Method for measuring three-dimensional morphology of gold minerals

Abstract

The present application provides a method for measuring the three-dimensional morphology of gold minerals, and belongs to the technical field of process mineralogy. The present application obtains a test sample by grinding, re-selection, magnetic separation, flotation and nitric acid treatment, and then prepares an automatic mineralogical analysis sample by rolling, mixing, shaking, solidifying, grinding and polishing, and carbon spraying in sequence. Then, the three-dimensional morphological characteristics of the gold mineral can be judged by combining automatic mineralogical analysis and specific calculation rules, and the corresponding three-dimensional morphological distribution rate can be calculated. The present invention adopts a special ore sample processing step to enrich enough gold minerals; through a specific automatic mineralogical analysis sample preparation step, the probability of visible gold can be greatly increased; the three-dimensional morphology of the gold mineral can be obtained by automatic mineralogical analysis and specific calculation rules, which saves manpower, has high test efficiency, avoids the influence of human subjective factors, and the data is more objective.

Description

Technical Field

[0001] The invention relates to the technical field of process mineralogy, and in particular to a method for measuring the three-dimensional morphology of gold minerals. Background Art

[0002] Gold ore resources are an important mineral resource, because gold is not only an important financial product, but also has a wide range of applications in the industrial field. The gold resources on the earth are limited. With the continuous mining and utilization of gold resources, the relevant technical requirements are also increasing, and higher requirements are put forward for mining, selection and smelting. The process mineralogy research of gold minerals is an important part of the above-mentioned technical field, and also includes the study of the morphological characteristics of gold minerals. The morphology of gold minerals is an important parameter because it has an important influence on the gold beneficiation process. For example, within the appropriate particle size range, gold minerals in the form of flakes, plates, blades, etc. in the monomer state are easy to use flotation technology, while gold minerals in the form of granules, angular particles, round particles, etc. are suitable for gravity selection. Therefore, the study of the three-dimensional morphology of gold minerals is a very necessary content in the field of gold mineral process mineralogy research.

[0003] Traditionally, the research methods of the three-dimensional morphology of gold minerals mainly adopt manual detection methods, such as detection under a stereo microscope or a polarizing microscope. This work is time-consuming and labor-intensive, and the workload is huge. In the process of measuring parameters, the complex morphology of gold, the fine particle size, and the different types of gold minerals that need to be identified for different types of ores increase the difficulty of operation. In addition, the actual measurement process is greatly influenced by human subjectivity. These factors affect the accuracy of gold morphology parameter measurement.

[0004] With the development of technology, the process mineral research of gold mineral three-dimensional morphological analysis is developing towards automation, visualization and mechanization. For the study of gold mineral three-dimensional morphology, except for the necessary traditional method of manual microscopic measurement, most of them are transferred to the measurement of mineral automatic analysis system. In the prior art, the patent with publication number CN113823363A discloses an evaluation method of process mineralogy factors affecting gold cyanide leaching in ore. The patent uses BPMA V2.0 process mineralogy automatic quantitative analysis system; the full particle measurement mode is used to measure all ore particles; the selected particle measurement mode is used to measure the specified grayscale range and the target minerals containing the specified elements; the matching method based on the energy spectrum peak shape is used to complete the automatic identification of the main minerals, and the main mineral composition and process mineralogy parameters in the ore are obtained; the matching method based on the position of the specified element line system is used to identify the gold-containing particles in the ore, and analyze and count the data such as the particle size, type and gold embedding characteristics of the gold mineral. The patent with the publication number CN114997540B discloses a method for predicting the recovery rate of associated precious metals in an ore and its application. The patent uses a mineral automatic analyzer to detect and count the ore to be predicted containing precious metal minerals, and obtains the microscopic morphology of each precious metal mineral, the precious metal content in each precious metal mineral, and the area of ​​each precious metal mineral; the precious metal minerals in the ore to be predicted are divided according to the distribution characteristics and the relationship of intergrowth, and the precious metal content in each type of the precious metal mineral is calculated; the sum of the mass percentage of the precious metal content in each type of precious metal mineral related to chalcopyrite to the total precious metal content in the ore to be predicted is obtained, which is the predicted value of the recovery rate of the precious metal associated with the ore to be predicted into the copper concentrate. However, it is currently limited to simply describing the particle size characteristics, types, distribution and plane morphology of gold minerals, and the research field of the measurement method of the three-dimensional morphology of gold minerals is currently blank.

