Method for preparing red mud sample based on mineralogical analysis stage

Abstract

The invention relates to the technical field of mineralogical analysis of red mud, in particular to a method for preparing a red mud sample based on a mineralogical analysis stage. The method comprises the following steps: mixing a red mud sample with a dispersing agent to obtain a dispersed red mud sample; sequentially carrying out mechanical stirring and first ultrasonic treatment on the red mud dispersed sample to obtain red mud turbid liquid; performing second ultrasonic treatment on the graphite and red mud suspension to obtain a mixture containing the red mud and the graphite; performing solid-liquid separation on the mixture to obtain a mixed solid with preset water content; performing third ultrasonic treatment on epoxy resin, a curing agent and the mixed solid to obtain pre-embedded slurry; introducing the pre-embedded slurry into a mold by using a filtering medium to obtain a pre-embedded body; and curing the pre-embedded body to obtain the embedded block containing the red mud sample. According to the method, through the synergistic effect of a plurality of steps, the accuracy of the red mud sample in mineralogical analysis is systematically improved from three dimensions of sample authenticity retention, observation condition optimization and analysis error elimination.

Description

Technical Field

[0001] This application relates to the field of mineralogy analysis technology for red mud, and more particularly to a method for preparing red mud samples based on the mineralogy analysis stage. Background Technology

[0002] Red mud is a solid waste produced during the alumina industrial production process. Red mud has a complex mineral composition and extremely fine particle size. At the same time, the surface of red mud adsorbs a large number of hydroxyl groups and soluble salts. These characteristics give red mud particles extremely high surface energy, and red mud particles with extremely high surface energy are prone to forming particle agglomerates in water.

[0003] However, in the mineralogical analysis stage of the alumina industry, it is difficult to achieve accurate analysis of red mud particles that are aggregated into granular aggregates. Summary of the Invention

[0004] This application provides a method for preparing red mud samples based on the mineralogical analysis stage, in order to solve the following technical problem: how to improve the accuracy of red mud in the mineralogical analysis stage. In a first aspect, embodiments of this application provide a method for preparing red mud samples based on a mineralogical analysis stage, the method comprising: The red mud sample and the dispersant were mixed to obtain a dispersed red mud sample; The red mud dispersion sample was subjected to mechanical stirring and first ultrasonic treatment in sequence to obtain a red mud suspension. The graphite and the red mud suspension were subjected to a second ultrasonic treatment to obtain a mixture containing red mud and graphite. The mixture is subjected to solid-liquid separation to obtain a mixed solid with a preset water content; The epoxy resin, curing agent, and the mixed solid with a preset moisture content are subjected to a third ultrasonic treatment to obtain a pre-embedded slurry. The pre-embedded slurry is introduced into the mold using a filter medium to obtain the pre-embedded body; The pre-embedded body is solidified to obtain an embedded block containing the red mud sample.

[0005] Optionally, the median particle size D1 of the graphite and the median particle size D2 of the red mud sample satisfy: D1:D2 = (0.5 to 2.0):1.

[0006] Optionally, the volume V1 of the graphite and the volume V2 of the red mud sample satisfy: V1:V2 = (1.5 to 3.0):1.

[0007] Optionally, the mass m1 of the dispersant and the mass m2 of the red mud sample satisfy the following condition: m1:m2 = (0.5 to 1.5):100.

[0008] Optionally, the dispersant may be sodium hexametaphosphate and / or sodium polyacrylate.

[0009] Optionally, the moisture content of the mixed solid is 8% to 15%.

[0010] Optionally, the mass m3 of the epoxy resin and the mass m4 of the curing agent satisfy the following: m3:m4:m5 = (7 to 8):1.

[0011] Optionally, the filter medium is filter paper or microporous filter membrane, and the pore size of the filter medium is 10μm to 50μm.

[0012] Optionally, the pre-embedded body is solidified to obtain an embedded block containing the red mud sample, followed by the following steps: The embedded block containing the red mud sample was subjected to gradient grinding and polishing to obtain the embedded block to be tested with a polished surface. The test embedding block with a polished surface is subjected to carbon spraying to obtain a test embedding body coated with a carbon film.

