Method for determining the particle size of silver minerals

Abstract

The application provides a silver mineral particle size determination method, and belongs to the technical field of process mineralogy. The method comprises the following steps: sample preparation, automatic mineralogical analysis, silver grade calibration, silver mineral identification and data analysis, and calculation of silver mineral particle size. During the automatic mineralogical analysis, the original particle size data obtained by measurement is adjusted according to the specific occurrence state of silver minerals in ores. During the silver mineral identification and data analysis, a correction coefficient K is introduced to correct the system deviation caused by factors such as uneven mineral composition, coarse silver particles, automatic mineral analysis identification threshold and the like, so that the subsequent particle size distribution calculation based on image analysis is established on a more reliable "quality basis". The application replaces a large amount of manual labor with automatic mineralogical analysis, reflects the real occurrence characteristics through the "process particle size" reorganization rule, corrects the system error through the chemical grade calibration, and finally obtains the particle size distribution data with high confidence.

Description

Technical Field

[0001] This invention relates to the field of process mineralogy, and in particular to a method for determining the grain size of silver minerals. Background Technology

[0002] The design of silver ore beneficiation processes is highly correlated with the accurate determination of the process grain size, liberation degree, and intercalation relationship of silver minerals. Traditional grain size analysis largely relies on manual operation, involving observation and statistical analysis of thin sections or slides under an optical microscope. This method has the following significant drawbacks:

[0003] 1) High subjectivity and low efficiency: Manual identification and measurement of silver mineral particle size characteristics are greatly influenced by the operator's experience, resulting in a limited number of statistically analyzed particles, insufficient representativeness, and high time and labor consumption. In addition, the variety of silver minerals is complex, and fine-grained silver minerals are even more difficult to judge intuitively, further posing a challenge to accurate quantitative data.

[0004] 2) Difficulty in handling complex intergrowth relationships: For silver minerals with complex intergrowth states such as intergrowths and inclusions, it is difficult to accurately define the boundaries of individual grains and measure their "process grain size" (i.e., the effective unit size that can be liberated or recovered during the beneficiation process).

[0005] 3) Disconnect between particle size data and chemical grade: The mineral content (area percentage) obtained by traditional microscopic analysis needs to be converted into element grade through theoretical chemical formula calculation. This process does not take into account factors such as mineral composition fluctuations and microscopic inclusions, resulting in a deviation between theoretical grade and actual test grade, which affects the guiding value of particle size distribution data for actual mineral processing technology.

[0006] 4) High sample preparation requirements: Traditional sample preparation methods are prone to causing brittle silver minerals (such as native silver and silver sulfide minerals) to fall off or trail, affecting the accuracy of observation.

[0007] The advent of automated mineralogical analysis technology has made it possible to identify silver minerals by combining backscattered electron imaging with energy dispersive spectroscopy (EDS). This technology enables the automatic and rapid identification of minerals and the measurement of parameters such as area and perimeter. However, a systematic approach is still lacking in designing a complete workflow, from sample preparation and image analysis to data processing and final grade calibration, specifically tailored to the unique characteristics of silver minerals, to obtain reliable and production-guiding "process granularity" data. Summary of the Invention

[0008] To address the shortcomings of the existing technology, the present invention aims to provide a systematic, objective, and accurate method for determining the particle size of silver minerals. This method combines refined sample preparation techniques, automated mineralogical analysis, particle size data processing based on embedding states, and chemical grade feedback correction to ultimately obtain silver mineral process particle size distribution data that accurately reflects beneficiation behavior and closely matches the measured grade.

[0009] To achieve the above objectives, the present invention provides a method for determining the grain size of silver minerals, comprising the following steps:

[0010] S1. Take several silver ore samples to be tested, cut and solidify them, and then grind, polish and carbon spray the surfaces to be measured. These samples are then recorded as An, where n is the sample number.

[0011] S2, perform mineralogy quantitative analysis on sample An, and determine the mineral exposure area Sf, grain size distribution characteristics df, and embedding characteristics Lf.e of silver minerals respectively; where e is 1, 2, 3, 4, representing the embedding state of silver minerals as: non-silver minerals encasing silver, intergranular silver between other minerals and other silver minerals, silver encased by other silver minerals, and fractured silver, respectively, and f is the grain number of silver minerals.

[0012] S3, Calculate the silver mineral processing grain size df':

[0013] When the silver mineral is embedded in the state of non-silver mineral-encased silver or in the state of fractured silver, df'=df;

[0014] When the silver mineral is embedded in the intergranular silver state between other minerals, df' = df1 + df2, where df1 and df2 are the grain sizes of the two silver minerals that are intercalated.

