Method for accurately measuring interaction force among mineral particles based on anisotropy of mineral crystal face

Abstract

The invention discloses a method for accurately measuring interaction force among mineral particles based on anisotropy of a mineral crystal face, and belongs to the field of measurement of physical and chemical interaction of mineral surfaces. According to the invention, the piezoelectric sensor drives the colloid probe on the AFM needle-point-free cantilever to get close to the surface of a single mineral crystal face and get away from the single mineral crystal face, so that the interaction process of two mineral particles is simulated, and accurate measurement of the interaction force between the particle surfaces is realized in combination with an EDLVO theoretical model. Compared with the traditional characterization means, the method has the advantages that the theoretical fitting error is greatly reduced, the interaction force in the particle aggregation process and the like can be measured more directly, microcosmically and accurately, the evolution rule of the anisotropy of the mineral crystal face is further clarified, and the crystal face dependence of the interaction force among the mineral particles is revealed.

Description

Technical Field

[0001] This invention belongs to the field of mineral surface physicochemical interaction measurement, and relates to a method for accurately measuring the interaction force between mineral particles based on the anisotropy of mineral crystal faces. Background Technology

[0002] Inter-particle interactions are the core factors determining mineral aggregation, dispersion, and surface adsorption behavior. Traditional research methods mainly rely on macroscopic experiments or indirect characterization techniques. For example, sedimentation experiments are used to infer particle aggregation kinetics, or double-layer interactions are calculated based on zeta potentials. However, these methods struggle to capture the influence of mineral crystal anisotropy on microscopic forces. Different crystal faces of minerals exhibit significantly different wettability, surface charge, and chemical reactivity due to variations in atomic density and surface functional group distribution. However, current technologies lack direct measurement methods for the inter-face interactions of specific crystal faces.

[0003] While atomic force microscopy (AFM) can characterize microscopic forces, existing experimental methods often employ probes to measure on flat mineral surfaces, failing to simulate the point-to-surface or surface-to-surface contact patterns between actual mineral particles and lacking in-depth research on the forces between real mineral particles. For example, the colloidal probe method disclosed in Chinese patent application CN 115290932 A can measure the forces between colloids and nanoparticles, but due to the random distribution of the nanoparticle coating, it is difficult to ensure the consistency of crystal orientation. This results in measuring the overall average force of the particles rather than the force precise to the crystal face, with a measurement accuracy of only a few to tens of nanometers. Furthermore, it does not consider the interference of the mineral surface oxide layer on the forces, ignoring the potential influence of the oxide layer under natural conditions. In addition, in real mineral slurry environments, ionic strength, dissolved oxygen content, and surface contaminants can significantly alter the properties of the mineral interface. Existing techniques often use simplified pure aqueous solutions or single electrolyte solutions, neglecting the dynamic equilibrium process of the test solution, leading to deviations between the measurement results and actual working conditions. Meanwhile, traditional AFM force curves have limited data acquisition, insufficient statistical significance of samples, and lack systematic screening of measurement areas. They are also prone to errors due to surface roughness, contaminant interference, etc., making it difficult to meet the high requirements for data reproducibility in crystal anisotropy studies.

[0004] The aforementioned limitations make it difficult for existing methods to accurately establish a quantitative correlation between mineral surface properties and microscopic forces, thus hindering the mechanism analysis and process optimization of mineral flotation, aggregation, and other processes. Therefore, there is an urgent need to develop a measurement method that can accurately correlate mineral crystal facet properties with microscopic forces, enabling high-precision measurement of specific crystal facet forces under controlled environmental conditions, and providing a theoretical basis for interface control in mineral processing. Summary of the Invention

[0005] To address the measurement errors caused by uncontrollable mineral crystal orientation, environmental simulation distortion, and insufficient data statistics in existing technologies, the present invention aims to provide a method for accurately measuring the interaction force between mineral particles based on the anisotropy of mineral crystal faces. By taking the anisotropy of mineral crystal faces as the starting point and combining atomic force microscopy colloidal probe technology and oriented crystal face exposure, the method solves the problem of force value deviation caused by ignoring crystal face differences in traditional measurements and reveals the crystal face dependence law of the interaction force between mineral particles.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a method for accurately measuring the interaction force between mineral particles based on the anisotropy of mineral crystal planes, comprising the following steps:

[0007] S1 involves removing the surface oxide layer from a single mineral particle and adhering it to the tip of a tipless cantilever in an AFM, then curing it to obtain a colloidal probe.

