

[0041] In one possible implementation, step S313 involves extracting key change sequences based on the inflection points of acidity change rate and dissolution rate changes, including: S3131, determine the acidity mutation time point when the acidity change rate first exceeds the preset change rate threshold based on the acidity change rate.

[0042] It is understandable that the preset change rate threshold is a pre-set acidity change rate. It can be manually input or obtained from the acid leaching database. The acid leaching database is a database that contains preset change rate thresholds. These data can be obtained through laboratory experiments, on-site measurements and monitoring, and past experience. After obtaining the data, it is sorted, classified and archived, useful information and patterns are extracted, and the relevant data is saved into the database to form the acid leaching database.

[0043] S3132, determine the corresponding dissolution rate easing time point based on the inflection point of dissolution rate change.

[0044] It can be understood that the dissolution rate easing point is the critical time point when the impurity dissolution efficiency transitions from rapid growth to a gradual and stable state. Using the dissolution rate change rate at the inflection point as the peak rate, a easing threshold ratio is set (usually 30%-50%). When the dissolution rate change rate drops below the product of the peak rate and the easing threshold ratio, and shows no significant rebound for three consecutive data points, the corresponding time point is the dissolution rate easing point. For example, if the peak rate at the dissolution rate change inflection point is 3% / min, and the easing threshold ratio is set to 40%, then the easing judgment value is 1.2% / min. When the dissolution rate change rate remains below 0.2% / min for three consecutive minutes (e.g., 1.1%, 1.0%, 0.9% / min), the timestamp corresponding to the third data point (e.g., t=35min) is the dissolution rate easing point.

[0045] S3133, the time periods corresponding to the acidity mutation time point and the dissolution rate easing time point were extracted from the acidity-dissolution rate coupled sequence and identified as the key change sequence.

[0046] It can be understood that aligning the acidity mutation time point and the dissolution rate easing time point with the acidity-dissolution rate coupling sequence at the time boundary, and extracting the corresponding segments of the acidity-dissolution rate coupling sequence, yields the key change sequence.

[0047] With this setup, the dual boundaries of the acidity mutation time point and the dissolution rate easing time point accurately lock the key change sequence. The key change sequence can truly reflect the strong correlation and coupling characteristics between acid consumption and impurity dissolution, making subsequent process parameter optimization more in line with the nature of the reaction and significantly enhancing the adaptability of the purification control method to raw material batch fluctuations and acid concentration changes.

[0048] S320, based on the key change sequence, determines the first holding time for the target temperature in the first stage.

[0049] For example, the corresponding impurity dissolution amount can be calculated based on the key change sequence, and the first holding time of the target temperature in the first stage can be determined according to the heating temperature corresponding to the end of the key change sequence; alternatively, the preset dissolution rate target in this stage can be determined first, and then the dissolution rate-time curve can be obtained from the key change sequence. The fitting equation of the curve can be calculated (such as linear fitting R(t)=a×t+b, or nonlinear fitting R(t)=R_max × [1-e^(-k × t)], where a, b, and k are fitting parameters, and R_max is the maximum dissolution rate in this stage). The preset dissolution rate target R_target is substituted into the fitting equation to calculate the total time t_total required to reach the target dissolution rate. Then, the time consumed by the subsequent heating process of the key change sequence is subtracted to obtain the required holding time, etc., but not limited to these methods.

[0050] This setup allows for the precise extraction of core reaction segments involving efficient acid consumption and rapid impurity dissolution from the complete acidity-dissolution rate coupling sequence. It effectively eliminates redundant data with slow reactions and weak correlations, significantly improving the targeting of subsequent holding time calculations. Then, based on the strong correlation dynamic characteristics between acidity and dissolution rate in the key change sequence, and combined with the kinetics of acid leaching reactions, it adapts to complex working conditions such as raw material batch fluctuations and changes in acid reaction state. This significantly reduces acid waste and energy consumption, while improving the stability and consistency of quartz sand purification quality.

[0051] In one possible implementation, step S320, determining the first holding time for the target temperature of the first stage based on the key change sequence, includes: S321, calculate the corresponding impurity dissolution amount based on the key change sequence; wherein, the impurity dissolution amount is used to indicate the total amount of impurities dissolved within the time of the key change sequence.