[0013] Optionally, the gradient grinding and polishing includes a gradient grinding stage and a polishing stage. The grinding media used in the gradient grinding stage has a particle size of 220 mesh to 1200 mesh, and the polishing media used in the polishing stage has a particle size of 1 μm to 9 μm.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for preparing red mud samples based on mineralogical analysis. The method first mixes a dispersant with the red mud sample, then uses mechanical stirring and a first ultrasonic treatment to adsorb the dispersant onto the surface of the red mud particles, breaking the initial agglomeration and initially improving the dispersion uniformity of the red mud particles. Furthermore, a second ultrasonic treatment is performed using a graphite and red mud suspension, allowing the graphite to be uniformly distributed on the surface of the red mud particles. The steric hindrance effect of graphite suppresses secondary agglomeration of the red mud particles, ensuring uniform dispersion within the embedded mass. Simultaneously, the electrical conductivity of graphite allows the formation of an internal conductive network between the red mud particles, contributing to improved conductivity. Additionally, a mixed solid with a preset moisture content is used to maintain a slightly moist state. A third ultrasonic treatment and the use of a mold then allow epoxy resin and curing agent to be uniformly dispersed in the mixed solid, forming a tightly bonded interface between the particles and the resin. Furthermore, during the curing stage, the curing agent and epoxy resin can be used to fix the red mud particles and graphite, optimizing the interface between the red mud particles and the epoxy resin. In the process of mineralogical analysis, it is possible to accurately identify the intergrowth relationship of minerals in red mud, thereby improving the accuracy of red mud in the mineralogical analysis stage. Attached Figure Description The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0015] To more clearly illustrate the technical solutions 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This application provides a schematic flowchart of a method for preparing red mud samples based on the mineralogical analysis stage, as shown in the embodiments of this application. Figure 2 A detailed flowchart illustrating a method for preparing red mud samples based on the mineralogical analysis stage, provided in this application embodiment; Figure 3 This is a diagram showing the detection results of the embedded body to be tested provided in Embodiment 1 of this application; Figure 4 This is a diagram showing the detection results of the embedded body to be tested provided in Embodiment 2 of this application; Figure 5 This is a diagram showing the detection results of the embedded body to be tested provided in Embodiment 3 of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The range descriptions used in this application, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "comprising" and others used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships involved in this document, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained by purchasing from the market or by existing methods.

[0019] It should be noted that in the mineralogical analysis stage of the alumina industry, traditional single mechanical stirring or ultrasonic dispersion methods are insufficient to break up red mud particles in agglomerated state. This results in uneven distribution of red mud particles in the samples during mineralogical analysis. During subsequent scanning electron microscopy (SEM) observation, these agglomerated red mud particles are easily misidentified as individual particles. In energy dispersive spectroscopy (EDS) analysis, the trace element signals from these misidentified particles will overlap, severely affecting the accuracy of mineral identification and quantitative statistics in mineralogical analysis. Furthermore, as an insulating mineral, red mud has poor interfacial compatibility with the epoxy resin embedding matrix frequently used in mineralogical analysis, and the bonding force between red mud and the epoxy resin embedding matrix is ​​weak. During the sample preparation and polishing process of the epoxy resin embedding matrix, red mud particles are prone to detachment, making it difficult to obtain a complete and smooth observation surface. Furthermore, under the electron beam bombardment during the scanning electron microscope (SEM) observation process, red mud particles and epoxy resin-embedded matrix will produce a severe charge accumulation effect, resulting in ghosting or even distortion in the SEM images obtained by SEM observation. It will also interfere with the energy dispersive spectroscopy (EDS) signal in the subsequent EDS analysis stage. This increases the difficulty of micro-area distribution and quantitative analysis of rare elements (such as scandium and titanium) in red mud.

[0020] Figure 1 An exemplary schematic diagram of a method for preparing red mud samples based on a mineralogical analysis stage, provided in an embodiment of this application, is shown. like Figure 1 As shown in the embodiment of this application, a method for preparing red mud samples based on the mineralogical analysis stage is provided, the method comprising: S1. Mix the red mud sample and the dispersant to obtain a dispersed red mud sample; S2. The red mud dispersion sample is subjected to mechanical stirring and first ultrasonic treatment in sequence to obtain a red mud suspension; S3. The graphite and the red mud suspension are subjected to a second ultrasonic treatment to obtain a mixture containing red mud and graphite; S4. Perform solid-liquid separation on the mixture to obtain a mixed solid with a preset water content; S5. The epoxy resin, curing agent and the mixed solid with a preset moisture content are subjected to a third ultrasonic treatment to obtain a pre-embedded slurry; S6. Using a filter medium, the pre-embedded slurry is introduced into a mold to obtain a pre-embedded body; S7. The pre-embedded body is solidified to obtain an embedded block containing the red mud sample.

