Method for determining the content of metal sulfide

Abstract

The present application provides a method for determining the content of metal sulfides, belonging to the technical field of process mineralogy. The method for determining the content of metal sulfides includes: grinding, sulfur phase analysis, then performing gravity separation and acid treatment on the sample after grinding, and then respectively performing sulfur phase analysis and automated mineralogy analysis on the sample after acid treatment again, and finally performing test analysis to obtain the content of metal sulfides. By respectively performing sulfur phase analysis on the sample after grinding and the sample after enrichment by gravity separation and acid treatment, and performing automated mineralogy analysis on the sample after enrichment by gravity separation and acid treatment, the present invention corrects the magnified data back to the data of the original sample, realizes accurate measurement of the content of low-content metal sulfides, and can respectively measure the content of different metal sulfides through automated mineralogy analysis. The test method provided by the present invention has accurate measurement data, greatly reduces the interference of human subjective factors, and provides reliable data support for the efficient utilization of such stone resources.

Description

Technical Field

[0001] The present invention relates to the technical field of process mineralogy, and particularly relates to a method for determining the content of metal sulfides. Background Art

[0002] Primary sulfide mineral resources are an important part of natural resources, and a large part of the minerals we currently utilize come from these metal sulfides. In the research of process mineralogy, the measurement of the content of metal sulfides is important data for evaluating the quality of ores and determining their industrial value. However, the measurement of low-content metal sulfides faces many difficulties. Especially when the content of metal sulfides is below a certain threshold, its measurement accuracy and reliability are often significantly affected.

[0003] Existing testing methods are mainly divided into chemical analysis methods and instrumental measurement methods. Chemical analysis methods are often interfered by reducing substances such as thiosulfates and sulfites, which will react with the measurement reagents, resulting in higher or lower measurement results. In addition, sampling representativeness, suspended solids, chromaticity, turbidity, and some heavy metal ions in the samples will also interfere with the measurement. Instrumental analysis includes a variety of techniques, such as spectral analysis, chromatographic analysis, mass spectrometry analysis, electrochemical analysis, etc. Each technique has its unique principle and application scope. However, when measuring samples of low-content metal sulfides to be measured, due to the low mineral content, large errors will also occur. Because instrumental measurement mainly scans a large number of mineral particles on the sample, and then statistically analyzes and calculates their content. The number of low-content metal sulfide particles is relatively small, the detection probability is also low, and the resulting data fluctuations are significant, which is prone to errors.

[0004] In the prior art, a calculation method and its application for the oxidation rate of gold ore are provided in the patent with the publication number CN 118225988 B. This calculation method introduces the measurement and analysis of the oxidation degree of carrier minerals, combines automated mineralogical analysis, and determines the gold grade through a gravity separation process. Through the combination of these three technical means, the gold-bearing analysis of the main metal sulfides, the determination of the contents of both the main metal sulfides and the main metal oxides, and the determination of the gold grade are respectively carried out on the gold ore samples to be measured, realizing the corrected calculation of the oxidation rate of gold ore, and thus obtaining an accurate theoretical oxidation rate of gold ore. This invention mainly targets gold ore with a certain sulfide content. When the sulfide content is very low, there will be certain errors in the automated mineralogical analysis data. The patent with the publication number CN 109975384 B provides a method for detecting the metal distribution rate in rocks, including: preparing polished sections, thin sections or probe sections of rock samples, and then coating them; measuring the mass percentage content of minerals in the rock using an automated mineralogical analysis instrument; measuring the mass content of metal element M in the minerals using a laser ablation inductively coupled plasma mass spectrometer, with the unit of ppm; calculating the grade of metal element M in the rock according to Equation 1, Equation 1 is: The grade of metal element M in the rock = (∑γi×βi×10 -4 )×100%, i = 1, 2,..., n, where i represents the i-th mineral in the rock, γi represents the mass percentage content of the i-th mineral in the rock, and βi represents the mass content (ppm) of metal element M in the i-th mineral; calculating the metal distribution rate of metal element M in the rock according to Equation 2, Equation 2 is: The metal distribution rate of metal element M in the i-th mineral = (γi×βi×10 -4 ÷ the grade of rubidium in the rock)×100%. This invention is a method for calculating the element content in a sample based on the measured mineral content and the element content in the ore species. However, it is difficult to accurately measure low-content minerals. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present application provides a method for determining the content of metal sulfides, aiming to solve the problems that the existing methods for testing the content of metal sulfides are difficult to accurately measure low-content metal sulfides and cannot separately measure the contents of different metal sulfides.