[0052] Understandably, firstly, the dissolution rate data for each time node in the key change sequence is extracted, and the cumulative dissolution amount for each node is calculated. Secondly, the difference between the cumulative dissolution amounts of adjacent time nodes is taken to obtain the instantaneous dissolution amount for each time interval. All instantaneous dissolution amounts are summed to obtain the total amount of impurities dissolved during the key change sequence period.

[0053] S322, extract the heating temperature corresponding to the end of the key change sequence.

[0054] It is understandable that each data point in the key change sequence contains three-dimensional information of timestamp, acidity, and dissolution rate, and shares the same time axis with the real-time data acquired by the temperature sensor. When extracting, the timestamp of the last data point in the key change sequence is directly located and matched with the real-time heating temperature corresponding to that timestamp in the temperature acquisition system, which is the target temperature data.

[0055] S323, the first holding time for determining the target temperature of the first stage based on the amount of impurity leaching and the heating temperature.

[0056] For example, the temperature difference between the heating temperature and the target temperature of the first stage can be calculated, and the basic holding time can be matched based on the amount of impurities dissolved. Then, a correction factor can be generated based on the temperature difference, and finally, the first holding time for the target temperature of the first stage can be determined based on the basic holding time and the correction factor. Alternatively, the average dissolution rate of the key change sequence can be calculated, and the remaining amount of impurities in the first stage holding stage can be derived based on the amount of impurities dissolved. Then, the remaining amount of impurities dissolved in the heating stage can be calculated based on the difference between the heating temperature and the target temperature of the first stage. The holding time can be calculated based on the remaining amount of impurities and the average dissolution rate, and so on, but not limited to these methods.

[0057] This setup first accurately calculates the total amount of impurities dissolved based on key change sequences, intuitively reflecting the dissolution progress in the efficient reaction stage and providing a quantitative basis for the required holding time. Then, it extracts the heating temperature at the end of the sequence to clarify the actual achievement of the target temperature in the first stage, laying a benchmark for the dissolution efficiency of subsequent holding. Finally, through the synergistic analysis of both, it determines the required additional reaction time by combining the dissolution gap and matches the corresponding dissolution rate based on temperature conditions, so that the holding time is precisely adapted to the actual reaction requirements.

[0058] In one possible implementation, step S323, determining the first holding time for the target temperature of the first stage based on the amount of impurity leaching and the heating temperature, includes: S3231 calculates the temperature difference between the heating temperature and the target temperature of the first stage.

[0059] It can be understood that the temperature difference = the target temperature of the first stage - the heating temperature corresponding to the end of the key change sequence.

[0060] S3232, based on the amount of impurities dissolved, matching the basic heat preservation time.

[0061] It's understandable that different levels of impurity leaching correspond to a specific baseline holding time. The baseline holding time can be matched to the impurity leaching level in an acid leaching database.

[0062] S3233, a correction factor is generated based on temperature difference.

[0063] The correction factor is understood to be a coefficient generated by quantifying the impact of temperature deviation on dissolution efficiency based on temperature difference, and used to adjust the basic holding time. Its core function is to compensate for the gap caused by the actual temperature not meeting the target, thus ensuring the holding time is compatible with the temperature conditions. The generation of the correction factor closely follows the kinetics of acid leaching reactions; the lower the temperature, the larger the correction factor. The temperature difference can be matched with the corresponding correction factor in the acid leaching database. In acid leaching reactions, the dissolution rate typically increases by 1-2 times for every 10°C increase in temperature (derived from the Arrhenius equation). The base value of the correction factor f is set to 1 (no correction is needed when the temperature difference ΔT = 0), f = 1 + (ΔT / 10) × k, where k is the temperature influence coefficient (calibrated using historical data, typically taken as 0.8-1.2, e.g., k = 1.0). For example, if ΔT = 7°C and k = 1.0, then f = 1 + (7 / 10) × 1.0 = 1.7.

[0064] S3234, the first insulation time for determining the target temperature of the first stage is based on the basic insulation time and the correction factor.

[0065] It is understandable that the first insulation time = the basic insulation time × the correction factor.

