Metal tailings and steel slag mixed prepared ceramsite and method thereof

Abstract

The application relates to the technical field of redeveloping and utilizing rare earth tailings, in particular to a ceramsite prepared by mixing metal tailings and steel slag and a method thereof, which comprises the following steps: crushing and grinding the metal tailings and the steel slag into powdery rare earth tailing mixture; performing solid-liquid separation on petroleum drilling slurry to obtain petroleum drilling waste liquid, and then immersing the rare earth tailing mixture in the petroleum drilling waste liquid to obtain immersed liquid and the rare earth tailing mixture after immersion; mixing and stirring the immersed liquid and the rare earth tailing mixture after immersion, industrial waste bricks, Suzhou soil, high-alumina bauxite, fly ash, silica ash, attapulgite, coal gangue, straw waste, industrial phosphoric acid, steel fiber, phosphogypsum, alumina sol, polypropylene fiber, sodium sulfate, citric acid, benzalkonium chloride, bentonite, river sand and graphite powder, homogenizing the mixture, balling and coating the mixture, screening and statically culturing the mixture, and cooking the mixture to obtain the ceramsite. The application can improve the preparation efficiency of the ceramsite and reduce the preparation cost of the ceramsite.

Description

Technical Field

[0001] This application relates to the field of rare earth metal tailings redevelopment and utilization technology, specifically to a method for preparing ceramsite by mixing metal tailings and steel slag. Background Technology

[0002] Rare earth tailings contain important metal resources and have high economic value. However, during the mining process, the utilization rate is often less than 100%, resulting in a large amount of rare earth tailings. The generation of rare earth tailings not only wastes resources but also occupies land and easily causes soil erosion. Therefore, the treatment of rare earth tailings restricts the development of the rare earth industry, and its comprehensive utilization has become an important factor affecting the development of the rare earth industry.

[0003] Currently, the development and utilization of rare earth tailings has significant practical implications. In existing technologies for preparing ceramsite from rare earth tailings, continuous mixing of the mixture is often required to ensure the strength of the ceramsite. However, current technologies often cannot precisely control the mixing time. Shorter mixing times can lead to poor uniformity of the mixture, resulting in weaker ceramsite that fails to meet the strength requirements for practical applications.

[0004] In order to ensure the strength requirements of the prepared ceramsite in practical applications, the mixing process is usually set to a long mixing time. When the mixture reaches the time required for full and uniform mixing, the existing technology cannot stop the mixing of the mixture in time while ensuring that the mixture is fully and uniformly mixed. This results in excessively long mixing time, which leads to waste of preparation time and electrical energy, resulting in low efficiency and high cost in the preparation of ceramsite. Summary of the Invention

[0005] To address the aforementioned technical problems, the purpose of this application is to provide a method for preparing ceramsite from a mixture of metal tailings and steel slag, the specific technical solution of which is as follows:

[0006] This application provides a method for preparing ceramsite by mixing metal tailings and steel slag, including the following steps:

[0007] Metal tailings and steel slag are crushed, and the crushed mixture is ground into powder to obtain rare earth tailings mixture.

[0008] The solid-liquid separation of oil drilling slurry yields oil drilling waste liquid, and the rare earth tailings mixture is impregnated to obtain impregnating solution after impregnation of oil drilling waste liquid and impregnated rare earth tailings mixture.

[0009] Take the impregnation solution and rare earth tailings mixture after impregnation with oil drilling waste fluid, industrial waste bricks, Suzhou soil, high-alumina bauxite, fly ash, silica fume, attapulgite, coal gangue, straw waste, industrial phosphoric acid, steel fiber, phosphogypsum, alumina sol, polypropylene fiber, sodium sulfate, citric acid, benzalkonium chloride, bentonite, river sand, and graphite powder, mix and stir. Analyze the stirring process using hyperspectral data to determine whether to stop stirring. The determination process is as follows:

[0010] Hyperspectral images of the mixture during the mixing process were acquired and divided into multiple sub-regions;

[0011] Based on the difference in reflectance between different pixels in each sub-region, the material similarity of each sub-region is constructed. All material similarity thresholds are used for segmentation, and the sub-regions are divided into material regions and non-material regions. The ratio of the number of non-material regions to the total number of sub-regions in the hyperspectral image at each time is determined as the material mixing probability at each time.

