Preparation method and inspection method of mineral proficiency testing sample

Abstract

The invention relates to the technical field of mineral detection, and particularly provides a preparation method and a detection method of a mineral proficiency testing sample. The method comprises the following steps: determining types and content ranges of target elements to be detected for mineral proficiency testing, screening and determining mineral raw materials for proficiency testing, grinding and uniformly mixing, carrying out primary detection on uniformity, and judging a data result and method applicability by utilizing a specific formula. And verifying the accuracy of detection data and the credibility of a capability verification result by adopting F test, t test and the like.

Description

Technical Field

[0001] This invention relates to the field of mineral testing technology, specifically to a method for preparing and testing mineral proficiency testing samples. Background Technology

[0002] Proficiency testing refers to the activity of evaluating the competence of participants according to pre-established criteria. It is usually carried out through inter-laboratory comparisons to demonstrate the reliability of a laboratory's measurement results.

[0003] Proficiency testing samples are test samples specifically designed for proficiency testing activities. These samples are prepared by the proficiency testing provider and distributed to participating laboratories. Participating laboratories, with little or no prior knowledge of the samples, test them according to their routine testing procedures and report the results to the organizer. Proficiency testing samples are used to evaluate the testing capabilities and reliability of the participating laboratories. The consistency of proficiency testing samples over time and space is crucial for proficiency testing activities utilizing inter-laboratory comparisons. When implementing a proficiency testing program, the organizer should ensure that unsatisfactory results are not attributable to variability between or within samples. Therefore, effective preparation and testing of proficiency testing samples are essential. Scientifically sound methods for preparing mineral proficiency testing samples and appropriate testing methods are prerequisites for the successful implementation of the proficiency testing program.

[0004] Currently, there is a lack of relatively scientific and effective preparation and testing methods for proficiency testing samples of minerals. Summary of the Invention

[0005] Therefore, it is necessary to provide a method for preparing and testing mineral proficiency testing samples.

[0006] The present invention adopts the following technical solutions: This invention provides a method for preparing a mineral proficiency testing sample, comprising the following steps: determining the target element type and content range to be detected in the mineral proficiency testing; screening mineral raw materials that meet the requirements of the target element type and content range; drying the mineral raw materials to constant weight and cooling them to obtain dried mineral material; grinding the dried mineral material to ensure that the particle size meets the requirement that 98% is less than 200 mesh (0.074 mm) to obtain ground mineral material; and mixing all the ground mineral materials to obtain the mineral proficiency testing sample. Preferably, a ball mill or rod mill is used to grind the dried mineral material, and a V-type mixer or a three-dimensional mixer is used to mix the ground mineral material.

[0007] This invention also provides a method for testing mineral proficiency testing samples, comprising the following steps: preparing mineral proficiency testing samples according to the above preparation method; performing a preliminary homogeneity test on the mineral proficiency testing samples, and using a one-way ANOVA method to perform an F-test on the results of the preliminary homogeneity test to preliminarily determine whether the homogeneity meets the requirement that the statistic (F) is less than the critical value (Fα); if the preliminary homogeneity test meets the preset requirements, a second homogeneity test is performed, wherein the second homogeneity test includes a suitability determination of the analytical method, and the determination formula is as follows: In the formula: n refers to the number of tests, S refers to the standard deviation of the test results, and r refers to the repeatability limit of the national standard method; If the suitability assessment result of the analytical method meets the preset requirements, the test results of the detection sequence and processing sequence are analyzed to determine whether they meet the requirements. If the suitability assessment result of the analytical method does not meet the preset requirements, the obtained analytical results must be discarded and a new analytical method must be used. If the analysis results of the detection sequence or processing sequence do not meet the preset requirements, the mineral proficiency testing sample is deemed unqualified. If the analysis results of the detection sequence or processing sequence meet the preset requirements, the homogeneity secondary test is deemed qualified. If the homogeneity secondary test meets the preset requirements, a stability test is performed to determine whether the stability meets the preset requirements. If the stability test does not meet the preset requirements, the mineral proficiency testing sample is deemed unqualified. If the stability test meets the preset requirements, the retained sample will be retested. The t-test method will be used to analyze and determine whether the stability of the sample can cover the entire proficiency testing cycle. If the test meets the requirements, the mineral proficiency testing sample will be deemed qualified; otherwise, the mineral proficiency testing sample will be deemed unqualified.