[0015] When the silver mineral is embedded in a state where other silver minerals encase silver, df'=df3, and the df4 data is discarded; where df3 is the grain size data of the silver mineral with the larger exposed area, and df4 is the grain size data of the encased silver mineral.

[0016] S4, Silver grade designation:

[0017] Take 1.0~2.0 kg of the silver ore to be tested, grind it, and control the grinding fineness to be -0.074 mm, accounting for 50~75%;

[0018] The grinding samples were sieved, and the sieved samples were denoted as Bi; where i represents 1, 2, 3, 4, and 5, which refer to samples with particle sizes greater than or equal to 1.000 mm, less than 1.000 mm but greater than or equal to 0.074 mm, less than 0.074 mm but greater than or equal to 0.037 mm, less than 0.037 mm but greater than or equal to 0.010 mm, and less than 0.010 mm, respectively.

[0019] Gravity separation was performed on samples B1 and B2 respectively, and the gravity separation yields were t1 and t2 respectively. The gravity separation concentrates were denoted as samples B11 and B21 respectively, and the gravity separation tailings were denoted as samples B12 and B22 respectively.

[0020] The silver grades of B11 and B21 in the gravity separation concentrate were analyzed in full volume, and the silver grades of B12 and B22 in the gravity separation tailings were analyzed by sampling, and recorded as b11 g / t, b21 g / t, b12 g / t, and b22 g / t, respectively.

[0021] If the silver grade of samples B1 and B2 is c1 g / t and c2 g / t respectively, then c1 = t1 b11+(1-t1) b12 g / t, c2=t2 b21+(1-t2) b22 g / t;

[0022] S5, take samples B1 and B2, and prepare samples for automated mineralogical analysis respectively; perform automated mineralogical analysis to determine the silver mineral composition as Gm1 and Gm2 respectively, where m is a natural number greater than or equal to 1, representing different types of silver minerals; calculate the silver content Gm' of different types of silver minerals.

[0023] Calculate the theoretical silver grades H1 and H2 for samples B1 and B2:

[0024] H1=∑Gm1 Gm';

[0025] H2=∑Gm2 Gm';

[0026] Calculate the correction factors for samples B1 and B2:

[0027] K1 = c1 / H1, K2 = c2 / H2;

[0028] S6, Calculate the grain size of silver minerals:

[0029] Di=∑df'.i Sf ρm / (∑df' Sf ρm); Di refers to the particle size distribution ratio of the sample of the i-th particle size class;

[0030] Among them, when the silver mineral state is the intergranular silver state between other minerals and other silver minerals.

[0031] Sf=0.5 (Sfn+Sf(n+1)), ρm=0.5 (ρmn+ρm(n+1));

[0032] n and n+1 represent the numbers of the two silver minerals that are interlocked;

[0033] Where df'.i is the particle size data for the corresponding particle size class, and i is 1, 2, 3, 4, 5, which respectively refer to particle sizes greater than or equal to 1.000 mm, less than 1.000 mm and greater than or equal to 0.074 mm, less than 0.074 mm and greater than or equal to 0.037 mm, less than 0.037 mm and greater than or equal to 0.010 mm, and less than 0.010 mm.

[0034] m is a natural number greater than or equal to 1, representing different types of silver minerals, and ρm is the density of the m-th type of silver mineral.

[0035] The corrected grain size of the silver mineral is:

[0036] D1'=K1 D1;

[0037] D2'=K2 D2;

[0038] D3' = (1 - D1' - D2') D3 / (D3+D4+D5);

[0039] D4' = (1 - D1' - D2') D4 / (D3+D4+D5);

[0040] D5' = (1 - D1' - D2') D5 / (D3+D4+D5).

[0041] Furthermore, in step S4, the reselection yields t1 and t2 range from 0.1% to 2.0%.

[0042] Furthermore, m = 1, 2, 3, 4 respectively represent the types of silver minerals: argentite, argyrite, brittle argentite, and silver-bearing chalcopyrite.

[0043] Furthermore, in step S5, Gm' is the average value of the silver content measurements of five or more silver minerals.

[0044] Furthermore, in step S1, the sample preparation process of sample An is as follows: a silver ore sample with a three-dimensional dimension of length, width, and height all greater than or equal to 10.0 cm is selected, and the sample is cut to obtain a sheet-like sample with a length and width of 5.0~7.5 cm and a thickness of 0.5~1.5 cm. The edges of the cutting plane containing the length and width are chamfered. The plane with a relatively large amount of metallic minerals in the length and width plane is selected as the measurement surface. The measurement surface of the sample is solidified, and the non-measurement bottom surface of the sample is rough ground until it is parallel to the measurement surface. Then, the surface to be measured is polished and carbon-sprayed. The sample after resin curing is demolded and polished with a polishing machine until the surface morphology of the polished sample is observed under an optical microscope, so that all particles are exposed.

