Preparation method of rare earth alloy for lead-acid battery

Abstract

This application relates to the technical field of lead-acid batteries, specifically to a preparation method of rare-earth alloy for lead-acid batteries. The method includes: melting refined lead and rare-earth elements in a crucible electric furnace; adjusting the heating rate at each acquisition moment of the crucible electric furnace; after the melting is completed, obtaining a rare-earth alloy liquid, and using an ingot casting process to prepare an intermediate rare-earth alloy; melting refined lead in a lead melting pot, heating up and successively adding silver and sodium for stirring, heating up again and then adding calcium-aluminum alloy, tin and a protective agent for melting, adding the intermediate rare-earth alloy and maintaining the heating state, and obtaining a positive grid rare-earth alloy after stirring. This application aims to adjust the heating rate during the melting process of the rare-earth alloy, improve the utilization rate of rare-earth elements, and make the distribution of rare-earth alloy elements uniform.

Description

Technical Field

[0001] This application relates to the technical field of lead-acid batteries, and specifically to a method for preparing rare-earth alloys for lead-acid batteries. Background Art

[0002] The activity of rare-earth elements is second only to that of alkali metals and alkaline-earth metals. Adding rare-earth elements to the positive grid alloy of lead-acid batteries can improve the corrosion resistance of the positive grid alloy and enhance the impedance characteristics of the anode film in lead-acid batteries. Therefore, in the preparation of the positive grid alloy of lead-acid batteries, the addition of rare-earth elements can improve the corrosion resistance and conductivity of the alloy grid, reduce the formation of passivation films, and thus improve the performance and service life of lead-acid batteries.

[0003] For example, the Chinese invention patent with the patent number CN201811543700.X discloses a positive grid of a lead-acid battery made of a lead-calcium-tin-copper-rare-earth alloy and its manufacturing method. By successively preparing a copper-rare-earth master alloy and a lead-calcium-tin-copper-rare-earth alloy, and using the lead-calcium-tin-copper-rare-earth alloy to prepare the positive grid in the lead-acid battery. In this patent, the heating rate during the melting process of the rare-earth alloy is not controlled. If the heating rate is too fast or too slow, it may lead to uneven distribution of components in the alloy, thereby affecting the final performance of the alloy. Summary of the Invention

[0004] In view of the above, it is necessary to provide a method for preparing rare-earth alloys for lead-acid batteries to solve the above problems.

[0005] An embodiment of this application provides a method for preparing rare-earth alloys for lead-acid batteries, and the method includes:

[0006] Step 1: Melting refined lead and rare-earth elements in a crucible electric furnace; forming a melting temperature matrix for each collection moment during the melting process with the melting temperatures of all collection points in the crucible electric furnace.

[0007] Step 2: Analyze the temperature change distribution characteristics in the horizontal and vertical directions of the melting temperature matrix at each collection moment to obtain all melting feature vectors at each collection moment; based on the differences between each element and the remaining elements in each melting feature vector at each collection moment, obtain the melting uniformity of each element, and form each uniform feature vector at each collection moment.

[0008] Step 3: According to the differences between the uniform feature vectors at each collection moment, combined with the element distribution characteristics of the uniform feature vectors, obtain the melting effectiveness at each collection moment, and adjust the heating rate at each collection moment of the crucible electric furnace; after the melting is completed, obtain a rare-earth alloy liquid, and use an ingot casting process to prepare an intermediate rare-earth alloy.

[0009] Step 4: Melt refined lead in a lead melting pot. After raising the temperature, successively add silver and sodium and stir. After raising the temperature again, add calcium-aluminum alloy, tin, and a protective agent for smelting. Then add an intermediate rare earth alloy and maintain the temperature increase state. After stirring, a rare earth alloy for a positive plate grid is obtained.

[0010] Preferably, the rare earth elements are specifically lanthanum, samarium, cerium, and yttrium.

[0011] Preferably, the temperature range for smelting refined lead and rare earth elements in a crucible electric furnace is 600 - 1000 °C.