[0006] The present application provides a method for determining the content of metal sulfides, comprising the following steps:

[0007] S1. Take the sample to be measured, grind it to obtain the ground sample;

[0008] S2. Uniformly sample the ground sample and conduct the first sulfur phase analysis to measure that the mass fraction of sulfur in the metal sulfides accounts for the total mass of the taken ground sample as C11;

[0009] S3. Perform gravity separation on the sample after grinding to obtain gravity separation concentrate J1 and gravity separation tailings W1;

[0010] S4. Acid-treat the gravity separation tailings W1, then wash the ore, filter, and dry to obtain sample W2;

[0011] S5. Mix the gravity separation concentrate J1 and sample W2 to obtain sample J12;

[0012] S6. Uniformly sample the sample J12 and conduct a second sulfur phase analysis. Measure the mass fraction C22 of sulfur in metal sulfides in the total mass of the sampled sample J12;

[0013] S7. Sample the sample J12 and prepare an automatic mineralogy analysis sample J13;

[0014] S8. Conduct an automatic mineralogy analysis on the sample J13. Measure the sum of the horizontal projection lengths of the cross-sections of various metal sulfides and the sulfur content of various metal sulfides respectively. Among them, the sum of the horizontal projection lengths of the cross-section of the i-th metal sulfide is denoted as Li, and the sulfur content of the i-th metal sulfide is denoted as Si; Li = , Lim represents the horizontal projection length of the cross-section of the m-th mineral particle in the i-th metal sulfide, i = 1, 2,..., n, n is the total number of types of metal sulfides measured, m = 1, 2, 3,..., N, N is the total number of mineral particles of the i-th metal sulfide;

[0015] S9. Calculate the content of each metal sulfide in the sample J13 respectively. Among them, the content of the i-th metal sulfide is denoted as Mi’, Mi’ = ρi * Di * X, and Ci = Mi’ * Si, C22 = ; where ρi is the density of the i-th metal sulfide; Di is the volume ratio of the i-th metal sulfide, Di = Li / ; X is the conversion coefficient; Ci is the mass fraction of sulfur in the i-th metal sulfide in the total mass of the sample J13;

[0016] S10. Calculate the content of each metal sulfide in the original sample. Among them, the content of the i-th metal sulfide in the original sample is denoted as Mi, then Mi = Mi’ * C11 / C22.

[0017] In the technical solution of the embodiment of the present application, the present application conducts sulfide phase analysis on the samples after grinding and after enrichment by gravity separation and acid treatment respectively, and conducts automated mineralogy analysis on the samples after enrichment by gravity separation and acid treatment. The magnified data is corrected back into the data of the original sample to achieve accurate measurement of the content of low-content metal sulfides. And through automated mineralogy analysis, the content of different metal sulfides can be measured respectively. The test method provided by the present invention has accurate measurement data, greatly reduces the interference of human subjective factors, saves manpower, and provides reliable data support for the efficient utilization of such stone resources.

[0018] In some embodiments, in step S1, the grinding fineness is such that the content of -0.074mm is 75% - 95%.

[0019] In this embodiment, by grinding the sample to be tested to a certain fineness, it is convenient for subsequent processing of the sample.

[0020] In some embodiments, in step S2, the first sulfide phase analysis includes: using the differential method or the acetic acid-hydrogen peroxide leaching method to measure the mass fraction of sulfur in the metal sulfides in the ground sample accounting for the total mass of the taken ground sample.

[0021] In this embodiment, by measuring the mass fraction of sulfur in the metal sulfides in the ground sample accounting for the total mass of the taken ground sample, and finally through conversion, the content of metal sulfides in the original sample is obtained.

[0022] In some embodiments, in step S3, the gravity separation uses the heavy liquid stirring separation method, and the gravity separation reagent is an aqueous solution mixture of thallium formate and thallium malonate.

[0023] In this embodiment, through gravity separation, the metal sulfides in the ore sample are enriched.

[0024] In some embodiments, in step S4, the acid in the acid treatment includes hydrofluoric acid and sulfuric acid, the temperature of the acid treatment is 90 - 95°C in a water bath, and the time of the acid treatment is 22 - 26h.

[0025] In this embodiment, through the treatment with hydrofluoric acid and sulfuric acid, gangue, quartz, carbonate minerals, mica minerals, pyroxene minerals, etc. in the ore sample can be dissolved, while the metal sulfides are retained for further enrichment of the metal sulfides.

[0026] In some embodiments, in step S7, the preparation process of the automated mineralogy analysis sample includes:

[0027] S71. Mix the sample J12 and the thermosetting embedding material evenly at a volume ratio of 1:0.5 to 1:3, and cure them in an embedding machine at a temperature of 100-150 °C and a pressure of 200-300 Bar; the thermosetting embedding material is thermosetting phenolic epoxy resin, and the particle size of the thermosetting embedding material is not greater than 38 μm;

[0028] S72. Grind, polish and carbon spray the cured sample; in the grinding and polishing process, the sizes of the abrasives include 150 μm, 23 μm and 13 μm, and the grinding time is 8-10 min; the sizes of the polishing materials include 6 μm, 3 μm and 1 μm, and the polishing time is 8-10 min; the carbon spraying method is ion sputtering, and the carbon spraying thickness is 5-10 nm.

