A method for quantitatively analyzing pore and fissure structure of ore

Abstract

The application provides a quantitative analysis method for ore pore and fissure structure, and relates to the technical fields of mineral processing, metallurgical engineering and geological analysis. The method realizes accurate prediction of effective porosity of heap leaching ore by coupling on-site particle size investigation, laboratory "quasi on-site" heap construction, ore block fissure microscopic measurement and mass-volume conservation calculation. The method effectively overcomes the technical problems that the traditional method depends on single scale measurement, and is difficult to comprehensively reflect the complex structure from nanoscale pore to centimeter scale fissure, especially for the mixed ore of coarse and fine particle grades. The existing technology often processes different particle grades respectively, lacks systematic integration and mutual correction, and causes deviation of the calculation results of porosity and fissure rate.

Description

Technical Field

[0001] This invention relates to the fields of mineral processing, metallurgical engineering and geological analysis, and specifically to a quantitative analysis method for the pore and fracture structure of ores used in heap leaching processes. Background Technology

[0002] In heap leaching of ores, the flow and permeation efficiency of the leachate directly determine the metal recovery rate and economic benefits. This efficiency is mainly controlled by the multi-scale structure of the ore, ranging from millimeters to centimeters, including microscopic fractures within the ore blocks and macroscopic pores in the overall heap. Therefore, the pore and fracture structure of the ore directly affects its crushing, beneficiation, and metallurgical properties. Traditional methods for measuring this crucial data often rely on single-scale measurements, making it difficult to comprehensively reflect the complex structure from nanoscale pores to centimeter-scale fractures. Especially for ores with a mixture of coarse and fine grains, existing technologies often process different grain sizes separately, lacking systematic integration and mutual correction, leading to deviations in the calculated porosity and fracture rate. Existing technologies have significant shortcomings: Firstly, traditional core porosity measurement methods (such as the helium porosimetry method) can only reflect the micropores within the rock matrix and cannot characterize the macroscopic heap pores and ore block fractures, which are more critical for leachate flow. Secondly, while laboratory-scale column leaching experiments can simulate overall permeability, they struggle to quantitatively separate the contributions of macroscopic porosity from the fractures within the ore block itself, leading to inaccurate predictions when scaled up to industrial scale. Thirdly, there is a lack of a systematic approach that couples in-situ particle size distribution, laboratory physical simulation, and microscopic analysis techniques.

[0003] Patent CN120558815A discloses a method for detecting the porosity of ore in in-situ heap leaching. This method involves taking ore samples on-site, preparing a filler, vacuum gradient impregnating, solidifying, dissolving, and separating the ore to obtain a pore model; then melting and softening the pore model to obtain the pore volume in the ore, ultimately yielding the ore's porosity. Patent CN120741295A discloses a method for detecting the porosity of ore in heap leaching. This method involves taking heap leaching ore samples, sieving, mixing, and reducing the sample size before feeding them into a heap leaching column. The volume of the reduced sample in the column is then obtained. The sample is then finely ground and fed back into the column to obtain the volume of the finely ground sample. Image analysis is then performed on the finely ground sample to obtain the pore volume between the particles. Finally, the porosity of the heap leached ore is calculated by converting these three volumes. However, the above technical solutions require the preparation of a filling agent, which is technically complex to manufacture. Furthermore, it is difficult to guarantee the filling content during the filling process, leading to an underestimation of the filling amount and affecting the accuracy of the measurement data. Alternatively, the above technical solutions involve measuring volume changes after fine grinding. Even with fine grinding, it is difficult to ensure that the pores are completely closed. Moreover, the introduction of image analysis technology is greatly affected by human factors in sample preparation before image measurement; more samples result in fewer pores, and fewer samples result in more pores, directly impacting the accuracy of the data.

[0004] In view of this, there is an urgent need for a method that can accurately quantify the full-scale structural parameters from macroscopic pores in ore piles to microscopic cracks in ore blocks, so as to provide accurate data support for the optimization of heap leaching process. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a systematic and accurate quantitative analysis method for the multi-scale pore and fracture structure of ores. This quantitative analysis method for ore pore and fracture structure achieves accurate prediction of the effective porosity of heap leaching ores by coordinating the steps of in-situ particle size survey, laboratory "pseudo-in-situ" heap construction, microscopic measurement of ore fractures, and mass-volume conservation calculation.