[0005] Therefore, it is urgent to develop an automated measurement method for the three-dimensional morphology of gold minerals to improve the comprehensive utilization rate of my country's gold resources. Summary of the invention

[0006] In view of the technical problems existing in the background technology, the present application provides a method for measuring the three-dimensional morphology of gold minerals, aiming to fill the gap in the existing automated measurement methods for the three-dimensional morphology of gold minerals.

[0007] The present application embodiment provides a method for measuring the three-dimensional morphology of gold minerals, comprising the following steps:

[0008] S1. Grinding the sample to be tested to obtain a raw ore sample;

[0009] S2. Re-selecting the raw ore sample to obtain a re-selected concentrate and a re-selected tailings;

[0010] S3. The gravity separation concentrate is subjected to nitric acid and magnetic separation to obtain a sample 1;

[0011] S4. Open circuit flotation is performed on the gravity separation tailings to obtain a flotation rough concentrate, which is recorded as sample 2;

[0012] S5. treating the sample 2 with nitric acid to obtain a sample 3;

[0013] S6. Mixing the sample three with the sample one to obtain sample four;

[0014] S7. The sample four is rolled, mixed, shaken, cured, polished, and carbon-sprayed to obtain sample five;

[0015] S8. Performing automatic mineralogical analysis on the sample 5, measuring the cross-sectional area Si, the cross-sectional perimeter Li, the first intercept ai, the second intercept bi of each gold mineral particle in the sample 5, and calculating the distance ci perpendicular to the cross section;

[0016] Wherein, ai is the distance between the two points with the longest intercept on the cross section of the i-th gold mineral particle in the sample 5; bi is the longest intercept of the line perpendicular to the two points with the longest intercept on the cross section on the i-th gold mineral particle in the sample 5; the calculation formula of ci is ci= ci'*di; di is the correction coefficient, di=(ai+bi) / Li; ci'=Si 0.5 ; i is the serial number of each gold mineral particle, i=1,2,......,m, m is the total number of gold mineral particles in the sample 5;

[0017] S9. Determine the three-dimensional morphology of each metal mineral particle according to the judgment conditions shown in the following table;

[0018]

[0019] Among them, ni1=ai / bi, ni2=bi / ci;

[0020] S10. Statistically calculate the distribution rate of each three-dimensional form in the gold mineral, and the calculation formula is as follows:

[0021] Kh=Sh / Stotal;

[0022] Among them, Stotal is the total area of ​​the gold mineral, Stotal=∑Si; Sh is the sum of the cross-sectional areas of the gold mineral particles in the hth three-dimensional form; Kh is the distribution rate of the hth three-dimensional form; the value range of h includes 1~13; 1 represents coarse grains; 2 represents round grains; 3 represents granules; 4 represents bean-shaped; 5 represents flakes; 6 represents rods; 7 represents wheat grains; 8 represents long-horned grains; 9 represents leaves; 10 represents plates; 11 represents needles and threads; 12 represents microparticles; 13 represents other forms.

[0023] In the technical scheme of the embodiment of the present application, the test sample is obtained by grinding, re-selection, magnetic separation, flotation and nitric acid treatment, and then the sample is rolled, mixed with glue, shaken, solidified, polished and carbon sprayed in sequence to prepare the automatic mineralogical analysis sample, and then combined with the automatic mineralogical analysis and specific calculation rules, a method for measuring the three-dimensional morphology of gold minerals is obtained, which can judge the three-dimensional morphological characteristics of gold minerals and calculate the corresponding three-dimensional morphological distribution rate. The special ore sample processing steps can enrich enough gold minerals; in the preparation of automatic mineralogical analysis samples, the gold minerals are first mixed with glue and then shaken to precipitate to the bottom layer, which can greatly improve the gold rate, and at the same time, make the gold minerals "lying flat", even if the length of the a and b axes of the parallel horizontal planes is not less than the c axis of the vertical horizontal plane; compared with the traditional manual detection method, the gold morphology measurement method saves manpower, has high test efficiency and avoids the influence of human subjective factors, and the data is more objective.

