Temperature control method for electrolytic aluminum solution purification

Abstract

The invention relates to the technical field of electrolytic aluminum, in particular to a temperature control method for purifying an electrolytic aluminum solution, which comprises the following steps: in an aluminum oxide electrolysis process, obtaining the concentration of the electrolytic aluminum solution; the electrolysis process time is divided into n analysis time periods, and the electrolytic aluminum liquid concentration in the analysis time periods is monitored; if the electrolysis of the current analysis time period does not meet the process standard, the electrolysis temperature of the analysis time period and the electrolytic aluminum liquid concentration of the analysis time period are obtained, the fluctuation influence of the electrolytic aluminum liquid concentration of the analysis time period is judged firstly through a fluctuation similarity degree method, and then the influence of the electrolysis temperature on the electrolytic aluminum liquid concentration is judged; if a signal that the electrolytic temperature has high influence on the concentration of the electrolytic aluminum liquid is generated, the concentration of the electrolytic aluminum liquid in the analysis period is subjected to difference compensation treatment, the compensated electrolytic temperature is determined, and the electrolytic temperature in the follow-up process is controlled; according to the method, the operation voltage of the electrolytic analysis time period is reasonably controlled, so that the electrolytic aluminum solution is efficiently and continuously purified.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic aluminum, and in particular to a temperature control method for purifying an electrolytic aluminum solution. Background Art

[0002] Electrolytic aluminum is aluminum obtained by electrolysis. Modern electrolytic aluminum industry production adopts cryolite-alumina molten salt electrolysis. Molten cryolite is the solvent, alumina is the solute, carbonite is the anode, and aluminum liquid is the cathode. After a strong direct current is passed through, an electrochemical reaction is carried out at the two electrodes in the electrolytic cell at 950℃-970℃.

[0003] In the existing technology, the main factors affecting the quality of electrolytic aluminum purification include the electrolysis temperature. If the electrolysis temperature is too high, although it can improve the solubility, it will increase the dissolution of impurities (such as Fe and Si), and accelerate the anode oxidation and electrolyte volatilization. If the temperature is too low, the solubility of Al2O3 decreases, resulting in precipitation and crusting, blocking the flow of electrolyte and triggering the anode effect. Therefore, in the purification process of electrolytic aluminum solution, how to improve the reasonable and accurate control of the electrolysis temperature in the electrolysis process is the key to ensuring the purification quality of the electrolytic aluminum solution. Summary of the invention

[0004] The object of the present invention is to provide a temperature control method for purifying electrolytic aluminum solution to solve at least one of the above-mentioned prior art problems.

[0005] A temperature control method for purifying an electrolytic aluminum solution comprises the following steps:

[0006] In the alumina electrolysis process, obtaining the concentration of the electrolytic aluminum liquid;

[0007] The electrolysis process time is divided into n analysis periods, and the concentration of the electrolytic aluminum liquid within the analysis period is monitored;

[0008] If the electrolysis in the current analysis period does not meet the process standard, the electrolysis temperature in the analysis period and the electrolytic aluminum liquid concentration in the analysis period are obtained, and the fluctuation similarity method is used to first determine the influence of the fluctuation of the electrolytic aluminum liquid concentration in the analysis period, and then determine the influence of the electrolysis temperature on the electrolytic aluminum liquid concentration;

[0009] If a signal indicating that the electrolysis temperature has a high impact on the concentration of the electrolytic aluminum liquid is generated, the concentration of the electrolytic aluminum liquid in the analysis period is compensated, the compensated electrolysis temperature is determined, and the electrolysis temperature in the subsequent process is controlled.

[0010] As a further technical solution of the present invention: the process of monitoring the concentration of electrolytic aluminum liquid within the analysis period:

[0011] Obtain the aluminum electrolysis liquid concentration detected at all times during the analysis period, perform fluctuation calculation on the aluminum electrolysis liquid concentrations detected at all times, and obtain the electrolysis process analysis value for the analysis period;

[0012] If the electrolysis process analysis value for the analysis period is less than the electrolysis process analysis threshold, it indicates that in the current alumina electrolysis process, the concentration of the electrolyzed aluminum liquid obtained does not meet the process requirements, and an electrolysis inefficiency signal is generated.

[0013] As a further technical solution of the present invention: the obtaining method of the electrolysis process analysis value for the analysis period:

[0014] Perform a product operation on the electrolysis concentration average value and the reciprocal of the electrolysis fluctuation coefficient to obtain the electrolysis process analysis value.

