A method for detecting the hardness of an ore

Abstract

The application discloses a kind of ore hardness detection methods, it is related to mining and testing analysis technical field.The method obtains the volume relative content of main mineral by automatic mineralogy quantitative analysis, obtains the hardness value of each mineral, calculates initial hardness;Calculate cementation correction coefficient, calculate comprehensive hardness value by nonlinear correction model.The present application realizes the accurate association of mineral composition, cementation state and ore hardness, realizes the accurate prediction of the ore hardness of multi-mineral aggregate;Effectively solve the problem that traditional macro hardness test cannot reflect the true mechanical characteristics of multi-mineral aggregate, significantly improve the detection accuracy of ore hardness of different cementation degree, weathering degree, suitable for hardness evaluation of various sedimentary rocks, metamorphic rocks and igneous rocks.

Description

Technical Field

[0001] This invention relates to the fields of mining and testing analysis technology, and specifically to a method for detecting the hardness of ores. Background Technology

[0002] In the mining industry, ore hardness is a core physical and mechanical parameter, its importance permeating the entire process of geological exploration, mining method selection, equipment selection, safety management, and economic cost control. Ore hardness directly determines the rock-breaking methods and mining techniques used in mining engineering; for example, softer ores can be cut mechanically, while harder ores are often blasted. It is also a decisive factor in drilling speed and drill bit wear, as well as ensuring the stability of the surrounding rock in the stope and roadways.

[0003] Currently, existing methods for determining ore hardness are mainly divided into two categories: macroscopic mechanical testing and localized hardness testing. Macroscopic mechanical testing, such as uniaxial compressive strength testing, can reflect the overall strength of the ore, but the testing process has strict requirements on sample size, is complex to prepare, and is time-consuming. Moreover, the test results are difficult to effectively distinguish the individual contributions of different mineral components and microstructures to hardness. On the other hand, the method of using microhardness testers (such as Vickers hardness and Knoop hardness) to indent a single mineral can accurately obtain the local hardness of a specific mineral. However, when applied to ore samples of multi-mineral aggregates, the overall hardness of the ore is usually estimated using only a simple arithmetic average or a linear weighted method that ignores the actual mineral content. This method fails to fully consider the complex influence of the non-uniform interaction between minerals of different hardness, the spatial distribution of particles, and the cementation state on the overall mechanical behavior. Especially for ores with significant differences in cementation (such as loose sandstone and dense quartzite), relying solely on mineral-weighted hardness often results in a large deviation from the actual macroscopic hardness. This leads to discrepancies between the crushing or grinding process parameters designed based on this and the actual production situation, resulting in energy waste or excessive equipment wear. Furthermore, existing technologies have several shortcomings in sample preparation. For example, samples used for automated mineralogical analysis (such as QEMSCAN and MLA) often differ significantly from those used for microhardness testing, making it difficult to accurately correlate mineral identification areas with hardness indentation locations, thus reducing the accuracy of the correlation analysis between mineral content and hardness values. In microhardness testing, the requirements for key quality indicators such as sample surface roughness and parallelism are not stringent enough or lack standardization, easily introducing measurement errors and affecting the comparability of data between different laboratories. Simultaneously, existing methods rarely systematically incorporate the cementation coefficient, which reflects the bonding strength between particles within the ore, into the hardness correction calculation model, and lack quantitative characterization methods for cementation sensitivity and matrix-based hardness.

[0004] In view of this, it is necessary to develop a comprehensive method for determining ore hardness that integrates automated quantitative mineralogical analysis, precise microhardness testing, and mechanical correction of cementation degree. This method can more objectively and comprehensively reflect the intrinsic hardness characteristics of the ore, and has significant practical significance and application value for improving the accuracy of mining process design, reducing production energy consumption, and optimizing equipment operating parameters. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a method for detecting the hardness of ores. This method can accurately identify the types and volume contents of the main minerals in the ore, obtain the true microhardness of each mineral, and on this basis, introduce a cementation correction coefficient for mechanical correction, and finally obtain an evaluation index that can accurately reflect the overall actual hardness of the ore.