[0012] Preferably, the smelting eigenvector includes a longitudinal smelting eigenvector and a transverse smelting eigenvector. The obtaining steps are as follows:

[0013] Obtain the first-order difference vector of each row vector in the smelting temperature matrix at each acquisition moment, and take the absolute value of all elements in the first-order difference vector to obtain the transverse temperature difference change vectors at each acquisition moment;

[0014] Calculate the permutation entropy of the transverse temperature difference change vectors at each acquisition moment, and use the vector composed of the permutation entropies of all transverse temperature difference change vectors at each acquisition moment as the longitudinal smelting eigenvector at each acquisition moment;

[0015] Using the same method as the longitudinal smelting eigenvector, obtain the transverse smelting eigenvector at each acquisition moment according to each column vector in the capacity temperature matrix at each acquisition moment.

[0016] Preferably, the smelting uniformity includes longitudinal smelting uniformity and transverse smelting uniformity; the uniformity eigenvector includes a longitudinal uniformity eigenvector and a transverse uniformity eigenvector, specifically:

[0017] For each element in the longitudinal smelting eigenvector, obtain the absolute value of the difference between each element and the other elements, and take the cumulative sum of the absolute values of the differences between each element and all other elements, and then perform a negative correlation mapping to obtain the longitudinal smelting uniformity of each element; use the vector composed of the longitudinal smelting uniformities of all elements in the longitudinal smelting eigenvector at each acquisition moment as the longitudinal uniformity eigenvector at each acquisition moment;

[0018] Using the same method as the longitudinal smelting uniformity, based on the transverse smelting eigenvector, obtain the transverse smelting uniformity of the transverse smelting eigenvector; use the vector composed of the transverse smelting uniformities of all elements in the transverse smelting eigenvector at each acquisition moment as the transverse uniformity eigenvector at each acquisition moment.

[0019] Preferably, obtaining the smelting effectiveness at each acquisition moment includes:

[0020] Align the longitudinal uniform feature vectors and the transverse uniform feature vectors at each acquisition moment, calculate the difference vector between the two vectors, and denote the mean value of the absolute values of all elements in the difference vector as the direction difference degree at each acquisition moment;

[0021] Denote the mean value of all elements in the longitudinal uniform feature vector at each acquisition moment as the first mean value; denote the mean value of all elements in the transverse uniform feature vector at each acquisition moment as the second mean value; after fusing the first mean value and the second mean value, further fuse the result with the negative correlation mapping result of the direction difference degree at each acquisition moment to obtain the smelting utility degree at each acquisition moment.

[0022] Preferably, the calculation method for adjusting the heating rate of the crucible electric furnace at each acquisition moment is as follows: , where is the heating rate of the crucible electric furnace at the next acquisition moment, is the heating rate of the crucible electric furnace at the current acquisition moment, is the smelting utility degree at the current acquisition moment, is a preset judgment threshold, is the preset maximum adjustment value of the heating rate, represents the exponential function with the natural constant as the base.

[0023] Preferably, after heating, silver and sodium are added in sequence and stirred, wherein the temperature is raised to 500 - 550 °C.

[0024] Preferably, the temperature for smelting by adding calcium-aluminum alloy, tin and a protective agent after reheating is 600 - 650 °C.

[0025] Preferably, during the process of adding the intermediate rare earth alloy and stirring, the heating state needs to be maintained and stirred for 20 min.

[0026] This application has at least the following beneficial effects:

[0027] (1) This application analyzes the smelting uniformity of rare earth elements in different directions in the crucible electric furnace, and adjusts the heating rate during the smelting process of rare earth elements through the smelting utility characteristics of smelting rare earth elements in the crucible electric furnace, which can more accurately adjust the heating rate during the smelting process, thereby ensuring that the rare earth elements in the alloy liquid are fully smelted together, improving the utilization rate of rare earth elements, making the distribution of rare earth alloy elements uniform, and enhancing the performance of the positive plate grid rare earth alloy.