[0024] In some embodiments, in step S1, the mass of the sample to be tested is 3-10 kg; the grinding fineness is -0.074 mm and the content is 65%-90%.

[0025] In this embodiment, the raw ore sample with a specific fineness is obtained by grinding, which is used for subsequent ore dressing.

[0026] In some embodiments, in step S2, during the re-selection, the re-selection yield is not less than 0.01%.

[0027] In this embodiment, gold minerals and heavy magnetite are separated by gravity separation, and the yield of the obtained gold minerals is not less than 0.01%, thereby ensuring the subsequent detection quantity of gold minerals.

[0028] In some embodiments, in step S3, the nitric acid treatment comprises the following steps:

[0029] Add nitric acid with a concentration of 65-68% to the gravity separation concentrate until the reaction is complete, then place in a water bath for 2 hours, filter and dry.

[0030] In this embodiment, concentrated nitric acid is added to the re-selected concentrate to dissolve the sulfides surrounding the gold minerals, leaving the gold minerals.

[0031] In some embodiments, in step S3, during the magnetic separation process, the magnetic field strength is not less than 1.5T.

[0032] In this embodiment, magnetite in the gravity separation concentrate is separated by strong magnetic separation, leaving gold minerals.

[0033] In some embodiments, in step S4, the open circuit flotation is a roughing process, and the roughing reagents include: 80-120 g / t of butyl xanthate, 45-55 g / t of butyl ammonium black medicine, 18-22 g / t of 2# oil, and 180-220 g / t of copper sulfate.

[0034] In this embodiment, the gold minerals are further separated and enriched through roughing.

[0035] In some embodiments, in step S5, the nitric acid treatment comprises the following steps:

[0036] Add nitric acid with a concentration of 65-68% to the sample 2 until the reaction is complete, place in a water bath for 2 hours, filter and dry.

[0037] In this embodiment, concentrated nitric acid is added to sample 2 to dissolve the sulfides surrounding the gold minerals, leaving the gold minerals.

[0038] In some embodiments, in step S7, the mixing is adding epoxy resin and curing agent to sample four.

[0039] In this embodiment, sample 4 is mixed with glue and then shaped after subsequent curing, which facilitates sample preparation.

[0040] In some embodiments, in step S7, the oscillation is ultrasonic oscillation, and the oscillation time is 25 to 35 minutes.

[0041] In this embodiment, the mixture is shaken after mixing to make the gold mineral settle to the bottom layer, and at the same time, the gold mineral is made to "lie flat", that is, the lengths of the a and b axes parallel to the horizontal plane are not less than the c axis perpendicular to the horizontal plane.

[0042] In some embodiments, in step S7, in the grinding and polishing process, during grinding, the abrasive size is less than 1000 mesh; during polishing, the abrasive particle size is less than 1 μm, and the grinding and polishing time is 5 to 10 minutes respectively.

[0043] In this embodiment, the cured sample is ground and polished to make the test surface smooth, which is convenient for subsequent testing.

[0044] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 This is a schematic diagram of the measurement method for measuring the three-dimensional morphology of gold minerals in this application;

[0047] Figure 2 The SEM images of various gold mineral forms in the method for measuring the three-dimensional form of gold minerals in the present application, wherein (a) is a coarse-grained gold mineral form, (b) is a tree-branched gold mineral form, (c) is a round-grained gold mineral form, and (d) is a microparticle-shaped gold mineral form;

[0048] Figure 3 This is an automatic mineralogical analysis diagram of gold minerals in the method for measuring the three-dimensional morphology of gold minerals in this application;

[0049] Figure 4 The measurement data of the automatic mineralogical analysis of gold minerals in the method for measuring the three-dimensional morphology of gold minerals in this application;

[0050] Figure 5 This is a stereomicroscope image of the gold mineral measured in Example 1 of the present application. DETAILED DESCRIPTION