[0008] In some embodiments, the method steps for the initial uniformity test are as follows: the mineral proficiency testing sample is laid flat and evenly divided into N regions. Each region is numbered from left to right and from top to bottom as region 1 to N. Sufficient mass samples are taken from the upper, middle and lower parts of each region and placed in three sample bags respectively to complete the sampling. The initial test samples are numbered according to the region number in the order of 1-1, 1-2, 1-3, ..., N-1, N-2, N-3. If N is even and N≥3, the target element content of the initial test sample shall be detected in the following order under the same conditions: 1-1—2-1—3-1—4-1—5-1···—N-1; N-2···—5-2—4-2—3-2—2-2—1-2; 1-3—3-3—5-3···—(N-1)-3—2-3—4-3···—N-3; If N is odd and N≥3, the detection shall be performed in the following order under the same conditions: 1-1—2-1—3-1—4-1—5-1···—N-1; N-2···—5-2—4-2—3-2—2-2—1-2; 1-3—3-3—5-3···—N-3—2-3—4-3···—(N-1)-3.

[0009] In some embodiments, the sampling method in the second uniformity inspection includes: disassembling the samples that pass the initial uniformity inspection into X units, numbering them 1 to X according to the disassembly order; randomly selecting Y units and recording them as numbered 1 to Y, and then sampling and testing again according to the sampling method and testing order of the initial uniformity inspection.

[0010] In some embodiments, the correspondence between the number of extracted units Y and the total number of units X is as follows: if X≤100, then Y takes the maximum value of 3, 10%X; if 100<X≤200, then Y≥11; if 200<X≤500, then Y≥15; if 500<X≤1000, then Y≥25; if X≥1000, then Y=30.

[0011] In some embodiments, the stability test includes: conducting a 7-day simulated experiment on the sample under shock conditions, taking samples on day 0, day 1, day 3, and day 7, and analyzing the test results using a linear fitting method to determine whether the transportation conditions affect the test results.

[0012] In some embodiments, a linear fitting method is used for analysis to determine whether the detection order and processing order affect the detection results; then a one-way ANOVA method (F test) is used for analysis to determine whether the uniformity of the packaged samples meets the requirements.

[0013] Compared with the prior art, the core advantages and beneficial effects of this invention are as follows: The mineral proficiency testing sample preparation method of this invention is prepared by screening mineral raw materials, calculating the proportion, drying, grinding, weighing, and mixing. In particular, by ensuring that the particle size meets the requirement that 98% of the samples are less than 200 mesh (0.074 mm), the consistency of the samples in time and space is guaranteed, which can meet the requirements of different proficiency testing programs for the types of mineral proficiency testing samples, the types of elements contained and the content.

[0014] This invention explores a formula for determining the applicability of analytical methods used in homogeneity testing for mineral proficiency testing. This formula can relatively scientifically and quickly eliminate interference from analytical methods in homogeneity testing. It also combines one-way variance method (F-test) and linear fitting method to eliminate the influence of testing order and processing order on the test results. In the sample stability testing process, not only is the t-test used to determine whether the sample stability can cover the entire proficiency testing program cycle, but the linear fitting method is also used to eliminate the influence of the transportation process on sample stability. Through simultaneous stability and classical stability studies, the accuracy of mineral proficiency testing sample test results and the reliability of proficiency testing results are comprehensively guaranteed. Attached Figure Description

[0015] Figure 1 This is a trend analysis chart of Au, Ag, and Cu content in the gold concentrate proficiency testing sample from Example 1.

[0016] Figure 2 This is a production trend analysis chart of Au, Ag, and Cu content in the gold concentrate capability verification sample of Example 1.

[0017] Figure 3 This is a trend analysis chart of Au, Ag, and Pb content in the lead concentrate proficiency testing sample from Example 2.

[0018] Figure 4 This is a production trend analysis chart of Au, Ag, and Pb content in the lead concentrate capability verification sample from Example 2.

[0019] Figure 5 A graph showing the processing trend of Cu content in the copper concentrate capability verification samples for comparative analysis. Detailed Implementation The present invention will be further described in detail below with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention. The following embodiments are only used to illustrate the present invention, and are not intended to limit the scope of the present invention. Based on the specific embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. In the embodiments of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the embodiments of the present invention, unless specifically specified, the technical means used are conventional means well known to those skilled in the art.