[0006] In a first aspect, embodiments of the present invention provide a method for detecting the hardness of an ore, comprising the following steps: S1, based on quantitative mineralogical analysis, obtain the types of major minerals in the ore to be tested and their relative volume content in the ore; S2, obtain the single mineral hardness value of each major mineral in the ore to be tested; S3. Calculate the initial hardness value of the ore to be tested based on the relative volume content and the single mineral hardness value. S4, Based on the cementation state of the ore to be tested, obtain the cementation correction coefficient of the ore to be tested; S5. Based on the initial hardness value and the cementation correction coefficient, calculate the comprehensive hardness value of the ore to be tested according to the nonlinear correction model. The nonlinear correction model causes the overall hardness value to increase nonlinearly with the strengthening of the cementation state and decrease nonlinearly with the weakening of the cementation state. When the cementation state is almost completely lost, the overall hardness value approaches the basic hardness value provided by the ore matrix.

[0007] As a further improvement of the present invention, step S4 specifically includes: The longitudinal wave velocity Vp and matrix wave velocity Vm of the ore to be tested are measured; the cementation correction coefficient C = (Vp / Vm)² is calculated, wherein the cementation correction coefficient C characterizes the degree of deviation of the actual cementation state of the ore from the fully cemented state, and the value of C ranges from 0 to 1.

[0008] As a further improvement of the present invention, in step S5, the nonlinear correction model is constructed based on the bonding correction coefficient C and combined with the bonding sensitivity index k and the matrix hardness constant Hs. The nonlinear correction model is: H = H0×C k+ Hs; where H is the overall hardness value, H0 is the initial hardness value, C is the cementation correction coefficient, k is the cementation sensitivity index, and Hs is the matrix hardness constant. When C approaches 1, the comprehensive hardness value H approaches H0+Hs, indicating that the hardness of the ore under strong cementation is mainly contributed by the mineral weighted hardness. When C approaches 0, the comprehensive hardness value H approaches Hs, indicating that the hardness of the ore in the uncemented state is provided by the basic hardness value only by interparticle friction or matrix.

[0009] As a further improvement of the present invention, the cementation sensitivity index k is determined according to the type of cementing material, characterizing the sensitivity of changes in cementation degree to ore hardness, and the value range is 0.30 to 1.50; the larger the k value, the faster the ore hardness decreases as the cementation correction coefficient decreases; the smaller the k value, the less sensitive the ore hardness is to the cementation correction coefficient. The higher the hardness of the cementitious material, the smaller the value of k; the higher the solubility of the cementitious material, the larger the value of k.

[0010] As a further improvement of the present invention, the matrix hardness constant Hs is determined according to the matrix type, and characterizes the basic compressive / scratch resistance that the ore body can provide when the ore is completely uncemented and relies only on the friction between particles or the extremely soft matrix for bonding, i.e., the basic hardness value. When the cementation correction factor C < 0.1, Hs takes the lower limit of the recommended range for the corresponding matrix type; when the cementation correction factor C ≥ 0.1, Hs takes the average value of the recommended range for the corresponding matrix type or is appropriately ignored.

[0011] As a further improvement of the present invention, the cementation sensitivity index k is also modified according to the degree of weathering of the ore: the k value of slightly weathered ore is increased by 0.10 from the original base; the k value of moderately weathered ore is increased by 0.25 from the original base; and the k value of strongly weathered ore is increased by 0.40 from the original base.

[0012] As a further improvement of the present invention, step S3 specifically includes: Calculate the volume relative content of each major mineral Di = ci / Σci, where ci is the volume percentage content of the i-th major mineral; Σci is the sum of the volume percentage contents of all i-th major minerals; The initial hardness value H0 is calculated by weighted summation of volume relative content = ∑(Di×Hi), where Hi is the single mineral hardness value of the i-th major mineral; and Di is the volume relative content of the i-th major mineral.

[0013] As a further improvement of the present invention, in step S2, the process of obtaining the single mineral hardness value is as follows: an automated mineralogical analysis sample is prepared, and an indentation test is performed on each major mineral using a microhardness tester to obtain the Vickers hardness value; wherein, the loading force of the indentation test is 50 gf to 500 gf, the holding time is 10 s to 15 s, at least 10 valid indentation data are obtained for each mineral, and the average value is taken as the single mineral hardness value; in the indentation test, it is specified that the parallelism deviation between the test surface and the bottom of the test sample is less than 1°, and the difference between the lengths of the two diagonals of the indentation does not exceed 5% of its average value.

[0014] As a further improvement of the present invention, a sample preparation step is included before step S1: The ore sample to be tested is crushed to a set particle size; the crushed sample is reduced and sampled, and then embedded in a fixed medium, cured, surface treated and conductive treated to prepare a sample for component analysis. The surface treatment includes: gradient grinding using abrasive media with progressively decreasing particle size, followed by sequential polishing on a flexible carrier containing abrasive particles of different sizes.