[0006] This invention provides a method for quantitative analysis of the pore and fracture structure of ores, comprising the following steps:

[0007] S1, On-site particle size distribution determination: Samples are taken and sieved at the mineral production site to obtain particle size distribution data of the samples;

[0008] S2, Laboratory sample preparation and total mass measurement: Based on the particle size distribution measured in step S1, raw ore samples are collected from the same ore source and laboratory samples with the same particle size distribution as on site are prepared, and the total mass M1 is measured.

[0009] S3, Construction of the "simulated field" stacking model and measurement of the stack volume: The laboratory sample prepared in step S2 is loaded into the stack leaching column to construct a physical model simulating the field stacking state, and the stack volume V1 is calculated.

[0010] S4, Representative ore block sampling and geometric volume measurement: Take several blocks from the coarse-grained ore in step S3, process them into regular geometric bodies Ei, and measure and calculate their total volume V2 and total mass M2.

[0011] S5, Fracture Ratio Measurement and Effective Volume Calculation: The regular geometric sample obtained in step S4 is inlaid to prepare an automated mineralogical analysis sample and perform automated mineralogical analysis. The average fracture ratio T is measured, and the effective volume V3 of the mineral sample is further calculated. Inlaying is resin inlaying, where epoxy resin and curing agent are mixed at a volume ratio (1:0.2~1.0) and ultrasonically vibrated until fully cured at room temperature.

[0012] S6, Calculation of full-scale effective porosity: Based on the principles of mass conservation and volume superposition, the full-scale effective porosity W of the ore is calculated using the total mass M1 of the laboratory sample measured in step S2, the pile volume V1 measured in step S3, the total volume V2 and total mass M2 of the ore block measured in step S4, and the effective volume V3 calculated in step S5.

[0013] As a further improvement of the present invention, in step S6, the formula for calculating the effective porosity W is:

[0014] W = [V1 - (V3×(M1 / M2))] / V1;

[0015] Wherein, V1 represents the macroscopic pile volume, which includes pile porosity and ore block fractures;

[0016] V3×(M1 / M2) represents the total solid skeleton volume of all the ore corresponding to the total mass M2 of the regular geometric sample;

[0017] V1-(V3×(M1 / M2)) represents the total effective volume of pores and fissures.

[0018] As a further improvement of the present invention, in step S5, the effective volume V3 of the ore sample is calculated as follows: V3 = V2 × (1-T).

[0019] As a further improvement of the present invention, the specific process of determining and calculating the average fracture rate in step S5 is as follows: the regular geometric sample Ei from step S4 is directly embedded to prepare an automated mineralogical analysis sample, denoted as Ci; the sample Ci is subjected to automated mineralogical analysis to measure the fracture area ratio, i.e., the sample fracture rate, denoted as ti; the average fracture rate T is further calculated using the formula: T=∑ti / i, where i is the corresponding sample number.

[0020] As a further improvement of the present invention, in step S3, the method for measuring and calculating the pile volume V1 is as follows: measure the sample stacking height h inside the pile immersion column, and calculate the pile volume V1 = π × R² × h based on the column radius R.

[0021] As a further improvement of the present invention, in step S4, the measurement and calculation process and formulas for the total volume V2 and the total mass M2 are as follows:

[0022] The length, width, and height of each regular geometric sample Ei are measured as ai, bi, and ci, respectively. The formula for calculating the total volume V2 of all regular geometric samples is: V2 = ∑(ai × bi × ci).

[0023] The dry weight of each regular geometric sample Ei after cutting is measured and denoted as mi. The formula for calculating the total mass M2 of all regular geometric samples is: M2=∑mi;

[0024] Where i is the corresponding sample number, with a value ranging from 5 to 15.

[0025] As a further improvement of the present invention, the representative ore sampling process is as follows: take i blocks from coarse-grained ore, and the length, width and height of the sample are all greater than 5.0 cm, and then process them into regular geometric shapes, denoted as Ei;

[0026] The regular geometric shape is a cuboid with dimensions ranging from 2.0 to 3.0 cm in length, 2.0 to 3.0 cm in width, and 2.0 to 3.0 cm in height.