[0020] In this invention, the standards for detecting the content of target elements in mineral materials are as follows: The method for determining the gold (Au) content is the fire assay gravimetric method (GB / T7739.1-2019 "Chemical Analysis Methods for Gold Concentrates - Part 1: Determination of Gold and Silver Content"). The sample is prepared and melted to obtain a suitable mass of lead briquettes containing precious metals and brittle slag. Gold and silver are separated from the lead briquettes by ash blowing to obtain gold-silver granules. After gold separation with nitric acid, the gold content is determined by gravimetric method.

[0021] The method for determining the content of silver (Ag) is flame atomic absorption spectrometry (GB / T7739.2-2019 "Chemical Analysis Methods for Gold Concentrates - Part 2: Determination of Silver Content by Flame Atomic Absorption Spectrometry"). The sample is decomposed by hydrochloric acid, nitric acid, and perchloric acid. In a dilute hydrochloric acid medium, the absorbance of silver is measured at a wavelength of 328.1 nm using an air-acetylene flame on a flame atomic absorption spectrometer. The amount of silver is calculated according to the standard curve method.

[0022] Method for determining copper (Cu) content: Flame atomic absorption spectrometry (GB / T7739.4-2021 "Chemical Analysis Methods for Gold Concentrates - Part 4: Determination of Copper Content"). The sample is decomposed by hydrochloric acid, nitric acid, and perchloric acid. In a dilute hydrochloric acid medium, the absorbance of copper is measured at a wavelength of 324.7 nm using an air-acetylene flame on a flame atomic absorption spectrometer. The copper content is calculated according to the standard curve method.

[0023] The method for determining lead (Pb) content is the EDTA titration method (GB / T8152.1-2006 "Chemical Analysis Methods for Lead Concentrate: Determination of Lead Content by Acid Dissolution-EDTA Titration"). The sample is dissolved in nitric acid, sulfuric acid, and bromine water. Arsenic, antimony, and tin are removed by treatment with hydrobromic acid. Lead is separated from other interfering elements by lead sulfate precipitation. The precipitate dissolves in ammonium acetate solution, and xylenol orange is used as an indicator. The lead in the solution is then titrated with EDTA.

[0024] The method for determining zinc (Zn) content is the precipitation-EDTA titration method (GB / T8151.1-2012 "Chemical Analysis Methods for Zinc Concentrates - Part 1: Determination of Zinc Content - Precipitation-EDTA Titration Method"). The sample is dissolved in hydrochloric acid, nitric acid, and sulfuric acid to precipitate and separate coexisting elements such as iron, manganese, and lead. A masking agent is added to the filtrate to mask any small amounts of interfering elements. Titration is performed in an acetate-sodium acetate buffer solution at pH 5-6, using xylenol orange as an indicator, with standard EDTA titration solution. The measured result is the combined amount of zinc and cadmium; subtracting the cadmium content gives the zinc content.

[0025] The following example illustrates this.

[0026] Example 1 This embodiment provides a method for preparing and testing gold concentrate proficiency testing samples, including the following steps: S1, determine the types and content ranges of target elements to be tested in the proficiency testing of gold concentrate.

[0027] Gold (Au) content: 40-50 g / t; Silver (Ag) content: 100-200 g / t; Copper (Cu) content: <2%.

[0028] S2, screening mineral raw materials that meet the requirements of the target element type and content range.

[0029] An investigation revealed that there is a commercially available gold concentrate raw material that meets the requirements for the types and content ranges of the target elements: gold content is approximately 44 g / t, silver content is approximately 130 g / t, and copper content is approximately 0.6%. S3, determine the amount of crude mineral feedstock required for the gold concentrate capability verification.

[0030] Approximately 10 kg of gold concentrate raw material was identified that met the requirements for the types and content ranges of the target elements.

[0031] S4, Prepare gold concentrate capability verification samples.

[0032] The gold concentrate raw material was dried at 100℃ to constant weight (weighed every hour until the weight no longer changed), and then placed in a desiccator to cool naturally, obtaining dried mineral material. The dried mineral material was then ground in a rod mill to ensure that 98% of the particles were less than 200 mesh, obtaining ground mineral material. The ground mineral material was then further mixed in a three-dimensional mixer to obtain a ground and mixed gold concentrate sample.