[0015] As a further technical solution of the present invention: the obtaining process of the electrolysis fluctuation coefficient is:

[0016] Obtain the aluminum electrolysis liquid concentrations detected at all times, and perform variance processing on them to obtain the electrolysis fluctuation coefficient.

[0017] As a further technical solution of the present invention: the obtaining process of the electrolysis concentration average value:

[0018] Obtain the aluminum electrolysis liquid concentrations detected at all times, and perform average value processing on them to obtain the electrolysis concentration average value.

[0019] As a further technical solution of the present invention: the process of judging the influence of the fluctuation of the aluminum electrolysis liquid concentration in the analysis period is:

[0020] Respectively fit to obtain the electrolysis temperature curve and the aluminum electrolysis liquid concentration curve for the analysis period;

[0021] Divide it into m intervals according to the analysis period, extract the electrolysis temperature curve and the aluminum electrolysis liquid concentration curve corresponding to each interval respectively, and use the finite difference method to calculate the average slope of the electrolysis temperature curve and the average slope of the aluminum electrolysis liquid concentration corresponding to each interval respectively;

[0022] Calculate the average slope of the aluminum electrolysis liquid concentration curve for each interval to obtain the average slope fluctuation coefficient of the aluminum electrolysis liquid concentration in the analysis period;

[0023] If the average slope fluctuation coefficient of the aluminum electrolysis liquid concentration in the analysis period is greater than or equal to the first preset value of the fluctuation coefficient, an unstable signal of the aluminum electrolysis liquid concentration in the analysis period is generated.

[0024] As a further technical solution of the present invention: the process of judging the influence of the electrolysis temperature on the aluminum electrolysis liquid concentration:

[0025] When an unstable signal of the electrolytic aluminum liquid concentration in the analysis period is generated, the influence proportionality coefficient of the m-th interval is obtained;

[0026] Based on all the influence proportionality coefficients within the analysis period, an influence set of the electrolysis temperature on the electrolytic aluminum liquid concentration is constructed, and then the fluctuation coefficient of the influence set of the electrolysis temperature on the electrolytic aluminum liquid concentration is calculated;

[0027] If the fluctuation coefficient of the influence set of the electrolysis temperature on the electrolytic aluminum liquid concentration is less than the second preset value of the fluctuation coefficient, a high influence signal of the electrolysis temperature on the electrolytic aluminum liquid concentration is generated.

[0028] As a further technical solution of the present invention: the process of obtaining the influence proportionality coefficient includes:

[0029] The ratio of the average slope of the electrolysis temperature curve to the average slope of the electrolytic aluminum liquid concentration is processed to obtain the influence proportionality coefficient of the m-th interval.

[0030] As a further technical solution of the present invention: the process of determining the electrolysis temperature to be compensated includes:

[0031] Obtain the electrolysis temperature curve of the analysis period, extract the minimum value of the electrolysis temperature curve of the analysis period, and perform a product operation on the minimum value of the electrolysis temperature curve of the analysis period and the lack proportionality coefficient of the electrolytic aluminum liquid concentration to obtain the minimum electrolysis temperature to be compensated in the current analysis period;

[0032] At the same time, extract the maximum value of the electrolysis temperature curve of the analysis period, and perform a product operation on the maximum value of the electrolysis temperature curve of the analysis period and the lack proportionality coefficient of the electrolytic aluminum liquid concentration to obtain the maximum electrolysis temperature to be compensated in the current analysis period.

[0033] As a further technical solution of the present invention: the process of obtaining the lack proportionality coefficient of the electrolytic aluminum liquid concentration includes:

[0034] Obtain the electrolytic aluminum liquid concentration and the process standard value of the electrolytic aluminum liquid concentration in the analysis period, and determine the lack amount of the electrolytic aluminum liquid concentration in the analysis period by the difference method; the lack amount of the electrolytic aluminum liquid concentration in the analysis period is ratio-processed with the process standard value of the electrolytic aluminum liquid concentration to obtain the lack proportionality coefficient of the electrolytic aluminum liquid concentration in the analysis period.