[0027] As a further improvement of the present invention, in step S3, when constructing a physical model simulating the on-site stacking state, the diameter D of the heap leaching column and the particle size d_max of the largest particle in the laboratory sample satisfy D / d_max>50.

[0028] As a further improvement of the present invention, in step S3, the "layered pouring-natural stacking" method is used for filling, in which the laboratory sample is poured into the column from a height of 10-30cm above the top of the heap leaching column, so that it naturally bridges and compacts under the action of gravity.

[0029] Step S3 also includes a saturation and pressurization process, which involves adding water to the top of the heap leaching column until it is saturated to simulate the liquid column pressure inside the heap; at the same time, applying a pressure consistent with the overburden pressure at the ore sampling point to simulate the effect of formation pressure on the pore structure.

[0030] As a further improvement of the present invention, in step S1, the sieving process divides the ore sample into at least five particle sizes: coarse particles (≥10mm), coarse particles (<10mm and ≥5mm), medium particles (<5mm and ≥1mm), fine particles (<1mm and ≥0.1mm), and microparticles (<0.1mm).

[0031] The beneficial effects of this invention are:

[0032] The quantitative analysis method for ore pore and fracture structure provided by this invention has the following technical advantages:

[0033] 1. Systematic: For the first time, it organically combines three scales: on-site particle size investigation, laboratory physical simulation (column leaching experiment) and microscopic analysis (automated mineralogy), forming a complete multi-scale analysis chain.

[0034] 2. Accuracy: The regular geometric volume V2 of the ore block is corrected by the micro-average fracture rate T to obtain the effective volume (effective skeleton volume) V3. This avoids confusing the macroscopically measured porosity with the fractures of the ore block itself, and the calculation result is closer to the effective porosity in the actual leaching process.

[0035] 3. Strong predictive power: The porosity W measured by this method fully considers the on-site particle size distribution and in-situ stress conditions, and has better predictive and guiding significance for the flow behavior of leachate in industrial heap leaching fields.

[0036] 4. Practicality: The methods and steps are clear, the parameters are well-defined, and they are easy to promote and apply in mining laboratories and research centers, providing a reliable quantitative tool for the design and optimization of heap leaching processes.

[0037] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0038] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0039] Figure 1 This is a schematic flowchart of the quantitative analysis method for ore pore and fracture structure provided in the embodiments of the present invention;

[0040] Figure 2 This is a micrograph of the ore measurement porosity provided in an embodiment of the present invention (the red circle in the figure indicates the measurement porosity). Detailed Implementation

[0041] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0042] Unless otherwise defined, 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 invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0043] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0044] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0045] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0046] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0047] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0048] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0049] To address the limitations of traditional methods that rely heavily on single-scale measurements, which fail to comprehensively reflect the complex structure from nanoscale pores to centimeter-scale fractures, especially for ores with a mixture of coarse and fine grains, existing technologies often process different grain sizes separately, lacking systematic integration and mutual correction, leading to deviations in porosity and fracture rate calculations. This invention provides a systematic and accurate quantitative analysis method for the multi-scale pore and fracture structure of ores. This method couples in-situ particle size surveys, laboratory "pseudo-in-situ" pile construction, microscopic measurement of ore fractures, and mass-volume conservation calculations to achieve accurate prediction of the effective porosity of heap-leached ores. Its main inventive points are: First, multi-scale coupled analysis: innovatively integrating in-situ particle size surveys, laboratory "pseudo-in-situ" pile construction, and microscopic fracture measurement, breaking through the limitations of traditional single-scale measurements and achieving full-scale coverage from nanoscale pores to centimeter-scale fractures. Secondly, on-site simulation optimization: By controlling the particle size ratio of the heap leaching column, stratified natural stacking, and saturated pressurization treatment, the on-site ore pile stacking state and stress conditions are accurately replicated, eliminating wall effects and human interference. Thirdly, precise parameter calculation: Automated mineralogical analysis is used to determine the average fracture rate of coarse-grained ore blocks. Combined with the dimensions and mass of regular geometric shapes, the effective skeleton volume of the ore blocks is corrected to distinguish the contributions of macroscopic porosity and microscopic fractures. Fourthly, scientific formula derivation: Based on the principles of mass conservation and volume superposition, an effective porosity calculation model is constructed to quantify the proportion of total pore and fracture volume, solving the problem of parameter calculation deviations in mixed coarse and fine-grained ores and improving the accuracy of industrial heap leaching predictions.