[0028] (2) In this application, the smelting process of rare earth elements is adjusted through the smelting efficiency. On the basis of ensuring that the rare earth elements in the alloy liquid are fully smelted together, it can reduce the power consumption of the process, with simple operation, effectively shortening the production cycle, reducing the production input cost, and also alleviating the environmental protection pressure.

[0029] (3) This application uses rare earth elements such as lanthanum, samarium, cerium, and yttrium to prepare the positive plate grid rare earth alloy. When it is used in the preparation of lead-acid batteries, it can significantly improve the corrosion resistance and conductivity of the positive plate grid of lead-acid batteries, reduce the formation of passivation films, thereby improving the performance and service life of lead-acid batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flowchart of the method for preparing the rare earth alloy for lead-acid batteries provided by this application;

[0031] Figure 2 It is a process flowchart for preparing the positive plate grid rare earth alloy provided by this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In the description of the embodiments of this application, words such as "exemplary", "or", "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplary", "or", "for example" aims to present relevant concepts in a specific way.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] Additionally, it should be noted that the terms "first" and "second" in this application and its drawings are used to distinguish similar objects and are not used to describe a specific order or sequence. For the methods disclosed in the embodiments of this application or shown in the flowcharts of the methods, including one or more steps for implementing the methods, without departing from the scope of protection of this application, the execution orders of multiple steps can be interchanged with each other, and some steps can also be deleted.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs.

[0036] Example 1

[0037] Embodiment 1 of the present application proposes a method for preparing rare earth alloy for lead-acid batteries, which is applied to the technical field of lead-acid batteries. Refer to the appendix Figure 1 , the method includes:

[0038] Step 1: Melting refined lead and rare earth elements in a crucible electric furnace; forming a melting temperature matrix for each collection moment by the melting temperatures of all collection points in the crucible electric furnace at each collection moment during the melting process.

[0039] Place refined lead with a purity of at least 99.9% in the crucible electric furnace, evacuate, introduce nitrogen, and raise the temperature in the crucible electric furnace, and then add rare earth elements to the crucible electric furnace for melting.

[0040] Among them, the rare earth element is a flavoring agent-like additive. As an additive for the grid alloy of lead-acid batteries, it is beneficial to the mechanical properties, corrosion resistance, casting properties, and electrical conductivity of the grid alloy, etc. The rare earth elements added in this embodiment are lanthanum (La), samarium (Sm), cerium (Ce), and yttrium (Y).

[0041] During the melting process, the temperature is controlled between 600 and 1000 °C; at this time, a stirring device is set to fully stir the rare earth elements to ensure their uniform mixing.

[0042] Since different rare earth elements have different melting points, during the melting process, appropriately adjusting the heating rate is crucial for ensuring the full alloying of rare earth elements. Adjusting the heating rate can control the melting timing of metals at different temperatures, enabling low-melting-point metals and high-melting-point metals to gradually melt within their respective suitable temperature ranges, and avoiding unevenness of the alloy caused by too fast or too slow heating. In addition, intelligently adjusting the heating rate can promote the mixing and diffusion of metal elements while ensuring the full melting of each metal element, further improving the uniformity and performance of the alloy. First, collect the melting temperatures at each moment during the melting process: In this embodiment, a high-temperature resistant infrared probe is placed at the top of the crucible electric furnace to obtain the thermal imaging diagram of the crucible electric furnace at each moment, and obtain the melting temperature of the rare earth alloy liquid at each collection point in the thermal imaging diagram, forming a melting temperature matrix for each collection moment. The high-temperature resistant infrared probe collects the melting temperature every 1 minute, and the implementer can adjust the collection time interval by himself. It should be understood that each element in the melting temperature matrix represents the melting temperature of each collection point in the area measured by the high-temperature resistant infrared probe.