[0029] In this embodiment, the enriched metal sulfide is made into an automatic mineralogical analysis sample, and then automatic mineralogical analysis is carried out.

[0030] In some embodiments, in step S6, the second sulfur phase analysis includes: using the differential method or the acetic acid-hydrogen peroxide leaching method to measure the mass fraction of sulfur in the metal sulfide in the sample J12 accounting for the total mass of the taken sample J12.

[0031] In this embodiment, the second sulfur phase analysis is carried out on the enriched ore sample to obtain the mass fraction of sulfur in the metal sulfide in the sample J12 accounting for the total mass of the taken sample J12, and the mass fraction of sulfur in the metal sulfide in the enlarged ore sample accounting for the total mass of the taken sample J12. Finally, combined with other data, the content of metal sulfide in the original sample is obtained.

[0032] In some embodiments, in step S8, the magnification of the automatic mineralogical analysis test is 300-1000 times, and the number of tested particles is 30000-50000 grains.

[0033] In this embodiment, by magnifying a certain multiple in the automatic mineralogical analysis test, relatively fine particles can be detected; by detecting a certain number of particles, the test data is more representative.

[0034] In some embodiments, in step S8, the horizontal projection length of the cross-section of the i-th metal sulfide refers to the maximum horizontal intercept of the exposed surface of the mineral particles of the i-th metal sulfide.

[0035] In this embodiment, by using the automatic mineralogical analysis to take the ratio of the maximum horizontal intercept of the particle exposed surface as the ratio of the particle volume, it is more convenient than the traditional method of using a scale on a microscope to measure the ratio of the intercepted line lengths of the particle series of parallel straight lines cutting through each mineral, which is equal to the ratio of the volumes of each mineral, and is more suitable for detection by automatic mineralogical analysis instruments, and greatly reduces the influence of human subjective factors.

[0036] In some embodiments, in step S8, the sulfur content Si of the i-th metal sulfide is the average value of the sulfur content measurement results of at least 10 mineral particles of the i-th metal sulfide.

[0037] In this embodiment, the sulfur content of the enriched metal sulfide is measured by automatic mineralogical analysis to obtain the enlarged sulfur content of the metal sulfide. Finally, the sulfur content of the metal sulfide in the original ore sample can be obtained by combining other data.

[0038] The above description is only an overview of the technical solution of the present application. In order to be able to more clearly understand the technical means of the present application, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically given below. Brief Description of the Drawings

[0039] In order to more clearly illustrate the technical solution of the present application, the drawings used in the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0040] Figure 1 It is a flowchart of the method for determining the content of metal sulfide in Example 1.

[0041] Figure 2 It is an automatic mineralogical analysis test chart of pyrite (red particles) in the method for determining the content of metal sulfide in Example 1.

[0042] Figure 3 It is a test chart of the horizontal projection length of the cross section of pyrite (red particles) in the method for determining the content of metal sulfide in Example 1. Detailed Description of the Embodiments

[0043] The embodiments of the technical solution of the present application will be described in detail below. The following embodiments are only used to more clearly illustrate the technical solution of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0044] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0045] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features.

[0046] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the front and back associated objects.

[0047] In order to solve the problems that the existing methods for measuring the content of metal sulfides have inaccurate test results for low-content metal sulfides and cannot measure the content of different metal sulfides separately, the present application provides a method for measuring the content of metal sulfides. By performing sulfur phase analysis on the samples after grinding and after beneficiation by gravity separation and acid treatment enrichment respectively, and performing automated mineralogy analysis on the samples after beneficiation by gravity separation and acid treatment enrichment, the magnified data is corrected back into the data of the original samples, realizing accurate measurement of the content of low-content metal sulfides. Moreover, through automated mineralogy analysis, the content of different metal sulfides can be measured separately. In addition, when measuring the volume ratio of particles, the ratio of the maximum horizontal intercept of the exposed surface of the particles is used as the ratio of the volume of the particles. Compared with the traditional method of using a scale on a microscope to measure the ratio of the intercept lengths of a series of parallel straight lines cutting through each mineral, which is equal to the volume ratio of each mineral, it is more convenient, more suitable for detection by automated mineralogy analysis instruments, and greatly reduces the influence of human subjective factors. The test method provided by the present invention measures data accurately, greatly reduces the interference of human subjective factors, saves manpower, and provides reliable data support for the efficient utilization of such stone resources.