[0021] It should be noted that the median particle size of the red mud sample can be from (5) μm to (30) μm.

[0022] It should be noted that the red mud sample and the dispersant can be mixed by mixing the dry red mud sample with an aqueous solution containing the dispersant, or by mixing the slurry-like red mud sample with dispersant particles.

[0023] It should be noted that the amount of epoxy resin and curing agent added is in excess relative to the mass of the mixed solid, so as to achieve complete encapsulation of the mixed solid by the epoxy resin and curing agent.

[0024] It should be noted that the power of the first ultrasonic treatment can be 300W to 400W, and the duration of the first ultrasonic treatment is 5 to 15 minutes. This first ultrasonic treatment effectively dissociates loose particle agglomerates from the red mud dispersion sample. Furthermore, the power of the second ultrasonic treatment can be 350W to 450W, and the duration of the second ultrasonic treatment is 5 to 15 minutes. This second ultrasonic treatment ensures that graphite is uniformly dispersed in the red mud suspension, and the steric hindrance effect of graphite stabilizes the dispersion state of the red mud particles in the suspension. Additionally, the power of the third ultrasonic treatment can be 150W to 300W, and the duration of the third ultrasonic treatment is 5 to 15 minutes. This third ultrasonic treatment ensures thorough mixing between the epoxy resin, curing agent, and mixed solids, and avoids the introduction of a large number of air bubbles due to excessive ultrasonic treatment. This staged and differentiated ultrasonic treatment strategy, involving the first, second, and third ultrasonic treatments, ensures the dispersion effect of the material while avoiding the breakage of red mud particles or energy waste caused by a single high-intensity ultrasonic treatment.

[0025] It should be noted that the mold can be made of polytetrafluoroethylene, and the surface of the mold can be coated with a silicone-based release agent, which is beneficial for the subsequent demolding of the embedded blocks.

[0026] It should be noted that the method for preparing red mud samples based on the mineralogical analysis stage provided in this application systematically improves the accuracy of red mud samples in mineralogical analysis through the synergistic effect of multiple steps, from three dimensions: sample authenticity preservation, observation condition optimization, and analytical error elimination. The specific mechanism is as follows: I. Collaborative Dispersion Logic: Solve the problem of misjudgment of composition or particle size caused by red mud particle agglomeration, and ensure the authenticity of the analysis object.

[0027] 1. The mechanism of collaborative decentralization (the core of improving accuracy): Through the synergistic effect of dispersant and graphite, multi-level dispersion and agglomeration inhibition of red mud particles are achieved: Dispersants (such as polycarboxylate and sodium hexametaphosphate) can be adsorbed on the surface of red mud particles, reducing the van der Waals forces between red mud particles and breaking the initial agglomeration of red mud particles. Graphite, as a steric hindrance agent, can be adsorbed on the surface of red mud particles and form a rigid barrier, preventing the red mud particles, after being dispersed by the dispersant, from approaching each other again (steric hindrance effect), thus fundamentally inhibiting the secondary agglomeration of red mud particles.

[0028] 3. Direct improvement in accuracy: Ultimately, the red mud particles can exist in a monodisperse state within the embedded mass, during the mineralogical analysis stage: Scanning electron microscopes and energy dispersive spectroscopy (EDS) instruments can accurately identify the mineral type of individual red mud particles (by matching elemental composition and morphological characteristics through EDS analysis), thus preventing red mud particle agglomerates from being misidentified as single minerals. The particle size distribution measurement results are consistent with the true values, providing reliable data for the analysis of mineral liberation degree and intercalation relationship.

[0029] II. Resin Premixing Logic: Solve the problem of information loss of red mud particles caused by grinding and polishing, and ensure the integrity of the analysis object.

[0030] 1. Defects of traditional embedding techniques (key factors affecting accuracy): Traditional encapsulation processes mostly involve mixing dry red mud particles with resin. However, the resin has difficulty fully penetrating the interparticle spaces of the dry red mud, leading to: The interface between red mud particles and resin is loose, and the red mud particles are easy to fall off during the grinding and polishing process of mineralogical analysis, forming pits in the sample. The detached red mud particles will be lost (leading to an underestimation of the mineral content of red mud), and the pits in the sample will obscure the true interface of the surrounding red mud particles, resulting in a misjudgment of the mineral intercalation relationship of red mud.