[0066] This setup first quantifies the impact of temperature deviation on leaching efficiency by calculating the temperature difference between the heating temperature and the target temperature of the first stage. Then, it matches the basic holding time to the gap between the impurity leaching amount and the preset leaching target, meeting the core leaching requirements. Subsequently, a correction factor is generated based on the temperature difference to dynamically compensate for leaching efficiency fluctuations caused by temperature deviations. Finally, through the coordinated calculation of the basic holding time and the correction factor, a precise holding time that adapts to both the leaching progress and the temperature conditions is obtained. This method reduces the blindness of traditional experience-based holding time settings that ignore leaching gaps and temperature fluctuations. It can dynamically respond to complex conditions such as batch differences in raw materials and deviations in the heating process. While efficiently achieving the impurity leaching target in the first stage, it significantly reduces acid waste and energy consumption, greatly improving the stability of quartz sand purification quality and the accuracy of process control.

[0067] S400, obtain the impurity dissolution curve under the first holding time.

[0068] It can be understood that the impurity dissolution curve is a continuous curve showing the change in the amount of impurities dissolved as a function of the holding time during the first holding stage. Taking the start time of the first holding time as the zero point, acid samples and corresponding dissolution data are acquired synchronously at a fixed acquisition frequency (e.g., once every 3 minutes), and converted into cumulative dissolution amount. At the same time, the corresponding timestamps are recorded. The time and dissolution amount data points are connected in sequence to form a continuous impurity dissolution curve.

[0069] S500, a second heating operation is determined based on the impurity dissolution curve; wherein, the second heating operation is used to indicate the heating rate of the heating device from the target temperature of the first stage to the target temperature of the second stage.

[0070] It is understandable that the impurity dissolution curve can reflect the stability of the reaction system and the dissolution state of the impurities. Therefore, the core of determining the second heating operation is to adapt the heating rate to the subsequent dissolution requirements of the poorly soluble impurities. For example, multiple curve slope characteristic values ​​can be generated based on the impurity dissolution curve, and then the mean and variance of these characteristic values ​​can be calculated. The second heating operation can then be determined based on the mean and variance. Alternatively, the endpoint characteristics of the impurity dissolution curve can be directly matched to the corresponding heating rate, and so on, but not limited to these methods.

[0071] In one possible implementation, in step S500, determining the second heating operation based on the impurity dissolution curve includes: S510 generates multiple curve slope characteristic values ​​based on the impurity dissolution curve; among them, the curve slope characteristic values ​​are used to indicate the change in the amount of impurities dissolved per unit time.

[0072] It can be understood that the curve slope characteristic value is the rate of change of impurity dissolution amount per unit time in each segment of the impurity dissolution curve. Its core function is to quantify the dissolution efficiency at different times during the first heat preservation stage and accurately capture the rhythmic changes in impurity dissolution. The curve slope characteristic value for each segment is calculated by performing a linear fit on the time-dissolution data within each time interval. The slope of the fitted line is the curve slope characteristic value for that segment (unit: kg / min or % / min). For example, in the 0-10 min interval, the dissolution amount increases from 6.8 kg to 8.2 kg. After linear fitting, the slope is (8.2-6.8) / 10 = 0.14 kg / min, which is the curve slope characteristic value for that segment.

[0073] S520 calculates the mean and variance of the slope characteristics of multiple curves.

[0074] It is understandable that the mean reflects the average rate of impurity leaching during the first heat preservation stage, while the variance reflects the degree of fluctuation in the leaching rate at different time periods.

[0075] S530 determines the second heating operation based on the mean and variance.

