Aluminum ingot refining process and device using aluminum ash slag

Abstract

The present application relates to the technical field of aluminum ash slag refining, and specifically to a process and apparatus for refining aluminum ingots using aluminum ash slag. The process comprises: introducing aluminum ash slag on the surface of a molten aluminum-silicon alloy into a slag pan for natural cooling; crushing and ball-milling the cooled aluminum ash slag; obtaining and sieving aluminum ash slag samples at preset time intervals during the ball milling process; obtaining a mass ratio vector and a set of all particle sizes for each aluminum ash slag sample at each time point based on the mass distribution of the sieved aluminum ash slag samples; obtaining the particle size distribution uniformity of the aluminum ash slag sample at each time point; obtaining an aluminum separation evaluation coefficient for each aluminum ash slag sample at each time point; obtaining a differential sequence of the evaluation coefficients for each aluminum ash slag sample at each time point and an aluminum separation threshold value as a criterion for stopping the ball milling of the aluminum ash slag; and after stopping the ball milling, sieving all the aluminum ash slag and selecting aluminum ash slag within a preset particle size range for high-temperature smelting to obtain aluminum ingots. The present application aims to reduce impurities in aluminum ingots and improve the quality of aluminum ingot refining.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum ash refining, and in particular to a process and device for refining aluminum ingots using aluminum ash. Background Art

[0002] During the melting and alloying process of aluminum, the molten aluminum encounters an oxidizing atmosphere, causing surface oxidation and the formation of a semi-solid skin on the molten metal. This mixture, called aluminum slag, is primarily composed of alumina, metallic aluminum, magnesium spinel, periclase, quartz, and salts containing small amounts of aluminum carbides and aluminum nitrides. Aluminum slag is unavoidably produced in aluminum smelters. There are generally two types of aluminum slag: white slag (primary aluminum slag) and black slag (secondary aluminum slag). White slag is formed during the primary aluminum production process and contains a high percentage of aluminum species, such as Al and Al2O3; black slag contains small amounts of metallic species and is produced during the secondary aluminum refining process.

[0003] Smelters use aluminum ash slag as raw material to refine aluminum ingots and other products. A common method is to use thermal metallurgy to release liquid aluminum metal from the slag for ingot refining. Thermal metallurgy requires pre-grinding the slag to facilitate subsequent melting of the aluminum. Currently, the thermal metallurgical process for refining aluminum ingots does not consider the differences in how the mechanical treatment during ball milling affects the different components of the slag. This results in a low concentration of metallic aluminum in the slag that participates in the melting process, causing an increase in impurities in the aluminum ingots and affecting the quality of the refined aluminum ingots. Summary of the Invention

[0004] In view of the above, it is necessary to provide an aluminum ingot refining process and device using aluminum ash slag to solve the above problems.

[0005] In a first aspect, the present application provides a process for refining aluminum ingots using aluminum ash slag, the method comprising:

[0006] Step 1: introducing aluminum ash residue on the surface of the molten aluminum-silicon alloy into a slag tray for natural cooling;

[0007] Step 2: crushing and ball-milling the cooled aluminum ash slag. During the ball-milling process, aluminum ash slag samples are obtained at preset time intervals and sieved. Based on the mass distribution of the sieved aluminum ash slag samples, the mass ratio vector of the aluminum ash slag samples at each time point and the set of all particle sizes are obtained.

[0008] Step 3: Obtain the particle size distribution uniformity of the aluminum ash slag sample at each moment based on the degree of dispersion of elements in all particle size sets corresponding to the aluminum ash slag sample at each moment; Obtain the aluminum separation evaluation coefficient of the aluminum ash slag sample at each moment based on the similarity of the mass ratio vector of the aluminum ash slag sample obtained at each moment during the ball milling process and the previous moment, combined with the degree of change in the particle size distribution uniformity;

[0009] Step 4: Analyze the variation characteristics of the aluminum separation evaluation coefficient of the aluminum ash slag samples at each moment and the previous moment during the ball milling process to obtain the evaluation coefficient difference sequence and aluminum separation threshold of the aluminum ash slag samples at each moment, which serve as the judgment condition for stopping the ball milling of the aluminum ash slag; after stopping the ball milling, screen all the aluminum ash slag and select aluminum ash slag within a preset particle size range;

[0010] Step 5: Smelting the selected aluminum ash at high temperature to obtain aluminum ingots.