[0031] 2. Optimization mechanism of resin premixing process (the core of improving accuracy): A resin premixing process is adopted, which involves mixing a mixture of solids (red mud + graphite) with a preset moisture content, epoxy resin, and ultrasonic mixing. A mixed solid with a preset moisture content can contain a small amount of water, so that the mixed solid is in a slightly moist state, and the slightly moist state of the mixed solid can promote the wetting and penetration of epoxy resin. Under the cavitation effect of the third ultrasonic treatment, the epoxy resin can fully fill the gaps between the mixed solid particles, encapsulate each mixed solid particle containing red mud and graphite, and form a tightly bonded interface between the particles and the resin (without voids or cracks).

[0032] 3. Direct improvement in accuracy: After polishing, the surface of the embedded block is smooth, with no red mud particles falling off or pitting. All red mud particles are fully exposed to ensure that the instrument can capture information about the minerals in all red mud particles, thus avoiding the omission of mineral types or the underestimation of mineral content in red mud. The interface between red mud particles and epoxy resin is clear, and the intercalation relationship of minerals in red mud (such as encapsulation, symbiosis, and replacement) can be accurately identified, providing a reliable basis for the feasibility analysis of sorting in process mineralogy.

[0033] III. Collaborative Conductivity Logic: Resolves imaging distortion caused by charge effects and ensures the reliability of analysis signals.

[0034] 1. Electrical conductivity defects in red mud (obstacles to accurate observation): Red mud is mainly composed of aluminosilicates and iron oxides, and is classified as a semiconductor or insulator. Scanning electron microscopy analysis shows that: When an electron beam irradiates the surface of an embedded body, it will accumulate charge (charge effect), which will cause bright spots, trailing, blurred edges, or even failure to form an image. The charge effect can interfere with the acquisition of elemental signals in energy dispersive spectroscopy (EDS), leading to deviations in elemental content measurements and consequently misidentification of mineral types in red mud (e.g., misidentifying a low-content target mineral as another mineral).

[0035] 2. The construction mechanism of cooperative conductivity (the core of improving accuracy): The design employs a dual conductive approach: an internal graphite conductive network and a surface-sprayed carbon film. Uniformly dispersed graphite forms a penetrating internal conductive network within the embedded block (graphite itself has excellent conductivity and is uniformly distributed between red mud particles). The carbon film sprayed on the surface can serve as an external conductive path, forming a surface-to-interior conductive path with the internal conductive network formed by graphite.

[0036] 3. Direct improvement in accuracy: The charge on the surface of the embedded block can be quickly discharged through the conductive path, completely eliminating the charging effect of the embedded body: The scanning electron microscope images are clear and detailed, accurately showing the microscopic morphology of minerals in red mud (such as crystal morphology, cleavage planes, surface defects) and the boundaries of red mud particles; Energy dispersive spectroscopy (EDS) provides stable elemental signals and significantly reduces the measurement error of elemental content, ensuring the accuracy of qualitative (based on elemental composition) and quantitative (based on elemental content) analysis of minerals.

[0037] In summary, the method for preparing red mud samples based on the mineralogical analysis stage provided in this application solves the three core problems of misjudgment of agglomeration, missed judgment of detachment, and imaging distortion in traditional red mud sample preparation during the mineralogical analysis stage by controlling the entire process from sample dispersion (source) → embedding and bonding (process) → conductivity optimization (observation). Ultimately, this method achieves: (1) The “authenticity” of the analysis object: individual red mud particles exist independently without agglomeration interference; (2) "Integrity" of the analysis object: no red mud particles were detached, and all mineral information was preserved; (3) Analysis of the “reliability” of the signal: There is no charge interference during the detection stage, and the image and element data are accurate; Therefore, by controlling the entire process from sample dispersion (source) → embedding and integration (process) → conductivity optimization (observation), it directly addresses the core needs of the mineralogical analysis process, thereby providing a high-precision and high-reliability data analysis foundation for the mineral composition, embedding characteristics, and sorting process design of red mud, and avoiding process decision errors caused by defects in red mud samples.