[0048] The present application provides a method for measuring the content of metal sulfides, comprising the following steps:

[0049] S1. Take a sample to be tested, grind it to obtain a sample after grinding;

[0050] S2. Uniformly sample the sample after grinding, perform the first sulfur phase analysis, and measure that the mass fraction of sulfur in the metal sulfide in the total mass of the sample after grinding taken is C11;

[0051] S3. Perform gravity separation on the sample after grinding to obtain a gravity separation concentrate J1 and a gravity separation tailing W1;

[0052] S4. Perform acid treatment on the gravity separation tailing W1, then wash the ore, filter, and dry to obtain a sample W2;

[0053] S5. Mix the gravity separation concentrate J1 and the sample W2 to obtain a sample J12;

[0054] S6. Uniformly sample the sample J12 and conduct a second sulfur phase analysis. The mass fraction of sulfur in the metal sulfide measured is C22, which is the mass of sulfur in the metal sulfide accounting for the total mass of the sampled sample J12.

[0055] S7. Sample the sample J12 to prepare an automatic mineralogy analysis sample J13.

[0056] S8. Conduct an automatic mineralogy analysis on the sample J13 to measure the sum of the horizontal projection lengths of the cross-sections of various metal sulfides and the sulfur content of various metal sulfides respectively. Among them, the sum of the horizontal projection lengths of the cross-section of the i-th metal sulfide is denoted as Li, and the sulfur content of the i-th metal sulfide is denoted as Si; Li = , where Lim represents the horizontal projection length of the cross-section of the m-th mineral particle in the i-th metal sulfide, i = 1, 2,..., n, n is the total number of types of metal sulfides measured, and m = 1, 2, 3,..., N, N is the total number of mineral particles of the i-th metal sulfide.

[0057] S9. Calculate the content of each metal sulfide in the sample J13 respectively. Among them, the content of the i-th metal sulfide is denoted as Mi’, Mi’ = ρi * Di * X, and Ci = Mi’ * Si, C22 = ; where ρi is the density of the i-th metal sulfide; Di is the volume ratio of the i-th metal sulfide, Di = Li / ; X is the conversion coefficient; Ci is the mass fraction of sulfur in the i-th metal sulfide accounting for the total mass of the sample J13.

[0058] S10. Calculate the content of each metal sulfide in the original sample. Among them, the content of the i-th metal sulfide in the original sample is denoted as Mi, then Mi = Mi’ * C11 / C22.

[0059] In the technical solution of the embodiment of the present application, by conducting sulfur phase analysis on the samples after grinding and after enrichment by gravity separation and acid treatment respectively, and conducting automatic mineralogy analysis on the samples after enrichment by gravity separation and acid treatment, the magnified data is corrected back to the data of the original sample, realizing the accurate measurement of the content of low-content metal sulfides. And through automatic mineralogy analysis, the content of different metal sulfides can be measured respectively. The test method provided by the present invention has accurate measurement data, greatly reduces the interference of human subjective factors, saves manpower, and provides reliable data support for the efficient utilization of such stone resources.

[0060] Further, in some embodiments, in step S1, the grinding fineness is that the content of -0.074mm is 75% - 95%.

[0061] In the technical solution of the embodiment of the present application, by grinding the sample to be measured to a certain fineness, it is convenient for the subsequent processing of the sample.

[0062] Further, in some embodiments, in step S2, the first sulfur phase analysis includes: using the differential method or the acetic acid-hydrogen peroxide leaching method to measure the mass fraction of sulfur in the metal sulfide in the ground sample accounting for the total mass of the taken ground sample.

[0063] In the technical solution of the embodiment of the present application, by measuring the mass fraction of sulfur in the metal sulfide in the ground sample accounting for the total mass of the taken ground sample, and finally through conversion, the content of metal sulfide in the original sample is obtained.

[0064] Further, in some embodiments, the differential method refers to the amount obtained by subtracting the sulfur in native sulfur and sulfates from the total sulfur amount. For the detection of the total sulfur amount, refer to GB / T7739.8-2007, and for the detection of sulfur in native sulfur and sulfates, refer to "Application of Determination Methods for Sulfur Phase Analysis"; for the acetic acid-hydrogen peroxide leaching method, refer to "Application of Determination Methods for Sulfur Phase Analysis".

[0065] Further, in some embodiments, in step S3, the gravity separation adopts the heavy liquid stirring separation method, and the gravity separation reagent is an aqueous solution mixture of thallium formate and thallium malonate; preferably, the mass ratio of thallium formate, thallium malonate and water is 7:7:1-2.

[0066] In the technical solution of the embodiment of the present application, through gravity separation, the metal sulfide in the ore sample is enriched.