[0045] Furthermore, the carbon spraying treatment refers to spraying carbon with a thickness of 10~30 nm using a multi-functional coating instrument.

[0046] Furthermore, the gravity separation refers to gravity separation performed using a Nelson centrifugal separator.

[0047] Furthermore, the polishing process includes coarse grinding, fine grinding, precision grinding, and polishing; the coarse grinding uses 200-500 mesh abrasive, the fine grinding uses 500-1000 mesh abrasive, the precision grinding uses 1000-1500 mesh abrasive, and the polishing uses 1-3μm abrasive.

[0048] The beneficial effects of this invention are:

[0049] The method for determining the grain size of silver minerals provided in this application reflects the true embedding characteristics through the "process grain size" reforming rule and corrects systematic errors through chemical level calibration, resulting in high-confidence grain size distribution data. The final output is a grain size distribution weighted by silver metal mass, which can be directly used for grinding fineness optimization, mineral processing flow prediction, and recovery rate assessment, demonstrating significant engineering practical value. This application replaces a large amount of manual labor with automated mineralogical analysis, offering fast analysis speed, strong statistical representativeness, and eliminating human subjective bias.

[0050] This application provides a standardized end-to-end solution from sample preparation, instrumental analysis, data processing to chemical verification, which has good reproducibility and promotional value. Attached Figure Description

[0051] Figure 1 Scanning electron microscopy backscattering of silver ore as measured in Example 1 Figure 1 In the diagram, 1, 2, and 3 refer to measuring point 1, measuring point 2, and measuring point 3, respectively.

[0052] Figure 2 for Figure 1 Energy dispersive spectroscopy (EDS) spectrum of measurement point 1.

[0053] Figure 3 for Figure 1 Energy dispersive spectroscopy (EDS) spectrum of measurement point 2.

[0054] Figure 4 for Figure 1 Energy dispersive spectroscopy (EDS) spectrum of measurement point 3.

[0055] Figure 5 Scanning electron microscopy backscattering of silver ore as measured in Example 1 Figure 2 .

[0056] Figure 6 for Figure 5 Energy dispersive spectroscopy (EDS) analysis of the main elements in the sample.

[0057] Figure 7 for Figure 5 The elemental surface scan diagram shows that red represents argentite, pink represents galena, and green represents pyrite. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0060] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Please see Figures 1 to 7 As shown, the present invention provides a method for determining the grain size of silver minerals, comprising the following steps:

[0062] S1. Take several silver ore samples to be tested, cut and solidify them, and then grind, polish and carbon spray the surfaces to be measured. These samples are then recorded as An, where n is the sample number.

[0063] The sample preparation process for sample An is as follows: A silver ore sample with dimensions (length, width, and height) all greater than or equal to 10.0 cm is selected. The sample is cut to obtain sheet-like samples with dimensions of 5.0–7.5 cm in length and width, and a thickness of 0.5–1.5 cm. The edges of the cut planes containing the length and width are chamfered (i.e., the edges are rounded or obtuse). Then, the plane with a relatively high concentration of metallic minerals in the length and width planes is selected as the measurement surface. The measurement surface of the sample is then cured: epoxy resin and its corresponding curing agent are mixed at a volume ratio of 1:(0.3–1.0). A thin layer of epoxy resin mixture is injected into the mold, and the measurement surface is immersed in the resin mixture (immersion depth 2.0–5.0 mm). Ultrasonic vibration is applied for 6.0–12.0 min, followed by further accelerated curing at 45–65℃. This step effectively seals the edges, preventing silver minerals from peeling off during subsequent polishing, and strengthens the internal structure of the ore, making it particularly suitable for protecting soft and brittle silver minerals.

[0064] The non-measured bottom surface of the sample (the plane containing the length and width opposite to the measurement surface) is coarsely ground until it is parallel to the measurement surface; 200~500 mesh abrasive is used for coarse grinding; then, the surface to be measured is ground, polished and carbon sprayed, the sample after resin curing is demolded, and polished by a polishing machine until the surface morphology of the polished sample is observed under an optical microscope, so that all particles are exposed and there are no obvious scratches at each step.

[0065] Polishing includes coarse grinding, fine grinding, precision grinding, and polishing.

[0066] Coarse grinding uses 200-500 mesh abrasive, fine grinding uses 500-1000 mesh abrasive, fine grinding uses 1000-1500 mesh abrasive, and polishing uses 1-3μm abrasive.