[0011] Preferably, the cooling atmosphere for natural cooling is argon, and the cooling time is 12 to 24 hours.

[0012] Preferably, the specific operation of ball milling is: the mass of aluminum ash slag during ball milling is 1 / 2 of the mass of steel balls in the ball mill. , the speed of the ball mill is 30~40 rpm.

[0013] Preferably, the specific process of obtaining the mass ratio vector of the aluminum ash slag sample at each moment and all particle size sets is:

[0014] During the ball milling process, a preset mass of aluminum ash slag sample is taken out at each time, and the aluminum ash slag sample at the same time of ball milling is screened into a preset number of portions through a multi-layer linear vibrating screen. The mass of each aluminum ash slag sample is weighed and arranged in order from largest to smallest average particle size;

[0015] Obtain the mass ratio of each aluminum ash slag sample as an element of the mass ratio vector of the aluminum ash slag sample at each moment;

[0016] The mass of each aluminum ash slag sample and the mass of a preset number of subsequent aluminum ash slag samples are set as each particle size set.

[0017] Preferably, the process of obtaining the particle size distribution uniformity of the aluminum ash slag sample at each moment is:

[0018] For the aluminum ash slag samples at each moment, the negative correlation mapping results of the discreteness of the elements in each particle size set are calculated, and the negative correlation mapping results are weighted and summed using the preset weight value of each particle size set to obtain the particle size distribution uniformity of the aluminum ash slag samples at each moment.

[0019] Preferably, the formula for obtaining the aluminum separation evaluation coefficient of the aluminum ash slag sample at each moment is: ;in, represents the aluminum separation evaluation coefficient of the aluminum ash sample at the i-th moment, represents the difference in particle size distribution uniformity between the aluminum ash slag sample at the i-th moment and the i-1-th moment; exp() represents an exponential function with a natural constant as the base; 、 Represent the mass ratio vectors of the aluminum ash slag samples at the i-th moment and the i-1-th moment respectively; represents the cosine similarity function; is a parameter that is preset to be greater than zero.

[0020] Preferably, the evaluation coefficient difference sequence and aluminum separation threshold of the aluminum ash slag sample at each moment are obtained as follows:

[0021] The sequence of aluminum separation evaluation coefficients of the aluminum ash slag samples at each moment and a set number of moments before is recorded as an evaluation sequence; the difference sequence of the evaluation sequence at each moment is recorded as the evaluation coefficient difference sequence at each moment;

[0022] The mean of all elements in the evaluation coefficient difference sequence at each moment is recorded as the aluminum separation threshold.

[0023] Preferably, the specific process of determining the stopping condition of the ball milling of aluminum ash slag is as follows:

[0024] If the last element value of the evaluation coefficient difference sequence of the aluminum ash slag sample at the current moment is greater than the aluminum separation threshold at the current moment, the ball milling of the aluminum ash slag is stopped.

[0025] Preferably, the particle size of the selected aluminum ash slag is greater than 1.25 mm, and the aluminum ash slag is subjected to high-temperature smelting using a plasma arc method, with the smelting temperature being 700-800° C. and the smelting time being 1-2 h.

[0026] In the second aspect, an embodiment of the present application also provides an aluminum ingot refining device using aluminum ash slag, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of an aluminum ingot refining process using aluminum ash slag as described above are implemented.

[0027] This application has at least the following beneficial effects:

[0028] The embodiment of the present application adopts dry ball milling to avoid the reaction between aluminum ash slag and water and reduce pollution. By real-time detection of the mass distribution of aluminum ash slag with different particle sizes in the ball mill, the separation degree of non-metallic phase particles and metallic aluminum phase particles in different batches of aluminum ash slag is analyzed: first, the mass ratio vector and particle size set of the aluminum ash slag sample at each moment in the ball milling process are obtained to provide a data basis for the subsequent analysis of the mass distribution of aluminum ash slag with different particle sizes; the element distribution in the particle size set is analyzed to obtain the uniformity of the particle size distribution, which helps to comprehensively reflect the mass distribution of aluminum ash slag in different particle size ranges; the aluminum separation evaluation coefficient of the aluminum ash slag sample at each moment is obtained, which has the beneficial effect of characterizing the metal phase of the aluminum ash slag during the ball milling process. The degree of separation from the non-metallic phase; the evaluation coefficient difference sequence of the aluminum ash slag samples at each moment and the aluminum separation threshold are obtained. The beneficial effect is to accurately judge the degree of separation between the metal phase and the non-metallic phase in the aluminum ash slag, control the ball milling time, increase the content of metallic aluminum in the aluminum ash slag after screening, reduce the impurities introduced into the aluminum ingot during the high-temperature melting process, and improve the refining quality of the aluminum ingot; finally, the plasma arc method is used to melt the primary aluminum ash slag, and the plasma arc is used as the external heat source. There is no need to add additional salt flux, which reduces the impurity content in the molten aluminum and avoids the smoke pollution generated by salt impurities in a high-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A flowchart of a process for refining aluminum ingots using aluminum ash slag according to one embodiment of the present application;

[0030] Figure 2 A schematic diagram of the process flow for refining aluminum ingots provided in one embodiment of the present application. DETAILED DESCRIPTION

[0031] In the description of the embodiments of this application, words such as "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "or," and "for example" is intended to present the relevant concepts in a concrete manner.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0033] It should also be noted that the terms "first" and "second" in this application and the accompanying drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the methods. Without departing from the scope of protection of this application, the order of executing multiple steps can be interchanged with each other, and some steps can also be deleted.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0035] The following describes in detail a specific solution of an aluminum ingot refining process and device using aluminum ash slag provided in this application with reference to the accompanying drawings.

[0036] Example 1

[0037] See also Figure 1 , which shows a flowchart of a process for refining aluminum ingots using aluminum ash slag provided in Example 1 of the present application, the process comprising the following steps:

[0038] Step 1: introduce the aluminum ash slag on the surface of the molten aluminum-silicon alloy into a slag tray for natural cooling.

[0039] This application uses the primary aluminum ash slag formed on the surface of the molten metal when producing 4000 series aluminum silicon alloys as raw material to refine aluminum ingots. During the melting process of the 4000 series aluminum silicon alloys, the aluminum liquid easily reacts with oxygen and nitrogen in the air to generate aluminum oxide and aluminum nitride. Aluminum oxide and aluminum nitride are insoluble in the aluminum liquid and float on the surface of the aluminum liquid to form aluminum ash slag. Slag is removed from the reverberatory furnace for producing aluminum silicon alloys, and the aluminum ash slag on the surface of the molten aluminum silicon alloy is introduced into the slag pan. It should be noted that the volume of the aluminum ash slag removed to the slag pan accounts for 80% of the volume of the slag pan to avoid excessive loading and overflow of the aluminum ash slag.

[0040] During the slag removal process, the aluminum ash slag inevitably encloses a certain amount of liquid metal aluminum and enters the slag pan. In order to avoid further oxidation of the metal aluminum in the aluminum ash slag, this application adopts an inert gas protection cooling method to naturally cool the aluminum ash slag in the slag pan. The cooling atmosphere uses argon and the cooling time is 12 hours.

[0041] Step 2: crush and ball-mill the cooled aluminum ash slag. During the ball-milling process, aluminum ash slag samples are obtained and sieved at preset time intervals. According to the mass distribution of the aluminum ash slag samples after sieving, the mass ratio vector of the aluminum ash slag samples at each moment and the set of all particle sizes are obtained.