[0008] S2. Minerals with anisotropic crystal planes are screened using suspension deposition or XRD to obtain single mineral crystal planes.

[0009] During S3 measurement, a test solution is dropped onto the surface of a single mineral crystal face, and the mineral morphology is imaged using contact mode. Based on the surface morphology image analysis, smooth regions with a root mean square roughness of <10 nm are selected. A piezoelectric sensor drives a colloidal probe to approach and move away from the single mineral crystal face within the selected region, monitoring the deflection of the AFM cantilever beam in real time. This deflection is then converted into a function F(D) of the interaction force F and the separation distance D. The Derjaguin approximation method is used to convert the force signal F measured during the approach and retraction processes into the interaction energy per unit area between the two planes, generating approach force curves and retraction force curves. Here, approach represents the process of mutual approach, retraction represents the process of mutual retraction, and the separation distance D is the relative distance obtained based on the piezoelectric ceramic displacement and the cantilever deflection voltage signal. The contact start point on the interaction force-separation distance curve is defined as zero.

[0010] S4. Change to different single mineral crystal faces and repeat step S3 to obtain the wire ingress force curve and wire regress force curve of single mineral particles and different crystal faces of minerals.

[0011] S5 compares all the ingress force curves and regression force curves to obtain the relationship of the interaction forces between minerals.

[0012] The technical solution of this invention can more accurately measure the interaction forces between mineral particles, greatly reduce theoretical fitting errors, and reveal the crystal plane dependence law of the interaction forces between mineral particles. The key lies in controlling the approach and distance of the colloidal probe and the single mineral crystal facet in AFM to facilitate exposure of the single crystal facet, as well as the screening of the measurement area. Specifically, mineral crystals exhibit significant differences in surface atomic arrangement, charge distribution, and chemical reactivity on different crystal faces. Single mineral crystal faces can be obtained through suspension deposition or XRD directional screening, and by combining AFM morphology imaging to screen areas with extremely low surface roughness, the interference of surface morphology fluctuations on force measurement can be minimized. Simultaneously, removing the surface oxide layer from the mineral also eliminates the interference of the oxide layer on the interaction forces. In a mineral slurry environment simulated by the test solution, the colloidal probe approaches and separates from the single mineral crystal facet at a controllable speed, recording the cantilever deflection change in real time and converting it into a force-distance curve. Using the Derjaguin approximation, the measured force signal is converted into interaction energy per unit area, allowing direct comparison of the interactions between different crystal faces, thereby systematically revealing the crystal plane dependence law of the interaction forces between mineral particles. In this process, the infeed force curve reflects the adsorption between mineral particles and single mineral crystal faces, while the defeed force curve reflects the adhesion during separation.

[0013] More importantly, this invention, through repeated measurements using different single mineral crystal faces, can screen out the mineral crystal faces with the strongest repulsive or attractive forces. In practical applications, this can provide precise crystal face-level control for mineral processing and flotation separation. For example, specific crystal faces can be preferentially hydrophobized in a suitable manner, thereby achieving more efficient and selective separation and significantly reducing reagent consumption. Furthermore, the method of this invention can also provide a theoretical basis for resource recovery and surface modification, opening up new pathways for the precise control of complex mineral systems.

[0014] In this invention, the deflection of the AFM cantilever beam is detected by reflecting a laser beam from the cantilever beam to a split photodiode detector, and the spring constant and Hooke's law are used to convert it into a force.

[0015] As a preferred embodiment, in S5, the comparison of all incoming and outgoing force curves is as follows: In the incoming force curve, a larger negative F / R value indicates a stronger attraction between a single mineral particle and a single mineral crystal facet, making them easier to aggregate; a larger positive value indicates a stronger repulsive force, making them easier to disperse in the flotation pulp. In the outgoing force curve, a larger negative F / R value indicates a stronger adhesive force, resulting in higher stability of the aggregated minerals. Here, R refers to the radius of the mineral particles adhered to the colloidal probe. Based on this comparison principle, this invention can determine the force relationship between two minerals and screen out the mineral crystal facet with the strongest repulsive or attractive force.

[0016] As a preferred embodiment, the method by which the single mineral particles remove the surface oxide layer includes, but is not limited to, ultrasound.

[0017] As a preferred method, when adhering a single mineral particle to the tip of a needleless cantilever, an adhesive is applied to the tip of the cantilever, the mineral particle is then adhered to the tip of the cantilever beam, and dried under vacuum.