[0067] Carbon spraying refers to spraying a layer of carbon with a thickness of 10-30 nm using a multi-functional coating instrument to ensure the conductivity of the sample.

[0068] For the non-measured bottom surface, attach fixing pins and secure it. Specifically, use conductive adhesive or other glue for fixation, and connect the carbon-sprayed position on the measurement surface to the fixing pins with conductive adhesive to increase the conductivity of the sample.

[0069] S2, perform mineralogy quantitative analysis on sample An, and determine the mineral exposure area Sf, grain size distribution characteristics df, and embedding characteristics Lf.e of silver minerals respectively; where e is 1, 2, 3, 4 representing the embedding state of silver minerals as follows: silver encased by non-silver minerals, silver between other minerals and other silver minerals, silver encased by other silver minerals, and silver in fractures, respectively, and f is the grain number of silver minerals.

[0070] The particle size is measured by the intercept through the centroid of the silver ore particles. Preferably, the intercepts in two mutually perpendicular directions are measured, and the average of the two intercepts is calculated.

[0071] S3, Calculate the silver mineral processing grain size df':

[0072] When the silver mineral is embedded in the state of non-silver mineral-encased silver or in the state of fractured silver, df'=df;

[0073] When the silver mineral is embedded in the intergranular silver state between other minerals, df' = df1 + df2, where df1 and df2 are the grain sizes of the two silver minerals that are intercalated; that is, different minerals in contact with each other are regarded as a "process aggregate" and only one data is recorded.

[0074] When silver minerals are embedded in a state where other silver minerals encase silver, df' = df3, and the df4 data is discarded. Here, df3 represents the grain size of the silver mineral with the largest exposed area, and df4 represents the grain size of the encased silver mineral. Encased silver minerals are often difficult to dissociate during the grinding process and are therefore discarded. This better reflects the actual situation of mineral dissociation after grinding.

[0075] In this application, the instrument's default equivalent diameter of a single particle was not simply adopted. Instead, the original particle size data obtained from the measurement was adjusted according to the specific embedding state of the silver mineral in the ore (which affects subsequent liberation characteristics). The silver mineral particle size characteristics measured in this application are a holistic concept of process particle size characteristics, which are more in line with actual production and provide stronger guidance for subsequent process flows.

[0076] S4, Silver grade designation:

[0077] Take 1.0~2.0 kg of the silver ore to be tested, grind it, and control the grinding fineness to be -0.074 mm, accounting for 50~75%;

[0078] The grinding samples were sieved, and the sieved samples were denoted as Bi; where i represents 1, 2, 3, 4, and 5, which refer to samples with particle sizes greater than or equal to 1.000 mm, less than 1.000 mm but greater than or equal to 0.074 mm, less than 0.074 mm but greater than or equal to 0.037 mm, less than 0.037 mm but greater than or equal to 0.010 mm, and less than 0.010 mm, respectively.

[0079] Gravity separation was performed on samples B1 and B2 respectively, with gravity separation yields t1 and t2 respectively. The gravity separation concentrates were denoted as samples B11 and B21 respectively, and the gravity separation tailings were denoted as samples B12 and B22 respectively.

[0080] Gravity separation refers to the separation process using a Nelson centrifugal concentrator. The gravity separation yields t1 and t2 range from 0.1% to 2.0%.

[0081] The silver grades of B11 and B21 in the gravity separation concentrate were analyzed in full volume, and the silver grades of B12 and B22 in the gravity separation tailings were analyzed by sampling, and recorded as b11 g / t, b21 g / t, b12 g / t, and b22 g / t, respectively.

[0082] If the silver grade of samples B1 and B2 is c1 g / t and c2 g / t respectively, then c1 = t1 b11+(1-t1) b12 g / t, c2=t2 b21+(1-t2) b22 g / t;

[0083] S5, take samples B1 and B2, and prepare samples for automated mineralogical analysis respectively; perform automated mineralogical analysis to determine the silver mineral composition as Gm1 and Gm2 respectively, where m is a natural number greater than or equal to 1, representing different types of silver minerals; calculate the silver content Gm' of different types of silver minerals.

[0084] In some embodiments, m is 1, 2, 3, 4, representing the types of silver minerals as argentite, argillite, brookite, and silver-bearing chalcopyrite, respectively.

[0085] Gm' is the average value of the silver content measurements of five or more silver minerals.