[0033] S5, Initial homogeneity test of the ground gold concentrate sample.

[0034] The ground gold concentrate sample was spread on a plastic film and evenly divided into 6 regions (m). Each region was numbered 1 to 6 in the order from left to right and from top to bottom. Sufficient mass of ground gold concentrate sample was then taken from the surface, middle and lower layers of each region and numbered 1 to 3 respectively. The samples were placed in 3 sample bags and tested in the order of 1-1 (region number 1 + upper layer number 1), 1-2, 1-3, 2-1... 6-3 (region number 6 + lower layer number 3).

[0035] Under the same conditions, the Au, Ag, and Cu contents were determined according to the following sample collection order: 1-1—2-1—3-1—4-1—5-1—6-1; 6-2—5-2—4-2—3-2—2-2—1-2; 1-3—3-3—5-3—2-3—4-3—6-3.

[0036] The initial homogeneity test results were analyzed using the one-way ANOVA method (F-test). The content tests for Au, Ag, and Cu are shown in the table below: Table 1. Statistical analysis of preliminary data on the uniformity of Au in ground gold concentrate samples. Table 2. Statistical analysis and test results of the initial test on the homogeneity of Ag in the ground gold concentrate samples. Table 3. Statistical analysis and test results of preliminary inspection data on the homogeneity of Cu in milled gold concentrate. The homogeneous gold concentrate that passed the initial homogeneity inspection was repackaged into 80 bags, numbered from 01 to 80. Eight bags were randomly selected and numbered sequentially from 1 to 8. Each bag sample was tested in triplicate. The measurement data were analyzed using a linear fitting method to determine whether the testing and processing order affected the results. A one-way ANOVA (F-test) was then used to determine whether the homogeneity of the repackaged samples met the requirements. The sampling sequence and numbering are shown in the table below: Table 4 Sampling sequence number and sample number of gold concentrate samples The eight gold concentrate samples were numbered 1-2-3-4-5-6-7-8, 8-7-6-5-4-3-2-1, and 1-3-5-7-2-4-6-8; a total of 24 test records were generated, numbered 1 to 24 (see table below). The test results are shown in the table below: Table 5. Serial Number and Result of Gold Concentrate Samples The suitability of the testing and analysis method is confirmed using the following formula: Where: S—standard deviation of the test data; n—Number of tests; r—Repeatability limit of the national standard method.

[0037] The calculation results are shown in the table below: Table 6. Results of Applicability Assessment of Detection Methods for Various Elements in Gold Concentrate Samples The linear fitting method was further used to determine whether the detection order and processing order had a significant impact on the detection and analysis results, and the F test was then used to determine whether the uniformity of the packaged samples met the requirements. The test results were analyzed according to the test sequence number. The analysis results are shown below. Figure 1 and the table below: Table 7. Analysis of the detection trends of Au, Ag, and Cu in gold concentrate samples. Based on the correspondence between the extracted sample numbers and the original sample numbers, the test results were reordered in ascending order of the original numbers. Then, the test results were analyzed according to the production sequence. The analysis results are shown in the table below: Table 8. Production Trend Analysis of Au, Ag, and Cu in Gold Concentrate Samples Based on the confirmation that neither the testing sequence nor the production sequence has a significant impact on the test results, the F-test was used to analyze the test data to determine whether its uniformity was acceptable. The analysis results are shown in the table below: Table 9. Homogeneity test of gold in gold concentrate samples Table 10 Homogeneity test of silver in gold concentrate samples Table 11 Homogeneity test of copper in gold concentrate samples After passing the homogeneity test, the samples underwent stability testing. To verify the stability of the samples under transportation conditions, the homogeneous samples were subjected to a 7-day simulated test under vibration conditions. Samples were taken at four time points: day 0, day 1, day 3, and day 7, and tested at each time point. The test data were analyzed using a linear fitting method to determine whether the transportation conditions affected the test results. After all proficiency testing participants returned their test data, the retained samples were tested again, and the measurement data were analyzed using a t-test to determine whether the sample stability covered the entire proficiency testing cycle. The test results and data analysis of the gold concentrate samples after the vibration test are shown in the table below: Table 12 Analysis of shock test data of gold in gold concentrate samples Table 13 Analysis of shock test data for silver in gold concentrate samples Table 14 Analysis of shock test data of copper in gold concentrate samples After all proficiency testing participants returned their test data, the prepared proficiency testing samples were tested again and compared with the test data before sample submission. The test data and comparison results are shown in the table below: Table 15 Analysis of Stability Test Data for Gold in Gold Concentrate Samples Table 16 Analysis of Stability Test Data of Silver in Gold Concentrate Samples Table 17 Analysis of Stability Test Data for Copper in Gold Concentrate Samples Example 2 This embodiment provides a method for preparing and testing lead concentrate proficiency testing samples, including the following steps: S1, determine the types and content ranges of target elements to be tested in the proficiency testing of lead concentrate.