[0035] The beneficial effects of the present invention:

[0036] In the process of electrolytic purification of aluminum electrolytic solution, the present invention monitors and judges the concentration of the specific aluminum electrolytic solution. Through the change of the concentration of the aluminum electrolytic solution, it reflects whether the current electrolytic purification efficiency meets the process requirements. In the case of non-compliance, since the electrolytic temperature is relatively sensitive to the concentration of the aluminum electrolytic solution and is one of the main factors affecting its purification efficiency, a correlation analysis is carried out on the electrolytic temperature to determine the influence relationship of the purification of the aluminum electrolytic solution, and then the impact caused by the electrolytic temperature is obtained. By reasonably controlling the operating voltage during the electrolytic analysis period, the efficient and continuous purification of the aluminum electrolytic solution is ensured, so as to complete the purification work of the aluminum electrolytic solution with high quality within the preset process time. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 It is a flowchart of a temperature control method for purifying aluminum electrolytic solution provided in Embodiment 1 of the present invention;

[0039] Figure 2 It is a schematic structural diagram of a temperature control system for purifying aluminum electrolytic solution provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In order to enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] Embodiment 1

[0042] Figure 1 It is a flowchart of a temperature control method for purifying aluminum electrolytic solution provided in Embodiment 1 of the present invention. The embodiments of the present invention are applicable to the situation where the purification effect is not good during the process time, such as Figure 1 As shown, a temperature control method for purifying aluminum electrolytic solution provided in the embodiments of the present invention specifically includes the following steps:

[0043] S1. In the alumina electrolysis process, obtain the concentration of the aluminum electrolytic solution;

[0044] In some embodiments, the alumina electrolysis process mainly includes the following steps:

[0045] Mix the electrolyte other than aluminum oxide. Cryolite is used as a solvent for electrolyzing aluminum oxide to dissolve aluminum oxide in cryolite. Heat the electrolyte mixture other than aluminum oxide until it reaches a molten state, and then add a cryolite solution containing aluminum oxide to obtain a melt.

[0046] Connect the electrodes of the electrolytic cell to a power source. Place the obtained melt in the electrolytic cell and carry out electrolysis at 800 - 820 °C. The current density is 1 A / cm 2 to obtain the electrolyzed aluminum liquid.

[0047] For the obtained aluminum liquid, remove the impurities entrained in the aluminum liquid through the steps of stirring and filtering to obtain pure aluminum.

[0048] The method for obtaining the concentration of electrolyzed aluminum liquid is as follows:

[0049] Measure through an on-line direct-reading spectrometer (OES); its principle: after sampling the aluminum liquid, an arc is excited, and the intensity of the characteristic peaks of elements is analyzed spectroscopically to quantitatively determine the impurity content; equipment: equipped with an automatic sampling probe, directly inserted into the aluminum liquid; advantages: high precision (ppm level), fast (<1 minute).

[0050] S2. Divide the electrolysis process time into n analysis periods, monitor the concentration of electrolyzed aluminum liquid during the analysis period, and determine whether the electrolysis in the current analysis period meets the process standards.

[0051] In some embodiments, divide the electrolysis process time into n analysis periods, obtain the concentrations of electrolyzed aluminum liquid detected at all times during the analysis period, perform a fluctuation calculation on the concentrations of electrolyzed aluminum liquid detected at all times to obtain the electrolysis process analysis value for the analysis period.

[0052] Compare the electrolysis process analysis value for the analysis period with the electrolysis process analysis threshold.

[0053] If the electrolysis process analysis value for the analysis period is less than the electrolysis process analysis threshold, it indicates that in the current aluminum oxide electrolysis process, the concentration of the electrolyzed aluminum liquid obtained does not meet the process requirements, and an electrolysis inefficiency signal is generated.

[0054] If the electrolysis process analysis value for the analysis period is greater than or equal to the electrolysis process analysis threshold, it indicates that in the current aluminum oxide electrolysis process, the concentration of the electrolyzed aluminum liquid obtained meets the process requirements, and an electrolysis high-efficiency signal is generated.

[0055] More specifically, the specific process of performing a fluctuation calculation on the concentrations of electrolyzed aluminum liquid detected at all times to obtain the electrolysis process analysis value for the analysis period is as follows:

[0056] Obtain the concentration of electrolytic aluminum liquid detected at all times, and perform variance processing on it to obtain the electrolysis fluctuation coefficient;

[0057] Obtain the concentration of electrolytic aluminum liquid detected at all times, and perform mean processing on it to obtain the average electrolysis concentration;

[0058] Perform a product operation on the average electrolysis concentration and the reciprocal of the electrolysis fluctuation coefficient to obtain the electrolysis process analysis value;

[0059] It should be noted that: the electrolysis process analysis value comprehensively evaluates the size and fluctuation degree of the aluminum liquid concentration after electrolysis in the electrolysis process. The smaller the average concentration of the aluminum liquid after electrolysis, the less it meets the process requirements of electrolytic aluminum, which can effectively indicate that the electrolysis effect is poor. The smaller the reciprocal of the electrolysis fluctuation coefficient, the greater the fluctuation of the aluminum liquid concentration after electrolysis, the less it meets the process requirements of electrolytic aluminum, which can effectively indicate that the electrolysis effect is poor;