[0012] Based on the average level of material similarity of all material regions at each time and the correlation between the reflectance of the pixels at the center of different material regions at each time, the material penetration resistance at each time is constructed, and the material movement complexity at each time is obtained by combining the material mixing probability.

[0013] The local time set of each time is formed by combining the multiple times closest to each time interval. Based on the degree of disorder and range of the material motion complexity distribution of all times in the local time set of each time, the degree of material mixing change at each time is determined to determine whether to stop stirring.

[0014] The mixture is homogenized, pelletized and coated, sieved, cured and cooked to obtain ceramsite.

[0015] Preferably, the weight ratio of the metal tailings and steel slag is 1:1, and the fineness of the mill output is 10% residue on a 0.08mm square hole sieve.

[0016] Preferably, the immersion temperature is 47°C and the immersion time is 24 hours.

[0017] Preferably, the mixture comprises 460 parts of rare earth tailings after impregnation with oil drilling waste fluid, 250 parts of impregnation solution, 10 parts of industrial waste bricks, 10 parts of Suzhou soil, 10 parts of high-alumina bauxite, 10 parts of fly ash, 10 parts of silica fume, 10 parts of attapulgite, 10 parts of coal gangue, 10 parts of straw waste, 3 parts of industrial phosphoric acid, 3 parts of steel fiber, 3 parts of phosphogypsum, 3 parts of alumina sol, 2 parts of polypropylene fiber, 2 parts of sodium sulfate, 2 parts of citric acid, 2 parts of benzalkonium chloride, 2 parts of bentonite, 2 parts of river sand, and 2 parts of graphite powder.

[0018] Preferably, the formula for calculating the material similarity of each sub-region is as follows:

[0019] In the formula, G i Let be the material similarity of the i-th sub-region, n be the number of pixels in the sub-region, dtw() be the dtw distance, ∈ be a value to avoid zero in the denominator, and g be the material similarity of the i-th sub-region. i,j and g i,j―1 Given the reflectance sequences of the j-th and (j-1)-th pixels within the i-th sub-region, arrange the reflectance of each pixel in ascending order of wavelength to form the reflectance sequence of each pixel.

[0020] Preferably, the formula for calculating the material permeation resistance at each time point is as follows:

[0021] In the formula, D t Let GX be the material permeation resistance at time t. t Let m be the mean of the material similarity among all material regions in the hyperspectral image at time t. t Let f be the number of material regions in the hyperspectral image at time t, cos() be the cosine similarity, and f be the number of material regions in the hyperspectral image at time t. t,d and f t,d―1 Let be the reflectance sequence of the d-th and d-1-th material region center pixels in the hyperspectral image at time t. The reflectance sequence of the center pixels is composed of the reflectance of the center pixels arranged in ascending order of wavelength.

[0022] Preferably, the material movement complexity at each moment is the ratio of the material mixing probability to the material penetration resistance at each moment.

[0023] Preferably, determining the degree of material mixing change at each time point to decide whether to stop mixing further includes:

[0024] H t =norm(σV) t ×zV t In the formula, H t Let σV be the degree of material mixing change at time t, norm() be the normalization function, and σV be the normalization function. t Let zV be the information entropy of the material motion complexity at all times in the local time set at time t. t Let be the range of material motion complexity corresponding to all times in the local time set at time t;

[0025] If the degree of material mixing change is less than the preset threshold, stop stirring; otherwise, continue stirring until the degree of material mixing change is less than the preset threshold.

[0026] Preferably, the output of the homogenized mixture is required to have a particle size of 0.6 mm and a sieve residue of 13%; the sieving and curing process involves screening out spheres smaller than 19 mm from the spheres and curing them in a curing machine for 24 hours; the cooking process involves steam-pressing the cured spheres and reacting them under a constant pressure of 1.0 MPa saturated steam for 4.5 hours.

[0027] This application also provides a type of ceramsite prepared by mixing metal tailings and steel slag, wherein the ceramsite is prepared by the steps of any of the methods described above.