[0015] Secondly, embodiments of the present invention provide a system for detecting the hardness of an ore, which is used to perform the above-described method for detecting the hardness of an ore, comprising: The mineralogy quantitative analysis unit includes an automated mineralogy analysis system, which is used to perform component analysis on the ore to be tested and obtain the types of major minerals in the ore and their relative volume content in the ore. The hardness testing unit includes a microhardness tester, used to test the single-mineral hardness values ​​of each major mineral. The hardness calculation unit is connected to the mineralogy quantitative analysis unit and the hardness detection unit, respectively, and is used to calculate the initial hardness value of the ore based on the volume relative content and the single mineral hardness value. The cementation state determination unit is used to determine the cementation state of the ore to be tested and to determine the cementation correction coefficient based on the acoustic parameters of the ore to be tested. The comprehensive hardness calculation unit is connected to the hardness calculation unit and the cementation state determination unit, respectively, and is used to calculate the comprehensive hardness value of the ore based on the initial hardness value and the cementation correction coefficient through a nonlinear correction model. The nonlinear correction model causes the overall hardness value to increase nonlinearly with the strengthening of the cementation state and decrease nonlinearly with the weakening of the cementation state. When the cementation state is almost completely lost, the overall hardness value approaches the basic hardness value provided by the ore matrix.

[0016] Beneficial effects: The method provided by this invention features a high degree of sample standardization, strictly limiting the measurement errors of grinding and polishing particle size, surface roughness, parallelism, and indentation, ensuring the repeatability and cross-laboratory comparability of test results. It is widely applicable to the hardness evaluation of metallic ores, non-metallic ores, sedimentary rocks, metamorphic rocks, and some igneous rocks. Specific technical benefits are as follows: 1. High-precision correlation between mineral identification and hardness measurement: Through a unified sample preparation process, the samples for automated mineralogical analysis and microhardness testing are highly consistent in mineral distribution, ensuring accurate correspondence between mineral content and hardness data.

[0017] 2. Accurately reflects the hardness characteristics of multi-mineral aggregates: The weighted summation of relative volume content avoids the bias of simple arithmetic average or empirical estimation, and scientifically characterizes the contribution of different minerals to the overall hardness of the ore.

[0018] 3. Introducing a cementation coefficient for mechanical correction: By measuring the P-wave velocity ratio, a cementation correction coefficient is obtained. Combined with the cementation sensitivity index and matrix hardness constant, a nonlinear correction model is constructed, significantly improving the prediction accuracy of hardness for loosely cemented, densely cemented, and transitional ores. Compared to traditional empirical estimation or single-index prediction, this invention significantly improves detection accuracy through a dual mechanism of mineral weighting and cementation correction, particularly suitable for accurately distinguishing between weakly cemented sandstone and strongly cemented quartzite with significant differences in cementation degree. Furthermore, by adjusting the cementation sensitivity index (0.30~1.50) and matrix hardness constant (0.20~56.00), the same process can be adapted to various cementation types such as mudstone, sandstone, limestone, granite, and basalt, eliminating the need to establish separate empirical formulas for each rock type. The weathering correction rules for the cementation sensitivity index (slight weathering +0.10, moderate weathering +0.25, strong weathering +0.40) enable the method to respond to dynamic geological conditions such as weathering zones on open-pit mine slopes and stress relaxation zones in underground mining areas, thereby improving the reliability of hardness evaluation throughout the entire life cycle.

[0019] 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 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

[0020] 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. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1This is a schematic flowchart of the method for detecting ore hardness provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the ore hardness comprehensive measurement system provided in an embodiment of the present invention. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] To address the technical problem that traditional macroscopic hardness testing cannot reflect the true mechanical properties of multi-mineral aggregates, this invention provides a method for detecting ore hardness. It constructs a detection process that integrates mineralogical quantitative analysis, single-mineral hardness determination, volume-weighted initial hardness, and nonlinear correction of cementation state, elevating ore hardness from empirical estimation to a traceable and quantifiable physical model prediction. Furthermore, it proposes a cementation correction coefficient C and a nonlinear correction model H, transforming the P-wave velocity ratio of the ore into a quantitative index of cementation state. A power-law relationship is used to characterize the nonlinear attenuation effect of cementation weakening on hardness, achieving full coverage from strongly cemented to uncemented rock types. A dual-parameter lookup table system is established for the cementation sensitivity index k and the matrix hardness constant Hs, incorporating complex geological factors such as cementation type, cement hardness / solubility, and weathering degree into a unified correction framework. This allows the same physical model to adapt to all rock types, from argillaceous cementation to crystalline cementation. This invention effectively overcomes the limitation of traditional macroscopic hardness testing, which cannot distinguish between the contribution of mineral components and the influence of cementation structure. It integrates macroscopic acoustic parameters and microscopic mechanical parameters across scales, filling the theoretical gap in the accurate prediction of hardness of multi-mineral ores.