[0051] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In order to fill the gap in the existing automated measurement methods for the three-dimensional morphology of gold mines, the present application provides a method for measuring the three-dimensional morphology of gold minerals. The present application obtains a test sample by grinding, re-selection, magnetic separation, flotation and nitric acid treatment, and then combines automatic mineralogical analysis and specific calculation rules to obtain a method for measuring the three-dimensional morphology of gold minerals. The present invention adopts special ore sample processing steps to enrich sufficient gold minerals; automatic mineralogical analysis and specific calculation rules are used to obtain the three-dimensional morphology of gold minerals, which saves manpower, has high test efficiency and avoids the influence of human subjective factors, and the data is more objective; in addition, the morphology corresponds to the process and fits the actual production.

[0055] The present application embodiment provides a method for measuring the three-dimensional morphology of gold minerals, comprising the following steps:

[0056] S1. Grinding the sample to be tested to obtain a raw ore sample;

[0057] S2. Re-selecting the raw ore sample to obtain a re-selected concentrate and a re-selected tailings;

[0058] S3. The gravity separation concentrate is subjected to nitric acid and magnetic separation to obtain a sample 1;

[0059] S4. Open circuit flotation is performed on the gravity separation tailings to obtain a flotation rough concentrate, which is recorded as sample 2;

[0060] S5. treating the sample 2 with nitric acid to obtain a sample 3;

[0061] S6. Mixing the sample three with the sample one to obtain sample four;

[0062] S7. The sample four is rolled, mixed, shaken, cured, polished, and carbon-sprayed to obtain sample five;

[0063] S8. Performing automatic mineralogical analysis on the sample 5, measuring the cross-sectional area Si, the cross-sectional perimeter Li, the first intercept ai, the second intercept bi of each gold mineral particle in the sample 5, and calculating the distance ci perpendicular to the cross section;

[0064] Wherein, ai is the distance between the two points with the longest intercept on the cross section of the i-th gold mineral particle in the sample 5; bi is the longest intercept of the line perpendicular to the two points with the longest intercept on the cross section on the i-th gold mineral particle in the sample 5; the calculation formula of ci is ci= ci'*di; di is the correction coefficient, di=(ai+bi) / Li; ci'=Si 0.5 ; i is the serial number of each gold mineral particle, i=1,2,......,m, m is the total number of gold mineral particles in the sample 5;

[0065] S9. Determine the three-dimensional morphology of each metal mineral particle according to the judgment conditions shown in the following table;

[0066]

[0067] Among them, ni1=ai / bi, ni2=bi / ci;

[0068] S10. Statistically calculate the distribution rate of each three-dimensional form in the gold mineral, and the calculation formula is as follows:

[0069] Kh=Sh / Stotal;

[0070] Among them, Stotal is the total area of ​​the gold mineral, Stotal=∑Si; Sh is the sum of the cross-sectional areas of the gold mineral particles in the hth three-dimensional form; Kh is the distribution rate of the hth three-dimensional form; the value range of h includes 1~13; 1 represents coarse grains; 2 represents round grains; 3 represents granules; 4 represents bean-shaped; 5 represents flakes; 6 represents rods; 7 represents wheat grains; 8 represents long-horned grains; 9 represents leaves; 10 represents plates; 11 represents needles and threads; 12 represents microparticles; 13 represents other forms.

[0071] The proportion of each gold mineral morphological feature is measured according to the method shown in the following table;

[0072]

[0073] In the technical scheme of the embodiment of the present application, the test sample is obtained by grinding, re-selection, magnetic separation, flotation and nitric acid treatment, and then the sample is rolled, mixed with glue, shaken, solidified, polished and carbon sprayed in sequence to prepare the automatic mineralogical analysis sample, and then combined with the automatic mineralogical analysis and specific calculation rules, a method for measuring the three-dimensional morphology of gold minerals is obtained, which can judge the three-dimensional morphological characteristics of gold minerals and calculate the corresponding three-dimensional morphological distribution rate. The special ore sample processing steps can enrich enough gold minerals, and the recovery rate of gold minerals is 60-80%; in the preparation of automatic mineralogical analysis samples, the gold minerals are first mixed with glue and then shaken to precipitate to the bottom layer, which can greatly improve the gold rate, and at the same time, make the gold minerals "lying flat", even if the length of the a and b axes of the parallel horizontal planes is not less than the c axis of the vertical horizontal plane; compared with the traditional manual detection method, the gold morphology measurement method saves manpower, has high test efficiency and avoids the influence of human subjective factors, and the data is more objective.