[0076] For example, the mean can be compared with a mean threshold, and the variance can be compared with a variance threshold. Based on different comparisons, a corresponding second heating operation can be matched. Alternatively, the mean and variance can be input into the learning model, and the model can output the corresponding second heating operation, and so on, but not limited to these methods. The training process of the learning model is as follows: collect complete production data for nearly 100-200 batches of gradient heating acid leaching of quartz sand, ensuring that the data covers different raw material impurity contents, acid concentrations, target temperatures in the first stage, and other operating conditions. Each batch of data must include: the impurity leaching curve of the first holding stage (used to calculate the mean and variance), the corresponding second heating operation (i.e., the actual heating rate v), and the second-stage leaching effect indicators after heating (such as the leaching rate of sparingly soluble impurities and product purity). The mean and variance are used as input features of the model, and the optimal heating rate is used as the output label to construct training samples. The optimal heating rate is labeled as follows: select the actual heating rate in the corresponding batch that ensures the dissolution rate of sparingly soluble impurities in the second stage is ≥ the preset target (e.g., 70%) and the acid loss rate is ≤ 5%; if multiple rates meet the conditions in a batch, take the average as the label. Divide the constructed samples into a training set (for model parameter learning), a validation set (for adjusting hyperparameters and avoiding overfitting), and a test set (for evaluating the final performance of the model) in a 7:2:1 ratio, and select a model that is suitable for small samples and has good regression prediction performance (e.g., Gradient Boosting Regression Tree (GBRT), Support Vector Regression (SVR), or Lightweight Neural Network (MLP). The model is trained using the training set data: Model hyperparameters are set (e.g., tree depth and learning rate for GBRT; kernel function type and penalty coefficient for SVR), with mean squared error (MSE) used as the loss function to measure the deviation between the model's predicted rate and the true label. During training, the MSE change on the validation set is monitored in real time. If the validation set MSE increases for five consecutive epochs, an early stopping strategy is adopted to prevent overfitting. Simultaneously, hyperparameters are optimized through cross-validation (e.g., 5-fold cross-validation) to improve the model's generalization ability. Model performance is evaluated using the test set data. Core evaluation metrics include: mean squared error (MSE ≤ 0.001, ensuring a small deviation between the predicted rate and the true value), coefficient of determination (R² ≥ 0.9, ensuring the model can explain most rate changes), and mean absolute error (MAE ≤ 0.2℃ / min, ensuring controllable error in practical applications). If the evaluation metrics are not met, the model is returned to the data preprocessing stage to supplement more working condition data, or the model hyperparameters are adjusted, the model type is changed, and retraining is performed. If the metrics are met, the model is denormalized (restoring the true numerical range of the input and output) to generate a final model that can be directly deployed.

[0077] This setup quantifies the impurity leaching rate at different times during the first heat preservation stage by using multiple curve slope characteristic values, comprehensively capturing changes in the leaching rhythm. Secondly, statistical analysis of the mean and variance enables a dual quantitative assessment of the overall leaching efficiency and the stability of the reaction system. The mean is used to lock in the basic range of the heating rate (adapting to leaching activity), while the variance is used to fine-tune the rate parameters (adapting to system stability), transforming the heating operation from experience-based judgment to scientific calculation. Finally, this logic deeply aligns with the kinetics of acid leaching reactions, enabling dynamic responses to complex conditions such as raw material batch fluctuations and differences in the leaching effect in the first stage.

[0078] In one possible implementation, step S530, determining the second heating operation based on the mean and variance, includes: S531, when the mean is greater than the upper limit of the mean threshold and the variance is less than the variance threshold, the second heating operation is determined to be heating at the first preset heating rate.

[0079] It is understandable that both the mean threshold and the variance threshold are preset values, which can be manually entered or obtained from the acid leaching database. When the mean is greater than the upper limit of the mean threshold and the variance is less than the variance threshold, it means that the average rate of impurity leaching in the first heat preservation stage is much higher than expected (mean exceeds the upper limit of the threshold), and the leaching rate fluctuates little in each time period (variance is less than the threshold). At this point, the easily soluble impurities have been basically exhausted, and the focus should then be on dissolving the sparingly soluble impurities. The first preset heating rate is set to the highest value, which can quickly raise the temperature to the target value of the second stage, shorten the production cycle, and ensure the stability of the reaction system.

[0080] S532, when the mean is within the mean threshold range and the variance is less than the variance threshold, determine that the second heating operation is to heat up at the second preset heating rate.

[0081] It is understandable that when the mean is within the mean threshold range and the variance is less than the variance threshold, it indicates that the dissolution progress of easily soluble impurities has met the standard and the reaction system is stable. The second preset heating rate is set to an intermediate value to balance production efficiency and reaction stability: it will not disrupt the existing stable environment due to an excessively fast rate, nor will it prolong the heating cycle due to an excessively slow rate, thus ensuring a smooth transition to the second stage and providing continuous and stable temperature conditions for the dissolution of sparingly soluble impurities.

[0082] S533, when the mean is less than the lower limit of the mean threshold or the variance is greater than the variance threshold, the second heating operation is determined to be heating at the third preset heating rate; wherein, the first preset heating rate is greater than the second preset heating rate, and the second preset heating rate is greater than the third preset heating rate.