[0038] In some alternative embodiments, the median particle size D1 of the graphite and the median particle size D2 of the red mud sample satisfy: D1:D2 = (0.5 to 2.0):1.

[0039] In these embodiments, graphite with a median particle size to red mud sample median particle size ratio of (0.5 to 2.0):1 can match the particle size of red mud particles in the red mud suspension, allowing graphite to effectively enter the gaps between red mud particles. This promotes graphite adsorption on the surface of red mud particles to form a rigid barrier. The steric hindrance effect of graphite can prevent red mud particles dispersed by dispersants from re-approaching each other, inhibiting secondary agglomeration of red mud particles, improving the dispersibility of red mud particles, and facilitating the subsequent construction of a through conductive pathway.

[0040] The median particle size D1 of the graphite can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5 or 2.0.

[0041] In some alternative embodiments, the volume V1 of the graphite and the volume V2 of the red mud sample satisfy: V1:V2 = (1.5 to 3.0):1.

[0042] In these embodiments, graphite with a volume-to-volume ratio of (1.5 to 3.0):1 can be uniformly dispersed into the red mud suspension through a second ultrasonic treatment. Through the adsorption of red mud particles, graphite can uniformly cover the red mud particles, forming a rigid barrier. The rigid barrier prevents the red mud particles after dispersion by the dispersant from approaching each other again, inhibits the secondary agglomeration of red mud particles, and improves the dispersibility of red mud particles.

[0043] The volume V1 of the graphite can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.5 or 3.0.

[0044] In some alternative embodiments, the mass m1 of the dispersant and the mass m2 of the red mud sample satisfy the following ratio: m1:m2 = (0.5 to 1.5):100.

[0045] In these embodiments, a dispersant with a mass-to-mass ratio of (0.5 to 1.5):100 for the red mud sample can reduce the van der Waals forces between red mud particles, break the initial agglomeration of red mud particles, facilitate the adsorption between graphite and red mud particles, and improve the dispersibility of red mud particles.

[0046] The mass m1 of the dispersant can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5.

[0047] In some alternative embodiments, the dispersant is sodium hexametaphosphate and / or sodium polyacrylate.

[0048] In these embodiments, sodium hexametaphosphate and / or sodium polyacrylate are used as dispersants. The dispersants can be adsorbed onto the surface of red mud particles through the action of the groups of sodium hexametaphosphate or polyacrylate, which effectively reduces the van der Waals forces between red mud particles and helps to break the initial agglomeration of red mud particles, forming uniformly dispersed red mud particles.

[0049] In some alternative embodiments, the moisture content of the mixed solids is 8% to 15%.

[0050] In these embodiments, the mixed solids with a moisture content of 8% to 15% can be in a slightly moist state. Slightly moist mixed solids exhibit good flowability and dispersibility, facilitating the penetration and uniform mixing of epoxy resin. Under the cavitation effect of the third ultrasonic treatment, the epoxy resin can fully fill the interparticle gaps of the mixed solids and encapsulate each mixed solid particle containing red mud and graphite, forming a tightly bonded particle-resin interface, which is beneficial for the subsequent formation of stable embedded masses. Furthermore, the slightly moist state of the mixed solids avoids the formation of irreversible hard agglomerates during the curing process, and provides favorable conditions for moisture removal during curing.

[0051] The moisture content of the mixed solid can be 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%.

[0052] In some alternative embodiments, the mass m3 of the epoxy resin and the mass m4 of the curing agent satisfy the following: m3:m4:m5 = (7 to 8):1.

[0053] In these embodiments, epoxy resin and curing agent in a mass ratio of (7 to 8):1 can fill the interparticle gaps of the mixed solid during the third ultrasonic treatment process and encapsulate each mixed solid particle containing red mud and graphite, forming a tightly bonded particle-resin interface, which is beneficial for the subsequent formation of a stable embedded mass.

[0054] The mass m3 of the epoxy resin can be 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9 or 8.0.

[0055] In some alternative embodiments, the filter medium is filter paper or a microporous membrane, and the pore size of the filter medium is 10 μm to 50 μm.