[0074] Furthermore, in some embodiments, in step S1, the mass of the sample to be tested is 3-10 kg; the grinding fineness is -0.074 mm and the content is 65%-90%.

[0075] In the technical solution of the embodiment of the present application, an ore sample of a specific fineness is obtained by grinding for subsequent mineral processing. The amount of ore sample and the grinding fineness are determined according to the actual situation of the sample, that is, the number of subsequent gold mineral tests. If the number of tests is small, the amount of ore sample or the grinding fineness should be increased.

[0076] Furthermore, in some embodiments, in step S2, during the re-selection, the re-selection yield is not less than 0.01%.

[0077] In the technical solution of the embodiment of the present application, gold minerals and heavy magnetite are separated by gravity separation, and the yield of the obtained gold minerals is not less than 0.01%, thereby ensuring the subsequent detection quantity of gold minerals.

[0078] Further, in some embodiments, in step S3, the nitric acid treatment comprises the following steps:

[0079] Add nitric acid with a concentration of 65-68% to the gravity separation concentrate until the reaction is complete, then place in a water bath for 2 hours, filter and dry.

[0080] In the technical solution of the embodiment of the present application, concentrated nitric acid is added to the re-selected concentrate to dissolve the sulfides surrounding the gold minerals, leaving the gold minerals.

[0081] Furthermore, in some embodiments, in step S3, during the magnetic separation process, the magnetic field strength is not less than 1.5T.

[0082] In the technical solution of the embodiment of the present application, magnetite in the gravity separation concentrate is separated by strong magnetic separation, leaving the gold mineral.

[0083] Furthermore, in some embodiments, in step S4, the open circuit flotation is a roughing process, and the roughing reagents include: 80-120 g / t of butyl xanthate, 45-55 g / t of butyl ammonium black medicine, 18-22 g / t of 2# oil, and 180-220 g / t of copper sulfate.

[0084] In the technical solution of the embodiment of the present application, the gold minerals are further separated and enriched through roughing.

[0085] Further, in some embodiments, in step S5, the nitric acid treatment comprises the following steps:

[0086] Add nitric acid with a concentration of 65-68% to the sample 2 until the reaction is complete, place in a water bath for 2 hours, filter and dry.

[0087] In the technical solution of the embodiment of the present application, concentrated nitric acid is added to sample 2 to dissolve the sulfide surrounding the gold mineral, leaving the gold mineral.

[0088] Furthermore, in some embodiments, in step S7, the mixing is to add epoxy resin and curing agent to sample four.

[0089] In the technical solution of the embodiment of the present application, sample four is mixed with glue and then shaped after subsequent curing, which facilitates sample preparation.

[0090] Furthermore, in some embodiments, in step S7, the oscillation is ultrasonic oscillation, and the oscillation time is 25 to 35 minutes.

[0091] In the technical solution of the embodiment of the present application, the mixing is followed by shaking to allow the gold minerals to settle to the bottom layer, and at the same time, the gold minerals are made to "lie flat", that is, the lengths of the a and b axes parallel to the horizontal plane are not less than the c axis perpendicular to the horizontal plane.

[0092] Furthermore, in some embodiments, in step S7, in the grinding and polishing process, during grinding, the abrasive size is less than 1000 mesh; during polishing, the abrasive particle size is less than 1 μm, and the grinding and polishing time is 5 to 10 minutes respectively.

[0093] In the technical solution of the embodiment of the present application, the test surface is made smooth by grinding and polishing the solidified sample to facilitate subsequent testing, and the polishing time cannot be too long or the abrasive is too coarse to avoid grinding away the gold minerals.