[0086] Calculate the theoretical silver grades H1 and H2 for samples B1 and B2:

[0087] H1=∑Gm1 Gm';

[0088] H2=∑Gm2 Gm';

[0089] Calculate the correction factors for samples B1 and B2:

[0090] K1 = c1 / H1, K2 = c2 / H2

[0091] S6, Calculate the grain size of silver minerals:

[0092] Di=∑df'.i Sf ρm / (∑df' Sf ρm); Di refers to the particle size distribution ratio of the sample of the i-th particle size class;

[0093] Among them, when the silver mineral state is the intergranular silver state (intercalation) between other minerals,

[0094] Sf=0.5 (Sfn+Sf(n+1)), ρm=0.5 (ρmn+ρm(n+1));

[0095] n and n+1 represent the numbers of the two silver minerals that are interlocked;

[0096] Where df'.i is the particle size data for the corresponding particle size class, and i is 1, 2, 3, 4, 5, which respectively refer to particle sizes greater than or equal to 1.000 mm, less than 1.000 mm and greater than or equal to 0.074 mm, less than 0.074 mm and greater than or equal to 0.037 mm, less than 0.037 mm and greater than or equal to 0.010 mm, and less than 0.010 mm.

[0097] m is a natural number greater than or equal to 1, representing different types of silver minerals, and ρm is the density of the m-th type of silver mineral.

[0098] The corrected grain size of the silver mineral is:

[0099] D1'=K1 D1;

[0100] D2'=K2 D2;

[0101] D3' = (1 - D1' - D2') D3 / (D3+D4+D5);

[0102] D4' = (1 - D1' - D2') D4 / (D3+D4+D5);

[0103] D5' = (1 - D1' - D2') D5 / (D3+D4+D5).

[0104] The method for determining the grain size of silver minerals provided by the present invention will be described below with reference to specific embodiments.

[0105] Example 1

[0106] This embodiment provides a method for determining the grain size of silver minerals, specifically for measuring the grain size of silver minerals in a silver mine in Heilongjiang Province.

[0107] like Figure 1-7 As shown, the main metallic sulfide in this ore is pyrite, followed by galena, with other metallic sulfides present in smaller quantities. The main metallic oxide is magnetite, and the main gangue mineral is quartz, followed by rhodochrosite and dolomite, with other gangue minerals present in smaller quantities. Silver, lead, and manganese minerals can be recovered from the ore, and the processing type is a polymetallic silver-bearing ore containing medium sulfide manganese, lead, and zinc.

[0108] The data from the three measuring points are as follows:

[0109] Test point 1: Brittle silver ore: Ag: 67.03%; S: 14.69%; Fe: 1.29%; Sb: 16.99%;

[0110] Measurement point 2: Deep red silver ore: Ag: 57.85%; Sb: 22.02%; S: 20.13%;

[0111] Measurement point 3: Rhodochrosite: Mn, Fe, O, Ca.

[0112] Depend on Figure 1-4 It can be seen that brittle silver ore and deep red silver ore are embedded in the gangue.

[0113] Depend on Figure 5-7It can be seen that pyrite encapsulates fine-grained brittle silver ore.

[0114] The specific procedure for determining the grain size of silver minerals is as follows:

[0115] Sampling:

[0116] Representative silver ore samples were selected, with all three dimensions (length, width, and height) greater than or equal to 10.0 cm.

[0117] The sample was cut into sections 5.0 cm long and 5.0 cm wide, and 1.0 cm thick. The edges of the cutting planes containing the length and width were chamfered (i.e., the edges were rounded or obtuse).

[0118] Select the measurement surface;

[0119] Curing treatment of the measurement surface of the sample: Mix epoxy resin and its corresponding curing agent at a volume ratio of 1:0.5, inject a thin layer of epoxy resin mixture into the mold, immerse the measurement surface in the resin mixture (immersion depth 3.0 mm), ultrasonically vibrate for 6.0 min, and then accelerate curing at 45℃.

[0120] The non-measured bottom surface of the sample (the plane containing the length and width opposite to the measurement surface) is coarsely ground with 200-mesh abrasive until the surface is flat (processed to be parallel to the measurement surface).

[0121] Sample processing:

[0122] The surfaces to be measured are ground, polished, and carbon-sprayed. After the resin has cured, the samples are demolded and polished using a polishing machine. Polishing includes coarse grinding, fine grinding, fine grinding, and polishing. Coarse grinding uses 200-mesh abrasive, fine grinding uses 500-mesh abrasive, fine grinding uses 1000-mesh abrasive, and polishing uses 1 μm abrasive. The process continues until the surface morphology of the polished samples is observed under an optical microscope, achieving complete particle exposure and no obvious scratches at each step.

[0123] Carbon spraying refers to the use of a multi-functional coating machine to spray carbon with a thickness of 10 nm.