[0018] As a preferred embodiment, the test solution is a 10 mM NaCl solution. The pH value of the NaCl solution of the present invention can be 5.5 or 8.5. The test solution of the present invention mainly simulates the actual slurry environment, so in actual operation, the test solution can be adjusted accordingly according to the simulated slurry environment.

[0019] As a preferred embodiment, flotation reagents may also be added to the test solution. In the technical solution of this invention, when flotation reagents are added to the test solution, the interaction force between the flotation reagents and different mineral crystal faces can be measured to determine whether the interaction between the flotation reagents and the mineral crystal faces is repulsive or attractive.

[0020] As a preferred embodiment, the single mineral crystal facet and colloidal probe with the oxide layer removed are cleaned and immersed in the test solution for 1-2 hours before being installed on the AFM to eliminate the influence of the solution on the force measurement results. Further, the cleaning process involves sequential cleaning in a UV-Ozone and plasma cleaner.

[0021] As a preferred embodiment, the suspension deposition method is for layered anisotropic minerals. The preparation process involves depositing a suspension of layered mineral particles with anisotropic crystal planes onto corresponding substrates, followed by washing with water to remove loosely adsorbed mineral particles, resulting in a coating surface exposing individual mineral crystal planes. This invention utilizes the electrostatic force between the mineral crystal planes and the substrate to orient the mineral crystal planes during deposition of the suspension of anisotropic mineral particles onto corresponding substrates.

[0022] As a preferred embodiment, the mineral with anisotropic crystal facets includes one of serpentine, rutile, anatase, pyrrhotite, chalcopyrite, galena, sphalerite, stibnite, quartz, calcite, fluorite, wolframite, dolomite, and spodumene; the adsorption substrate includes one of mica sheets, glass sheets, graphite substrates, polydimethylsiloxane, polyethylene, and polypropylene. The serpentine includes one of foliated serpentine, fibrous serpentine, clinoptilolite, and limonite nanosheets. The single mineral particles in this invention can be selected from a multi-element mineral system such as sulfides, oxides, and silicates.

[0023] As a preferred embodiment, the XRD method is for bulk anisotropic minerals. The preparation process is as follows: after breaking the bulk mineral with anisotropic crystal faces, XRD is used to determine and mark the orientation of the exposed crystal faces. The small crystal pieces are then wrapped and fixed with epoxy resin to form rectangular blocks, ensuring that the exposed surfaces are consistent with the markings, resulting in rectangular mineral blocks with a single exposed crystal face. Further, the size of the rectangular mineral blocks is 1~2 mm.

[0024] As a preferred approach, in S3, 3 to 5 smooth regions are selected each time, and multiple measurements are taken within each region to obtain a total of 80 to 100 curves. The final result is the average value.

[0025] As a preferred embodiment, in S3, the driving speed of the colloidal probe is controlled at 300~500 nm / s, and the pressure is controlled at 3~5 nN during measurement. Within the driving speed and pressure range selected in this invention, a clearer morphological image can be obtained, leading to more accurate force curve results.

[0026] As a preferred approach, in S4, each time a single mineral crystal face is replaced, the test solution needs to be re-dropped onto the crystal face surface, and the concentration and pH value of the test solution should be kept consistent before and after the replacement.

[0027] As a preferred approach, the incoming force curve data is fitted based on the EDLVO theoretical model to determine the contribution rates of van der Waals forces, electrostatic forces, and hydrophobic forces to the interaction; the outgoing force curve data is fitted with a normal distribution to obtain the relationship of the adhesion forces between mineral particles.

[0028] Compared with the prior art, the beneficial technical effects of this invention are as follows:

[0029] (1) This invention directly measures the interaction force between mineral particles and specific mineral crystal faces by directional exposure of mineral crystal faces and combining atomic force microscopy colloidal probe technology. This solves the problem of data deviation caused by neglecting the anisotropy of crystal faces in traditional methods, eliminates the interference of polycrystalline facet mixing at the microscopic level, and significantly improves the scientificity and accuracy of the measurement results.

[0030] (2) By removing the surface oxide layer of the mineral and screening smooth areas with AFM, and by taking multiple measurements in multiple smooth areas, the present invention eliminates the interference of surface morphology fluctuations and surface oxide layer on the force to the greatest extent, and avoids measurement errors caused by environmental simulation distortion and insufficient data statistics.