[0094] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0095] Example 1

[0096] This embodiment provides a method for measuring the three-dimensional morphology of gold minerals, which specifically includes the following steps:

[0097] (1) Preparation of test samples: Weigh 5 kg of the sample to be tested, grind it to a fineness of -0.074 mm and a content of 70% to obtain a raw ore sample; re-select the raw ore sample in a Nielsen re-selection device to obtain a re-selection concentrate and a re-selection tailing; add nitric acid with a concentration of 68% to the re-selection concentrate until the reaction is complete (no yellow smoke), place it in a water bath for 2 hours, filter, dry, and then perform magnetic separation in a magnetic separation device with a magnetic field strength of 1.5 T to obtain sample 1; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 2; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 3; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 4; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 5; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 6; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 7; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 8; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 9; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 10; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 11; add nitric acid with a concentration of 68% to the re-selection concentrate to obtain sample 12. 100 g / t of butyl xanthate, 50 g / t of butyl ammonium black powder, 20 g / t of 2# oil and 200 g / t of copper sulfate were added to the tailings for rough selection to obtain a flotation rough concentrate; open circuit flotation of gold minerals was performed on the gravity separation tailings to obtain a flotation rough concentrate; 68% nitric acid was added to the flotation rough concentrate until the reaction was complete (no yellow smoke), and then the mixture was placed in a water bath for 2 hours, filtered and dried to obtain sample three; 3 g of sample three was sampled and mixed with sample one to obtain sample four.

[0098] (2) Preparation of automatic mineralogical analysis samples: Sample 4 was crushed and dispersed with a sample spoon, and then 8 ml of epoxy resin and 4 ml of curing agent were added, followed by ultrasonic vibration for 30 min, and the sample was cured in a casting mold, and then 1000 mesh abrasive was added for grinding for 5 min, and then abrasive with a particle size of 1 um was added for polishing for 5 min; finally, carbon spraying was performed to obtain automatic mineralogical analysis sample 5.

[0099] (3) Automatic mineralogical analysis: Sample 5 was subjected to automatic mineralogical analysis, and the relevant parameters of gold minerals were obtained as shown in Table 1. Figure 1 Taking the particles in as an example, we get a1=84.685μm, b1=44.575μm. Figure 4 As shown, automatic mineralogy measurement shows that S1=2220.784μm 2 , L1=398.778μm, c1'=S1 0.5 =2220.784 0.5 =47.1252, d1=(a1+b1) / L1=(84.685+44.575) / 398.778=0.3241, then c1= c1'*d1=47.1252*0.3241=15.275; n11=a1 / b1=84.685 / 44.575=1.90, n12=b1 / c1=44.575 / 15.275=2.92. Judging from the classification table of three-dimensional morphological characteristics of gold minerals, its shape is a grain-like shape with rounded boundaries and no obvious edges.

[0100] (4) Statistical calculation of the distribution rate of gold mineral forms: the calculation formula is Kh=Sh / Stotal; where Stotal is the total area of ​​the gold mineral, Stotal=∑Si; Sh is the sum of the cross-sectional areas of the gold mineral particles in the hth three-dimensional form; Kh is the distribution rate of the hth three-dimensional form; the value range of h includes 1~13; 1 represents coarse particles; 2 represents round particles; 3 represents particles; 4 represents beans; 5 represents flakes; 6 represents rods; 7 represents wheat grains; 8 represents long-horned particles; 9 represents leaves; 10 represents plates; 11 represents needles and threads; 12 represents microparticles; 13 represents other forms; the measurement results of the distribution rate of the three-dimensional form of gold minerals are detailed in Table 2. Example Figure 1 Medium particle description: the sum of the areas of wheat-shaped gold mineral particles S6 = S1 + S2 + S4 + S12 + S19 = 2220.784 + 2201.772 + 1785.141 + 767.580 + 544.234 = 7519.511 μm 2 , Stotal = ∑Si = S1 + S2 + ... + S20 = 2220.784 + 2201.772 + ... + 4283.3532 = 24680.273 μm 2 , then K6=S6 / Stotal=7519.511 / 24680.273=30.47%.