[0124] For the non-measured bottom surface, use conductive adhesive to fix the fixing pins; and use conductive adhesive to connect the carbon spraying position of the measuring surface to the fixing pins to increase the conductivity of the sample.

[0125] After the above processing, sample An is obtained, where n is the sample number. In this embodiment, there are 5 samples.

[0126] Automated mineralogical analysis:

[0127] Mineralogical quantitative analysis was performed on the obtained sample An, determining the outcrop area Sf of silver minerals (not the total mineral content measured by traditional methods, but automatically measured by machine), the grain size distribution characteristics df of silver minerals, and the embedding characteristics Lf.e. Here, e represents the silver mineral embedding state as follows: silver encased in non-silver minerals, silver between other minerals and other silver minerals, silver encased in other silver minerals, and silver in fractures, respectively; f is the grain number of the silver mineral. See Table 1 below for details.

[0128] Table 1 Results of Automated Mineralogical Analysis

[0129]

[0130] Grain size data processing, calculating the process grain size df' of silver minerals:

[0131] When the silver mineral is embedded in a non-silver mineral-encased silver state or a fractured silver state (i.e., e is 1 or 4), df'=df.

[0132] For example: when the silver mineral embedding state of particles 5 and 198 is a non-silver mineral encapsulated silver state (e is 1), then:

[0133] d5'=d5=57.62μm;

[0134] D198'=d198=65.57μm.

[0135] When the silver mineral is embedded in the intergranular silver state between other minerals (i.e., e is 2), df' = df1 + df2, where df1 and df2 are the grain sizes of different types of silver minerals that are interconnected.

[0136] For example: if particle 1 and particle 2 are silver particles between other minerals and other silver minerals, then:

[0137] df'=df1+df2=43.72+15.86=59.85μm.

[0138] When the silver mineral is embedded in a state where it is encased by other silver minerals (i.e., e is 3), df' = df3, and the df4 data is discarded. Here, df3 represents the grain size of the silver mineral with the largest exposed area, and df4 represents the grain size of the encased silver mineral.

[0139] For example: if particles 3 and 4 are silver encapsulated by other silver minerals, and the exposed area of ​​particle 4 is larger than that of particle 3, then:

[0140] df'=d4=237.44μm.

[0141] Silver grade designation:

[0142] Take a 2.0 kg sample and grind it to control the grinding fineness to -0.074 mm (200 mesh), accounting for 65%.

[0143] The grinding samples were sieved, and the sieve openings were divided into i levels (i = 1, 2, 3, 4, 5, representing greater than or equal to 1.000 mm, less than 1.000 mm and greater than or equal to 0.074 mm, less than 0.074 mm and greater than or equal to 0.037 mm, less than 0.037 mm and greater than or equal to 0.010 mm, and less than 0.010 mm, respectively); each particle size was denoted as Bi.

[0144] The ground samples B1 and B2 were subjected to gravity separation (the gravity separation equipment was a Nelson centrifugal concentrator). The gravity separation yields were t1=0.10% and t2=0.10%, respectively. The gravity separation concentrates were denoted as samples B11 and B21, and the gravity separation tailings were denoted as samples B12 and B22, respectively.

[0145] The silver grades of the gravity separation concentrates B11 and B21 were analyzed in full volume, and the silver grades of the gravity separation tailings B12 and B22 were analyzed by sampling. They were recorded as b11=1478.95 g / t, b21=1566.23 g / t, b12=354.23 g / t, and b22=399.57 g / t, respectively.

[0146] The silver grade of the silver ore sample is denoted as c1 g / t and c2 g / t.

[0147] c1=t1 b11+(1-t1) b12=0.10% 1478.95+ (1-0.10%) 354.23 = 354.36 g / t

[0148] c2=t2 b21+(1-t2) b22 = 0.10% 1566.23 + (1 - 0.10%) 399.57 = 400.74 g / t.

[0149] Silver mineral identification and data analysis:

[0150] Samples B1 and B2 were taken to prepare samples for automated mineralogical analysis.

[0151] Then, automated mineralogical analysis was performed to determine the composition of silver minerals as Gm1 and Gm2 (m is 1, 2, 3... representing different types of silver minerals respectively), and Gm' is the silver content of each type of silver mineral.

[0152] Wherein, Gm' is the average value of the silver content analysis results of 5 or more silver minerals. See Table 2 below for details.

[0153] Table 2. Calculation results of relative content of silver minerals and metal distribution rate of silver.

[0154]

[0155] Calculate the theoretical silver grade of the sample:

[0156] H1=∑Gm1 Gm'=0.025% 88.24% + 0.014% + 59.25% + ... + 0.023% 3.02%

[0157] =357.479g / t;

[0158] H2=∑Gm2 Gm'=404.028g / t.