[0038] Gold (Au) content: 2-5 g / t; Silver (Ag) content: 500-1000 g / t; Lead (Pb) content: >60%.

[0039] S2, screen mineral raw materials and crude dosage that meet the requirements of target element type and content range.

[0040] Investigation revealed that commercially available single lead concentrate raw materials could not meet the target element type and content range, necessitating the use of a mixture of commercially available lead concentrate raw materials and high-grade gold concentrate raw materials. Commercially available lead concentrate raw materials contain approximately 0.8 g / t of gold, approximately 800 g / t of silver, and approximately 67% lead.

[0041] Commercially available high-grade gold concentrate raw materials: gold content is approximately 450g / t, silver content is approximately 300g / t, and lead content is approximately 8%. The required amount of mineral raw materials for the gold concentrate capability verification is approximately 10 kg. The proportion of mineral raw materials that meet the requirements of the target element type and content range is calculated as follows: approximately 9 kg of lead concentrate raw material and approximately 1 kg of high-grade gold concentrate raw material.

[0042] S3, Prepare lead concentrate capability verification samples.

[0043] Commercially available lead concentrate and high-grade gold concentrate were dried at 100℃ to constant weight (weighed every hour until the weight no longer changed), and then naturally cooled in a desiccator to obtain dried mineral materials. The dried mineral materials were then ground separately in a rod mill to ensure that 98% of the particles were less than 200 mesh, yielding ground mineral materials. Commercially available lead concentrate ground mineral materials and high-grade gold concentrate ground mineral materials were weighed at a mass ratio of 9:1 and thoroughly mixed in a three-dimensional mixer to obtain the ground and mixed lead concentrate sample. Initial homogeneity testing was performed on the ground lead concentrate sample: The ground lead concentrate sample was spread on a plastic film and evenly divided into 6 areas. Each area was numbered 1 to 6 from left to right and top to bottom. Sufficient mass of ground mineral material samples were then taken from the upper, middle, and lower layers of each area and numbered 1 to 3 respectively. These samples were placed in 3 sample bags and numbered in the order of 1-1, 1-2, 1-3, 2-1, up to 6-3. Under the same conditions, the Au, Ag, and Pb contents were tested according to the same testing sequence as in the above embodiment.

[0044] The results of Au, Ag, and Pb content testing and preliminary uniformity inspection were analyzed using the one-way ANOVA method (F-test), as shown in the table below: Table 18 Statistical analysis and test results of preliminary inspection data on the homogeneity of gold in lead concentrate samples. Table 19 Statistical analysis and test results of preliminary inspection of silver homogeneity in lead concentrate samples Table 20. Statistical analysis and test results of preliminary inspection of lead homogeneity in lead concentrate samples. After passing the initial uniformity test, the samples were divided into 80 bags and numbered 1 to 80 according to the packaging order. Eight bags were randomly selected using a random number table method, and their numbers (1 to 8) were recorded. Each bag was tested three times. The sampling sequence and numbering are shown in the table below: Table 21 Sampling sequence number and sample number of lead concentrate samples The eight lead concentrate samples were tested using the same method described above. The test numbers and results are shown in the table below: Table 22 Serial Number and Result of Lead Concentrate Samples The suitability of the testing method is confirmed using the following formula: Where: S—standard deviation of test data; n—number of tests; r—repeatability limit of national standard method.