[0101] Table 1 Automatic mineralogy measurement results

[0102]

[0103] Table 2 Distribution rate results of three-dimensional morphology of gold minerals

[0104]

[0105] In this embodiment, the recovery rate of gold minerals obtained from the ore dressing test is 75%; the SEM image of the gold mineral morphology is as follows Figure 2 As shown, (a) is a coarse-grained gold mineral morphology, (b) is a tree-like gold mineral morphology (i.e., the morphology in which the a or b value cannot be determined), (c) is a round-grained gold mineral morphology, and (d) is a microparticle-like gold mineral morphology; the automatic mineralogical analysis diagram of the three-dimensional morphology of gold minerals is shown in Figure 3 shown.

[0106] The gold minerals in the examples of this application were counted by stereo microscope. The stereo microscope image of the gold mineral morphology in this example is as follows: Figure 5 The measurement results of gold mineral morphological characteristics are shown in Table 3.

[0107] Table 3 Stereomicroscope measurement results of gold mineral morphology

[0108]

[0109] It can be seen from the test results in Table 2 and Table 3 that the gold mineral morphological characteristic measurement results obtained by the gold mineral three-dimensional morphology measurement method in this application are close to the stereomicroscope measurement results, indicating that the gold mineral three-dimensional morphology measurement method of this patent is reliable.

[0110] Comparative Example 1

[0111] This comparative example provides a method for measuring the three-dimensional morphology of gold minerals. Compared with Example 1, the difference is that the preparation steps of the automatic mineralogical analysis samples are different, that is, ultrasonic vibration is first performed for 30 minutes, and then 8 ml of epoxy resin and 4 ml of curing agent are added, and the sample is cured in a casting mold. The other steps are roughly the same as Example 1 and will not be repeated here.

[0112] The automatic mineralogical analysis sample prepared in this comparative example was found through automatic mineralogical analysis to have a very low visibility of the gold mineral particles, making it impossible to measure. However, in Example 1, the mixture was first mixed and then shaken, which allowed the gold to sink to the bottom and greatly improved the visibility of the gold mineral particles.

[0113] Comparative Example 2

[0114] This comparative example provides a method for measuring the three-dimensional morphology of gold minerals. Compared with Example 1, the difference lies in that the preparation method of the test sample is different, that is, 5 kg of the sample to be tested is weighed, and the sample to be tested is ground to a grinding fineness of -0.074 mm and a content of 70% to obtain a raw ore sample; the raw ore sample is re-selected in a Nelson re-selection device to obtain a re-selection concentrate and a re-selection tailings; nitric acid with a concentration of 68% is added to the re-selection concentrate until the reaction is complete (no yellow smoke is emitted), and then the concentrate is placed in a water bath for 2 hours, filtered, dried, and then magnetically separated in a magnetic separation device with a magnetic field strength of 1.5 T to obtain sample one, and sample one is the test sample. The other steps are roughly the same as those in Example 1 and will not be repeated here.

[0115] In the test sample prepared in this comparative example, the recovery rate of gold minerals obtained from the ore dressing test was 5.30%, which was much lower than the recovery rate of gold minerals in Example 1.

[0116] In summary, the present application provides a method for measuring the three-dimensional morphology of gold minerals. In the technical scheme of the embodiment of the present application, a test sample is obtained by grinding, re-selection, magnetic separation, flotation and nitric acid treatment, and then rolling, mixing, shaking, solidifying, grinding and polishing, and carbon spraying are performed in sequence to prepare an automatic mineralogical analysis sample. Then, a method for measuring the three-dimensional morphology of gold minerals is obtained by combining automatic mineralogical analysis and specific calculation rules, which can judge the three-dimensional morphological characteristics of gold minerals and calculate the corresponding three-dimensional morphological distribution rate. By adopting a special ore sample processing step, sufficient gold minerals can be enriched, and the recovery rate of gold minerals is 60-80%; in the preparation of automatic mineralogical analysis samples, the gold minerals are first mixed with glue and then shaken to precipitate to the bottom layer, which can greatly improve the gold rate. At the same time, the gold minerals are made to "lie flat", even if the length of the a and b axes of the parallel horizontal planes is not less than the c axis of the vertical horizontal plane; compared with the traditional manual detection method, the gold morphology measurement method saves manpower, has high test efficiency, avoids the influence of human subjective factors, and the data is more objective.