[0060] S3. When an electrolysis inefficiency signal occurs, obtain the electrolysis temperature during the analysis period and the concentration of electrolytic aluminum liquid during the analysis period. Using the method of fluctuation similarity degree, first judge the influence of the fluctuation of the concentration of electrolytic aluminum liquid during the analysis period, and then judge the influence of the electrolysis temperature on the concentration of electrolytic aluminum liquid;

[0061] In some embodiments, when an electrolysis inefficiency signal is generated, the electrolysis temperature during the analysis period is obtained through a current sensor (Hall effect sensor); the principle: the current value is deduced by measuring the magnetic field intensity (Hall voltage) around the conductor, and the electrolysis temperature is calculated in combination with the electrode area.

[0062] Use the method of fluctuation similarity degree to judge the electrolysis temperature and the concentration of electrolytic aluminum liquid during the collected analysis period. If there is an obvious fluctuation in the concentration of electrolytic aluminum liquid during the analysis period, then judge the influence of the electrolysis temperature on the concentration of electrolytic aluminum liquid, that is, if the similarity degree of the fluctuation degree is high, it means that the influence of the electrolysis temperature on the concentration of electrolytic aluminum liquid is high; if the similarity degree of the fluctuation degree is low, it means that the influence of the electrolysis temperature on the concentration of electrolytic aluminum liquid is low; if there is no obvious fluctuation in the concentration of electrolytic aluminum liquid during the analysis period, then check the equipment or parameters related to electrolysis;

[0063] Specifically, the process of judging using the method of fluctuation degree similarity is as follows:

[0064] Taking the analysis period as the X-axis and the electrolysis temperature as the Y-axis, construct a first coordinate system, substitute the electrolysis temperature during the collected analysis period into the first coordinate system, and draw the electrolysis temperature curve during the analysis period;

[0065] Taking the analysis period as the X-axis and the concentration of electrolytic aluminum liquid as the Y-axis, construct a second coordinate system, substitute the concentration of electrolytic aluminum liquid during the collected analysis period into the second coordinate system, and draw the concentration curve of electrolytic aluminum liquid during the analysis period;

[0066] It is segmented into m intervals according to the analysis period, and the electrolysis temperature curve and the molten aluminum electrolyte concentration curve corresponding to each interval are extracted respectively. The finite difference method is used to calculate the average slope of the electrolysis temperature curve and the average slope of the molten aluminum electrolyte concentration corresponding to each interval, which are denoted as KUm and KCm respectively. First, through algorithms for data fluctuation degrees such as variance and standard deviation, the average slope of the molten aluminum electrolyte concentration curve in each interval is calculated to obtain the fluctuation coefficient of the average slope of the molten aluminum electrolyte concentration in the analysis period, and it is compared with the first preset value of the fluctuation coefficient.

[0067] If the fluctuation coefficient of the average slope of the molten aluminum electrolyte concentration in the analysis period is greater than or equal to the first preset value of the fluctuation coefficient, an unstable signal of the molten aluminum electrolyte concentration in the analysis period is generated.

[0068] If the molten aluminum electrolyte concentration in the analysis period is less than the first preset value of the fluctuation coefficient, a stable signal of the molten aluminum electrolyte concentration in the analysis period is generated.

[0069] When an unstable signal of the molten aluminum electrolyte concentration in the analysis period is generated, through the ratio processing of KUm and KCm, the influence proportion coefficient Km of the m-th interval is obtained.

[0070] Based on all the influence proportion coefficients in the analysis period, an influence set {K1, K2,..., Km} of the electrolysis temperature on the molten aluminum electrolyte concentration is constructed. The fluctuation coefficient of the influence set of the electrolysis temperature on the molten aluminum electrolyte concentration can be calculated through algorithms for data fluctuation degrees such as variance and standard deviation.

[0071] The fluctuation coefficient of the influence set of the electrolysis temperature on the molten aluminum electrolyte concentration is compared with the second preset value of the fluctuation coefficient.

[0072] If the fluctuation coefficient of the influence set of the electrolysis temperature on the molten aluminum electrolyte concentration is greater than or equal to the second preset value of the fluctuation coefficient, a low influence signal of the electrolysis temperature on the molten aluminum electrolyte concentration is generated.

[0073] If the fluctuation coefficient of the influence set of the electrolysis temperature on the molten aluminum electrolyte concentration is less than the second preset value of the fluctuation coefficient, a high influence signal of the electrolysis temperature on the molten aluminum electrolyte concentration is generated.