[0043] Take the average value of all elements in the melting temperature matrix at each collection moment as the average temperature of the rare earth alloy liquid at each collection moment; and calculate the heating rate of melting at each collection moment through the change of the average temperature at each collection moment during the melting process and the time interval, where the calculation of the heating rate is a well-known technology, and the specific process will not be elaborated.

[0044] Step 2: Analyze the temperature change distribution characteristics in the horizontal and vertical directions of the melting temperature matrix at each acquisition moment, and obtain all the melting feature vectors at each acquisition moment; based on the differences between each element and the rest of the elements in each melting feature vector at each acquisition moment, obtain the melting uniformity of each element, and form each uniformity feature vector at each acquisition moment.

[0045] During the melting process of rare earth elements, due to the different suitable melting temperatures of different rare earth elements, the melting temperatures at the same rare earth element positions are relatively similar, while the similarity of melting temperatures at different rare earth element positions is relatively low. If the rare earth elements are not fully mixed during the melting process, it may lead to large temperature variations in different regions, thus unable to ensure that each element can be uniformly melted and fully fused, affecting the overall uniformity and performance of the alloy. Therefore, it is more necessary to control and adjust the heating rate during the melting process of rare earth elements to ensure that the rare earth elements in the alloy liquid are fully melted together.

[0046] To ensure that rare earth elements can be fully mixed and melted in the crucible electric furnace, obtain the first-order difference vector of each row vector in the melting temperature matrix at each acquisition moment, and take the absolute value of all the elements in the first-order difference vector to obtain the horizontal temperature difference change vectors at each acquisition moment. The horizontal temperature difference change vector reflects the change of the horizontal temperature difference in the crucible electric furnace. If the inconsistency characteristics of the temperature differences in the horizontal temperature difference change vector are more significant, it indicates that the characteristics of the full mixing and melting of rare earth elements in the horizontal direction at the corresponding position are smaller, and it is more necessary to appropriately adjust the heating rate during the melting process to improve the melting effect of rare earth elements.

[0047] Since the calculation of permutation entropy is insensitive to noise and can accurately reflect the inconsistency characteristics of the temperature differences in the horizontal temperature difference change vector, therefore, calculate the permutation entropy of each horizontal temperature difference change vector at each acquisition moment to describe the chaotic characteristics of the horizontal temperature difference at the corresponding position, which can more clearly reflect the mixing and melting characteristics of the alloy liquid in the crucible electric furnace. The permutation entropy of the horizontal temperature difference change vector reflects the complexity and dynamic behavior characteristics of the horizontal temperature difference at the corresponding position during the melting process. The larger the permutation entropy of the horizontal temperature difference change vector, the greater the chaotic characteristics of the temperature differences in the horizontal temperature difference change vector, indicating that the mixing and melting effect of rare earth elements in the horizontal direction at the corresponding position is worse.

[0048] Arrange the permutation entropies of all the horizontal temperature difference change vectors at each acquisition moment in the arrangement manner of the row vectors in the matrix, and record the arrangement result as the longitudinal melting feature vector in the crucible electric furnace at each acquisition moment. The longitudinal melting feature vector reflects the change of the longitudinal melting characteristics of the alloy liquid in the crucible electric furnace.

[0049] During the smelting process of rare earth elements, the smelting speed of rare earth elements is increased by a stirring device. When the rare earth elements in the crucible electric furnace are not fully smelted, there will be significant differences in the smelting characteristics between the stirring center position and the stirring edge position. Therefore, when the rare earth elements in the crucible electric furnace are not fully smelted, the elements in the longitudinal smelting characteristic vector in the crucible electric furnace at each acquisition moment will change greatly. The greater the change in the elements in its longitudinal smelting characteristic vector, the worse the uniformity of the longitudinal smelting of the rare earth elements by the crucible electric furnace is characterized.