[0042] A hammer crusher is used to fully crush the cooled aluminum ash slag, and the crushed aluminum ash slag and grinding steel balls are fed into a ball mill, where the mass of the steel balls is twice the mass of the aluminum ash slag. The speed of the ball mill is set to 30 rpm and the ball mill is started to ball mill the aluminum ash slag to facilitate the subsequent high-temperature smelting of metallic aluminum; after the ball mill is turned on, the discharge port of the ball mill is opened at a predetermined time interval, and 1 kg of the crushed aluminum ash slag sample is taken and fed into a multi-layer linear vibrating screen. In this application, the multi-layer linear vibrating screen is provided with a total of 5 layers of screen mesh, and the screen hole sizes are 10 mm, 4 mm, 2 mm, 1.25 mm, and 1 mm, respectively. After screening, aluminum ash slag of different particle sizes enters different material boxes respectively, and the mass of the aluminum ash slag in the 6 material boxes is weighed, and the ratio thereof to the total mass of the aluminum ash slag weighed before screening is calculated respectively, and recorded as the mass ratio of the aluminum ash slag in the material boxes with different particle sizes. The mass ratios of the 6 material boxes are arranged in sequence from small to large in the order of the number of layers passing through the multi-layer linear vibrating screen, that is, in the order of large to small average particle size, to form a mass ratio vector, which is used to reflect the mass distribution of aluminum ash slag of different particle sizes in the aluminum ash slag sample; it is convenient for subsequent analysis of the change of the reference mass ratio vector with ball milling time, and to obtain the influence of mechanical treatment on particles of different components of this batch of aluminum ash slag during ball milling.

[0043] During the primary aluminum slag pretreatment process, multiple slag removal operations are performed during aluminum alloy production. Due to the varying feed composition during each production process, the degree of oxidation of the molten aluminum metal varies, resulting in differences in the composition of the aluminum slag from batch to batch. Given the varying effects of mechanical treatment during ball milling on the various aluminum slag components and the fluctuations in the compositional ratios of different batches of aluminum slag, it is difficult to determine a fixed ball milling time. If the ball milling time is too short, the separation between the metallic aluminum phase and the non-metallic phase is poor, introducing excessive impurities during melting. If the ball milling time is too long, the metallic aluminum phase particles are smaller in size, reducing the utilization rate of the aluminum slag.

[0044] In the crushed aluminum ash, the metallic aluminum is typically coated with layers of aluminum oxide and aluminum nitride. Because the metallic aluminum phase is highly ductile, it is not easily broken into smaller particles. However, the non-metallic phases of aluminum oxide, aluminum nitride, and silicon dioxide are relatively hard and brittle, and can be easily crushed into smaller particles.

[0045] The content of metallic aluminum in primary aluminum ash slag is relatively high, and the content of metallic aluminum in the crushed aluminum ash slag decreases with the decrease of particle size. Therefore, the aluminum ash slag samples obtained in the early stage of ball milling are mostly concentrated in the material box with larger particle size; in the early stage of ball milling, the particle size of non-metallic phase particles changes rapidly with the increase of ball milling time, and the larger non-metallic phase particles are crushed into smaller particles under the mechanical action of steel balls, thereby changing the mass distribution of aluminum ash slag with different particle sizes; the particle size of metallic aluminum particles changes slowly with the increase of ball milling time, and the mass distribution of metallic aluminum particles with different particle sizes does not change significantly.

[0046] When the degree of separation between the metallic aluminum phase particles and the non-metallic phase particles is high, the ball mill will grind or break the metallic aluminum that is difficult to grind, resulting in a reduction in the mass of the metallic aluminum phase particles with larger particle size. In addition, due to the higher proportion of metallic aluminum content in the primary aluminum ash, the distribution of particle size in different particle size ranges becomes more uniform.

[0047] Taking into account the differences in the particle sizes of non-metallic phase particles and metallic aluminum phase particles affected by mechanical action, in order to more accurately judge the separation state of aluminum ash slag in the ball mill, M particle size sets are constructed, where M takes a value of 4. The specific construction method is as follows: obtain the mass of aluminum ash slag samples in each particle size range, and take the mass of aluminum ash slag in each particle size range and the mass of aluminum ash slag in a preset number of particle size ranges as each particle size set.

[0048] In this embodiment, the preset number is 2. Specifically, the mass of aluminum ash slag with a particle size less than 1 mm is recorded as a; the mass of aluminum ash slag with a particle size between 1 and 1.25 mm is recorded as b; the mass of aluminum ash slag with a particle size between 1.25 and 2 mm is recorded as c; the mass of aluminum ash slag with a particle size between 2 and 4 mm is recorded as d; the mass of aluminum ash slag with a particle size between 4 and 10 mm is recorded as e; the mass of aluminum ash slag with a particle size greater than 10 mm is recorded as f; the set consisting of a, b, and c is recorded as the first particle size set; the set consisting of b, c, and d is recorded as the second particle size set; the set consisting of c, d, and e is recorded as the third particle size set, and the set consisting of d, e, and f is recorded as the fourth particle size set.