[0159] Calculate the correction factor:

[0160] K1=c1 / H1=354.35 / 357.479=0.9912,

[0161] K2=c2 / H2=400.74 / 404.028=0.9919.

[0162] According to the formula Di=∑df'.i Sf ρm / (∑df' Sf The grain size of silver minerals is calculated using ρm, as detailed in Table 3.

[0163] Table 3. Particle size analysis calculation results

[0164]

[0165] Example calculations are as follows:

[0166] Particle 1 and particle 2 are intergranular silver particles (intergranular state) formed by other minerals and other silver minerals, thus forming intergranular particles.

[0167] S1-2=0.5 (Sfn + Sf(n+1)) = 0.5 (Sf1 + Sf2) = 0.5 (1513.29 + 184.58) = 848.935;

[0168] S1-2 indicates that particle 1 and particle 2 are in the state of silver mineral 1 embedded in other minerals and silver mineral 2 in the intergranular silver state.

[0169] ρ1-2=0.5 (ρmn + ρm(n+1)) = 0.5 (ρm1 + ρm2) = 0.5 (7.35 + 5.82) = 6.585;

[0170] ρ1-2 represents the density of the intercrystalline particles formed by particles 1 and 2.

[0171] df' Sf ρm=59.85 848.935 6.585 = 334575.683.

[0172] Other calculation results are shown in Table 3. Due to space limitations, only data from a portion of the samples are presented as examples.

[0173] The corrected silver mineral grain size is shown in Table 4:

[0174] Table 4. Results of Silver Mineral Grain Size Analysis

[0175]

[0176] The calculation process is as follows:

[0177] D1'=D1 K1=1.57% 0.9912 = 1.56%;

[0178] D2'=D2 K2=3.31% 0.9919 = 3.28%;

[0179] D3' = (1 - D1' - D2') D3 / (D3+D4+D5)=(1-1.56%-3.28%) 35.77% / (35.77% + 32.42% + 26.93%) = 35.79%;

[0180] D4' = (1 - D1' - D2') D4 / (D3+D4+D5)=(1-1.56%-3.28%) 32.42% / (35.77% + 32.42% + 26.93%) = 32.43%;

[0181] D5' = (1 - D1' - D2') D5 / (D3+D4+D5)=(1-1.56%-3.28%) 26.93% / (35.77% + 32.42% + 26.93%) = 26.92%.

[0182] This application reflects the true embedding characteristics through a "process particle size" reforming rule and corrects systematic errors through chemical level calibration, resulting in high-confidence particle size distribution data. The final output is a silver metal mass-weighted particle size distribution, which can be directly used for grinding fineness optimization, mineral processing flow prediction, and recovery rate assessment, demonstrating significant engineering practical value. This application replaces a large amount of manual labor with automated mineralogical analysis, offering fast analysis speed, strong statistical representativeness, and eliminating human subjective bias.