[0056] In these embodiments, filter paper or microporous membranes are used as the filter medium, and the pore size of the filter medium is controlled to be 10 μm to 50 μm. This can effectively intercept any trace particle agglomerates (particle size usually greater than 50 μm) that may remain in the pre-embedded slurry, and ensure that individual red mud particles (particle size usually less than 20 μm) and mixed solids in the pre-embedded slurry pass through smoothly. This achieves terminal control of the red mud sample and promotes uniform dispersion of the pre-embedded slurry in the mold under the action of gravity, which is beneficial to the subsequent curing process to form a pre-embedded body with uniform particle dispersion.

[0057] The pore size of the filter medium can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm.

[0058] It should be noted that the filter paper can be quantitative filter paper; the microporous filtration membrane can be a polymer microporous filtration membrane.

[0059] Figure 2 A detailed flowchart illustrating a method for preparing red mud samples based on a mineralogical analysis stage, provided in an embodiment of this application, is shown as an example. In some alternative implementations, such as Figure 2 As shown, the pre-embedded body is solidified to obtain an embedded block containing the red mud sample, followed by the following steps: S8. The embedded block containing the red mud sample is subjected to gradient grinding and polishing to obtain the embedded block to be tested with a polished surface; S9. The test embedding block with a polished surface is subjected to carbon spraying treatment to obtain a test embedding body coated with a carbon film.

[0060] In these embodiments, gradient polishing of the embedded block can form a test embedded block with a smooth polished surface and avoid the formation of pits due to the shedding of red mud particles in the embedded block; in addition, carbon spraying treatment of the test embedded block can form external conductive paths on the surface of the test embedded block. These external conductive paths will form a surface-to-interior conductive path with the internal conductive network formed by graphite in the test embedded block, which is beneficial to improving the accuracy of the mineralogical analysis stage.

[0061] In some optional embodiments, the gradient polishing includes a gradient grinding stage and a polishing stage, wherein the grinding media used in the gradient grinding stage has a particle size of 220 mesh to 1200 mesh, and the polishing media used in the polishing stage has a particle size of 1 μm to 9 μm.

[0062] In these embodiments, gradient grinding and polishing are divided into a gradient grinding stage and a polishing stage. The particle size of the grinding media used in the gradient grinding stage is controlled within the range of 220 mesh to 1200 mesh. The surface of the embedded block can be gradually ground by the gradient distribution of grinding media to avoid the detachment of red mud particles in the embedded block and the generation of pits. In addition, the particle size of the polishing media used in the polishing stage is within the range of 1 μm to 9 μm, which can optimize the interface between red mud particles and epoxy resin, and help improve the accuracy of the embedded body in the mineralogical analysis process.

[0063] The particle size of the grinding media used in this gradient grinding stage can be 220 mesh, 240 mesh, 260 mesh, 280 mesh, 300 mesh, 400 mesh, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, 1100 mesh or 1200 mesh.

[0064] The particle size of the polishing medium used in this polishing stage can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm or 9μm.

[0065] It should be noted that the grinding medium can be a diamond grinding disc; the polishing medium can be a suspension containing diamond.

[0066] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0067] Example 1 like Figure 2 As shown, a method for preparing red mud samples based on the mineralogical analysis stage includes: S1. Mix the red mud sample and the dispersant to obtain a dispersed red mud sample; S2. The red mud dispersion sample is mechanically stirred and subjected to the first ultrasonic treatment in sequence to obtain a red mud suspension; S3. The graphite and red mud suspension is subjected to a second ultrasonic treatment to obtain a mixture containing red mud and graphite; S4. Perform solid-liquid separation on the mixture to obtain a mixed solid with a preset water content; S5. The epoxy resin, curing agent and mixed solid with a preset moisture content are subjected to a third ultrasonic treatment to obtain a pre-embedded slurry; S6. Use a filter medium to introduce the pre-embedded slurry into the mold to obtain the pre-embedded body; S7. The pre-embedded body is solidified to obtain an embedded block containing the red mud sample; S8. The embedded block containing the red mud sample is subjected to gradient grinding and polishing to obtain the embedded block to be tested with a polished surface; S9. The test embedding block with a polished surface is subjected to carbon spraying treatment to obtain a test embedding body coated with a carbon film.

[0068] The power of the first ultrasonic treatment is 350W, and the duration of the first ultrasonic treatment is 10 minutes.

[0069] The power of the second ultrasonic treatment can be 400W, and the duration of the second ultrasonic treatment is 10 minutes.

[0070] The power of the third ultrasonic treatment can be 250W, and the duration of the third ultrasonic treatment is 10 minutes.