[0083] It is understandable that when the mean is less than the lower limit of the mean threshold or the variance is greater than the variance threshold, it indicates that there may still be residual easily soluble impurities. Slow heating can give the residual easily soluble impurities sufficient time to dissolve, avoiding premature heating that would affect their dissolution; at the same time, it reduces the disturbance to the unstable system during the heating process and reduces the risk of acid volatilization and particle agglomeration.

[0084] S600, acquire the stage purification information of the second heating operation, and determine the second holding time of the target temperature of the second stage based on the stage purification information; wherein, the stage purification information is used to reflect the purification characteristics of the acid solution during the process of heating from the target temperature of the first stage to the target temperature of the second stage.

[0085] It is understandable that the purification process in the subsequent stages is fundamentally different from that in the initial stages. The first stage focuses on the rapid dissolution of easily soluble impurities (such as iron and aluminum oxides), with mild reaction conditions and high dissolution efficiency. The subsequent stages target insoluble impurities (such as silicides and some calcium and magnesium compounds). These impurities have more stable chemical bonds, and the purification phenomena they exhibit are also different. The dissolution process is characterized by a long induction period, slow reaction rate, and high sensitivity to temperature and acid environment. The corresponding purification phenomena are also quite different (such as a gradual increase in dissolution during heating, a decrease in acid viscosity with increasing temperature but an increase in volatility, and the need for high-temperature activation of dissolution sites on the surface of quartz sand particles).

[0086] For example, the dissolution rate of deep impurities per unit time can be obtained based on the steady-state value of acid concentration and the target temperature of the second stage. Then, based on the cumulative dissolution amount of impurities and the dissolution rate of deep impurities, the initial holding time can be obtained. The compensation time can be determined based on the dissolution delay time of deep impurities. The second holding time can be obtained based on the initial holding time and the compensation time. Alternatively, the key features of the curves of temperature and dissolution increment of sparingly soluble impurities in the stage purification information can be extracted, focusing on the temperature range with the most significant dissolution increment. By calculating the cumulative dissolution increment and average dissolution rate in this range, and combining the characteristics of long induction period and slow rate of sparingly soluble impurities, the basic holding time can be matched. If the dissolution increment meets the target and the rate is stable, it can be set at 1.5 times the basic time. If the rate is on the rise, it can be extended by 2 times to cover the stable dissolution stage. If the rate is extremely low, a basic value is set and the target temperature is adjusted subsequently. At the same time, the induction period compensation time can be superimposed.

[0087] In one possible implementation, in step S600, the stage purification information includes the cumulative amount of impurities dissolved, the steady-state value of the acid concentration, and the leaching delay time of deep impurities. Based on the stage purification information, the second holding time for determining the target temperature of the second stage includes: S610, based on the steady-state value of acid concentration, yields the dissolution rate of deep impurities per unit time.

[0088] It can be understood that the steady-state acid concentration is the value at which the acid concentration no longer decreases significantly and tends to stabilize during the second heating process. In this state, the reaction between the acid and the sparingly soluble impurities reaches a dynamic equilibrium, reflecting the acid's ability to dissolve deep impurities. The target temperature in the second stage is the core condition for activating the dissolution of deep, sparingly soluble impurities; the higher the temperature, the lower the dissolution barrier and the stronger the reactivity. The steady-state acid concentration can be numerically matched with the acid concentration during the second heating process to obtain the time point at which the steady-state acid concentration first appears. Then, based on the steady-state acid concentration and time, the dissolution rate of deep impurities per unit time can be calculated.

[0089] S620, based on the cumulative dissolution of impurities and the dissolution rate of deep impurities, obtains the initial heat preservation time.

[0090] It is understandable that the cumulative dissolution amount of impurities is the total amount of deep, sparingly soluble impurities that have dissolved during the second heating process, reflecting the current dissolution progress. For example, the deep impurity dissolution coefficient can be obtained based on the cumulative dissolution amount, and the target deep impurity dissolution amount can be determined based on the deep impurity coefficient. Finally, the initial holding time can be obtained based on the target deep impurity dissolution amount and the deep impurity dissolution rate. Alternatively, the maximum allowable residual amount of deep impurities after the second stage can be clearly defined, and the total content of deep impurities at the end of the second heating process can be calculated based on the cumulative dissolution amount. The required additional dissolution amount = total content - cumulative dissolution amount of impurities; then, the required additional dissolution amount is divided by the deep impurity dissolution rate to obtain the initial holding time, and so on, but not limited to these methods.