[0031] (3) This invention can screen out the mineral crystal face with the strongest repulsive or attractive force by repeatedly measuring different single mineral crystal faces. In practical applications, it can provide a precise crystal face level control basis for mineral processing flotation separation, and can also provide a theoretical basis for resource recovery and surface modification, opening up a new path for the precise control of complex mineral systems.

[0032] (4) The method of the present invention can not only test the interaction force between mineral particles, but also test the interaction force relationship between flotation reagent and mineral when flotation reagent is added to the test solution. It has wide applicability and the mineral particles can be adapted to multi-element mineral systems such as sulfides, oxides, and silicates, making it highly universal.

[0033] (5) By reducing uncontrollable variables in the experiment, the present invention can shorten the process development cycle, avoid trial and error costs caused by force measurement deviation, save R&D investment, and improve economic benefits.

[0034] (6) By using AFM compared to SFA, the interaction force measured by this invention is more sensitive and can reach the piconewton level. It has a wider range of applications, a more flexible operation process, and lower requirements for the substrate to be tested. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the colloidal probe measuring the applied force in this invention.

[0036] Figure 2 This is the advance force curve of the interaction force between the pyrite colloidal probe and the serpentine MgOH surface during the approach process in a liquid environment with a pH of 8.5, according to Example 1 of the present invention.

[0037] Figure 3 This is the advance force curve of the interaction force between the pyrite colloidal probe and the serpentine SiO surface during the approach process in a liquid environment with a pH of 8.5, as described in Example 1 of the present invention.

[0038] Figure 4 The curve of the ingress force between the interaction force and the separation distance between the pyrite colloidal probe and the serpentine end face during the approach process in a liquid environment with a pH of 8.5 in Example 1 of the present invention.

[0039] Figure 5 This is the advance force curve of the interaction force between the pyrite colloidal probe and the serpentine MgOH surface during the approach process in a liquid environment with a pH of 5.5, as described in Example 2 of the present invention.

[0040] Figure 6This is the advance force curve of the interaction force between the pyrite colloidal probe and the serpentine SiO surface during the approach process in a liquid environment with a pH of 5.5, as described in Example 2 of the present invention.

[0041] Figure 7 This is the advance force curve of the interaction force between the pyrite colloidal probe and the serpentine end face during the approach process in a liquid environment with a pH of 5.5, as described in Example 2 of the present invention.

[0042] in, Figures 2-7 In the diagram, the black lines represent the actual measurement point data, while the colored lines represent the lines fitted based on the EDLVO theoretical model.

[0043] Figure 8 The bar charts are the adhesion force histograms of pyrite colloidal probes and serpentine crystal faces during the separation process of Examples 1 and 2 of the present invention. The bar charts are obtained by converting the delamination force curves. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] The method for accurately measuring the interaction force between mineral particles based on the anisotropy of mineral crystal planes, provided by the present invention, will be described in detail below.

[0046] To further understand the present invention, the following detailed description of the invention is based on the example of measuring the interaction force between pyrite particles and different crystal planes of serpentine, in order to help those skilled in the art to better understand the concept and technical solution of the present invention, but is not limited to the following embodiments.

[0047] Example 1

[0048] The interaction forces between pyrite colloidal probes and different crystal faces of serpentine in a NaCl solution liquid environment with a pH of 8.5.

[0049] A method for accurately measuring the interaction forces between mineral grains based on the anisotropy of mineral crystal faces includes the following steps:

[0050] (1) Pyrite particles (contact particle size of 1µm) were ultrasonically treated to remove the oxide layer on the mineral surface and then placed in a UV-Ozone and a plasma cleaner for cleaning to obtain pretreated pyrite particles.

[0051] (2) Apply epoxy AB adhesive to the top of the cantilever of the AFM, and then use an inverted microscope to adhere the pretreated pyrite particles to the top of the cantilever beam. Dry it in vacuum at 40°C for 24 hours to solidify it and obtain a pyrite colloidal probe.

[0052] (3) The pyrite colloidal probe was cleaned in a UV-Ozone and a plasma cleaner in sequence, and then immersed in 10 mM NaCl with a pH of 8.5 for 1 hour before being installed on the AFM.

[0053] (4) After crushing and sieving serpentine through a 600-mesh sieve, grind it to a particle size of -3μm. Weigh 0.15g of powder and disperse it in 50mL of isopropanol. Ultrasonic treatment is performed at 480W for 2 hours to obtain a serpentine nanosheet suspension. After adding about 10μL of the serpentine nanosheet suspension, it is deposited on Mg(OH)2 and mica substrates respectively. The functional groups on the substrate are used to combine with different crystal faces of the serpentine nanosheets to expose a single crystal face. The loose adsorbed mineral particles are removed by washing with water to obtain coatings exposing the MgOH face of serpentine and coatings exposing the SiO face of serpentine respectively.