[0074] The first thing to explain is that the first preset value of the fluctuation coefficient and the second preset value of the fluctuation coefficient are 0.13 and 0.16. A value greater than this indicates a greater degree of data fluctuation in the subset in the set, and a value less than this indicates a smaller degree of data fluctuation in the subset in the set.

[0075] The second thing to explain is that the high influence signal of electrolysis temperature on the concentration of electrolytic aluminum liquid indicates that the low efficiency of the concentration of electrolytic aluminum liquid in the current analysis period is highly affected by the electrolysis temperature factor; the low influence signal of electrolysis temperature on the concentration of electrolytic aluminum liquid indicates that the low efficiency of the concentration of electrolytic aluminum liquid in the current analysis period is less affected by the electrolysis temperature factor;

[0076] S4. When a signal is generated that the electrolysis temperature has a high influence on the concentration of the electrolytic aluminum liquid, the concentration of the electrolytic aluminum liquid in the analysis period is compensated, the compensated electrolysis temperature is determined, and the electrolysis temperature in the subsequent process is controlled;

[0077] In some embodiments, when a signal of the high influence of the electrolysis temperature on the concentration of the electrolytic aluminum liquid is generated, the concentration of the electrolytic aluminum liquid in the analysis period is first analyzed, the concentration of the electrolytic aluminum liquid in the analysis period and the process standard value of the concentration of the electrolytic aluminum liquid in the analysis period are obtained, and the lack of the concentration of the electrolytic aluminum liquid in the analysis period is determined by the difference method; the lack of the concentration of the electrolytic aluminum liquid in the analysis period is processed by ratio with the process standard value of the concentration of the electrolytic aluminum liquid to obtain the lack of proportional coefficient of the concentration of the electrolytic aluminum liquid in the analysis period;

[0078] Then, the electrolysis temperature in the analysis period is analyzed, the electrolysis temperature curve in the analysis period is obtained, the minimum value of the electrolysis temperature curve in the analysis period is extracted, and the minimum value of the electrolysis temperature curve in the analysis period is multiplied by the lack of proportionality coefficient of the electrolytic aluminum liquid concentration to obtain the minimum electrolysis temperature that needs to be compensated in the current analysis period;

[0079] At the same time, the maximum value of the electrolysis temperature curve in the analysis period is extracted, and the maximum value of the electrolysis temperature curve in the analysis period is multiplied by the lack of proportionality coefficient of the electrolytic aluminum liquid concentration to obtain the maximum electrolysis temperature that needs to be compensated in the current analysis period;

[0080] It needs to be explained that the compensation principle of the electrolysis temperature is as follows: according to the influence relationship between the electrolysis temperature and the concentration of the electrolytic aluminum liquid obtained by S3 analysis, it is determined that the lack of electrolytic aluminum liquid concentration in the current analysis period is mainly affected by the electrolysis temperature, and according to the electrolysis temperature is too high: although it can improve the solubility, it will increase the dissolution of impurities (such as Fe, Si), and accelerate the anode oxidation and electrolyte volatilization; the temperature is too low: the solubility of Al2O3 decreases, resulting in precipitation and crusting, blocking the flow of electrolyte, and triggering the anode effect; therefore, the lack of electrolytic aluminum liquid concentration corresponding to the analysis period is also caused by the unreasonable operation of the electrolysis temperature in the current analysis period, so it can be determined that the lack of electrolytic aluminum liquid concentration proportional coefficient in the analysis period is the proportional coefficient to be compensated by the electrolysis temperature;

[0081] The technical solution of the embodiment of the present invention is as follows: in the alumina electrolysis process, the concentration of the electrolytic aluminum liquid is obtained; the electrolysis process time is divided into n analysis time periods, the concentration of the electrolytic aluminum liquid in the analysis time period is monitored, and whether the electrolysis in the current analysis time period meets the process standard is determined; when the electrolysis inefficiency signal is generated, the electrolysis temperature in the analysis time period and the concentration of the electrolytic aluminum liquid in the analysis time period are obtained, and the influence of the fluctuation of the concentration of the electrolytic aluminum liquid in the analysis time period is first determined by using the method of fluctuation similarity, and then the influence of the electrolysis temperature on the concentration of the electrolytic aluminum liquid is determined; when the electrolysis temperature has a high influence on the concentration of the electrolytic aluminum liquid, the concentration of the electrolytic aluminum liquid in the analysis time period is compensated, and the compensation electrolysis temperature is determined, and the subsequent process is carried out. The electrolysis temperature is controlled; the embodiment of the present invention monitors and determines the unique concentration of the electrolytic aluminum solution during the electrolytic purification process of the electrolytic aluminum solution, and reflects whether the current electrolytic purification efficiency meets the process requirements through the change of the concentration of the electrolytic aluminum solution. In the case of non-compliance with the requirements, since the electrolysis temperature is more sensitive to the concentration of the electrolytic aluminum solution and is one of the main factors affecting its purification efficiency, a correlation analysis is performed on the electrolysis temperature to determine the influence relationship of the purification of the electrolytic aluminum solution, and then the electrolysis temperature is obtained. By reasonably controlling the operating voltage during the electrolytic analysis period, the purification of the electrolytic aluminum solution is ensured to be efficient and continuous, thereby completing the purification of the electrolytic aluminum solution with high quality within the preset process time.