[0050] Please refer to Figures 1 to 2 As shown, this invention provides a quantitative analysis method for the pore and fracture structure of ores, comprising the following steps:

[0051] S1, On-site particle size distribution determination:

[0052] Samples were taken from representative locations at the mineral production site, and the actual particle size distribution of the samples was determined using a sieving system.

[0053] In some implementations, a vibrating sieve is used to separate the sample into five particle sizes: coarse particles (≥10 mm), coarse particles (<10 mm and ≥5 mm), medium particles (<5 mm and ≥1 mm), fine particles (<1 mm and ≥0.1 mm), and microparticles (<0.1 mm).

[0054] Record the percentage of each particle size in the total mass, denoted as Fn (where n = 1, 2, 3, 4, 5 correspond to the above particle sizes respectively).

[0055] S2, Laboratory Sample Preparation and Total Mass Measurement:

[0056] Representative raw ore samples were collected from the same ore source, crushed, and then prepared for laboratory use based on the particle size distribution Fn measured in step S1. This ensured that the particle size composition of the laboratory samples was consistent with that of the field samples. The total mass of the prepared laboratory samples was weighed and recorded as M1.

[0057] S3, Construction of a simulated on-site stacking model and measurement of stack volume:

[0058] The prepared laboratory samples were loaded into a heap leaching column to construct a physical model simulating the on-site stacking state.

[0059] Among them, the scaling principle is that the diameter (D) of the leaching column and the particle size (d_max) of the largest particle in the sample must satisfy D / d_max>50 to eliminate the influence of the wall effect.

[0060] In the specific operation, the filling method is as follows: the "layered pouring-natural accumulation" method is adopted. The sample is poured into the column from a height of 10-30cm above the top of the column, allowing it to naturally bridge and compact under the action of gravity. External strong vibration is prohibited; only slight tapping of the column wall is allowed to eliminate abnormally large pores, thereby realistically reproducing the macroscopic pore structure of the on-site ore pile.

[0061] Furthermore, saturation and pressurization treatments were carried out. Specifically, water was added from the top of the column until it was saturated to simulate the liquid column pressure within the pile. Simultaneously, pressure consistent with the overburden pressure at the sampling point was applied to simulate the effect of formation pressure on the pore structure.

[0062] Finally, the bulk volume is measured and calculated: the height h of the sample packing inside the column is measured, and the bulk volume V1 = π × R² × h is calculated based on the column radius R. Here, R is the column radius, and h is the column height.

[0063] S4, Representative ore block sampling and geometric volume measurement:

[0064] Take i samples from the coarse-grained ore sample in step S3, where i ranges from 5 to 15. The dimensions of the sample are preferably greater than 5.0 cm in length, width, and height. Then cut the sample to a suitable size to obtain a regular geometric shape with a length, width, and height range of 2.0 to 3.0 cm, preferably with equal length, width, and height, denoted as Ei.

[0065] Measure the length, width, and height of each regular geometric sample Ei, and denote them as ai, bi, and ci (i being the serial numbers of the ore samples, 1, 2, 3, 4, etc.). The total volume of all samples in this step is V2, calculated using the formula: V2 = ∑(ai... bi ci).

[0066] Measure the dry weight of each regular geometric sample Ei after cutting, and record it as mi; then the total mass of all samples in this step is M2, and the calculation formula is: M2=∑mi.

[0067] In some embodiments, the preferred size of the cuboid (regular geometric shape) sample after the ore block sample is cut is 2.5 cm × 2.5 cm × 2.5 cm.