[0028] Please see Figure 1 As shown, this embodiment of the invention provides a method for comprehensively determining the hardness of ores, comprising the following steps: S0, Sample Preparation Take a representative ore sample of 1.0~2.0 kg, grind it, and control the grinding fineness to 200 mesh with a content of 65~75%; denoted as sample A; Sample A was reduced to 3-5 g and used to prepare an automated mineralogical analysis sample, resulting in sample B. The steps for preparing samples for automated mineralogy analysis are: mixing the sample and the adhesive (sample to adhesive volume ratio 1:(1~2), the adhesive being epoxy resin and corresponding curing agent), curing, polishing, and carbon spraying (10~15 nm). The polishing process involves polishing with 100-200 grit, 600-800 grit, and 1200-1500 grit sandpaper, respectively, until no obvious scratches are visible. Then, polishing is performed for at least 10 minutes each on a cloth containing 3-micron and 1-micron abrasive particles.

[0029] S1, Determination of mineral types and content Automated mineralogical quantitative analysis was performed on sample B in step S0 to accurately determine the volume percentage ci of the main minerals (i is 1, 2, 3, 4, 5... which are the main mineral numbers respectively). Then the relative volume content (volume percentage) of the main minerals is Di = ci / ∑ci; The main mineral volume content is greater than or equal to 1.00% and ∑ci≥90.00%. The ore is composed of multiple minerals. When selecting a single mineral, only those with a content greater than 1% are considered; those with a content less than 1% are not counted. The total content of all minerals is controlled to be above 90%.

[0030] S2, Pressure method for measuring mineral hardness S21, take sample A from step S0 and sieve it, n is 1 or 2, representing sieve hole size greater than or equal to 0.037~0.074 mm and sieve hole size less than or equal to 0.010 mm, to obtain sample Dn (a combination of coarse and fine particles, simulating the original sample, with fine particles and resin glue binding coarse particles).

[0031] S22, take sample D1 and sample D2 in a mass ratio of 1:(0.6~0.3) to prepare an automated mineralogical analysis sample, following the same steps as step S0 above; Sample surface treatment: It needs to be carefully prepared according to the requirements of metallographic grinding. The surface roughness usually needs to reach ▽9 or above (Ra≤ 0.2μm). The test surface and the bottom need to be parallel, and the angle difference between the upper and lower surfaces should be <1° to avoid the indentation from deforming (causing "tailing" phenomenon), which will lead to data measurement error.

[0032] S23, for coarse-grained (0.037~0.074 mm) minerals, use a microhardness tester to hold the indentation at a loading force of 50 gf~500 gf for 10 s~15 s, measure the diagonal length of the indentation, and calculate the Vickers hardness Hi; Where, Hi = 1.854×F / d 2 F is the load (kgf), and d is the average length of the indentation diagonal (mm). At least 10 valid indentations are measured for each mineral, and the average value is taken.

[0033] To ensure measurement accuracy, the parallelism deviation between the test surface and the bottom of the sample is specified to be less than 1°, and the difference in length between the two diagonals of the indentation shall not exceed 5% of their average value.

[0034] The ore is composed of a variety of minerals. By measuring the hardness of each mineral and combining it with the degree of subsequent cementation, the overall hardness of the ore can be inferred.

[0035] S3, Calculation of initial hardness of the ore to be tested The initial hardness H0 is calculated by weighted summation of the relative volume content, H0 = ∑(Di × Hi).

[0036] S4, Degree of Bonding Measurement Obtain the cementation correction factor C, and measure the longitudinal wave velocity Vp of the ore and the matrix wave velocity Vm. Then C = (Vp / Vm) 2 .