[0117] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for measuring the three-dimensional morphology of gold minerals, characterized in that: The steps include: S1. Grinding the sample to be tested to obtain a raw ore sample; S2. Re-selecting the raw ore sample to obtain a re-selected concentrate and a re-selected tailings; S3. The gravity separation concentrate is subjected to nitric acid and magnetic separation to obtain a sample 1; S4. Open circuit flotation is performed on the gravity separation tailings to obtain a flotation rough concentrate, which is recorded as sample 2; S5. treating the sample 2 with nitric acid to obtain a sample 3; S6. Mixing the sample three with the sample one to obtain sample four; S7. The sample four is rolled, mixed, shaken, cured, polished, and carbon-sprayed to obtain sample five; S8. Performing automatic mineralogical analysis on the sample 5, measuring the cross-sectional area Si, the cross-sectional perimeter Li, the first intercept ai, the second intercept bi of each gold mineral particle in the sample 5, and calculating the distance ci perpendicular to the cross section; Wherein, ai is the distance between the two points with the longest intercept on the cross section of the i-th gold mineral particle in the sample 5; bi is the longest intercept of the line perpendicular to the two points with the longest intercept on the cross section on the i-th gold mineral particle in the sample 5; the calculation formula of ci is ci= ci'*di; di is the correction coefficient, di=(ai+bi) / Li; ci'=Si 0.5 ; i is the serial number of each gold mineral particle, i=1,2,......,m, m is the total number of gold mineral particles in the sample 5; S9. Determine the three-dimensional morphology of each metal mineral particle according to the judgment conditions shown in the following table; Among them, ni1=ai / bi, ni2=bi / ci; S10. Statistically calculate the distribution rate of each three-dimensional form in the gold mineral, and the calculation formula is as follows: Kh=Sh / Stotal; Among them, Stotal is the total area of ​​the gold mineral, Stotal=∑Si; Sh is the sum of the cross-sectional areas of the gold mineral particles in the hth three-dimensional form; Kh is the distribution rate of the hth three-dimensional form; the value range of h includes 1~13; 1 represents coarse grains; 2 represents round grains; 3 represents granules; 4 represents bean-shaped; 5 represents flakes; 6 represents rods; 7 represents wheat grains; 8 represents long-horned grains; 9 represents leaves; 10 represents plates; 11 represents needles and threads; 12 represents microparticles; 13 represents other forms.

2. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S1, the mass of the sample to be tested is 3-10 kg; the grinding fineness is -0.074 mm and the content is 65%-90%.

3. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S2, in the re-selection, the re-selection yield is not less than 0.01%.

4. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S3, the nitric acid treatment comprises the following steps: Add nitric acid with a concentration of 65-68% to the gravity separation concentrate until the reaction is complete, then place in a water bath for 2 hours, filter and dry.

5. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S3, during the magnetic separation process, the magnetic field strength is not less than 1.5T.

6. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S4, the open circuit flotation is a roughing selection, and the roughing reagents include: 80-120 g / t of butyl xanthate, 45-55 g / t of butyl ammonium black medicine, 18-22 g / t of 2# oil, and 180-220 g / t of copper sulfate.

7. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S5, the nitric acid treatment comprises the following steps: Add nitric acid with a concentration of 65-68% to the sample 2 until the reaction is complete, place in a water bath for 2 hours, filter and dry.

8. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S7, the mixing step is to add epoxy resin and curing agent to sample four.

9. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S7, the oscillation is ultrasonic oscillation, and the oscillation time is 25 to 35 minutes.

10. The method for measuring the three-dimensional morphology of gold minerals according to claim 1, characterized in that: In step S7, in the grinding and polishing process, during grinding, the abrasive size is less than 1000 mesh; during polishing, the abrasive particle size is less than 1 μm, and the grinding and polishing time is 5 to 10 minutes respectively.

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