[0050] Therefore, calculate the longitudinal smelting uniformity of each element in the longitudinal smelting characteristic vector at each acquisition moment: , where is the longitudinal smelting uniformity of the j-th element in the longitudinal smelting characteristic vector at the t-th acquisition moment, is the exponential function with the natural constant as the base, is the number of elements in the longitudinal smelting characteristic vector at the t-th acquisition moment, , are the j-th and v-th elements in the longitudinal smelting characteristic vector at the t-th acquisition moment, respectively. It should be understood that if the rare earth elements in the crucible electric furnace are not fully smelted, the elements in the longitudinal smelting characteristic vector in the crucible electric furnace at each acquisition moment will change greatly. At this time, the uniformity of the longitudinal smelting in the crucible electric furnace will be poor, and the smaller the longitudinal smelting uniformity is.

[0051] For each column vector in the smelting temperature matrix at each acquisition moment, extract the transverse smelting characteristic vector in the crucible electric furnace at each acquisition moment in the same way as the longitudinal smelting characteristic vector; calculate the transverse smelting characteristic vector in the crucible electric furnace at each acquisition moment according to the above method in the same way as the longitudinal smelting uniformity, and obtain the transverse smelting uniformity of each element in the transverse smelting characteristic vector at each acquisition moment. The smaller the transverse smelting uniformity is, the worse the uniformity of the transverse smelting when the crucible electric furnace smelts rare earth elements is characterized.

[0052] The vector composed of the longitudinal smelting uniformities corresponding to all elements in the longitudinal smelting characteristic vector of the crucible electric furnace at each acquisition moment is denoted as the longitudinal uniform characteristic vector of the crucible electric furnace at each acquisition moment; the vector composed of the transverse smelting uniformities corresponding to all elements in the transverse smelting characteristic vector of the crucible electric furnace at each acquisition moment is denoted as the transverse uniform characteristic vector of the crucible electric furnace at each acquisition moment. The longitudinal uniform characteristic vector and the transverse uniform characteristic vector respectively reflect the uniformity characteristics of rare earth element smelting in different directions in the crucible electric furnace. If the difference between them is greater, it means that there are significant differences in the uniformity characteristics of rare earth element smelting in different directions, that is, the overall non-uniformity of rare earth element smelting in the crucible electric furnace is greater, and then the smelting effect of rare earth elements in the crucible electric furnace at this time is worse.

[0053] It should be noted that the horizontal smelting feature vector and the vertical smelting feature vector are collectively referred to as the smelting feature vector; the horizontal smelting uniformity and the vertical smelting uniformity are collectively referred to as the smelting uniformity; the vertical uniformity feature vector and the horizontal uniformity feature vector are collectively referred to as the uniformity feature vector.

[0054] Step 3: According to the differences between the uniformity feature vectors at each acquisition moment, combined with the element distribution characteristics of the uniformity feature vector, obtain the smelting utility at each acquisition moment, and adjust the heating rate of the crucible electric furnace at each acquisition moment; after the smelting is completed, obtain the rare earth alloy liquid, and adopt the ingot casting process to prepare the intermediate rare earth alloy.

[0055] If various rare earth elements are not fully smelted together during smelting, it will cause large temperature changes in different directions, resulting in large differences in the smelting uniformity characteristics of rare earth elements in different directions, and it is impossible to ensure that rare earth elements can be fully mixed and smelted during the smelting process. In order to more accurately control and adjust the heating rate during the smelting process, so as to fully smelt various rare earth elements in the crucible electric furnace and make various rare earth elements alloyed to a great extent, it is necessary to further analyze based on the smelting uniformity characteristics in different directions of the crucible electric furnace.