[0028] As can be seen from the above, the method for preparing ceramsite from a mixture of metal tailings and steel slag provided in this application has at least the following beneficial effects:

[0029] This application analyzes the mixing probability and permeation resistance characteristics of different material particles during mixing to construct the material motion complexity between different material particles. Material motion complexity reflects the strong collision, permeation, and convective mixing characteristics between different material particles. The greater the material motion complexity, the better it is for the uniformity of the mixture. Based on the material motion complexity, the mixing variation degree is obtained during the mixing process. The greater the change in material motion complexity between the mixture, the smaller the material mixing variation degree, indicating that the change in material motion complexity between different material particles is approaching stability, which further suggests that the mixture is not sufficiently homogeneous. Therefore, this invention uses the material mixing variation degree to determine whether to stop mixing. Compared with existing technologies, this invention can stop mixing in a timely manner while ensuring sufficient and uniform mixing of the mixture, avoiding waste of preparation time and energy, effectively improving the efficiency of ceramsite preparation and reducing the preparation cost of ceramsite. Attached Figure Description

[0030] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A flowchart illustrating the steps of a method for preparing ceramsite from a mixture of metal tailings and steel slag, as provided in this application;

[0032] Figure 2 This is a schematic diagram of data acquisition during the mixing and stirring process provided in this application;

[0033] Figure 3A schematic diagram of the material region and non-material region in the hyperspectral image provided in this application;

[0034] Figure 4 This application provides a flowchart for determining whether stirring should stop during the mixing and stirring process in the preparation of ceramsite.

[0035] Figure 5 A comparative diagram illustrating the effects of the eight implementation combinations provided in this application. Detailed Implementation

[0036] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a method for preparing ceramsite from a mixture of metal tailings and steel slag according to this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0037] Unless otherwise specified and limited, terms such as “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the article or device that includes said element. Furthermore, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. 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 pertains.

[0038] The following description, in conjunction with the accompanying drawings, details a specific scheme for preparing ceramsite from a mixture of metal tailings and steel slag, and the method thereof provided in this application.

[0039] Please see Figure 1 It shows a flowchart of the steps of a method for preparing ceramsite by mixing metal tailings and steel slag according to an embodiment of this application, specifically:

[0040] The purpose of this embodiment is to precisely control the mixing time during the mixing and stirring process of the ground mixture, and to stop the mixing and stirring of the mixture in a timely manner while ensuring that the mixture is fully and evenly mixed, so as to avoid the waste of preparation time and power energy, which would lead to low efficiency and high preparation cost of ceramsite.

[0041] This embodiment uses metal tailings and steel slag as basic raw materials to prepare ceramsite through the following process:

[0042] S1, Crushing and Screening: Metal tailings and steel slag are fed into a crusher in a 1:1 weight ratio for crushing. The crushed mixture is then fed into a grinding mill and ground into powder. The fineness of the powder is 10% residue on a 0.08mm square hole sieve, resulting in a rare earth tailings mixture.

[0043] S2, Oil drilling waste liquid impregnation: The oil drilling slurry is subjected to solid-liquid separation to obtain oil drilling waste liquid. The rare earth tailings mixture is impregnated with the oil drilling waste liquid at an impregnation temperature of 47℃ for 24 hours to obtain the impregnation liquid after oil drilling waste liquid impregnation and the rare earth tailings mixture after oil drilling waste liquid impregnation.

[0044] S3, Mixing and Stirring: Take the following parts by weight and mix them. In this embodiment, 460 parts of rare earth tailings mixture after impregnation with oil drilling waste fluid, 10 parts of industrial waste bricks, 10 parts of Suzhou soil, 10 parts of high-alumina bauxite, 10 parts of fly ash, 10 parts of silica fume, 10 parts of attapulgite, 10 parts of coal gangue, 10 parts of straw waste, 3 parts of industrial phosphoric acid, 3 parts of steel fiber, 3 parts of phosphogypsum, 3 parts of alumina sol, 2 parts of polypropylene fiber, 2 parts of sodium sulfate, 2 parts of citric acid, 2 parts of benzalkonium chloride, 2 parts of bentonite, 2 parts of river sand, 2 parts of graphite powder, and 250 parts of impregnation solution after impregnation with oil drilling waste fluid are sent to the mixing chamber of the mixer for mixing and stirring. The original fixed stirring time is set to 40 minutes. In order to accurately control the mixing and stirring time, this embodiment will analyze the stirring of the mixture based on hyperspectral data during the stirring process, specifically including the following steps:

[0045] Step 1: Acquire hyperspectral images of the mixture during the mixing process and divide it into multiple sub-regions.

[0046] In this embodiment, starting from the beginning of the mixing process, a hyperspectral camera is used to acquire hyperspectral images of the mixture in real time during the mixing process, obtaining hyperspectral images of the mixture at each moment in the mixing process. In this embodiment, the hyperspectral image at each moment is uniformly divided into K rectangular grid regions, and each rectangular grid region is denoted as a sub-region. In this embodiment, K is set to 64, and the spectral reflectance of each pixel is arranged in ascending order of wavelength to form a sequence, which is denoted as the reflectance sequence of each pixel.