[0054] (5) The coating on the exposed serpentine MgOH surface was cleaned in a UV-Ozone and plasma cleaner in sequence, and then immersed in 10 mM NaCl with pH 8.5 for 1 hour before being placed on the AFM sample stage.

[0055] (6) A 10mM NaCl solution with a pH of 8.5 was dropped onto the coating on the exposed serpentine MgOH surface. The morphology of the coating on the serpentine MgOH surface was imaged using contact mode. Five smooth regions with a root mean square roughness of <10nm were selected from the morphology image.

[0056] (7) In each smooth region, the pyrite colloidal probe is driven by a piezoelectric sensor to approach the coating of the exposed serpentine MgOH surface with a loading force of 5nN and a speed of 500nm / s. After contact, it moves away. The deflection of the AFM cantilever beam is monitored in real time and converted into the interaction force F and the separation distance D as a function F(D). Each region is measured multiple times. The approach line represents the process of approaching each other, and the retreat line represents the process of moving away from each other. The separation distance D is the relative distance obtained based on the piezoelectric ceramic displacement and the cantilever deflection voltage signal. The contact start point on the interaction force-separation distance curve is defined as zero point. The force signal F measured during the approach and retreat processes is converted into the interaction energy per unit area between the two planes using the Derjaguin approximation method to generate the approach force curve and the retreat force curve.

[0057] (8) Replace the coating on the exposed serpentine MgOH surface with the coating on the exposed serpentine SiO surface and the coating on the exposed serpentine end face in turn (serpentine has a significant layered crystal structure, and its end face is easy to distinguish, and can be obtained by polishing). Repeat steps (5) to (7) to obtain the ingress force curve and regress force curve of pyrite particles and different crystal faces.

[0058] (9) The results are as follows Figures 2-4 as well as Figure 8 The histogram of adhesion forces along the regression line is shown. By comparing all the force curves along the regression line and the force curves along the regression line, the interaction force relationship between minerals can be obtained. In the forward line, a negative force F / R indicates that there is an attractive force that promotes adsorption between pyrite particles and serpentine crystal faces, while a positive value represents a repulsive force that hinders the adsorption of functional groups. In the regression line, a negative force F / R indicates that there is an adhesive force when the two separate, and no negative force was detected, indicating that there is no adhesive force. Figures 2-4 The results show that at pH 8.5, pyrite exhibits a strong attractive force to the MgOH surface of serpentine and a repulsive force to the SiO surface and end face, with the repulsive force order being: SiO surface > end face. The adhesion force results obtained from the stripping process are as follows: Figure 8 As shown, under pH 8.5 conditions, the relationship between the adhesion forces between the crystal faces of pyrite and serpentine is: MgOH face > SiO face > end face.

[0059] Example 2

[0060] The difference between this embodiment and Embodiment 1 is that the test solution is changed from a 10mM NaCl solution with a pH of 8.5 to a 10mM NaCl solution with a pH of 5.5. All other conditions and steps are the same.

[0061] The results are as follows Figures 5-7 As shown and Figure 8 The histogram of adhesion forces along the regression line is shown. By comparing all the force curves along the regression line and the force curves along the regression line, the interaction force relationship between minerals can be obtained. In the forward line, a negative force F / R indicates that there is an attractive force that promotes adsorption between pyrite particles and serpentine crystal faces, while a positive value represents a repulsive force that hinders the adsorption of functional groups. In the regression line, a negative force F / R indicates that there is an adhesive force when the two separate, and no negative force was detected, indicating that there is no adhesive force. Figures 5-7 The results show that under pH 5.5 conditions, pyrite exhibits a strong attractive force to the MgOH surface of serpentine and a repulsive force to the SiO surface and end face, with the repulsive force order being: SiO surface > end face. The statistical results of the adhesion force obtained from the delamination are as follows: Figure 8 As shown, under pH 5.5 conditions, the relationship between the adhesion forces between pyrite and serpentine crystal faces is: MgOH face > SiO face > end face.