[0049] Step 3: According to the degree of discreteness of elements in all particle size sets corresponding to the aluminum ash slag samples at each moment, the particle size distribution uniformity of the aluminum ash slag samples at each moment is obtained; according to the similarity of the mass ratio vectors of the aluminum ash slag samples obtained at each moment and the moment before the ball milling process, combined with the degree of change in the particle size distribution uniformity, the aluminum separation evaluation coefficient of the aluminum ash slag samples at each moment is obtained.

[0050] The larger the particle size of the aluminum ash slag within the particle size set, the higher the content of metallic aluminum. When the degree of separation between the metallic aluminum phase particles and the non-metallic phase particles is high, the steel balls in the ball mill begin to act on the metallic aluminum, and the particle size change of the aluminum ash slag in the corresponding particle size set becomes more obvious. In order to stop the ball milling in time when the metallic aluminum phase particles and the non-metallic phase particles are separated, a larger weight is set for the mass ratio standard deviation of the material bin within the particle size set with larger particle size, so as to improve the subsequent detection effect when the mass distribution of the aluminum ash slag within the particle size set with larger particle size changes. The calculation weights of the first particle size set, the second particle size set, the third particle size set, and the fourth particle size set are set to be respectively 、 、 、 In this embodiment, the values are 0.1, 0.2, 0.3, and 0.4 respectively; and .

[0051] The particle size distribution uniformity of the aluminum ash slag is calculated based on the mass ratio of the material boxes in different particle size sets: the negative correlation mapping results of the discreteness of the elements in each particle size set are calculated, and the negative correlation mapping results are weighted and summed with the preset weight value of each particle size set to obtain the particle size distribution uniformity of the aluminum ash slag.

[0052] In this embodiment, the standard deviation is used to measure the dispersion of all elements in each particle size set; the opposite number of the dispersion is used as the exponent of an exponential function with a natural constant as the base, and the exponential function is used as the negative correlation mapping result of the dispersion.

[0053] It should be understood that the larger the standard deviation of the elements in each particle size set, the smaller the uniformity of the particle size distribution; the uniformity of the particle size distribution of aluminum ash slag is used to comprehensively reflect the mass distribution of aluminum ash slag in different particle size ranges.

[0054] The mass distribution of aluminum ash slag with different particle sizes changes differently at different stages of ball milling. In the early stage of ball milling, the steel balls in the ball mill mainly act on the non-metallic phase particles. Since the mass proportion of non-metallic phase particles in the primary aluminum ash slag is relatively small, and their particle sizes are concentrated in a smaller particle size range, the calculated particle size distribution uniformity does not change much. When the degree of separation between the metallic aluminum phase particles and the non-metallic phase particles is high, the particle size of the metallic aluminum phase particles begins to decrease, the mass of the aluminum ash slag in the small particle size range increases, and the mass in the large particle size range decreases, thereby increasing the particle size distribution uniformity. At the same time, the similarity between the mass ratio vectors of the two adjacent aluminum ash slag samples is smaller.

[0055] According to the degree of change of the mass ratio vector of the aluminum ash sample at different times of ball milling, the aluminum separation evaluation coefficient is calculated, and its formula is as follows: ;in, represents the aluminum separation evaluation coefficient of the aluminum ash sample at the i-th moment, It represents the difference in particle size distribution uniformity between the aluminum ash slag sample at the i-th moment and the i-1-th moment; exp() represents an exponential function with a natural constant as the base, the purpose of which is to Mapped to positive values; 、 Represent the mass ratio vectors of the aluminum ash slag samples at the i-th moment and the i-1-th moment respectively; represents the cosine similarity function; The value is 2, the purpose is to map the cosine similarity to a positive value, where , implementers can choose the value according to actual conditions; the aluminum separation evaluation coefficient is used to reflect the degree of separation between the metallic aluminum phase and the non-metallic phase particles in the aluminum ash slag. The higher the degree of separation between the two, the greater the calculated aluminum separation evaluation coefficient.

[0056] Step 4: Analyze the change characteristics of the aluminum separation evaluation coefficient of the aluminum ash slag samples at each moment and before the ball milling process, and obtain the evaluation coefficient difference sequence and aluminum separation threshold of the aluminum ash slag samples at each moment as the stopping judgment condition of the ball milling of the aluminum ash slag; after stopping the ball milling, screen all the aluminum ash slag and select aluminum ash slag within a preset particle size range.