[0037] S5, Comprehensive Hardness Correction Calculation Based on the initial hardness value and the cementation correction coefficient, the comprehensive hardness value H of the ore to be tested is calculated according to the nonlinear correction model, H = H0 × C. k +Hs; Among them, C→1 (strong cementation): represents that the hardness of the ore is close to or even exceeds the weighted hardness of the mineral; C→0 (no cementation): represents that the hardness of the ore comes only from the friction between particles or the matrix.

[0038] K is the cementation sensitivity index (0.30-1.50, with a smaller value for poor cementation), reflecting the sensitivity of changes in cementation degree to ore hardness: the larger the K value, the faster the overall hardness decreases as the cementation coefficient decreases; the smaller the value, the less sensitive K hardness is to the cementation correction coefficient, as detailed in Table 1. The harder the cement, the smaller the K value; the higher the solubility of the cement, the larger the K value. The degree of weathering affects the K value; therefore, the original K value increases by 0.10, 0.25, and 0.40 under slight, moderate, and strong weathering conditions, respectively.

[0039] Hs is the matrix hardness constant (the basic hardness value provided by the ore matrix). Specifically, it refers to the basic compressive / scratch resistance provided by the ore itself when it is completely uncemented (i.e., cementation coefficient C = 0) and only bound by interparticle friction or extremely soft matrix (such as argillaceous or clayey material). See Table 2 for details. If C < 0.1 (extremely weak cementation), Hs should be biased towards the lower limit; if C ≥ 0.1 (moderate cementation), Hs contributes little to the final hardness and can be appropriately ignored or the average value can be taken.

[0040] Table 1 Recommended Cementation Sensitivity Index k Table 2 Recommended matrix hardness constant Hs Example 1 Embodiment 1 of the present invention provides a comprehensive method for determining the hardness of an ore, specifically applied to the hardness determination of a fresh granite ore, comprising the following steps: S0, Sample Preparation Take a representative ore sample of 2.0 kg and grind it to a fineness of 200 mesh with a content of 65%; this sample is designated as sample A. Sample A was reduced to 3-5 g and used to prepare an automated mineralogical analysis sample, resulting in sample B. The sample preparation steps for automated mineralogy analysis are as follows: mixing the sample and the adhesive (sample to adhesive volume ratio 1:1, the adhesive being epoxy resin and corresponding curing agent), curing, polishing, and carbon spraying at 10 nm. The polishing process involves grinding on 100-grit, 600-grit, and 1200-grit sandpaper, respectively, until no obvious scratches are visible. Then, polishing is performed for at least 10 minutes each on a cloth containing 3-micron and 1-micron abrasive particles.

[0041] S1, Determination of mineral types and content Automated mineralogical quantitative analysis was performed on sample B in step S0 to accurately determine the volume percentage ci of the main minerals (i is 1, 2, 3, 4, 5... which are the main mineral numbers respectively), as detailed in Table 3.

[0042] Table 3 Results of Automated Mineralogical Analysis S2, Pressure method for measuring mineral hardness S21, take samples from step S0 and sieve them, n is 1 or 2, representing sieve aperture size greater than or equal to 0.074 mm and sieve aperture size less than or equal to 0.010 mm, to obtain sample Dn; S22, take sample D1 and sample D2 at a mass ratio of 1:0.5 to prepare an automated mineralogical analysis sample, following the same steps as step S0 above; S23, for hardness analysis of coarse-grained minerals, see Table 4 for details.

[0043] Equipment model: HVS-1000 digital display micro Vickers hardness tester; Loading force (F) selection: Based on the estimated hardness range of each mineral, select the following loads respectively: Quartz, potassium feldspar, plagioclase, amphibole, pyrite: 200 gf; Biotite (relatively soft): 50 gf; Chalcopyrite (medium hardness): 100 gf; Holding time: All minerals are held for a uniform 12 seconds; Indentation measurement: 10 valid indentations were selected for each mineral.

[0044] Table 4 Summary of Test Results Table 5. Results of Quartz Vickers Hardness Measurement (Examples) S3, Calculation of initial hardness of ore The initial hardness H0 is calculated by weighted summation of relative volume content. H0 = ∑ (Di × Hi) =33.03%×1558.65+40.62%×632.14+……+1.28%×2213.94+1.12%×689.04 =945.18 kgf / mm².