[0183] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for determining the size of silver mineral particles, characterized by, It comprises the following steps: S1, taking a plurality of silver ore samples to be measured, cutting, solidifying, polishing and carbon spraying the surface to be measured, and marking the samples as An, n being the sample number; S2, performing mineralogical quantitative analysis on the sample An, measuring the mineral exposed area Sf of the silver mineral, the particle size distribution characteristics df of the silver mineral, and the embedding characteristics Lf.e of the silver mineral; wherein e is 1, 2, 3, or 4, representing the silver mineral embedding state as: non-silver mineral inclusions, other minerals and other silver minerals intergranular silver, other silver minerals inclusions, and fissure silver, respectively, and f is the particle number of the silver mineral; S3, calculating the silver mineral process particle size df': When the silver mineral embedding state is non-silver mineral inclusions or fissure silver, df'=df; When the silver mineral embedding state is other minerals and other silver minerals intergranular silver, df'=df1+df2, df1 and df2 being the particle sizes of two mutually intergrown silver minerals, respectively; When the silver mineral embedding state is other silver minerals inclusions, df'=df3, while df4 data is discarded; wherein df3 is the particle size data of the silver mineral with a large exposed area, and df4 is the particle size data of the inclusions; S4, silver grade calibration: Taking 1.0-2.0 kg of the silver ore to be measured, grinding, and controlling the grinding fineness to be 50-75% of -0.074 mm; Screening the ground sample, and marking the screened samples as Bi; wherein i is 1, 2, 3, 4, or 5, respectively, indicating the sample of the particle size of greater than or equal to 1.000 mm, less than 1.000 mm and greater than or equal to 0.074 mm, less than 0.074 mm and greater than or equal to 0.037 mm, less than 0.037 mm and greater than or equal to 0.010 mm, and less than 0.010 mm; Respectively, performing gravity separation on the samples B1 and B2, and corresponding the gravity separation yield as t1 and t2, and marking the gravity separation concentrates as samples B11 and B21, and the gravity separation tailings as samples B12 and B22; Performing total analysis on the gravity separation concentrates B11 and B21, and sampling and analyzing the silver grade of the gravity separation tailings B12 and B22, and marking the silver grade as b11 g / t, b21 g / t, b12 g / t, and b22 g / t, respectively; The silver grade of samples B1, B2 is c1 g / t and c2 g / t, then c1 = t1 b11 + (1 - t1) b12 g / t, c2 = t2 b21 + (1 - t2) b22 g / t; S5, taking the samples B1 and B2, and respectively preparing automatic mineralogical analysis samples; performing automatic mineralogical analysis, and respectively measuring the silver mineral matter composition Gm1 and Gm2, m being a natural number greater than or equal to 1, representing different types of silver minerals; and calculating the silver content of different types of silver minerals Gm'; Calculating the theoretical silver grade H1 and H2 of the samples B1 and B2: H1 =∑Gm1 Gm’; H2 = ∑Gm2 Gm’; Calculating the correction coefficients of the samples B1 and B2: K1=c1 / H1, K2=c2 / H2; S6, calculating the silver mineral particle size: Di =∑df'.i Sf ρm / (∑df' Sf ρm); Di refers to the particle size distribution ratio of the sample of the i-th particle size fraction; When the silver mineral state is other minerals and other silver minerals intergranular silver, Sf=0.5 (Sfn+Sf(n+1), pm=0.5 (pmn+pm(n+1)); n and n+1 represent the numbers of two mutually intergrown silver minerals; Wherein, df'.i is the particle size data corresponding to the particle size, i is 1, 2, 3, 4, 5, which respectively represents the particle size greater than or equal to 1.000 mm, less than 1.000 mm and greater than or equal to 0.074 mm, less than 0.074 mm and greater than or equal to 0.037 mm, less than 0.037 mm and greater than or equal to 0.010 mm, less than 0.010 mm particle size; M is a natural number greater than or equal to 1, representing different kinds of silver minerals, and ρm is the density of the mth silver mineral; The silver mineral particle size is obtained by correction: D1' = K1 D1; D2' = K2 D2; D3' = (1 - D1' - D2') D3 / (D3+D4+D5); D4' = (1 - D1' - D2') D4 / (D3 + D4 + D5); D5' = (1 - D1' - D2') D5 / (D3 + D4 + D5).

2. The method of determining silver ore mineral grain size according to claim 1, characterized in that: In step S4, the values of the reselection yield t1 and t2 are in the range of 0.1% to 2.0%.

3. The method of determining silver ore mineral grain size according to claim 1, characterized in that: M is 1, 2, 3, 4, which respectively represents that the type of silver mineral is argentite, erythrosic silver, fragile silver, and silver-containing black copper.

4. The method of determining silver ore particle size according to claim 1, characterized in that: In step S5, the Gm' is the average value of the silver content measurement results of 5 or more silver minerals.

5. The method of determining silver ore mineral grain size according to claim 1, characterized in that: In step S1, the sample An is prepared as follows: a silver ore sample with a three-dimensional size of length, width and height greater than or equal to 10.0 cm is selected, the sample is cut to obtain a sheet-shaped sample with a length and width of 5.0-7.5 cm and a thickness of 0.5-1.5 cm, and the edges of the cutting plane where the length and width are located are chamfered; A plane with relatively more metal minerals in the length-width plane is selected as the measurement plane, the measurement plane of the sample is cured, and the non-measurement bottom surface of the sample is coarsely ground until it is parallel to the measurement plane; then, the measurement surface is ground and polished, and the sample after resin curing is demolded and polished by a polishing machine until the surface morphology of the polished sample is observed under an optical microscope, and all particles are exposed.

6. The method of determining silver ore mineral grain size according to claim 5, characterized in that: The carbon spraying treatment refers to spraying 10-30 nm thick carbon with a multifunctional coating instrument.

7. The method of determining silver ore particle size according to claim 1, characterized in that: The reselection refers to reselection by a Nelson centrifugal concentrator.

8. The method of determining silver ore particle size according to claim 5, characterized in that: The polishing and grinding include coarse grinding, fine grinding, precision grinding and polishing treatment; the coarse grinding uses 200-500 mesh abrasive, the fine grinding uses 500-1000 mesh abrasive, and the precision grinding uses 1000-1500 mesh abrasive.

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