[0047] In this embodiment, the data acquisition time interval is 2 seconds, and the data acquisition diagram is shown below. Figure 2 As shown, Figure 2 Number 1 is the hyperspectral camera, number 2 is the acquisition window, and number 3 is the mixing tank.

[0048] Step 2: Construct the material similarity of each sub-region based on the difference in reflectance between different pixels in each sub-region, segment all material similarity thresholds, and divide the sub-regions into material regions and non-material regions. The ratio of the number of non-material regions to the total number of sub-regions in the hyperspectral image at each time step is determined as the material mixing probability at each time step.

[0049] Typically, at the start of a mixing process, the mixture is in its initial stage, exhibiting low homogeneity and noticeable agglomeration, indicating weak interpenetration between different materials. Furthermore, a greater difference in spectral reflectance between pixels in different regions of a hyperspectral image at a given moment, compared to a smaller difference in spectral reflectance between pixels within the same region, further suggests weaker interpenetration between different materials.

[0050] In order to accurately control the mixing time, it is necessary to analyze the penetration characteristics between different materials during the mixing process.

[0051] Generally, the smaller the difference in spectral reflectance between pixels within a sub-region, the more likely the material composition within that sub-region is to be of the same type, indicating a more homogeneous material composition within the sub-region, which to some extent suggests poorer uniformity of the mixture.

[0052] Based on the above analysis, and considering the differences in reflectance between different pixels within each sub-region, the material similarity of each sub-region is calculated using the following expression:

[0053] In the formula, G i Let be the material similarity of the i-th sub-region, n be the number of pixels in the sub-region, dtw() be the dtw distance, and g be the material similarity of the i-th sub-region. i,j and g i,j―1 Let dtw(g be the reflectance sequence of the j-th and (j-1)-th pixels within the i-th sub-region. i,j ,g i,j―1 ) is the reflectance sequence g i,j and g i,j―1 The dtw distance between them, ∈, is set to 1 in this embodiment to avoid a value with a denominator of zero. Material similarity reflects the degree of uniformity of material composition within a sub-region. That is, the smaller the material similarity, the more likely the material composition within the sub-region is to belong to the same type of material. To a certain extent, this indicates that the uniformity of the mixture is worse and the degree of uniformity of material composition within the sub-region is higher.

[0054] Typically, when a mixture undergoes strong penetration, it causes continuous collisions between different material particles, resulting in a uniform mixture. To analyze the characteristics of collision and mixing between different materials, all sub-regions in the hyperspectral image at each time step are used as input to the Otsu thresholding algorithm to obtain a segmentation threshold. In this embodiment, sub-regions with material similarity above the segmentation threshold are designated as material regions, and sub-regions with material similarity below the segmentation threshold are designated as non-material regions. This yields all material and non-material regions in the hyperspectral image at each time step. The Otsu thresholding algorithm is a well-known technique, and its specific process will not be elaborated further. A schematic diagram of material and non-material regions in the hyperspectral image is shown below. Figure 3 As shown in the figure, the black area represents all material areas, and the white area represents all non-material areas.

[0055] The fact that the proportion of material regions in the hyperspectral image is relatively large, while the proportion of non-material regions is relatively small, indicates that the mixing process is in the initial stage. At this time, the probability of collision and mixing between different materials is small, which is not conducive to the thorough and uniform mixing of the mixture.

[0056] Therefore, in this embodiment, the ratio of the number of all non-material regions to the total number of sub-regions in the hyperspectral image at each moment is recorded as the material mixing probability at each moment. The material mixing probability reflects the probability of collision and mixing between different material particles. That is, the greater the material mixing probability, the greater the probability of collision and mixing between different material particles at this time, which is more conducive to the thorough and uniform mixing of the mixture.

[0057] Step 3: Based on the average level of material similarity of all material regions at each time and the correlation between the reflectance of the central pixels of different material regions at each time, construct the material penetration resistance at each time, and obtain the material movement complexity at each time by combining the material mixing probability.

[0058] During the mixing process, to stop the mixing of the mixture in a timely manner and avoid the phenomenon of excessive mixing time, it is necessary to analyze the penetration between different material particles. The stronger the penetration between different material particles, the more it indicates that the mixture has been fully and evenly mixed. Thus, the mixing of the mixture should be stopped in time to avoid wasting preparation time and electrical energy.