[0082] Embodiment 2

[0083] Figure 2 A schematic diagram of a temperature control system for purifying an electrolytic aluminum solution provided in the second embodiment of the present invention; Figure 2 As shown, a temperature control system for purifying an electrolytic aluminum solution provided by an embodiment of the present invention specifically includes:

[0084] Monitoring module 100: in the alumina electrolysis process, obtaining the concentration of electrolytic aluminum liquid;

[0085] Evaluation module 200: divide the electrolysis process time into n analysis periods, monitor the concentration of electrolytic aluminum liquid in the analysis period, and determine whether the electrolysis in the current analysis period meets the process standard;

[0086] In this embodiment, the process of judging whether the electrolysis in the current analysis period meets the process standard is as follows:

[0087] If the electrolysis process analysis value in the analysis period is less than the electrolysis process analysis threshold, it means that in the current alumina electrolysis process, the concentration of the aluminum liquid after electrolysis does not meet the process requirements, and an electrolysis inefficiency signal is generated;

[0088] If the electrolysis process analysis value in the analysis period is greater than or equal to the electrolysis process analysis threshold, it means that in the current alumina electrolysis process, the concentration of the aluminum liquid after electrolysis meets the process requirements, and an electrolysis high efficiency signal is generated;

[0089] Perform fluctuation calculations on the aluminum electrolysis liquid concentrations detected at all times to obtain the specific process of the electrolysis process analysis value for the analysis period as follows:

[0090] Obtain the aluminum electrolysis liquid concentrations detected at all times and perform variance processing on them to obtain the electrolysis fluctuation coefficient;

[0091] Obtain the aluminum electrolysis liquid concentrations detected at all times and perform mean processing on them to obtain the average electrolysis concentration;

[0092] Perform a product operation on the average electrolysis concentration and the reciprocal of the electrolysis fluctuation coefficient to obtain the electrolysis process analysis value;

[0093] Judgment module 300: When there is an electrolysis inefficiency signal, obtain the electrolysis temperature and the aluminum electrolysis liquid concentration in the analysis period, and use the method of fluctuation similarity degree to first judge the influence of the fluctuation of the aluminum electrolysis liquid concentration in the analysis period, and then judge the influence of the electrolysis temperature on the aluminum electrolysis liquid concentration;

[0094] In this embodiment, the method of using the similarity degree of the fluctuation degree for judgment is as follows:

[0095] Taking the analysis period as the X-axis and the electrolysis temperature as the Y-axis, construct a first coordinate system, substitute the electrolysis temperature collected in the analysis period into the first coordinate system, and draw the electrolysis temperature curve for the analysis period;

[0096] Taking the analysis period as the X-axis and the aluminum electrolysis liquid concentration as the Y-axis, construct a second coordinate system, substitute the aluminum electrolysis liquid concentration collected in the analysis period into the second coordinate system, and draw the aluminum electrolysis liquid concentration curve for the analysis period;

[0097] Divide it into m intervals according to the analysis period, extract the electrolysis temperature curve and the aluminum electrolysis liquid concentration curve corresponding to each interval respectively, and use the finite difference method to calculate the average slope of the electrolysis temperature curve and the average slope of the aluminum electrolysis liquid concentration corresponding to each interval respectively, denoted as KUm and KCm; First, through algorithms for data fluctuation degrees such as variance and standard deviation, calculate the average slope fluctuation coefficient of the aluminum electrolysis liquid concentration curve for each interval, and compare it with the first preset fluctuation coefficient value;

[0098] If the average slope fluctuation coefficient of the aluminum electrolysis liquid concentration in the analysis period is greater than or equal to the first preset fluctuation coefficient value, then generate an unstable signal for the aluminum electrolysis liquid concentration in the analysis period;

[0099] If the aluminum electrolysis liquid concentration in the analysis period is less than the first preset fluctuation coefficient value, then generate a stable signal for the aluminum electrolysis liquid concentration in the analysis period;