[0068] S5, Crack Ratio Measurement and Effective Volume Calculation:

[0069] The regular geometric sample Ei from step S4 is directly embedded to prepare an automated mineralogical analysis sample (vacuum embedding, polishing), denoted as Ci; the sample Ci is subjected to automated mineralogical analysis to measure the percentage of fracture area (on the measurement surface: the percentage of fracture area to the entire measurement surface), denoted as ti.

[0070] The average fracture rate T is further calculated using the formula: T = ∑ti / i.

[0071] Based on the average fracture rate, the effective volume V3 of the ore block is calculated using the formula: V3 = V2 × (1-T);

[0072] In some specific implementations, the automated mineralogical analysis employs an MLA (mineral liberation analyzer) or QEMSCAN system.

[0073] S6, Calculation of effective porosity: Based on the principle of mass conservation and volume superposition, the effective porosity W of the entire ore deposit is calculated. The calculation formula is: W=(V1-V3×M1 / M2) / V1;

[0074] Where V1 represents the macroscopic pile volume (including pile porosity and ore block fractures);

[0075] V3 × (M1 / M2) represents the total solid skeleton volume of all ores corresponding to the total mass M2 of the regular geometric sample.

[0076] The molecule V1 - (V3×(M1 / M2)) represents the total effective volume of pores and fissures.

[0077] Figure 2 The experimental ore sample is shown in a micrograph of its pore size, revealing a distinct pore structure.

[0078] Example 1

[0079] Embodiment 1 of the present invention provides a quantitative analysis method for the pore and fracture structure of ore, using a porphyry copper in-situ heap leaching ore as a sample, specifically including the following steps:

[0080] S1, On-site particle size distribution determination: A sample of 145.58 kg was taken at the outlet of the crushing workshop, sieved to obtain the particle size distribution, and the percentage of each particle size to the total mass was recorded as Fn. The specific particle size distribution is as follows: coarse particles F1 = 24.25%, large particles F2 = 28.65%, medium particles F3 = 16.74%, fine particles F4 = 18.65%, and microparticles F5 = 11.71%.

[0081] S2, Laboratory Sample Preparation and Total Mass Measurement: Take 500 kg of raw ore from the mine, crush it, and prepare a laboratory column leaching sample according to the above Fn ratio. The total mass M1 = 242.00 kg.

[0082] S3, “Simulated Site” Accumulation Model Construction and Accumulation Volume Measurement: Laboratory samples were loaded into a heap leaching column with a diameter of D = 30 cm (satisfying D / d_max > 50). The “layered dumping-natural accumulation” method was used for loading, followed by water saturation and an application of 50 kPa pressure to simulate the pressure of the overlying strata. The accumulation height h = 150.00 cm was measured, and the accumulation volume V1 = π × 15² × 150 ≈ 106,028 cm³ was calculated.

[0083] S4, Representative ore block sampling and geometric volume measurement: Ten ore blocks (i=10) were randomly selected from the giant-grain sample ore blocks and cut into cubes of approximately 2.5 cm. The total volume of the representative ore blocks was measured and calculated as V2 = 156.25 cm³, and the total mass as M2 = 945.42 g.

[0084] S5, Crack Rate Measurement and Effective Volume Calculation: MLA analysis was performed on the above 10 cubic samples to measure the crack rate (crack area ratio) ti of each sample. The average crack rate T = ∑ti / i = 8.5% was further calculated. Then the effective volume (effective skeleton volume) V3 = 156.25×(1 - 0.085) = 142.97 cm³.

[0085] S6, Effective Porosity Calculation: Calculate the effective porosity W of the entire ore deposit.

[0086] W=(V1-V3×M1 / M2) / V1=[106028-(142.97×(242000 / 945.42))] / 106028

[0087] = [106028 - (142.97 × 255.97)] / 106028

[0088] = [106028 - 36596.03] / 106028

[0089] ≈65.48%.

[0090] The accuracy of the effective porosity calculated in Embodiment 1 of the present invention reaches less than ±1% error. Through actual liquid injection verification, it is significantly improved compared with the 58% accuracy measured by the traditional method.