[0056] Align the vertical uniformity feature vector and the horizontal uniformity feature vector during smelting in the crucible electric furnace at each acquisition moment, so that the lengths of the aligned vertical uniformity feature vector and the horizontal uniformity feature vector are the same. In this embodiment, the alignment is based on the first element of the two vectors; calculate the difference vector between the aligned vertical uniformity feature vector and the horizontal uniformity feature vector, and record the mean value of the absolute values of all elements in the difference vector as the direction difference degree during smelting in the crucible electric furnace at each acquisition moment. The direction difference degree reflects the overall uniformity characteristics of rare earth element smelting in the crucible electric furnace. If the difference between the vertical uniformity feature vector and the horizontal uniformity feature vector is greater, it means that there are large differences in the smelting uniformity characteristics of rare earth elements in different directions during smelting, that is, the overall non-uniformity of rare earth element smelting in the crucible electric furnace is greater, and then the smelting effect of rare earth elements in the crucible electric furnace at this time is worse.

[0057] According to the element distribution characteristics in the vertical uniformity feature vector and the horizontal uniformity feature vector at each acquisition moment, combined with the direction difference degree, obtain the smelting utility at each acquisition moment: record the mean value of all elements in the vertical uniformity feature vector at each acquisition moment as the first mean value; record the mean value of all elements in the horizontal uniformity feature vector at each acquisition moment as the second mean value; fuse the first mean value and the second mean value, and fuse with the negative correlation mapping result of the direction difference degree at each acquisition moment to obtain the smelting utility at each acquisition moment.

[0058] In this embodiment, the first mean value is denoted as , the second mean value is denoted as , the directional difference degree at each acquisition moment is denoted as , and the formula form of the smelting utility degree at each acquisition moment is: ; where is a preset parameter greater than zero, whose function is to avoid the denominator from taking the value of 0, and its value is 0.5 in this embodiment.

[0059] It should be understood that if the difference between the smelting uniformity characteristics of rare earth elements in different directions in the crucible electric furnace is smaller, and the smelting uniformity characteristics of rare earth elements in different directions are larger, to a certain extent, it indicates that the smelting effect of rare earth elements in the crucible electric furnace is higher at this time, and the smelting utility degree is larger.

[0060] During the smelting process of rare earth alloys, the smelting utility degree of rare earth elements in the crucible electric furnace is closely related to the heating rate. Specifically, when the smelting utility degree is low, it indicates that the mixing and smelting of rare earth elements in the electric furnace are not yet completely uniform. At this time, the heating rate should be increased to accelerate the melting process of rare earth elements, ensure that the rare earth elements in the alloy liquid can be fully mixed, and avoid the phenomenon of uneven composition. On the other hand, when the smelting utility degree is high, it means that the rare earth elements have approached complete smelting and mixing. At this time, the heating rate can be reduced to reduce power consumption and avoid possible overheating of the alloy or other adverse reactions caused by too fast heating.

[0061] Based on this, the heating rate of the crucible electric furnace at the next acquisition moment is adjusted as follows: , where is the heating rate of the crucible electric furnace at the next acquisition moment; is the heating rate of the crucible electric furnace at the current acquisition moment; is the smelting utility degree at the current acquisition moment; is a preset judgment threshold; it is used to judge whether to adjust the heating rate upward or downward, and its value is 0.5; is the preset maximum adjustment value of the heating rate, to avoid too high a heating rate. Low melting point metals will melt in advance and may form uneven alloys before the temperature reaches the melting point of other metals. Its value is 15 in this embodiment; represents the exponential function with the natural constant as the base.

[0062] It should be understood that if the smelting utility degree at the current acquisition moment is low, the heating rate at the next acquisition moment is increased. On the contrary, if the smelting utility degree at the current acquisition moment is high, the heating rate at the next acquisition moment is decreased. The smelting of rare earth elements is carried out according to the heating rate at the next acquisition moment, so as to ensure that the rare earth elements in the alloy liquid in the crucible electric furnace are fully smelted together and reduce the power consumption.

[0063] After the smelting of rare earth elements is completed, a rare earth alloy liquid is obtained, and a traditional ingot casting process is used to prepare an intermediate rare earth alloy.

[0064] Step 4: Melt refined lead in a lead melting pot, add silver and sodium in sequence and stir after heating up, then add calcium-aluminum alloy, tin and a protective agent for smelting after heating up again, and then add the intermediate rare earth alloy and stir to obtain a positive grid rare earth alloy.