[0059] Generally, the higher the similarity of materials in a material region, the higher the uniformity of the material composition in that region. At the same time, the greater the difference in spectral reflectance between pixels in different material regions, the smaller the penetration between different materials during the mixing process, reflecting the poorer uniformity of the mixture.

[0060] Based on the above analysis, and according to the average level of material similarity across all material regions at each time point and the correlation between the reflectance of pixels at the center of different material regions at each time point, the material penetration resistance at each time point is calculated. The specific expression is as follows:

[0061] In the formula, D t Let GX be the material permeation resistance at time t. t Let m be the mean of the material similarity among all material regions in the hyperspectral image at time t. t Let f be the number of material regions in the hyperspectral image at time t, cos() be the cosine similarity, and f be the number of material regions in the hyperspectral image at time t. t,d and f t,d―1 Let be the reflectance sequence of the center pixel of the d-th and (d-1)-th material region in the hyperspectral image at time t. The purpose of adding 1 to the denominator is to avoid the denominator being zero. It can be understood that the larger the mean of material similarity and the larger the cosine similarity, the smaller the penetration effect of different material particles at the corresponding time. In this case, the material penetration resistance is greater, that is, the uniformity of the mixture is worse.

[0062] Generally, the higher the probability of collision and mixing between different material particles during the mixing process, and the smaller the resistance to penetration between different material particles, the higher the complexity of the mixing motion between different material particles. For example, the mixing particles will undergo strong collision, penetration and convection mixing phenomena, which is more conducive to the uniformity of the mixture. When the mixing motion between the mixing particles approaches stability, it means that the mixture has been fully mixed and uniform, and the mixing and stirring of the mixture should be stopped in time.

[0063] Based on the above analysis, the material movement complexity at each time step is obtained by combining the material penetration resistance at each time step with the material mixing probability. The material movement complexity at each time step is the ratio of the material mixing probability to the material penetration resistance at that time step. It should be noted that, to avoid the denominator being zero during the ratio calculation, a value to prevent the denominator from being zero needs to be added to the denominator; in this embodiment, this value is set to 0.01.

[0064] It is understandable that the complexity of material movement reflects the degree of complexity of the movement of different material particles in the mixture. The greater the complexity of material movement, the stronger the collision, penetration and convection mixing characteristics between different material particles, which is more conducive to the uniformity of the mixture.

[0065] Step 4: Form a local time set for each time by taking the multiple times closest to the time interval of each time. Based on the degree of disorder and range of the material motion complexity distribution of all times in the local time set of each time, determine the degree of material mixing change at each time to determine whether to stop stirring.

[0066] Typically, as mixing time continues, the complexity of material motion between different particle sizes changes significantly at various points in time, and the homogeneity of the mixture increases. When the homogeneity of the mixture stabilizes, the change in the complexity of material motion between different particle sizes also tends to stabilize, indicating that the mixture has been sufficiently homogenized, and mixing should be stopped promptly. Therefore, to identify the moment when the mixture is sufficiently homogenized and to precisely control the mixing time, further analysis of the changes in material motion complexity is needed.

[0067] To analyze the changes in material movement complexity within a local time interval, this embodiment uses the 20 closest time intervals to each time interval to form a local time set for each time interval. Then, based on the degree of disorder and range of the material movement complexity distribution across all time intervals in the local time set for each time interval, the degree of material mixing change at each time interval is calculated. The calculation formula in this embodiment is:

[0068] H t =norm(σV) t ×zV t In the formula, H t Let σV be the degree of material mixing change at time t, norm() be the normalization function, and σV be the normalization function. t Let zV be the information entropy of the material motion complexity at all times in the local time set at time t. t Let be the range of material motion complexity across all times in the local time set at time t. The calculation of information entropy and range values ​​are well-known techniques, and the specific process will not be elaborated further. A larger information entropy and a larger range indicate a greater variation in material motion complexity between particles of the same material, suggesting that the mixture is not sufficiently homogeneous at this point, and thus a greater degree of material mixing variation.

[0069] Normally, when the mixture is fully and evenly mixed, the change in the complexity of material movement between different material particles will tend to stabilize, and the degree of material mixing change is at a low level. Therefore, this embodiment calculates the degree of material mixing change at each moment in real time to analyze the mixing situation during the stirring process.