[0091] Example 2

[0092] Embodiment 2 of the present invention provides a quantitative analysis method for the pore and fracture structure of ore, using ore from an in-situ heap leaching process in a gold mine as a sample, specifically including the following steps:

[0093] S1, On-site particle size distribution determination: A sample of 120.00 kg was taken at the outlet of the crushing workshop, sieved to obtain the particle size distribution, and the percentage of each particle size in the total mass was recorded as Fn. The specific particle size distribution is as follows: coarse particles F1=18.43%, large particles F2=24.38%, medium particles F3=24.66%, fine particles F4=16.78%, and microparticles F5=15.75%.

[0094] S2, Laboratory Sample Preparation and Total Mass Measurement: Take 300 kg of raw ore from the mine, crush it, and prepare a laboratory column leaching sample according to the above Fn ratio. The total mass M1 = 178.00 kg.

[0095] S3, “Simulated Site” Accumulation Model Construction and Accumulation Volume Measurement: Laboratory samples were loaded into a heap leaching column with a diameter of D = 30 cm (satisfying D / d_max > 50). The “layered dumping-natural accumulation” method was used for filling, followed by water saturation and an application of 73 kPa pressure to simulate the pressure of the overlying strata. The accumulation height h = 102.29 cm was measured, and the accumulation volume V1 = π × 15² × 102.29 ≈ 72267.885 cm³ was calculated.

[0096] S4, Representative ore block sampling and geometric volume measurement: Ten ore blocks (i=10) were randomly selected from the giant-grained sample ore blocks and cut into cubes of approximately 2.5 cm. The total volume of the representative ore blocks was measured and calculated as V2 = 142.05 cm³, and the total mass as M2 = 822.10 g.

[0097] S5, Crack Rate Measurement and Effective Volume Calculation: MLA analysis was performed on the above 10 cubic samples to measure the crack rate (crack area ratio) ti of each sample. The average crack rate T = ∑ti / i = 5.42% was further calculated. Then the effective volume (effective skeleton volume) V3 = 142.05×(1 - 0.0542) = 134.35 cm³.

[0098] S6, Effective Porosity Calculation: Calculate the effective porosity W of the entire ore deposit.

[0099] W=(V1-V3 M1 / M2) / V1 = [72267.885-(134.35×(178000 / 822.10))] / 72267.885≈59.75%.

[0100] In summary, this invention provides a quantitative analysis method for the porosity and fracture structure of ores, relating to the fields of mineral processing, metallurgical engineering, and geological analysis. This method achieves accurate prediction of the effective porosity of heap leaching ores by coupling on-site particle size surveys, laboratory "simulated on-site" heap construction, microscopic measurement of ore fractures, and mass-volume conservation calculations. This method is the first to organically combine three scales—on-site particle size surveys, laboratory physical simulations (column leaching experiments), and microscopic analysis (automated mineralogical analysis)—forming a complete analytical chain. Furthermore, by correcting the geometric volume of the ore block using the microscopic average fracture rate, the effective framework volume is obtained, avoiding confusion between macroscopically measured porosity and the fractures within the ore block itself. The calculated results are closer to the effective porosity in the actual leaching process. The porosity measured by this method fully considers the on-site particle size distribution and in-situ stress conditions, providing better prediction and guidance for the flow behavior of leachate in industrial heap leaching fields. This method has clear steps and well-defined parameters, making it easy to promote and apply in mining laboratories and research centers. It provides a reliable quantitative tool for the design and optimization of heap leaching processes. In this way, it effectively overcomes the technical problem that traditional methods rely on single-scale measurements and cannot fully reflect the complex structure from nanoscale pores to centimeter-scale fractures. Especially for ores with a mixture of coarse and fine particles, existing technologies often process different particle sizes separately, lacking systematic integration and mutual correction, which leads to deviations in the calculation results of porosity and fracture rate.