[0100] When the unstable concentration signal of the electrolytic aluminum liquid in the analysis period is generated, the influence proportional coefficient Km of the mth interval is obtained by processing the ratio of KUm and KCm;

[0101] Based on all the influencing proportional coefficients in the analysis period, the influence set {K1, K2, ..., Km} of the electrolysis temperature on the electrolytic aluminum liquid concentration is constructed. The fluctuation coefficient of the influence set of the electrolysis temperature on the electrolytic aluminum liquid concentration can be calculated by using the algorithms of data fluctuation degree such as variance and standard deviation;

[0102] Compare the fluctuation coefficient of the set of effects of electrolysis temperature on electrolytic aluminum liquid concentration with a second fluctuation coefficient preset value;

[0103] If the fluctuation coefficient of the electrolysis temperature on the electrolytic aluminum liquid concentration effect set is greater than or equal to the second fluctuation coefficient preset value, a low influence signal of the electrolysis temperature on the electrolytic aluminum liquid concentration is generated;

[0104] If the fluctuation coefficient of the set of influences of the electrolysis temperature on the concentration of the electrolytic aluminum liquid is less than the second fluctuation coefficient preset value, a signal indicating that the electrolysis temperature has a high influence on the concentration of the electrolytic aluminum liquid is generated;

[0105] Control module 400: when a signal indicating that the electrolysis temperature has a high impact on the concentration of the electrolytic aluminum liquid is generated, the concentration of the electrolytic aluminum liquid in the analysis period is compensated, the compensated electrolysis temperature is determined, and the electrolysis temperature in the subsequent process is controlled;

[0106] In this embodiment, when the electrolysis temperature has a high impact on the concentration of the electrolytic aluminum liquid, the concentration of the electrolytic aluminum liquid in the analysis period is first analyzed, the concentration of the electrolytic aluminum liquid in the analysis period and the process standard value of the concentration of the electrolytic aluminum liquid in the analysis period are obtained, and the lack of the concentration of the electrolytic aluminum liquid in the analysis period is determined by the difference method; the lack of the concentration of the electrolytic aluminum liquid in the analysis period is processed by ratio with the process standard value of the concentration of the electrolytic aluminum liquid, and the lack of the proportional coefficient of the concentration of the electrolytic aluminum liquid in the analysis period is obtained;

[0107] Then, the electrolysis temperature in the analysis period is analyzed, the electrolysis temperature curve in the analysis period is obtained, the minimum value of the electrolysis temperature curve in the analysis period is extracted, and the minimum value of the electrolysis temperature curve in the analysis period is multiplied by the lack of proportionality coefficient of the electrolytic aluminum liquid concentration to obtain the minimum electrolysis temperature that needs to be compensated in the current analysis period;

[0108] At the same time, the maximum value of the electrolysis temperature curve in the analysis period is extracted, and the maximum value of the electrolysis temperature curve in the analysis period is multiplied by the proportional coefficient of the electrolytic aluminum liquid concentration to obtain the maximum electrolysis temperature that needs to be compensated in the current analysis period.

[0109] The above has described in detail an embodiment of the present invention, but the above content is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A temperature control method for purifying an electrolytic aluminum solution, characterized in that, The following steps are involved: In the alumina electrolysis process, obtaining the concentration of the electrolytic aluminum liquid; The electrolysis process time is divided into n analysis periods, and the concentration of the electrolytic aluminum liquid within the analysis period is monitored; If the electrolysis in the current analysis period does not meet the process standard, the electrolysis temperature in the analysis period and the electrolytic aluminum liquid concentration in the analysis period are obtained, and the fluctuation similarity method is used to first determine the influence of the fluctuation of the electrolytic aluminum liquid concentration in the analysis period, and then determine the influence of the electrolysis temperature on the electrolytic aluminum liquid concentration; If a signal indicating that the electrolysis temperature has a high impact on the concentration of the electrolytic aluminum liquid is generated, the concentration of the electrolytic aluminum liquid in the analysis period is compensated, the compensated electrolysis temperature is determined, and the electrolysis temperature in the subsequent process is controlled.

2. The temperature control method for purifying an electrolytic aluminum solution according to claim 1, characterized in that The process of monitoring the concentration of electrolytic aluminum liquid during the analysis period: The concentration of the electrolytic aluminum liquid detected at all times during the analysis period is obtained, and the fluctuation of the concentration of the electrolytic aluminum liquid detected at all times is calculated to obtain the electrolytic process analysis value of the analysis period; If the electrolysis process analysis value in the analysis period is less than the electrolysis process analysis threshold, it means that in the current alumina electrolysis process, the concentration of the aluminum liquid obtained after electrolysis does not meet the process requirements, and an electrolysis inefficiency signal is generated.