[0067] Further, in some embodiments, in step S4, the acids in the acid treatment include hydrofluoric acid and sulfuric acid, the temperature of the acid treatment is 90-95°C in a water bath, and the time of the acid treatment is 22-26h; preferably, the hydrofluoric acid is of analytical purity, the concentration of sulfuric acid is 10%, the volume ratio of hydrofluoric acid to sulfuric acid is 1:1; the solid-liquid ratio of the gravity separation tailings W1 to the acid is 1:4.

[0068] In the technical solution of the embodiment of the present application, through the treatment with hydrofluoric acid and sulfuric acid, gangue, quartz, carbonate minerals, mica minerals, pyroxene minerals, etc. in the ore sample can be dissolved, while the metal sulfide is retained, and the metal sulfide is further enriched.

[0069] Further, in some embodiments, in step S7, the preparation process of the automatic mineralogy analysis sample includes:

[0070] S71. Mix the sample J12 and the thermosetting embedding material evenly at a volume ratio of 1:0.5 to 1:3, and cure them in an embedding machine at a temperature of 100 - 150 °C and a pressure of 200 - 300 Bar; the thermosetting embedding material is thermosetting phenolic epoxy resin, and the particle size of the thermosetting embedding material is not greater than 38 μm;

[0071] S72. Grind, polish and carbon spray the cured sample; in the grinding process, the sizes of the abrasives include 150 μm, 23 μm and 13 μm, and the grinding time is 8 - 10 min; the sizes of the polishing materials include 6 μm, 3 μm and 1 μm, and the polishing time is 8 - 10 min; the carbon spraying method is ion sputtering, and the thickness of the carbon spraying is 5 - 10 nm.

[0072] In the technical solution of the embodiment of the present application, the enriched metal sulfide is made into an automatic mineralogical analysis sample, and then automatic mineralogical analysis is carried out.

[0073] Further, in some embodiments, in step S6, the second sulfur phase analysis includes: using the difference method or the acetic acid - hydrogen peroxide leaching method to measure the mass fraction of sulfur in the metal sulfide in the sample J12 accounting for the total mass of the taken sample J12.

[0074] In the technical solution of the embodiment of the present application, the second sulfur phase analysis is carried out on the enriched ore sample to obtain the mass fraction of sulfur in the metal sulfide in the sample J12 accounting for the total mass of the taken sample J12, obtain the mass fraction of sulfur in the metal sulfide in the magnified ore sample accounting for the total mass of the taken sample J12, and finally combine other data to obtain the content of the metal sulfide in the original sample.

[0075] Further, in some embodiments, the difference method refers to the amount obtained by subtracting the sulfur in native sulfur and sulfates from the total sulfur amount. For the detection of the total sulfur amount, refer to GB / T7739.8 - 2007, and for the detection of sulfur in native sulfur and sulfates, refer to "Application of Determination Methods for Sulfur Phase Analysis"; for the acetic acid - hydrogen peroxide leaching method, refer to "Application of Determination Methods for Sulfur Phase Analysis".

[0076] Further, in some embodiments, in step S8, the magnification of the automatic mineralogical analysis test is 300 - 1000 times, and the number of tested particles is 30000 - 50000 grains.

[0077] In the technical solution of the embodiment of the present application, by magnifying a certain multiple in the automatic mineralogical analysis test, relatively fine particles can be detected; by detecting a certain number of particles, the test data is more representative.

[0078] Further, in some embodiments, in step S8, the horizontal projected length of the cross-section of the i-th metal sulfide refers to the maximum horizontal intercept of the exposed surface of the mineral particles of the i-th metal sulfide.

[0079] In the technical solution of the embodiment of the present application, by automatic mineralogical analysis, the ratio of the maximum horizontal intercept of the exposed surface of the particles is used as the ratio of the volume of the particles. Compared with the traditional method of using a scale on a microscope to measure the ratio of the intercepted line lengths of a series of parallel straight lines cutting through each mineral, which is equal to the volume ratio of each mineral, it is more convenient, more suitable for detection by an automatic mineralogical analysis instrument, and greatly reduces the influence of human subjective factors.

[0080] Further, in some embodiments, in step S8, the sulfur content Si of the i-th metal sulfide is the average value of the sulfur content measurement results of at least 10 mineral particles of the i-th metal sulfide.

[0081] In the technical solution of the embodiment of the present application, the sulfur content of the enriched metal sulfide is measured by automatic mineralogical analysis to obtain an amplified sulfur content of the metal sulfide. Finally, the sulfur content of the metal sulfide in the original ore sample can be calculated by combining other data.