[0057] The aluminum ash slag samples taken out at the previous t moments are used as references. When the aluminum ash slag samples are taken out, the sequence of aluminum separation evaluation coefficients of the aluminum ash slag samples at the current moment and the aluminum ash slag samples at the previous t moments in chronological order is recorded as the evaluation sequence at the current moment. The differential sequence of the evaluation sequence at the current moment is calculated and recorded as the evaluation coefficient differential sequence. In this embodiment, t is taken as 3. When the number of aluminum separation evaluation coefficients is less than t, linear interpolation is used to supplement it. The linear interpolation method is an existing well-known technology and will not be described in detail in this application.

[0058] In the early stages of ball milling, non-metallic phase particles gradually separate from the metallic aluminum phase under the mechanical action of the ball mill, increasing the aluminum separation evaluation coefficient and the corresponding evaluation coefficient difference sequence. As the two continue to separate, the rate of increase in the aluminum separation evaluation coefficient gradually decreases, and the corresponding evaluation coefficient difference sequence gradually decreases. When the degree of separation between the two is greater, the rate of increase in the aluminum separation evaluation coefficient becomes significantly faster. This is mainly because the ball mill primarily acts on the metallic aluminum phase particles, rapidly increasing the uniformity of the aluminum ash particle size distribution and rapidly changing the particle size mass distribution between adjacent times. At this point, the ball mill is shut down to prevent the metallic aluminum from being milled into finer particles, thereby increasing the metallic aluminum content in the screened aluminum ash.

[0059] The average of all values in the evaluation coefficient difference sequence is recorded as the aluminum separation threshold, reflecting the average change in the degree of separation between the metallic aluminum phase and the non-metallic phase in the t time periods before the aluminum ash slag sample was taken. The last value of the evaluation coefficient difference sequence represents the change in the degree of separation between the metallic aluminum phase and the non-metallic phase in the aluminum ash slag samples at two adjacent time periods.

[0060] As ball milling time increases, the aluminum separation evaluation coefficient's growth rate decreases, and the evaluation coefficient difference sequence becomes smaller and smaller. Before the steel balls in the ball mill begin to act on the metallic aluminum phase particles, the final value of the evaluation coefficient difference sequence does not exceed the aluminum separation threshold. When the final value of the evaluation coefficient difference sequence exceeds the aluminum separation threshold, it indicates that the separation degree of the metallic aluminum phase and non-metallic phase in the ball mill is high, and the ball mill begins to act on the metallic aluminum phase particles. At this time, the ball mill is shut down, completing the ball milling of the aluminum ash.

[0061] The aluminum ash from the ball mill is passed through the multi-layer linear vibrating screen and fed into different bins to obtain aluminum ash of different particle sizes. Because the metallic aluminum phase particles in the ball-milled aluminum ash are significantly larger than the non-metallic phase particles, the aluminum ash with a particle size greater than 1.25mm is removed from the bin for subsequent processing.

[0062] Step 5: Smelting the selected aluminum ash at high temperature to obtain aluminum ingots.

[0063] The taken out aluminum ash slag is loaded into a plasma arc rotary furnace, the plasma torch is installed on the charging door of the rotary furnace, and the plasma torch is turned on for high temperature smelting.

[0064] Air or nitrogen is introduced between the thin gaps between the two electrodes of the plasma torch. The electrodes conduct electricity, generating an arc that partially ionizes the gas to produce plasma, which heats the aluminum slag in the rotary furnace to 800°C. The aluminum slag melts in the heated gas atmosphere, while the plasma arc rotary furnace rotates, mechanically stirring the slag, rupturing the oxide film and converging the aluminum metal.

[0065] After 2 hours of high-temperature smelting, the molten aluminum metal is separated from the non-metallic phase products in the aluminum ash slag. By tilting the plasma arc rotary furnace, the molten aluminum metal is poured out from the loading door to complete the refining of the aluminum ingot.

[0066] Among them, the process flow diagram of aluminum ingot refining is as follows Figure 2 shown.