[0070] Furthermore, in this embodiment, the determination of whether to stop stirring is based on the degree of material mixing change. Specifically, if the degree of material mixing change at the current moment is less than a preset threshold, it is determined that the mixture has been fully and evenly mixed, and the mixing is stopped to proceed to the next step; if the degree of material mixing change at the current moment is greater than the preset threshold, it is determined that the mixture has not been fully and evenly mixed, and the mixing continues until the mixture is fully and evenly mixed, that is, the degree of material mixing change is less than the preset threshold. In this embodiment, the preset threshold is set to 0.1.

[0071] Specifically, in this embodiment, a flowchart is provided to determine whether stirring should stop during the mixing and stirring process in the preparation of ceramsite, as shown below. Figure 4 As shown.

[0072] S4 involves homogenizing, pelletizing and coating, sieving and curing, and cooking the thoroughly mixed material to obtain ceramsite.

[0073] Preferably, in this embodiment, the homogenization process is as follows: the fully mixed material is fed into a homogenization device, and the output of the homogenized material is controlled as follows: the particle size is controlled at 0.6 mm and the sieve residue is 13%, thus obtaining the homogenized material.

[0074] Preferably, in this embodiment, the pelletizing and coating process is as follows: the homogenized mixture is fed into a pelletizing machine for pelletizing, and then fed into a coating machine for coating to obtain coated pellets. The pelletizing machine is equipped with a water spraying device.

[0075] Preferably, the specific process of screening and curing in this embodiment is as follows: In this embodiment, spheres smaller than 19mm are screened out from the spheres, and the screened spheres are put into a curing machine for curing. The curing time is 24 hours. In this embodiment, the curing temperature is 45 degrees and the humidity is 95% for the first six hours. During the subsequent curing time, it is advisable to spray until the surface of the spheres is visually moist.

[0076] Preferably, the specific process of steaming and cooking in this embodiment is as follows: the spheres after static curing are placed in a pressure vessel for steaming and pressure treatment, and reacted for 4.5 hours under constant pressure of saturated steam at 1.0 MPa. In this embodiment, the drop height of the spheres entering the pressure vessel is 3 meters to obtain non-fired ceramsite.

[0077] To demonstrate the efficiency of using this embodiment to determine the stirring time, the difference between the original fixed stirring time and the stirring time of this embodiment is further analyzed. The ratio of this difference to the original fixed stirring time is used as the improvement rate, and multiple sets of implementation combinations are used for comparison. Specifically, for example... Figure 5 As shown in the figure, this is a schematic diagram comparing the effects of this embodiment with the original fixed stirring time in 8 implementation combinations. Figure 5Bar charts without diagonal lines indicate the original fixed stirring time, while bar charts with diagonal lines indicate the stirring time of this embodiment. The black broken line represents the change in lift rate, corresponding to the lift rate in different implementation combinations.

[0078] Compared to existing technologies that involve mixing and stirring the ground mixture, this embodiment can stop mixing and stirring the mixture in a timely manner while ensuring that the mixture is fully and evenly mixed, thus avoiding waste of preparation time and electrical energy. This can effectively improve the efficiency of ceramsite preparation and reduce the preparation cost of ceramsite.

[0079] Based on the same inventive concept as the above methods, this application also provides a type of ceramsite prepared by mixing metal tailings and steel slag, wherein the ceramsite is prepared by the steps of any of the methods described above.

[0080] It is understood that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0081] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0082] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the protection scope of this application.