3. The temperature control method for purifying an electrolytic aluminum solution according to claim 2, characterized in that Method for obtaining electrolytic process analysis values during the analysis period: The electrolysis process analysis value is obtained by multiplying the mean electrolysis concentration with the inverse of the electrolysis fluctuation coefficient.

4. The temperature control method for purifying electrolytic aluminum solution according to claim 3, characterized in that, The process of obtaining the electrolysis fluctuation coefficient is: The concentration of the electrolytic aluminum liquid detected at all times is obtained, and variance processing is performed on it to obtain the electrolysis fluctuation coefficient.

5. The temperature control method for purifying an electrolytic aluminum solution according to claim 4, characterized in that The process of obtaining the mean electrolytic concentration: The concentration of the electrolytic aluminum liquid detected at all times is obtained, and averaged to obtain the average electrolytic concentration.

6. The temperature control method for purifying an electrolytic aluminum solution according to claim 5, characterized in that, The process of judging the influence of the concentration fluctuation of electrolytic aluminum liquid during the analysis period is as follows: The electrolysis temperature curve and the electrolytic aluminum liquid concentration curve of the analysis period are fitted respectively; The analysis period is divided into m intervals, and the electrolytic temperature curve and the electrolytic aluminum liquid concentration curve corresponding to each interval are extracted. The average slope of the electrolytic temperature curve and the average slope of the electrolytic aluminum liquid concentration corresponding to each interval are calculated by using the finite difference method; The average slope of the electrolytic aluminum liquid concentration curve in each interval is calculated to obtain the average slope fluctuation coefficient of the electrolytic aluminum liquid concentration during the analysis period; If the average slope fluctuation coefficient of the electrolytic aluminum liquid concentration during the analysis period is greater than or equal to the first fluctuation coefficient preset value, an unstable signal of the electrolytic aluminum liquid concentration during the analysis period is generated.

7. A temperature control method for purifying an electrolytic aluminum solution according to claim 6, characterized in that, The process of judging the effect of electrolysis temperature on the concentration of electrolytic aluminum liquid: When an unstable signal of the electrolytic aluminum liquid concentration in the analysis period is generated, the influence proportional coefficient of the mth interval is obtained; Based on all the impact proportional coefficients in the analysis period, the influence set of electrolysis temperature on electrolytic aluminum liquid concentration is constructed, and then the fluctuation coefficient of the influence set of electrolysis temperature on electrolytic aluminum liquid concentration is calculated; If the fluctuation coefficient of the set of influences of the electrolysis temperature on the concentration of the electrolytic aluminum liquid is less than the second fluctuation coefficient preset value, a signal indicating that the electrolysis temperature has a high influence on the concentration of the electrolytic aluminum liquid is generated.

8. A temperature control method for purifying an electrolytic aluminum solution according to claim 7, characterized in that, The process of obtaining the proportional coefficient is affected by: The average slope of the electrolysis temperature curve and the average slope of the electrolytic aluminum liquid concentration are processed to obtain the influence proportional coefficient of the mth interval.

9. The temperature control method for purifying electrolytic aluminum solution according to claim 8, characterized in that, The process of determining the compensated electrolysis temperature includes: Obtaining the electrolysis temperature curve of the analysis period, extracting the minimum value of the electrolysis temperature curve of the analysis period, performing a product operation on the minimum value of the electrolysis temperature curve of the analysis period and the lack ratio coefficient of the molten aluminum electrolyte concentration, and obtaining the minimum electrolysis temperature to be compensated in the current analysis period; At the same time, extracting the maximum value of the electrolysis temperature curve of the analysis period, performing a product operation on the maximum value of the electrolysis temperature curve of the analysis period and the lack ratio coefficient of the molten aluminum electrolyte concentration, and obtaining the maximum electrolysis temperature to be compensated in the current analysis period.

10. The temperature control method for purifying an electrolytic aluminum solution according to claim 9, characterized in that, The process of obtaining the lack ratio coefficient of the molten aluminum electrolyte concentration includes: Obtaining the molten aluminum electrolyte concentration and the process standard value of the molten aluminum electrolyte concentration in the analysis period, determining the lack amount of the molten aluminum electrolyte concentration in the analysis period by the difference method; performing a ratio process on the lack amount of the molten aluminum electrolyte concentration in the analysis period and the process standard value of the molten aluminum electrolyte concentration, and obtaining the lack ratio coefficient of the molten aluminum electrolyte concentration in the analysis period.

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