[0067] Example 2

[0068] See also Figure 1 , which shows a flow chart of the steps of an aluminum ingot refining process using aluminum ash slag provided in Example 2 of the present application, the process includes the following steps:

[0069] Step 1: adopt the same process as step 1 of Example 1 to obtain cooled aluminum ash slag; wherein the cooling time is 24 hours.

[0070] Step 2, using the same process as step 2 of Example 1, obtain the mass ratio vector of the aluminum ash slag sample at each moment and all particle size sets; wherein the mass of the aluminum ash slag during ball milling is the mass of the steel balls in the ball mill. , the speed of the ball mill is 40 rpm.

[0071] In step 3, the same process as step 3 of Example 1 is used to obtain the aluminum separation evaluation coefficient of the aluminum ash slag sample at each time.

[0072] Step 4, using the same process as step 4 of Example 1, select aluminum ash slag with a particle size greater than 2 mm;

[0073] In step 5, the same process as step 5 of embodiment 1 is adopted to obtain an aluminum ingot; wherein, the temperature for high-temperature smelting is 700° C., and the time for high-temperature smelting is 2 h.

[0074] Example 3

[0075] See also Figure 1 , which shows a flowchart of a process for refining aluminum ingots using aluminum ash slag provided in Example 3 of the present application, the process comprising the following steps:

[0076] Step 1: adopt the same process as step 1 of Example 1 to obtain cooled aluminum ash slag; wherein the cooling time is 18 hours.

[0077] Step 2, using the same process as step 2 of Example 1, obtain the mass ratio vector of the aluminum ash slag sample at each moment and all particle size sets; wherein the mass of the aluminum ash slag during ball milling is the mass of the steel balls in the ball mill. , the speed of the ball mill is 40 rpm.

[0078] In step 3, the same process as step 3 of Example 1 is used to obtain the aluminum separation evaluation coefficient of the aluminum ash slag sample at each time.

[0079] Step 4: Using the same process as step 4 of Example 1, select aluminum ash slag with a particle size greater than 4 mm;

[0080] In step 5, the same process as step 5 of embodiment 1 is adopted to obtain an aluminum ingot; wherein, the temperature for high-temperature smelting is 800° C., and the time for high-temperature smelting is 1 hour.

[0081] Comparative Example 1

[0082] The ball milling time of Comparative Example 1 was 6 h, and the other parameters were consistent with those of Example 1 to obtain an aluminum ingot.

[0083] Comparative Example 2

[0084] The ball milling time of Comparative Example 2 was 9 h, and the other parameters were consistent with those of Example 2 to obtain an aluminum ingot.

[0085] Comparative Example 3

[0086] The ball milling time of Comparative Example 3 was 12 h, and the other parameters were consistent with those of Example 3 to obtain an aluminum ingot.

[0087] Finally, the aluminum ingots refined at different ball milling times were subjected to XRD analysis using a Zeiss Ultra 55 scanning electron microscope (SEM) combined with energy dispersive X-ray spectroscopy (EDS). The aluminum content in the aluminum ingots under different embodiments and comparative examples, as well as the mass ratios of the aluminum ingots and aluminum ash slag, were obtained as shown in the following table:

[0088]

[0089] Examples 1, 2, and 3 show that as the particle size of the smelting aluminum ash increases, the aluminum content in the refined aluminum ingot gradually increases, but the aluminum content in the aluminum ingot refined from the aluminum ash with a particle size greater than 4 mm does not increase significantly compared to that from the aluminum ash with a particle size greater than 2 mm, and the utilization rate of the aluminum ash decreases significantly.

[0090] Example 1 and Comparative Example 1, as well as Example 2 and Comparative Example 2, show that the ball milling time of Comparative Example 1 is too short, and the metallic aluminum phase and the non-metallic phase cannot be separated to a large extent, resulting in a high impurity content in the aluminum ingot.

[0091] Example 3 and Comparative Example 3 show that as the ball milling time increases, the aluminum content in the refined aluminum ingot in the comparative example increases, but the ball milling time of Comparative Example 3 is too long, so that too much metal aluminum phase particles are screened out, resulting in a decrease in the utilization rate of aluminum ash slag.

[0092] Based on the same inventive concept as the above method, an embodiment of the present application also provides an aluminum ingot refining device using aluminum ash slag, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, any step in the above-mentioned aluminum ingot refining process using aluminum ash slag is implemented.