[0045] The calculation results are shown in the table below: Table 23 Results of Applicability Assessment of Detection Methods for Each Element in Lead Concentrate Samples The measurement data were analyzed using a linear fitting method to determine whether the testing and processing order affected the test results. Then, a one-way ANOVA (F-test) was used to determine whether the homogeneity of the packaged samples met the requirements. The test results were analyzed according to the testing sequence number, and the results are shown in the table below: Table 24 Analysis of the detection trend of gold in lead concentrate samples Based on the correspondence between the extracted sample numbers and the original sample numbers, the test results were reordered in ascending order of the original numbers. Then, the test results were analyzed according to the production sequence. The analysis results are shown in the table below: Table 25 Analysis of Gold Production Trends in Lead Concentrate Samples Based on the confirmation that neither the testing sequence nor the production sequence has a significant impact on the test results, the F-test was used to analyze the test data to determine whether its uniformity was acceptable. The analysis results are shown in the table below: Table 26 Homogeneity test of gold in lead concentrate samples Table 27 Homogeneity test of silver in lead concentrate samples Table 28 Homogeneity test of lead in lead concentrate samples After the homogeneity test is passed, the stability test is performed on the samples. In order to test the stability of the samples under transportation conditions, the samples are subjected to a 7-day simulated experiment under shock conditions. Samples are taken and tested on day 0, day 1, day 3, and day 7. The test data are analyzed and tested using the linear fitting method to determine whether the transportation conditions affect the test results.

[0046] After all proficiency testing participants return their test data, the retained samples are tested again. The measurement data are analyzed using a t-test to determine whether the stability of the samples can cover the entire proficiency testing cycle.

[0047] The test results and data analysis of the lead concentrate samples after the shock test are shown in the table below: Table 29 Analysis of shock test data for gold in lead concentrate samples Table 30 Analysis of shock test data for silver in lead concentrate samples Table 31 Analysis of shock test data of lead in lead concentrate samples After all proficiency testing participants returned their test data, the prepared proficiency testing samples were tested again and compared with the test data before the samples were sent. The test data and comparison results are shown in the table below: Table 32 Analysis of Stability Test Data for Gold in Lead Concentrate Samples Table 33 Analysis of Stability Test Data for Silver in Lead Concentrate Samples Table 34 Analysis of Stability Test Data of Lead in Lead Concentrate Samples The data above shows that the proficiency testing samples prepared by the detection and analysis methods have good homogeneity and stability, and the proficiency testing sample qualification determination method is scientific and applicable.

[0048] Comparative Example 1 This comparative study provides a method for preparing and testing copper concentrate proficiency testing samples, which differs from the preparation method in Example 1 only in the following steps: S1, Determine the target element to be tested in the copper concentrate proficiency test: copper (Cu) content 10~20%.

[0049] S2, screening mineral raw materials that meet the requirements of the target element type and content range.

[0050] An investigation revealed that a commercially available copper concentrate raw material contains approximately 19% copper. The initial uniformity test results were analyzed using the one-way ANOVA method (F-test), and the Cu content was determined using flame atomic absorption spectrometry. The results and analysis are shown in the table below: Table 35 Statistical analysis and test results of preliminary inspection data on the homogeneity of copper in copper concentrate samples. The data in the table above leads to the conclusion that the samples are uneven. However, this conclusion is incorrect because it is drawn without assessing the suitability of the testing method. The reasons are as follows: Use the determination formula The above data will be analyzed.

[0051] The results are shown in the table below: Table 36 Results of the Test Methods for Copper Concentrate Samples As can be seen from the table above, the detection method used is not suitable for homogeneity testing. That is, the conclusion that the homogeneity test is unqualified may not be due to insufficient homogeneity of the sample itself, but due to insufficient precision of the detection method. The homogeneity test should be re-tested on the sample after using a suitable detection method.

[0052] Comparative Example 2 This comparative study provides a method for preparing and testing zinc concentrate proficiency testing samples, including the following steps: S1, determine the types and content ranges of target elements to be tested in the proficiency testing of zinc concentrate.

[0053] Lead (Pb) content: 5-10%; Zinc (Zn) content: 40-50%.

[0054] S2, screen mineral raw materials that meet the requirements of target element types and content ranges, and determine their crude usage.

[0055] An investigation revealed a commercially available zinc concentrate raw material with a lead content of approximately 6% and a zinc content of approximately 43%. Approximately 10 kg of zinc concentrate raw material was identified as meeting the requirements for the target element types and content ranges.