[0071] The median particle size D1 of graphite and the median particle size D2 of red mud sample satisfy the following: D1:D2=1.5:1.

[0072] The volume V1 of graphite and the volume V2 of red mud sample satisfy: V1:V2=2.0:1.

[0073] The mass m1 of the dispersant and the mass m2 of the red mud sample satisfy the following condition: m1:m2=1.0:100.

[0074] The dispersant is sodium hexametaphosphate.

[0075] The moisture content of the mixed solids is 10%.

[0076] The mass m3 of epoxy resin and the mass m4 of curing agent satisfy the following ratio: m3:m4:m5 = 7.5:1.

[0077] The filter medium is a microporous membrane with a pore size of 40 μm.

[0078] Gradient grinding and polishing includes a gradient grinding stage and a polishing stage. The grinding media used in the gradient grinding stage have a particle size distribution of 220 mesh, 500 mesh and 1200 mesh, while the polishing media used in the polishing stage has a particle size of 5μm.

[0079] Example 2 Compared to Example 1, the differences in this example are as follows, while the rest are the same: The power of the first ultrasonic treatment can be 300W, and the duration of the first ultrasonic treatment is 15 minutes.

[0080] The power of the second ultrasonic treatment can be 350W, and the duration of the second ultrasonic treatment is 15 minutes.

[0081] The power of the third ultrasonic treatment can be 300W, and the duration of the third ultrasonic treatment is 15 minutes.

[0082] The median particle size D1 of graphite and the median particle size D2 of red mud sample satisfy the following: D1:D2=0.5:1.

[0083] The volume V1 of graphite and the volume V2 of the red mud sample satisfy the following: V1:V2=1.5:1.

[0084] The mass m1 of the dispersant and the mass m2 of the red mud sample satisfy the following condition: m1:m2=0.5:100.

[0085] The moisture content of the mixed solids is 9%.

[0086] The mass m3 of epoxy resin and the mass m4 of curing agent satisfy the ratio m3:m4:m5 = 7:1.

[0087] The filter medium has a pore size of 20μm.

[0088] The polishing media used in the polishing stage has a particle size of 3μm.

[0089] Example 3 Compared to Example 1, the differences in this example are as follows, while the rest are the same: The power of the first ultrasonic treatment can be 400W, and the duration of the first ultrasonic treatment is 5 minutes.

[0090] The power of the second ultrasonic treatment can be 450W, and the duration of the second ultrasonic treatment is 5 minutes.

[0091] The power of the third ultrasonic treatment can be 150W, and the duration of the third ultrasonic treatment is 5 minutes.

[0092] The median particle size D1 of graphite and the median particle size D2 of red mud sample satisfy the following: D1:D2=2.0:1.

[0093] The volume V1 of graphite and the volume V2 of the red mud sample satisfy: V1:V2=3.0:1.

[0094] The mass m1 of the dispersant and the mass m2 of the red mud sample satisfy the following condition: m1:m2=1.5:100.

[0095] The moisture content of the mixed solids is 12%.

[0096] The mass m3 of epoxy resin and the mass m4 of curing agent satisfy the following ratio: m3:m4:m5 = 8:1.

[0097] The filter medium has a pore size of 40μm.

[0098] The polishing media used in the polishing stage has a particle size of 8μm.

[0099] Comparative Example 1 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: No dispersants or graphite are added.

[0100] Comparative Example 2 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: No dispersant is added.

[0101] Comparative Example 3 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: No graphite is added.

[0102] Comparative Example 4 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: The median particle size D1 of graphite and the median particle size D2 of red mud sample satisfy: D1:D2=5.0:1.

[0103] Relevant experimental and effect data: 1. Collect the implants to be tested from Examples 1, 2, and 3, and statistically analyze the results of these implants. The results are as follows: Figures 3 to 5 As shown, this indicates that the red mud particles in the tested embedded body can be evenly distributed.

[0104] 2. Twenty red mud samples with different components were used to prepare the test embeddings according to the methods of each embodiment and comparative example, and mineralogical analysis was performed. The analysis results were compared with the composition of the red mud samples. The numerical difference was set to be within ±10% as the accurate value. The accuracy of the analysis results of the test embeddings of each embodiment and comparative example was statistically analyzed. The results are shown in Table 1.

[0105] Table 1. Accuracy of the analytical results of the test embeddings in various embodiments and comparative examples.