Claims

1. A method for preparing ceramsite by mixing metal tailings and steel slag, characterized in that, Includes the following steps: Metal tailings and steel slag are crushed, and the crushed mixture is ground into powder to obtain rare earth tailings mixture. The solid-liquid separation of oil drilling slurry yields oil drilling waste liquid, and the rare earth tailings mixture is impregnated to obtain impregnating solution after impregnation of oil drilling waste liquid and impregnated rare earth tailings mixture. Take the impregnation solution and rare earth tailings mixture after impregnation with oil drilling waste fluid, industrial waste bricks, Suzhou soil, high-alumina bauxite, fly ash, silica fume, attapulgite, coal gangue, straw waste, industrial phosphoric acid, steel fiber, phosphogypsum, alumina sol, polypropylene fiber, sodium sulfate, citric acid, benzalkonium chloride, bentonite, river sand, and graphite powder, mix and stir. Analyze the stirring process using hyperspectral data to determine whether to stop stirring. The determination process is as follows: Hyperspectral images of the mixture during the mixing process were acquired and divided into multiple sub-regions; Based on the difference in reflectance between different pixels in each sub-region, the material similarity of each sub-region is constructed. All material similarity thresholds are used for segmentation, and the sub-regions are divided into material regions and non-material regions. The ratio of the number of non-material regions to the total number of sub-regions in the hyperspectral image at each time is determined as the material mixing probability at each time. Based on the average level of material similarity of all material regions at each time and the correlation between the reflectance of the central pixels of different material regions at each time, the material penetration resistance at each time is constructed, and the material movement complexity at each time is obtained by combining the material mixing probability. The local time set of each time is formed by combining the multiple times closest to each time interval. Based on the degree of disorder and range of the material motion complexity distribution of all times in the local time set of each time, the degree of material mixing change at each time is determined to determine whether to stop stirring. The thoroughly mixed material is homogenized, pelletized and coated, sieved, cured and cooked to prepare ceramsite. The formula for calculating the material similarity of each sub-region is as follows: In the formula, Let i be the material similarity of the i-th sub-region. This represents the number of pixels within the sub-region. for distance, To avoid values ​​with a denominator of zero, and Given the reflectance sequences of the j-th and (j-1)-th pixels within the i-th sub-region, arrange the reflectance of each pixel in ascending order of wavelength to form the reflectance sequence of each pixel. The formulas for calculating the material permeation resistance at each time point are as follows: In the formula, Let be the material permeation resistance at time t. Let be the mean of the material similarity among all material regions in the hyperspectral image at time t. The number of material regions in the hyperspectral image at time t. For cosine similarity, and Let be the reflectance sequence of the center pixel of the d-th and d-1-th material region in the hyperspectral image at time t. The reflectance sequence of the center pixel is composed of the reflectance of the center pixel arranged in ascending order of wavelength. Determine the degree of material mixing change at each time point to determine whether to stop mixing, including: In the formula, Let be the degree of change in material mixing at time t. For normalization function, Let be the information entropy of the material motion complexity corresponding to all times in the local time set at time t. Let be the range of material motion complexity corresponding to all times in the local time set at time t; If the degree of material mixing change is less than the preset threshold, stop stirring; otherwise, continue stirring until the degree of material mixing change is less than the preset threshold.

2. The method for preparing ceramsite from a mixture of metal tailings and steel slag as described in claim 1, characterized in that, The weight ratio of metal tailings to steel slag is 1:1, and the fineness of the mill output is 10% residue on a 0.08mm square hole sieve.

3. The method for preparing ceramsite from a mixture of metal tailings and steel slag as described in claim 1, characterized in that, The immersion temperature was 47℃ and the immersion time was 24 hours.

4. The method for preparing ceramsite from a mixture of metal tailings and steel slag as described in claim 1, characterized in that, The mixture consists of 460 parts of rare earth tailings after impregnation with oil drilling waste fluid, 250 parts of impregnation solution, 10 parts of industrial waste bricks, 10 parts of Suzhou soil, 10 parts of high-alumina bauxite, 10 parts of fly ash, 10 parts of silica fume, 10 parts of attapulgite, 10 parts of coal gangue, 10 parts of straw waste, 3 parts of industrial phosphoric acid, 3 parts of steel fiber, 3 parts of phosphogypsum, 3 parts of alumina sol, 2 parts of polypropylene fiber, 2 parts of sodium sulfate, 2 parts of citric acid, 2 parts of benzalkonium chloride, 2 parts of bentonite, 2 parts of river sand, and 2 parts of graphite powder.

5. The method for preparing ceramsite from a mixture of metal tailings and steel slag as described in claim 1, characterized in that, The material movement complexity at each time step is the ratio of the material mixing probability to the material penetration resistance at each time step.

6. The method for preparing ceramsite from a mixture of metal tailings and steel slag as described in claim 1, characterized in that, The output requirements of the homogenized mixture are a particle size of 0.6 mm and a sieve residue of 13%; the screening and curing process involves screening out spheres smaller than 19 mm from the spheres and curing them in a curing machine for 24 hours; the cooking process involves steam-pressing the cured spheres and reacting them under a constant pressure of 1.0 MPa saturated steam for 4.5 hours.

7. A type of ceramsite prepared by mixing metal tailings and steel slag, characterized in that, The expanded clay aggregate is prepared by the steps of the method described in any one of claims 1-6.

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