[0093] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the part of the module, program segment or code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

[0094] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, from any point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive; modifications to the technical solutions described in the above embodiments, or equivalent replacement of some of the technical features therein, do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application.

Claims

1. A process for refining aluminum ingots using aluminum ash slag, characterized in that: The process includes the following steps: Step 1: introducing aluminum ash residue on the surface of the molten aluminum-silicon alloy into a slag tray for natural cooling; Step 2: crushing and ball milling the cooled aluminum ash slag, obtaining and sieving aluminum ash slag samples at preset time intervals during the ball milling process, taking out aluminum ash slag samples of a preset mass at each time point during the ball milling process, and sieving the aluminum ash slag samples obtained at the same time point of ball milling into a preset number of portions through a multi-layer linear vibrating screen, weighing the mass of each aluminum ash slag sample, and arranging them in order from largest to smallest according to the average particle size; obtaining the mass ratio of each aluminum ash slag sample as an element of the mass ratio vector of the aluminum ash slag samples at each time point; and taking the mass of each aluminum ash slag sample and the mass of the subsequent preset number of aluminum ash slag samples as each particle size set; Step 3: Obtain the particle size distribution uniformity of the aluminum ash slag sample at each moment based on the degree of discreteness of the elements in all particle size sets corresponding to the aluminum ash slag sample at each moment; obtain the aluminum separation evaluation coefficient of the aluminum ash slag sample at each moment based on the similarity of the mass ratio vector of the aluminum ash slag sample obtained at each moment during the ball milling process and the previous moment, combined with the degree of change in the particle size distribution uniformity. The specific formula is: ;in, represents the aluminum separation evaluation coefficient of the aluminum ash sample at the i-th moment, represents the difference in particle size distribution uniformity between the aluminum ash slag sample at the i-th moment and the i-1-th moment; exp() represents an exponential function with a natural constant as the base; 、 Represent the mass ratio vectors of the aluminum ash slag samples at the i-th moment and the i-1-th moment respectively; represents the cosine similarity function; is a parameter that is preset to be greater than zero; Step 4: Record the sequence of aluminum separation evaluation coefficients of the aluminum ash slag samples at each moment and a set number of moments before as an evaluation sequence; record the difference sequence of the evaluation sequence at each moment as the evaluation coefficient difference sequence at each moment; record the mean value of all elements in the evaluation coefficient difference sequence at each moment as the aluminum separation threshold; if the last element value of the evaluation coefficient difference sequence of the aluminum ash slag sample at the current moment is greater than the aluminum separation threshold at the current moment, stop ball milling the aluminum ash slag; after stopping ball milling, sieve all the aluminum ash slag to select aluminum ash slag within a preset particle size range; Step 5: Smelting the selected aluminum ash at high temperature to obtain aluminum ingots.

2. The aluminum ingot refining process using aluminum ash slag according to claim 1, characterized in that: The cooling atmosphere for natural cooling is argon, and the cooling time is 12 to 24 hours.

3. The aluminum ingot refining process using aluminum ash slag according to claim 1, characterized in that: The specific operation of ball milling is: the mass of aluminum ash slag during ball milling is 1 / 2 of the mass of steel balls in the ball mill. , the speed of the ball mill is 30~40 rpm.

4. The aluminum ingot refining process using aluminum ash slag according to claim 1, characterized in that: The process of obtaining the particle size distribution uniformity of the aluminum ash slag sample at each moment is as follows: For the aluminum ash slag samples at each moment, the negative correlation mapping results of the discreteness of the elements in each particle size set are calculated, and the negative correlation mapping results are weighted and summed using the preset weight value of each particle size set to obtain the particle size distribution uniformity of the aluminum ash slag samples at each moment.

5. The aluminum ingot refining process using aluminum ash slag according to claim 1, characterized in that: The selected aluminum ash slag has a particle size greater than 1.25 mm and is subjected to high-temperature melting using a plasma arc method at a melting temperature of 700-800° C. for a melting time of 1-2 hours.

6. An aluminum ingot refining device using aluminum ash slag, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the aluminum ingot refining process using aluminum ash slag as described in any one of claims 1 to 5 are implemented.

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