[0106] As shown in Table 1, the method for preparing red mud samples based on the mineralogical analysis stage provided in this application embodiment systematically improves the accuracy of red mud samples in mineralogical analysis from three dimensions: sample authenticity preservation, observation condition optimization, and analysis error elimination through the synergistic effect of multiple steps.

[0107] Compared to Example 1, Comparative Example 1 did not use a dispersant or graphite, which made the red mud particles prone to agglomeration, affecting the accuracy of the mineralogical analysis results. Comparative Example 2, without a dispersant, relied solely on the steric hindrance effect of graphite, making it difficult to improve the dispersion of the red mud particles, thus affecting the accuracy of the mineralogical analysis of the red mud sample. Furthermore, Comparative Example 3 did not use graphite, resulting in poor electrical conductivity of the embedded material and significant differences in the mineralogical analysis results. In addition, Comparative Example 4 used graphite with a larger particle size, making it difficult for the graphite to be fully adsorbed by the red mud particles and affecting the uniformity of the dispersion of the mixed solid particles.

[0108] In summary, the embodiments of this application provide a method for preparing red mud samples based on the mineralogical analysis stage. This method solves the three core problems of misjudgment of agglomeration, missed judgment of detachment, and imaging distortion in the traditional red mud sample preparation stage by controlling the entire process from sample dispersion (source) → embedding and bonding (process) → conductivity optimization (observation). Ultimately, it achieves the authenticity, integrity and reliability of red mud particle detection, thereby providing a high-precision and high-reliability data analysis basis for the mineral composition, embedding characteristics and sorting process design of red mud, and avoiding process decision errors caused by defects in red mud samples.

[0109] In addition, this application provides a method for preparing red mud samples based on the mineralogical analysis stage. This method can prepare a uniformly dispersed, tightly bonded, and highly conductive embedded body for testing, providing a high-precision and high-reliability guarantee for the mineralogical analysis of red mud samples.

[0110] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method of preparing a sample of red mud based on a mineralogical analysis phase, characterized in that, The method comprises: mixing a red mud sample and a dispersant to obtain a dispersed red mud sample; mechanically stirring and first ultrasonic treating the red mud dispersed sample in sequence to obtain a red mud suspension; second ultrasonic treating graphite and the red mud suspension to obtain a mixture containing red mud and graphite; solid-liquid separating the mixture to obtain a mixed solid with a preset water content; third ultrasonic treating an epoxy resin, a curing agent and the mixed solid with the preset water content to obtain a pre-embedding slurry; using a filter medium to guide the pre-embedding slurry into a mold to obtain a pre-embedding body; solidifying the pre-embedding body to obtain an embedding block containing the red mud sample.

2. The method of claim 1, wherein, The median particle size D1 of the graphite and the median particle size D2 of the red mud sample satisfy: D1:D2=(0.5 to 2.0):

1.

3. The method of claim 1, wherein, The volume V1 of the graphite and the volume V2 of the red mud sample satisfy: V1:V2=(1.5 to 3.0):

1.

4. The method of claim 1, wherein, The mass m1 of the dispersant and the mass m2 of the red mud sample satisfy: m1:m2=(0.5 to 1.5):

100.

5. The method according to claim 1 or 5, characterized in that, The dispersant is sodium hexametaphosphate and / or sodium polyacrylate.

6. The method of claim 1, wherein, The preset water content is 8% to 15%.

7. The method of claim 1, wherein, The mass m3 of the epoxy resin and the mass m4 of the curing agent satisfy: m3:m4:m5=(7 to 8):

1.

8. The method of claim 1, wherein, The filter medium is filter paper or microporous filter membrane, and the filter medium has a filter pore size of 10 μm to 50 μm.

9. The method of claim 1, wherein, Solidifying the pre-embedding body to obtain an embedding block containing the red mud sample, and then comprising the steps of: Gradient polishing the embedding block containing the red mud sample to obtain a to-be-tested embedding block with a polished surface; Spraying carbon on the to-be-tested embedding block with the polished surface to obtain a to-be-tested embedding body coated with a carbon film.

10. The method of claim 9, wherein, The gradient polishing comprises a gradient grinding stage and a polishing stage, the grinding medium used in the gradient grinding stage has a particle size of 220 mesh to 1200 mesh, and the polishing medium used in the polishing stage has a particle size of 1 μm to 9 μm.

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