[0082] The following lists some specific embodiments. 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 a limitation of the present application. For those without specific techniques or conditions noted in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in this field or according to the product specifications. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0083] Example 1

[0084] This embodiment provides a method for determining the content of metal sulfide, as Figure 1 shown, which specifically includes the following steps:

[0085] (1) Weigh 1000 g of the sample to be measured, and the grinding fineness is 85% with a particle size of -0.074 mm.

[0086] (2) Weigh 5 g of the ground sample, and use the "Application of Sulfide Phase Analysis and Determination Method" to measure that the mass fraction C11 of sulfur in the metal sulfide in it accounts for the total mass of the taken ground sample is 0.244%.

[0087] (3) Weigh 500 g of the ground sample, and use the heavy liquid stirring separation method for gravity separation to obtain gravity separation concentrate J1 and gravity separation tailings W1. Among them, the gravity separation reagent is a mixed solution prepared with thallium formate: thallium malonate: water = 7:7:1 by mass ratio.

[0088] (4) Prepare a 1000 mL mixture of analytical pure hydrofluoric acid and 10% sulfuric acid with a volume ratio of 1:1 and add it to the gravity separation tailings W1. Treat it in a 90 °C water bath for 25 h, then wash, filter, and dry to obtain sample W2.

[0089] (5) Mix the gravity separation concentrate J1 and sample W2 to obtain sample J12.

[0090] (6) Weigh 5 g of sample J12 and use the "Application of Sulfide Phase Analysis and Determination Method" to measure that the mass fraction C22 of sulfur in metal sulfides in the taken sample J12 accounts for the total mass of the sample J12 is 25.622%.

[0091] (7) Preparation of the automatic mineralogy analysis sample: Mix sample J12 and thermosetting phenolic epoxy resin with a particle size of 400 mesh all passing through evenly at a volume ratio of 1:3, and cure it in an embedding machine at a temperature of 150 °C and a pressure of 200 Bar; Grind and polish the cured sample and perform carbon spraying treatment to obtain sample J13; The abrasive sizes are 150 μm, 23 μm, and 13 μm, and grind for 8 min; The sizes of the polishing materials are 6 μm, 3 μm, and 1 μm, and polish for 8 min; The carbon spraying method is ion sputtering, and the carbon spraying thickness is 5 nm.

[0092] (8) Conduct automatic mineralogy analysis on sample J13. Adjust the magnification of the automatic mineralogy analysis instrument to 800 times, and measure the sum of the horizontal projection lengths Li of the cross-sections of a certain metal sulfide and the sulfur content Si of a certain metal sulfide in 50000 grains of the sample respectively. Li = , Lim represents the horizontal projection length of the cross-section of the m-th mineral particle of the i-th metal sulfide, i = 1, 2,..., n, n is the total number of types of metal sulfides measured, m = 1, 2, 3,..., N, N is the total number of mineral particles of the i-th metal sulfide; In this embodiment, the mineral contains two metal sulfides. When i = 1, it is pyrite, and when i = 2, it is chalcopyrite. Taking pyrite as an example, its automatic mineralogy analysis test is as Figure 2 shown, and the measurement of the horizontal projection length of its cross-section is as Figure 3 shown; Then L2 = L1m + L2m = 1.570687 cm, S1 = 53.50%, S2 = 32.20%.

[0093] (9) Calculate the content of each metal sulfide in sample J13 respectively. Among them, the content of the i-th metal sulfide is denoted as Mi', Mi' = ρi * Di * X, and Ci = Mi' * Si, C22 = ; Among them, ρi is the density of the i-th metal sulfide; Di is the volume ratio of the i-th metal sulfide, Di = Li / ; X is the conversion coefficient; Ci is the mass fraction of sulfur in the i-th metal sulfide in the total mass of the sample J13; then M1’ = ρ1 * D1 * X, M2’ = ρ2 * D2 * X, C1 = M1’ * S1, C2 = M2’ * S2, C22 = C1 + C2 = 25.622%; D1 = L1m / (L1m + L2m) = 0.843703, D2 = L2m / (L1m + L2m) = 0.156297; X = 10.05184% is obtained, M1’ = 44.10%, M2’ = 6.30%.

[0094] (10) Calculate the content of each metal sulfide in the original sample. Among them, the content of the i-th metal sulfide in the original sample is denoted as Mi, then M1 = M1’ * C11 / C22 = 44.10% * 0.24402 / 25.6221 = 0.42%, M2 = M2’ * C11 / C22 = 6.30% * 0.24402 / 25.6221 = 0.06%.

[0095] Comparative Example 1

[0096] This comparative example provides a method for determining the content of metal sulfides, which specifically includes the following steps:

[0097] (1) Weigh 1000 g of the ore sample in Example 1 as the sample to be tested, and the grinding fineness is 85% with a particle size of -0.074 mm.