[0101] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for quantitatively analyzing the pore and fissure structure of an ore, characterized by, The method comprises the following steps: S1, on-site particle size distribution measurement: sampling and sieving at the production site of the ore source to obtain particle size distribution data of the sample; S2, laboratory sample preparation and total mass measurement: based on the particle size distribution measured in step S1, collecting raw ore samples from the same ore source and preparing laboratory samples consistent with the on-site particle size distribution, and measuring the total mass M1; S3, construction of a "pseudo on-site" stacking model and measurement of the heap volume: loading the laboratory samples prepared in step S2 into a heap leaching column, constructing a physical model simulating the on-site stacking state, and calculating the heap volume V1; S4, representative ore block sampling and geometric volume measurement: sampling several blocks of coarse-grained ore from the coarse-grained ore in step S3, processing them into regular geometric bodies Ei, measuring and calculating the total volume V2 and the total mass M2; S5, fissure rate measurement and effective volume calculation: preparing the regular geometric body samples obtained in step S4 into automatic mineralogical analysis samples and performing automatic mineralogical analysis, measuring the average fissure rate T, and further calculating the effective skeleton volume V3 of the ore block sample; S6, effective porosity calculation: based on the mass conservation and volume superposition principle, the effective porosity W of the entire ore stacking body is calculated; In step S6, the calculation formula of the effective porosity W is: W = [V1 - (V3×(M1 / M2))] / V1; Wherein, V1 represents the macroscopic heap volume, including the heap porosity and the ore block fissure; V3×(M1 / M2) represents the total solid skeleton volume of all ores corresponding to the total mass M2 of the regular geometric body sample; V1-(V3×(M1 / M2)) represents the total volume of effective porosity and fissure; In step S5, the calculation formula of the effective skeleton volume V3 of the ore block sample is: V3=V2×(1-T).

2. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, characterized by, In step S5, the specific process of average fissure rate measurement and calculation is: directly embedding the regular geometric body samples Ei of step S4 to prepare automatic mineralogical analysis samples, denoted as Ci; performing automatic mineralogical analysis on the sample Ci to measure the sample fissure rate, denoted as ti; further calculating the average fissure rate T, the calculation formula is: T=∑ti / i, wherein i is the sample serial number.

3. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, characterized by, In step S3, the measurement and calculation method of the heap volume V1 is: measuring the sample stacking height h in the heap leaching column, and calculating the heap volume V1=π×R²×h according to the column radius R.

4. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, characterized by, In step S4, the measurement and calculation process and formula of the total volume V2 and the total mass M2 are: Measure the length, width and height of each regular geometric body sample Ei as ai, bi and ci, then the calculation formula of the total volume V2 of all regular geometric body samples is: V2=∑(ai×bi×ci); Measure the dry weight of each regular geometric body sample Ei after cutting, denoted as mi, then the calculation formula of the total mass M2 of all regular geometric body samples is: M2=∑mi; Wherein, i is the sample serial number, and the value range is 5~15.

5. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 4, characterized by, The representative ore block sampling process is: sampling i blocks from the coarse-grained ore, and the sampling size length, width and height are all greater than 5.0 cm, then processing them into regular geometric bodies, denoted as Ei; The regular geometric body is a cuboid with a size ranging from 2.0 cm to 3.0 cm in length, from 2.0 cm to 3.0 cm in width, and from 2.0 cm to 3.0 cm in height.

6. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, characterized by, In step S3, when the physical model simulating the in-situ stacking state is constructed, the diameter D of the heap leaching column and the particle size d_max of the largest particle in the laboratory sample satisfy D / d_max > 50.

7. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, wherein In step S3, the "stratified pouring-natural stacking" method is used for filling, and the laboratory sample is poured into the column from a height of 10-30 cm above the top of the heap leaching column, so as to be naturally bridged and compacted under the action of gravity. In step S3, the process further includes a saturation and pressurization treatment process, which is: adding water from the upper end of the heap leaching column to saturation to simulate the liquid column pressure in the heap body; at the same time, a pressure consistent with the overburden pressure of the ore sampling point is applied to simulate the influence of the formation pressure on the pore structure.

8. The method for quantitatively analyzing the pore and fissure structure of an ore according to claim 1, characterized by, In step S1, the screening process divides the ore sample into at least five particle sizes: the macro-particle with a particle size ≥10 mm, the coarse particle with a particle size <10 mm and ≥5 mm, the medium particle with a particle size <5 mm and ≥1 mm, the fine particle with a particle size <1 mm and ≥0.1 mm, and the micro-particle with a particle size <0.1 mm.

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