[0091] In one possible implementation, in step S620, the initial holding time is obtained based on the cumulative dissolution amount of impurities and the dissolution rate of deep impurities, including: S621, the deep impurity dissolution coefficient is obtained based on the cumulative dissolution amount of impurities.

[0092] It can be understood that the deep impurity dissolution coefficient refers to the ability of impurities to dissolve at a given stage. Different cumulative dissolution amounts of impurities correspond to different deep impurity dissolution coefficients. The cumulative dissolution amounts of impurities can be matched against an acid leaching database to obtain the corresponding deep impurity dissolution coefficients.

[0093] S622, Determine the target deep impurity solubility based on the deep impurity coefficient.

[0094] It's understandable that the target deep impurity solubility is the amount of dissolution required during the second-stage heat preservation process. A larger coefficient indicates stronger dissolution capacity, more deep impurities, and a greater amount of dissolution required, meaning more undissolved deep impurities can still be extracted. The target deep impurity solubility can be matched using the deep impurity coefficient.

[0095] S623, based on the target deep impurity solubility and deep impurity dissolution rate, the initial heat preservation time is obtained.

[0096] It can be understood that the initial heat preservation time = target deep impurity dissolution amount ÷ deep impurity dissolution rate.

[0097] This setup allows for the quantification of the dissolution capacity and the deep impurity dissolution coefficient based on the cumulative dissolution amount of impurities. Then, based on this coefficient, the target deep impurity dissolution amount is predicted to be suitable for the current working conditions. Finally, the initial holding time is obtained through the quantitative calculation of the target deep impurity dissolution amount and the deep impurity dissolution rate. This allows the initial holding time to dynamically respond to changes in the working conditions of raw material batches and dissolution progress.

[0098] S630 determines the compensation time based on the leaching delay time of deep impurities.

[0099] It is understandable that heat needs to be transferred from the acid solution to the interior of the quartz sand particles to activate the dissolution of deep impurities. At high temperatures, the chemical reaction between the acid solution and the impurities also requires a start-up and acceleration process. The deep impurity dissolution delay time refers to the lag time from the arrival of the target temperature in the second stage and the start of the holding period to the actual dissolution of deep, insoluble impurities at a stable rate. The deep impurity dissolution delay time is calculated starting from the beginning of the heating phase in the second stage. Then, based on the changes in acid concentration in the stage purification information, the time point when the change in acid concentration exceeds a preset threshold is taken as the end point of the deep impurity dissolution delay time. A compensation time is corresponding to the deep impurity dissolution delay time.

[0100] S640, the second insulation time is obtained based on the initial insulation time and the compensation time.

[0101] It is understandable that the second insulation time = initial insulation time + compensation time.

[0102] This setup allows for precise acquisition of the stable dissolution rate of deep impurities by using the steady-state value of acid concentration. Combined with the cumulative dissolution amount of impurities, the initial holding time required to meet the core dissolution requirements is calculated. Simultaneously, considering the time required for heat transfer and the lag in reaction start-up of deep, sparingly soluble impurities, a compensation time is set based on the dissolution delay time to cover the reaction start-up period. Finally, the second holding time is obtained by integrating the initial time and the compensation time, achieving refined control of the second-stage purification process. This reduces the residue of sparingly soluble impurities due to insufficient holding time, while also reducing acid loss and energy waste caused by excessive holding time. Furthermore, it dynamically adapts to the dissolution patterns of deep impurities and changes in the process environment, ensuring the consistency of product quality and the stability of production efficiency.

[0103] It should be noted that if there are subsequent stages, such as the third stage or the fourth stage, the heating rate of the heating stage and the holding time of the holding stage can be obtained through steps S400 to S600.

[0104] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0105] Corresponding to the quartz sand gradient temperature acid leaching purification control method described in the above embodiments, this application also provides a quartz sand gradient temperature acid leaching purification control system. Each module of this system can realize each step of the quartz sand gradient temperature acid leaching purification control method. Figure 2 The diagram shows a structural block diagram of the quartz sand gradient heating acid leaching purification control system provided in the embodiments of this application. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0106] Reference Figure 2 The quartz sand gradient temperature acid leaching purification control system includes: The first acquisition module is used to acquire initial purification information in response to the initial heating operation; wherein the initial heating operation is used to indicate the operation of the heating device to heat to the target temperature of the first stage for the first time.