[0098] (2) Preparation of the automatic mineralogy analysis sample: Weigh 5 g of the ground sample, mix it evenly with thermosetting phenolic epoxy resin with a particle size of 400 mesh all passing through at a volume ratio of 1:3, and cure it in an embedding machine at a temperature of 150 °C and a pressure of 200 Bar; Grind and polish the cured sample and perform carbon spraying treatment to obtain sample J13; The abrasive sizes are 150 μm, 23 μm, and 13 μm, and grind for 8 min; The polishing material sizes are 6 μm, 3 μm, and 1 μm, and polish for 8 min; The carbon spraying method is ion sputtering, and the carbon spraying thickness is 5 nm.

[0099] (3) Conduct automatic mineralogy analysis. Adjust the magnification of the automatic mineralogy analysis instrument to 800 times, and the content of pyrite in 50,000 grains of the sample is measured to be 0.33%, and the content of chalcopyrite is 0.15%.

[0100] Comparing the test results of the gold content in Comparative Example 1 and Comparative Ratio 1, it can be seen that the content of pyrite obtained by directly using the conventional automated mineralogical analysis method in Comparative Ratio 1 is significantly lower, while the content of chalcopyrite is higher. This is because for low-content metal sulfides, the conventional automated mineralogical analysis method uses the area method to determine the content of metal sulfides. On the one hand, the number of measured particles is too small, and on the other hand, the area of low-content metal sulfides is smaller than that of other gangue minerals, resulting in a large contingency and significant deviation in the data.

[0101] Example 2

[0102] This example provides a method for determining the volume ratio of metal sulfides, which specifically includes the following steps:

[0103] Sample J13 in Example 1 was sampled 5 times, and the sum of the horizontal projection lengths Li of the cross-sections of each metal sulfide in the sample was measured by the automated mineralogical analysis method using the method in step (8) of Example 1, and the volume ratio Di of each metal sulfide in the sample was calculated therefrom. The results are shown in Table 1.

[0104] Table 1 Sum of the horizontal projection lengths and volume ratios of the cross-sections of each metal sulfide in the sample obtained from the 5 tests in Example 2

[0105]

[0106] Comparative Ratio 2

[0107] This comparative ratio provides a method for determining the volume ratio of metal sulfides, which specifically includes the following steps:

[0108] The volume ratios of each metal sulfide in sample J13 in Example 1 were measured 5 times respectively by the straight-line method, and the test results are shown in Table 2.

[0109] The test method is as follows: First, place an eyepiece micrometer scale (scale length 1 cm, divided into 100 equal parts, and each small grid is 0.1 mm long) at the focal plane of the eyepiece barrel, and hold the prepared polished section with a mechanical stage on the stage. After adjusting the focus, a 100-equal-part grid scale will be seen superimposed on various mineral particles on the polished section in the field of view. Then, use the mechanical stage to move the first field of view to be measured to a certain base angle of the polished section. At this time, the number of grids intercepted by various mineral particles on the eyepiece scale, that is, the intercept distance Bi, can be counted. Count one field of view after another on a straight line. After measuring one straight line, move the polished section 2 mm with the mechanical stage and continue to measure the intercept distances of various mineral particles on the second measurement line. Continue until the entire polished section is measured, and measure 20 fields of view.

[0110] Finally, the intercept distance Bi and volume ratio D of each metal sulfide in the sample are obtained ， See Table 2 for details.

[0111] Table 2 Intercept distance and volume ratio of each metal sulfide in the samples obtained from the five tests in Comparative Example 2

[0112]

[0113] By comparing the test results of the volume ratio of metal sulfides in Example 2 and Comparative Example 2, it can be seen that the test results of Example 2 and Example 2 are not much different, but the test result data of 5 in Example 2 is more stable, indicating that the test method results of this scheme are reliable, and the interference factors of manual operation are reduced, the test results are more stable, and the operation is simpler.

[0114] In summary, the present application provides a method for determining the content of metal sulfides. By performing sulfide phase analysis on samples after grinding and after re-selection and acid treatment enrichment, and performing automatic mineralogical analysis on samples after re-selection and acid treatment enrichment, the amplified data is corrected back to the data of the original sample, so as to achieve accurate measurement of the content of low-content metal sulfides, and the content of different metal sulfides can be measured separately through automatic mineralogical analysis. In addition, when testing the volume ratio of the particles, the ratio of the horizontal maximum intercepts of the particle exposure surface is used as the ratio of the volume of the particles. Compared with the traditional method of adding a scale to a microscope, measuring the ratio of the intercept lengths of the parallel straight lines of the particle series that cut through each mineral, which is equal to the volume ratio of each mineral, the method is more convenient and more suitable for automatic mineralogical analysis instrument detection, and greatly reduces the influence of human subjective factors. The test method provided by the present invention measures data accurately, greatly reduces the interference of human subjective factors, saves manpower, and provides reliable data support for the efficient use of such stone resources.