[0045] S4, Degree of Bonding Measurement To obtain the cementation correction factor C, the measured longitudinal wave velocity of the ore is Vp = 5800 m / s, and the reference mineral matrix wave velocity (quartz, feldspar compact body) is Vm = 6000 m / s. Therefore, C = (5800 / 6000).2 =0.935.

[0046] S5, Hardness Correction Calculation Calculate the overall hardness H of the ore: H = H0 × C k +Hs =945.18×(0.935) 0.8 +3.0 =898.78 kgf / mm².

[0047] Among them, C = 0.935, close to the theoretical maximum value of 1.0, reflecting the characteristics of highly dense granite with tightly interwoven crystals. The granite contains very little residual matrix (biotite, a small amount of alteration minerals), and the crystals are in rigid contact. Based on the table above: Hs = 3.0, k = 0.8 (no soft matrix contribution, crystalline cementation state).

[0048] Validation: The standard Bond ball milling work index test was performed on the sample, and the measured Wi = 18.60 kWh / t (typical range for high-hardness granite). Other types of samples (silicified rock) were also tested; the hardness determined by this method was 902.41 kgf / mm², and the standard Bond ball milling work index test was performed on them, with a measured Wi = 18.72 kWh / t. This validates the accuracy of the numerical values ​​determined by this method.

[0049] Comparative verification: The Vickers hardness tester was used to test the standard hardness block (a sandstone ore of a certain standard size). The average reading of multiple points was 900.45 kgf / mm², and the measured Wi = 6.37 kWh / t (the Vickers hardness is high, but the actual wear resistance hardness is low. The Vickers hardness data is much higher than the Bond ball milling work index), which proves the accuracy of this method.

[0050] Example 2 Embodiment 2 of the present invention provides a comprehensive method for determining the hardness of ores, specifically applied to the hardness determination of quartz vein-type gold ore, comprising the following steps: S0, Sample preparation, for details please refer to Example 1; S1, Determination of mineral types and content Automated mineralogical quantitative analysis was performed on sample B in step S0 to accurately determine the volume percentage ci of the main minerals (i is 1, 2, 3, 4, 5... which are the main mineral numbers respectively), as detailed in Table 6.

[0051] Table 6 Results of Automated Mineralogical Analysis S2, Pressure method for measuring mineral hardness S21, S22, for specific operation, please refer to Example 1; S23, for hardness analysis of coarse-grained minerals, the test conditions are the same as above, see Table 7 for details.

[0052] Table 7 Summary of Test Results S3, Calculation of initial hardness of ore The initial hardness H0 is calculated by weighted summation of relative volume content. H0 = ∑ (Di × Hi) =64.50%×1576.32+16.51%×643.27+……+2.59%×152.33+1.31%×2162.68 =1227.82 kgf / mm².

[0053] S4, Degree of Bonding Measurement Obtain the cementation correction factor C. The measured longitudinal wave velocity of the ore is Vp = 5250 m / s, and the reference mineral matrix wave velocity (a dense siliceous framework mainly composed of quartz and containing feldspar) is Vm = 5950 m / s. Therefore: C = (Vp / Vm)² = (5250 / 5950)² = 0.779.

[0054] S5, Hardness Correction Calculation Calculate the overall hardness H of the ore: H = H0 × C k +Hs =1227.82 × (0.779) 1.2 +6.0 =915.81 kgf / mm².

[0055] Since the combined soft matrix of sericite and calcite accounts for nearly 10%, and the layered sericite is sensitive to the cementation state, the correction index is appropriately increased to K=1.2; Hs = 6.0 (soft matrix, with calcite having perfect cleavage and sericite having layered cleavage, contributing more significantly to the overall hardness degradation).

[0056] Verification: Three samples were prepared independently for the same ore sample using the same steps, and their overall hardness was measured. The measured hardness values ​​were 905.33 kgf / mm², 912.65 kgf / mm², and 910.20 kgf / mm², respectively, with a relative standard deviation of 0.41%, which is far better than the industry standard of less than 1%. This indicates that the method has extremely high stability under repeated testing conditions and the data measurement is accurate.