[0062] The mineral system and substrate material of this invention are replaceable or expandable. The colloidal probe fixation method, crystal face orientation exposure process, and precise force measurement technology between mineral particles can all be adapted to different mineral crystal forms. Any reasonable substitution, combination, or optimization of mineral types, substrate materials, or experimental parameters based on the core principle of measuring interaction forces by mineral crystal face anisotropy is considered an equivalent technical solution of this invention and falls within the scope of protection of the claims.

Claims

1. A method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces, characterized in that: Includes the following steps: S1 involves removing the surface oxide layer from a single mineral particle and adhering it to the tip of a tipless cantilever in an AFM, then curing it to obtain a colloidal probe. S2. Minerals with anisotropic crystal planes are screened using suspension deposition or XRD to obtain single mineral crystal planes. During S3 measurement, a test solution is dropped onto the surface of a single mineral crystal face, and the mineral morphology is imaged using contact mode. Based on the surface morphology image analysis, smooth regions with a root mean square roughness of <10 nm are selected. A piezoelectric sensor drives a colloidal probe to approach and move away from the single mineral crystal face within the selected region, monitoring the deflection of the AFM cantilever beam in real time. This deflection is then converted into a function F(D) of the interaction force F and the separation distance D. The Derjaguin approximation method is used to convert the force signal F measured during the approach and retraction processes into the interaction energy per unit area between the two planes, generating approach force curves and retraction force curves. Here, approach represents the process of mutual approach, retraction represents the process of mutual retraction, and the separation distance D is the relative distance obtained based on the piezoelectric ceramic displacement and the cantilever deflection voltage signal. The contact start point on the interaction force-separation distance curve is defined as zero. S4. Change to different single mineral crystal faces and repeat step S3 to obtain the wire ingress force curve and wire regress force curve of single mineral particles and different crystal faces of minerals. S5 compares all the ingress force curves and regression force curves to obtain the relationship of the interaction forces between minerals.

2. The method for accurately measuring the interaction force between mineral particles based on the anisotropy of mineral crystal faces according to claim 1, characterized in that: In S5, the comparison of all incoming and outgoing force curves is as follows: In the incoming force curve, the larger the negative value of F / R, the stronger the attraction between a single mineral particle and a single mineral crystal face, and the easier it is for them to aggregate. The larger the positive value, the stronger the repulsive force between them, and the easier it is to disperse in the flotation pulp. In the outgoing force curve, the larger the negative value of F / R, the stronger the adhesion between them, and the higher the stability of the aggregate after mineral aggregation. Here, R refers to the radius of the mineral particles adhered to the colloidal probe.

3. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 1, characterized in that: The test solution was a 10 mM NaCl solution.

4. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 2, characterized in that: Before installing the single mineral crystal facet and colloidal probe with the oxide layer removed, they are cleaned and immersed in the test solution for 1-2 hours to allow the system to balance and reduce the influence of sporadic ions in the solution on the force measurement results.

5. A method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces, as described in any one of claims 1 to 4, characterized in that: The suspension deposition method is for layered anisotropic minerals. The preparation process is as follows: after depositing a suspension of layered mineral particles with anisotropic crystal planes onto the corresponding substrates, the loosely adsorbed mineral particles are removed by water washing to obtain a coating surface that exposes a single mineral crystal plane.

6. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 5, characterized in that: The XRD method is for bulk anisotropic minerals. The preparation process is as follows: after breaking up the bulk mineral with anisotropic crystal faces, XRD is used to assist in the determination and marking of the exposed crystal face orientation. The small crystal pieces are wrapped and fixed with epoxy resin to form a rectangular block, and the exposed surface is kept consistent with the marking to obtain a rectangular mineral block with a single exposed crystal face.

7. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 1, characterized in that: In S3, 3 to 5 smooth regions are selected each time, and multiple measurements are taken within each region to obtain a total of 80 to 100 curves. The final result is the average value.

8. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 6, characterized in that: In S3, the driving speed of the colloidal probe is controlled at 300~500nm / s and the pressure is controlled at 3~5nN during measurement.

9. The method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal faces according to claim 8, characterized in that: In S4, the test solution needs to be added again each time a single mineral crystal face is changed, and the concentration and pH value of the test solution should be kept consistent before and after the change.

10. A method for accurately measuring the interaction force between mineral grains based on the anisotropy of mineral crystal planes, as described in claim 1 or 9, characterized in that: The ingress force curve data were fitted based on the EDLVO theoretical model to determine the contribution rates of van der Waals forces, electrostatic forces, and hydrophobic forces to the interaction; the regress force curve data were fitted with a normal distribution to obtain the relationship of the adhesion forces between mineral particles.

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