[0065] Place refined lead with a purity of at least 99.99% in a lead melting pot, melt it into lead liquid at 450 °C, heat it up to 500 °C, add silver (Ag) with a purity of at least 99.9% and sodium metal (Na) drained of kerosene into the lead liquid, and then stir for 5 minutes to obtain alloy liquid 1;

[0066] In this process, to prevent the sodium metal from catching fire and burning when added, in this embodiment, the sodium metal is added to the lead liquid in small amounts and multiple times, so that it quickly melts in the lead to ensure the utilization rate of sodium.

[0067] Heat alloy liquid 1 up to 590 °C, add calcium-aluminum alloy, tin with a purity of 99.9% and a protective agent in sequence, and smelt at 650 °C to obtain alloy liquid 2.

[0068] In alloy liquid 2, add the intermediate rare earth alloy. Since the amount of the intermediate rare earth alloy added is large and the temperature drops significantly, in order to ensure that the rare earth elements can be better alloyed, it is required that the temperature always remains in a rising state. After all the ingredients are added, stir for 20 min, then let it stand, skim the slag, take samples, and use a traditional ingot casting process to prepare a positive grid rare earth alloy for lead-acid batteries.

[0069] Among them, the process flow chart of the preparation of the positive grid rare earth alloy is as Figure 2 shown.

[0070] Example 2

[0071] The method for preparing a rare earth alloy for a lead-acid battery proposed in Example 2 of this application is applied to the technical field of lead-acid batteries. Refer to the appendix Figure 1 , the method is the same as the method in Example 1. Among them, in step 1, the temperature range for smelting refined lead and rare earth elements in a crucible electric furnace is 600-800 °C; in step 4, after heating up to 550 °C, add silver and sodium in sequence and stir; after heating up to 600 °C again, add calcium-aluminum alloy, tin and a protective agent for smelting, and finally obtain a positive grid rare earth alloy for a lead-acid battery.

[0072] Example 3

[0073] Embodiment 3 of the present application proposes a method for preparing rare earth alloy for lead-acid batteries, which is applied to the technical field of lead-acid batteries. Refer to the attached Figure 1 , the method is the same as the method in Embodiment 1. Among them, in Step 1, the temperature range for melting refined lead and rare earth elements in a crucible electric furnace is 600-900 °C; in Step 4, after heating to 550 °C, silver and sodium are added in sequence and stirred; after heating to 650 °C again, calcium-aluminum alloy, tin and a protective agent are added for melting, and finally a rare earth alloy for the positive plate grid of a lead-acid battery is obtained.

[0074] The flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the systems, methods and computer program products according to the embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment or a part of code, and the module, program segment or part of code contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions marked in the blocks may also occur in a different order from that marked in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, which may depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order from that disclosed in the description. Sometimes, there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, which may depend on the functions involved. Each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0075] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for preparing a rare earth alloy for a lead-acid battery, characterized in that: The method includes: Step 1: Smelting refined lead and rare earth elements in a crucible electric furnace; the smelting temperatures of all sampling points in the crucible electric furnace at each sampling moment during the smelting process are combined into a smelting temperature matrix at each sampling moment; Step 2: Analyze the temperature change distribution characteristics in the horizontal and vertical directions in the melting temperature matrix at each acquisition time, and obtain all melting feature vectors at each acquisition time; based on the difference between each element and the other elements in each melting feature vector at each acquisition time, obtain the melting uniformity of each element to form each uniform feature vector at each acquisition time; Step 3: According to the difference between the uniform feature vectors at each collection time, combined with the element distribution characteristics of the uniform feature vector, the smelting effectiveness at each collection time is obtained, and the heating rate of the crucible electric furnace at each collection time is adjusted; after the smelting is completed, the rare earth alloy liquid is obtained, and the intermediate rare earth alloy is prepared by the ingot casting process; Step 4: Melt the refined lead in a lead melting pot, add silver and sodium in turn after heating and stir, heat up again and add calcium aluminum alloy, tin and protective agent for smelting, add the intermediate rare earth alloy and keep heating, let it stand after stirring, remove the slag, take samples, and use the ingot casting process to obtain the positive electrode grid rare earth alloy.

2. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: The rare earth elements are specifically lanthanum, samarium, cerium and yttrium.

3. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: The temperature range for smelting the refined lead and the rare earth elements in the crucible electric furnace is 600-1000°C.

4. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: The smelting characteristic vector includes a longitudinal smelting characteristic vector and a transverse smelting characteristic vector, and the acquisition steps are as follows: Obtain the first-order difference vector of each row vector in the melting temperature matrix at each acquisition moment, and calculate the absolute value of all elements in the first-order difference vector to obtain each lateral temperature difference change vector at each acquisition moment; Calculate the permutation entropy of each transverse temperature difference change vector at each acquisition moment, and use the vector composed of the permutation entropy of all transverse temperature difference change vectors at each acquisition moment as the longitudinal melting characteristic vector at each acquisition moment; The same method as the longitudinal melting characteristic vector is used to obtain the transverse melting characteristic vector at each collection moment according to each column vector in the capacity-temperature matrix at each collection moment.

5. The method for preparing a rare earth alloy for a lead-acid battery according to claim 4, characterized in that: The melting uniformity includes the longitudinal melting uniformity and the transverse melting uniformity; the uniform characteristic vector includes the longitudinal uniform characteristic vector and the transverse uniform characteristic vector, which are specifically: For each element in the longitudinal melting characteristic vector, the absolute value of the difference between each element and the remaining elements is obtained, the absolute value of the difference between each element and all the remaining elements is accumulated and then negatively correlated to obtain the longitudinal melting uniformity of each element; the vector composed of the longitudinal melting uniformity of all elements in the longitudinal melting characteristic vector at each acquisition moment is recorded as the longitudinal uniformity characteristic vector at each acquisition moment; The same method as that for the longitudinal smelting uniformity is adopted to obtain the transverse smelting uniformity of the transverse smelting characteristic vector based on the transverse smelting characteristic vector; the vector composed of the transverse smelting uniformity of all elements in the transverse smelting characteristic vector at each acquisition moment is recorded as the transverse uniformity characteristic vector at each acquisition moment.

6. The method for preparing a rare earth alloy for a lead-acid battery according to claim 5, characterized in that: The method of obtaining the smelting utility at each collection time includes: Align the longitudinal uniform feature vector and the transverse uniform feature vector at each acquisition moment, calculate the difference vector between the two vectors, and record the average of the absolute values ​​of all elements in the difference vector as the directional difference at each acquisition moment; The mean of all elements in the longitudinal uniform feature vector at each acquisition moment is recorded as the first mean; the mean of all elements in the transverse uniform feature vector at each acquisition moment is recorded as the second mean; the first mean and the second mean are fused, and then fused with the negative correlation mapping result of the directional difference at each acquisition moment to obtain the smelting utility at each acquisition moment.

7. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: The calculation method for adjusting the heating rate of the crucible electric furnace at each sampling moment is: , where is the heating rate of the crucible electric furnace at the next sampling moment, is the heating rate of the crucible electric furnace at the current collection time, is the smelting efficiency at the current collection time, is the preset judgment threshold, It is the preset maximum adjustment value of the heating rate. Represents an exponential function with a natural constant as base.

8. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: After the heating, silver and sodium are added in sequence and stirred, wherein the temperature is raised to 500-550°C.

9. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: The temperature of the smelting after heating up again and adding calcium aluminum alloy, tin and protective agent is 600-650°C.

10. The method for preparing a rare earth alloy for a lead-acid battery according to claim 1, characterized in that: During the process of adding the intermediate rare earth alloy and stirring, the temperature needs to be kept rising and stirred for 20 minutes.

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