[0057] Example 3 Please see Figure 2As shown, Embodiment 3 of the present invention provides a comprehensive ore hardness testing system for performing the methods described in the above embodiments, including: The mineralogy quantitative analysis unit includes an automated mineralogy analysis system, which is used to perform component analysis on the ore to be tested and obtain the types of major minerals in the ore and their relative volume content in the ore. The hardness testing unit includes a microhardness tester, used to test the single-mineral hardness values ​​of each major mineral. The hardness calculation unit is connected to the mineralogy quantitative analysis unit and the hardness detection unit, respectively, and is used to calculate the initial hardness value of the ore based on the volume relative content and the single mineral hardness value. The cementation state determination unit includes an acoustic / ultrasonic testing instrument for determining the cementation state of the ore to be tested and determining a cementation correction coefficient based on the acoustic parameters of the ore to be tested. The comprehensive hardness calculation unit is connected to the hardness calculation unit and the cementation state determination unit, respectively, and is used to calculate the comprehensive hardness value of the ore based on the initial hardness value and the cementation correction coefficient through a nonlinear correction model. The nonlinear correction model causes the overall hardness value to increase nonlinearly with the strengthening of the cementation state and decrease nonlinearly with the weakening of the cementation state. When the cementation state is almost completely lost, the overall hardness value approaches the basic hardness value provided by the ore matrix.

[0058] In summary, this invention discloses a method for detecting ore hardness, belonging to the field of mining and testing analysis technology. This method obtains the volume percentage information of major minerals through automated mineralogical quantitative analysis, acquires the Vickers hardness values ​​of each mineral through microhardness testing, and calculates the initial mineralogical hardness by weighted summation based on relative volume content. It also measures the longitudinal wave velocity and matrix wave velocity of the ore, calculates the cementation correction coefficient C, and combines it with the cementation sensitivity index k and the matrix hardness constant Hs to calculate the comprehensive hardness value through a nonlinear correction model H. This invention achieves a precise correlation between mineral composition, cementation state, and ore hardness, enabling accurate prediction of the hardness of multi-mineral aggregates. It effectively solves the problem that traditional macroscopic hardness testing cannot reflect the true mechanical properties of multi-mineral aggregates, significantly improving the detection accuracy of ore hardness for different degrees of cementation and weathering. It is applicable to the hardness evaluation of various sedimentary rocks, metamorphic rocks, and igneous rocks.

[0059] 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 testing the hardness of an ore, characterized in that, Includes the following steps: S1, based on quantitative mineralogical analysis, obtain the types of major minerals in the ore to be tested and their relative volume content in the ore; S2, obtain the single mineral hardness value of each major mineral in the ore to be tested; S3. Calculate the initial hardness value of the ore to be tested based on the relative volume content and the single mineral hardness value. S4, Based on the cementation state of the ore to be tested, obtain the cementation correction coefficient of the ore to be tested; S5. Based on the initial hardness value and the cementation correction coefficient, calculate the comprehensive hardness value of the ore to be tested according to the nonlinear correction model. The nonlinear correction model causes the overall hardness value to increase nonlinearly with the strengthening of the cementation state and decrease nonlinearly with the weakening of the cementation state. When the cementation state is almost completely lost, the overall hardness value approaches the basic hardness value provided by the ore matrix.

2. The method for detecting the hardness of an ore according to claim 1, characterized in that, Step S4 specifically includes: Determine the longitudinal wave velocity Vp and matrix wave velocity Vm of the ore to be tested; Calculate the cementation correction factor C = (Vp / Vm)², where the cementation correction factor C characterizes the degree of deviation of the actual cementation state of the ore from the fully cemented state, and the value of C ranges from 0 to 1.

3. The method for detecting the hardness of an ore according to claim 2, characterized in that, In step S5, the nonlinear correction model is constructed based on the cementation correction coefficient C and combined with the cementation sensitivity index k and the matrix hardness constant Hs. The nonlinear correction model is: H = H0×C k + Hs; where H is the overall hardness value and H0 is the initial hardness value; When C approaches 1, the comprehensive hardness value H approaches H0+Hs, indicating that the hardness of the ore under strong cementation is mainly contributed by the mineral weighted hardness. When C approaches 0, the comprehensive hardness value H approaches Hs, indicating that the hardness of the ore in the uncemented state is provided by the basic hardness value only by interparticle friction or matrix.

4. The method for detecting the hardness of an ore according to claim 3, characterized in that, The cementation sensitivity index k is determined according to the type of cement and characterizes the sensitivity of changes in cementation degree to ore hardness. The value ranges from 0.30 to 1.

50. The larger the value of k, the faster the ore hardness decreases as the cementation correction coefficient decreases. The smaller the k value, the less sensitive the ore hardness is to the cementation correction coefficient; The higher the hardness of the cementitious material, the smaller the value of k; the higher the solubility of the cementitious material, the larger the value of k.