[0115] 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 the same effect as 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 determining the content of metal sulfide, characterized in that: The following steps are involved: S1. Take the sample to be tested, grind it, and obtain a ground sample; S2. uniformly sampling the ground sample, performing a first sulfur phase analysis, and measuring the mass fraction of sulfur in the metal sulfide to the total mass of the ground sample as C11; S3. Re-select the sample after grinding to obtain a gravity-selected concentrate J1 and a gravity-selected tailing W1; S4. The gravity separation tailings W1 are treated with acid, then washed, filtered, and dried to obtain a sample W2; S5. Mixing the gravity separation concentrate J1 and sample W2 to obtain sample J12; S6. uniformly sample the sample J12, perform a second sulfur phase analysis, and measure the mass fraction of sulfur in the metal sulfide to the total mass of the sample J12 to be C22; S7. Sampling the sample J12 and preparing the sample J13 for automatic mineralogical analysis; S8. Perform automatic mineralogical analysis on the sample J13, and measure the sum of the horizontal projection lengths of the cross sections of various metal sulfides and the sulfur content of various metal sulfides, wherein the sum of the horizontal projection lengths of the cross sections of the i-th metal sulfide is recorded as Li, and the sulfur content of the i-th metal sulfide is recorded as Si; Li= , Lim represents the horizontal projection length of the cross section of the mth mineral grain in the i-th metal sulfide, i=1, 2, ..., n, n is the total number of types of metal sulfides measured, m=1, 2, 3, ..., N, N is the total number of mineral grains of the i-th metal sulfide; S9. Calculate the content of each metal sulfide in the sample J13, wherein the content of the i-th metal sulfide is recorded as Mi', Mi'=ρi*Di*X, ​​and Ci=Mi'*Si, C22= ; where ρi is the density of the i-th metal sulfide; Di is the volume fraction of the i-th metal sulfide, Di=Li / ; X is the conversion coefficient, which can be obtained from C22 measured in step S6, and Ci=Mi'*Si, C22= , Mi'=ρi*Di*X is obtained by reverse deduction, Ci is the mass fraction of sulfur in the i-th metal sulfide to the total mass of the sample J13; S10. Calculate the content of each metal sulfide in the original sample, wherein the content of the i-th metal sulfide in the original sample is recorded as Mi, then Mi=Mi'*C11 / C22.

2. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S1, the grinding fineness is -0.074 mm and the content is 75% to 95%.

3. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S2, the first sulfur phase analysis includes: using a differential method or an acetic acid-hydrogen peroxide leaching method to measure the mass fraction of the mass of sulfur in the metal sulfide in the ground sample to the total mass of the ground sample.

4. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S3, the gravity separation adopts a heavy liquid stirring separation method, and the gravity separation reagent is a mixture of aqueous solutions of thallium formate and thallium malonate.

5. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S4, the acid in the acid treatment includes hydrofluoric acid and sulfuric acid; the temperature of the acid treatment is 90-95° C. in a water bath, and the time of the acid treatment is 22-26 hours.

6. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S7, the automatic mineralogical analysis sample preparation process includes: S71. The sample J12 is mixed with a thermosetting inlay material in a volume ratio of 1:0.5 to 1:3, and cured in an inlay machine at a temperature of 100 to 150°C and a pressure of 200 to 300 Bar; the thermosetting inlay material is a thermosetting phenolic epoxy resin, and the particle size of the thermosetting inlay material is not greater than 38 μm; S72. Grind and polish the solidified sample and perform carbon spraying. In the grinding and polishing, the sizes of the abrasives include 150 μm, 23 μm and 13 μm, and the grinding time is 8 to 10 min. The sizes of the polishing materials include 6 μm, 3 μm and 1 μm, and the polishing time is 8 to 10 min. The carbon spraying method is ion sputtering, and the thickness of the carbon spraying is 5 to 10 nm.

7. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S6, the second sulfur phase analysis includes: using a differential method or an acetic acid-hydrogen peroxide leaching method to measure the mass fraction of the mass of sulfur in the metal sulfide in the sample J12 to the total mass of the sample J12.

8. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S8, the magnification of the automatic mineralogical analysis test is 300-1000 times, and the number of particles tested is 30,000-50,000.

9. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S8, the horizontal projection length of the cross section of the i-th metal sulfide refers to the horizontal maximum intercept of the surface where the mineral particles of the i-th metal sulfide appear.

10. The method for determining the content of metal sulfide according to claim 1, characterized in that: In step S8, the sulfur content Si of the i-th metal sulfide is an average value of the sulfur content measurement results of at least 10 mineral particles of the i-th metal sulfide.

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