[0107] The generation module is used to generate acidity-dissolution rate coupled sequences based on initial purification information.

[0108] The first determining module is used to determine the first holding time for the target temperature in the first stage based on the acidity-dissolution rate coupling sequence.

[0109] The second acquisition module is used to acquire the impurity dissolution curve during the first heat preservation time.

[0110] The second determining module is used to determine the second heating operation based on the impurity dissolution curve; wherein the second heating operation is used to indicate the heating rate of the heating device from the target temperature of the first stage to the target temperature of the second stage.

[0111] The third determining module is used to acquire the stage purification information of the second heating operation, and to determine the second holding time of the target temperature of the second stage based on the stage purification information; wherein, the stage purification information is used to reflect the purification characteristics of the acid solution during the process of heating from the target temperature of the first stage to the target temperature of the second stage.

[0112] It should be noted that the information interaction and execution process between the above modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0113] Those skilled in the art will understand that, for the sake of convenience and brevity, the above-described module division is merely an example. In practical applications, the above functions can be assigned to different modules as needed, that is, the internal structure of the system can be divided into different modules to complete all or part of the functions described above. The modules in the embodiments can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0114] This application also provides a gradient temperature acid leaching purification device for quartz sand, including a heating device, an acidity monitoring device, and a control device, wherein the control device is electrically connected to the heating device and the acidity monitoring device. Figure 3 This is a schematic diagram of the structure of a control device 6 provided in an embodiment of this application. Figure 3 As shown, the control device 6 in this embodiment includes: at least one processor 60 ( Figure 3 Only one is shown in the image), at least one memory 61 ( Figure 3 (Only one is shown in the image) and a computer program 62 stored in the at least one memory 61 and executable on the at least one processor 60. When the processor 60 executes the computer program 62, it causes the control device 6 to perform the steps in any of the above embodiments of the quartz sand gradient heating acid leaching purification control method, or causes the control device 6 to perform the functions of each module in the above system embodiments.

[0115] For example, the computer program 62 may be divided into one or more modules / units, which are stored in the memory 61 and executed by the processor 60 to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 62 in the control device 6.

[0116] The control device 6 can be a desktop computer, laptop, handheld computer, or cloud server, etc. The quartz sand gradient temperature acid leaching purification equipment may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will understand that... Figure 3This is merely an example of control device 6 and does not constitute a limitation on control device 6. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0117] The processor 60 can be a Central Processing Unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0118] In some embodiments, the memory 61 may be an internal storage unit of the control device 6, such as a hard disk or memory of the control device 6. In other embodiments, the memory 61 may be an external storage device of the control device 6, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the control device 6. Furthermore, the memory 61 may include both internal storage units and external storage devices of the control device 6. The memory 61 is used to store operating systems, applications, bootloaders, data, and other programs, such as the program code of computer programs. The memory 61 can also be used to temporarily store data that has been output or will be output.

[0119] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0120] This application provides a computer program product that, when run on a quartz sand gradient heating acid leaching purification device, enables the quartz sand gradient heating acid leaching purification device to perform the steps in any of the above-described method embodiments.

[0121] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a quartz sand gradient heating acid leaching purification device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0122] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0123] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0124] In the embodiments provided in this application, it should be understood that the disclosed quartz sand gradient temperature acid leaching purification equipment and method can be implemented in other ways. For example, the embodiments of the quartz sand gradient temperature acid leaching purification system described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0125] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for controlling the gradient temperature acid leaching purification of quartz sand, characterized in that, include: In response to the initial heating operation, initial purification information is acquired; wherein, the initial heating operation is used to indicate the operation of the heating device heating to the target temperature of the first stage for the first time; Based on the initial purification information, an acidity-dissolution rate coupled sequence is generated; Based on the acidity-dissolution rate coupling sequence, the first holding time for the target temperature in the first stage is determined. Obtain the impurity dissolution curve under the first heat preservation time; The second heating operation is determined based on the impurity dissolution curve; wherein the second heating operation is used to indicate the heating rate at which the heating device heats from the target temperature of the first stage to the target temperature of the second stage; Acquire the stage purification information of the second heating operation, and determine the second holding time for the target temperature of the second stage based on the stage purification information; wherein the stage purification information is used to reflect the purification characteristics of the acid solution during the process of heating from the target temperature of the first stage to the target temperature of the second stage.

2. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 1, characterized in that, The determination of the first holding time for the target temperature in the first stage based on the acidity-dissolution rate coupling sequence includes: Based on the acidity-dissolution rate coupled sequence, key change sequences were extracted; The first holding time for the target temperature in the first stage is determined based on the key change sequence.

3. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 2, characterized in that, The extraction of key change sequences based on the acidity-dissolution rate coupled sequence includes: Based on the acidity-dissolution rate coupling sequence, the rate of change of acidity and the rate of change of dissolution rate between adjacent data points are calculated. The inflection point of the dissolution rate change is determined based on the aforementioned dissolution rate change rate; Key change sequences were extracted based on the acidity change rate and the inflection point of the dissolution rate change.

4. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 3, characterized in that, The extraction of key change sequences based on the acidity change rate and the inflection point of the dissolution rate change includes: Based on the acidity change rate, determine the acidity abrupt change time point when the acidity change rate first exceeds a preset change rate threshold; The corresponding time point for easing dissolution rate is determined based on the inflection point of the dissolution rate change. The time periods corresponding to the acidity mutation time point and the dissolution rate easing time point are extracted from the acidity-dissolution rate coupled sequence and identified as key change sequences.

5. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 4, characterized in that, The first holding time for determining the target temperature of the first stage based on the key change sequence includes: The corresponding impurity dissolution amount is calculated based on the key change sequence; wherein, the impurity dissolution amount is used to indicate the total amount of impurities dissolved within the time period of the key change sequence. Extract the heating temperature corresponding to the end of the key change sequence; The first holding time for determining the target temperature of the first stage is based on the amount of impurity leaching and the heating temperature.

6. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 5, characterized in that, The first holding time for determining the target temperature of the first stage based on the amount of impurity leaching and the heating temperature includes: Calculate the temperature difference between the heating temperature and the target temperature of the first stage; The basic heat preservation time is matched based on the amount of impurity dissolution. A correction factor is generated based on the aforementioned temperature difference; The first insulation time for determining the target temperature of the first stage is determined based on the basic insulation time and the correction factor.

7. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 1, characterized in that, The step of determining the second heating operation based on the impurity dissolution curve includes: Based on the impurity dissolution curve, multiple curve slope feature values ​​are generated; wherein, the curve slope feature values ​​are used to indicate the change in the amount of impurity dissolved per unit time. Calculate the mean and variance of the slope characteristic values ​​of the multiple curves; The second heating operation is determined based on the mean and the variance.

8. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 7, characterized in that, The determination of the second heating operation based on the mean and the variance includes: When the mean is greater than the upper limit of the mean threshold and the variance is less than the variance threshold, the second heating operation is determined to be heating at the first preset heating rate. When the mean is within the mean threshold range and the variance is less than the variance threshold, the second heating operation is determined to be heating at the second preset heating rate. When the mean is less than the lower limit of the mean threshold or the variance is greater than the variance threshold, the second heating operation is determined to be heating at a third preset heating rate; wherein, the first preset heating rate is greater than the second preset heating rate, and the second preset heating rate is greater than the third preset heating rate.

9. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 1, characterized in that, The stage purification information includes the cumulative amount of impurities dissolved, the steady-state value of acid concentration, and the leaching delay time of deep impurities. The second holding time for determining the target temperature of the second stage based on the stage purification information includes: Based on the steady-state value of the acid concentration, the dissolution rate of deep impurities per unit time is obtained; The initial heat preservation time is obtained based on the cumulative dissolution amount of the impurities and the dissolution rate of the deep impurities; The compensation duration is determined based on the deep impurity dissolution delay time. The second insulation time is obtained based on the initial insulation time and the compensation time.

10. The method for controlling the gradient temperature acid leaching purification of quartz sand as described in claim 9, characterized in that, The initial holding time is obtained based on the cumulative dissolution amount of the impurities and the dissolution rate of the deep impurities, including: The deep impurity dissolution coefficient is obtained based on the cumulative dissolution amount of the impurities. The target deep impurity concentration is determined based on the deep impurity coefficient. The initial heat preservation time is obtained based on the target deep impurity solubility and the deep impurity dissolution rate.

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