5. The method for detecting the hardness of an ore according to claim 3, characterized in that, The matrix hardness constant Hs is determined according to the matrix type and characterizes the basic compressive / scratch resistance that the ore body can provide when the ore is completely uncemented and relies solely on interparticle friction or extremely soft matrix bonding, i.e., the basic hardness value. When the cementation correction factor C < 0.1, Hs takes the lower limit of the recommended range for the corresponding matrix type; when the cementation correction factor C ≥ 0.1, Hs takes the average value of the recommended range for the corresponding matrix type or is appropriately ignored. The recommended range for Hs corresponding to the matrix type is as follows: When the matrix type is silty or clayey, Hs is 3.00 to 10.00; When the matrix type is calcareous mud or calcareous, Hs is 10.00 to 27.50; When the matrix type is ferrous or weathered, Hs is 27.50 to 56.

00. When the matrix type is uncemented, loose sand layer or crystalline state, Hs is 0.20 to 6.00; When the matrix type is siliceous / calcareous with very low residual, Hs is 0.50 to 4.

00.

6. The method for detecting the hardness of an ore according to claim 4, characterized in that, The cementation sensitivity index k is further adjusted according to the degree of weathering of the ore: the k value of slightly weathered ore is increased by 0.10 from the original base; the k value of moderately weathered ore is increased by 0.25 from the original base; and the k value of strongly weathered ore is increased by 0.40 from the original base.

7. The method for detecting the hardness of an ore according to claim 1, characterized in that, Step S3 specifically includes: Calculate the volume relative content of each major mineral Di = ci / Σci, where ci is the volume percentage content of the i-th major mineral; Σci is the sum of the volume percentage contents of all i-th major minerals; The initial hardness value H0 is calculated by weighted summation of relative volume content = Σ(Di×Hi), where Hi is the single mineral hardness value of the i-th major mineral.

8. The method for detecting the hardness of an ore according to claim 1, characterized in that, In step S2, the process of obtaining the single mineral hardness value is as follows: prepare an automated mineralogical analysis sample, and use a microhardness tester to perform indentation tests on each major mineral to obtain Vickers hardness values; wherein, the loading force of the indentation test is 50 gf to 500 gf, the holding time is 10 s to 15 s, at least 10 valid indentation data are obtained for each mineral, and the average value is taken as the single mineral hardness value; in the indentation test, it is specified that the parallelism deviation between the test surface and the bottom of the test sample is less than 1°, and the difference between the lengths of the two diagonals of the indentation does not exceed 5% of its average value.

9. The method for detecting the hardness of an ore according to claim 1, characterized in that, Before step S1, a sample preparation step is also included: The ore sample to be tested is crushed to a set particle size; the crushed sample is reduced and sampled, and then embedded in a fixed medium, cured, surface treated and conductive treated to prepare a sample for component analysis. The surface treatment includes: gradient grinding using abrasive media with progressively decreasing particle size, followed by sequential polishing on a flexible carrier containing abrasive particles of different sizes.

10. A system for detecting the hardness of an ore, characterized in that, A method for detecting the hardness of an ore according to any one of claims 1 to 9, comprising: The mineralogy quantitative analysis unit includes an automated mineralogy analysis system, which is used to perform component analysis on the ore to be tested and obtain the types of major minerals in the ore and their relative volume content in the ore. The hardness testing unit includes a microhardness tester, used to test the single-mineral hardness values ​​of each major mineral. The hardness calculation unit is connected to the mineralogy quantitative analysis unit and the hardness detection unit, respectively, and is used to calculate the initial hardness value of the ore based on the volume relative content and the single mineral hardness value. The cementation state determination unit includes an acoustic / ultrasonic testing instrument for determining the cementation state of the ore to be tested and determining a cementation correction coefficient based on the acoustic parameters of the ore to be tested. The comprehensive hardness calculation unit is connected to the hardness calculation unit and the cementation state determination unit, respectively, and is used to calculate the comprehensive hardness value of the ore based on the initial hardness value and the cementation correction coefficient through a nonlinear correction model. The nonlinear correction model causes the overall hardness value to increase nonlinearly with the strengthening of the cementation state and decrease nonlinearly with the weakening of the cementation state. When the cementation state is almost completely lost, the overall hardness value approaches the basic hardness value provided by the ore matrix.

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