[0056] S3, Preparation of gold concentrate capability verification samples.

[0057] The zinc concentrate raw material was dried at 100℃ to constant weight and then naturally cooled in a desiccator to obtain dried mineral material. The dried mineral material was then ground in a rod mill for 2 hours according to conventional experience to obtain ground mineral material. The ground mineral material was then further mixed in a three-dimensional mixer to obtain a ground and mixed zinc concentrate sample.

[0058] Initial homogeneity test of the ground zinc concentrate sample: The ground zinc concentrate sample was placed on a plastic film and evenly divided into 6 areas. Each area was numbered 1 to 6 in the order from left to right and from top to bottom. Sufficient mass of ground mineral material samples were then taken from the upper, middle and lower parts of each area and numbered 1 to 3 respectively. The samples were placed in 3 sample bags. The ground mineral material samples of each small area were numbered in the order of 1-1, 1-2, 1-3, 2-1 up to 6-3.

[0059] Under the same conditions, the Pb and Zn contents were determined according to the following sequence of ground mineral samples: 1-1—2-1—3-1—4-1—5-1—6-1, 6-2—5-2—4-2—3-2—2-2—1-2, 1-3—3-3—5-3—2-3—4-3—6-3.

[0060] The initial homogeneity test results were analyzed using the one-way ANOVA method (F-test). The content tests for Pb and Zn are shown in the table below: Table 37 Statistical analysis and test results of preliminary test data on lead homogeneity in zinc concentrate samples Table 38. Preliminary data and test results on the homogeneity of zinc in zinc concentrate samples. The data in the table above shows that the sample uniformity does not meet the requirements. An investigation revealed that particle size testing was not performed on the ground samples. Experiments showed that only 95% of the particles were smaller than 200 mesh, failing to meet the requirement of at least 98% being smaller than 200 mesh, thus resulting in the sample uniformity failing to meet the requirements.

[0061] Comparative Example 3 This comparative study provides a method for preparing and testing copper concentrate proficiency testing samples, including the following steps: S1, Determine the target element to be tested in the copper concentrate proficiency test: copper (Cu) content 0.1~1.0%.

[0062] S2, screening mineral raw materials that meet the requirements of the target element type and content range.

[0063] An investigation revealed that a commercially available copper concentrate contains approximately 0.6% copper. S3, determine the amount of crude mineral raw materials required for copper concentrate capability verification, approximately 10 kg.

[0064] Identify gold concentrate raw materials that meet the requirements for the types and content ranges of the target elements.

[0065] S4, Prepare copper concentrate capability verification samples.

[0066] The copper concentrate raw material was dried at 100℃ to constant weight (weighed every hour until the weight no longer changed), and then placed in a desiccator to cool naturally, obtaining dried mineral material. The dried mineral material was then ground in a rod mill to ensure that 98% of the particles were less than 200 mesh, obtaining ground mineral material. The ground mineral material was then further mixed in a three-dimensional mixer to obtain a ground and mixed copper concentrate sample.

[0067] A preliminary homogeneity test was conducted on the mixed copper concentrate samples. Based on the satisfactory homogeneity, the samples were repackaged into 80 bags, numbered 1 to 80 according to the packaging order. Eight bags were randomly selected using a random number list method, and their numbers (1 to 8) were recorded. Each bag was tested three times.

[0068] The detection order is: 1-2-3-4-5-6-7-8, 8-7-6-5-4-3-2-1, 1-3-5-7-2-4-6-8.

[0069] The measurement data were analyzed using the one-way ANOVA method (F-test) to determine whether the homogeneity of the packaged samples met the requirements. The sampling sequence and numbering of the copper concentrate samples are shown in the table below: Table 39 Sampling sequence number and sample number of copper concentrate samples The eight copper concentrate samples were tested in the specified order. The test numbers and results are shown in the table below: Table 40. Serial Number and Result of Copper Concentrate Sample Testing The F-test was used to analyze the test data to determine whether the homogeneity of the repackaged samples met the requirements. The analysis results are shown in the table below: Table 41 Homogeneity test of copper in copper concentrate samples As shown in the table above, the homogeneity of the copper concentrate proficiency testing sample meets the requirements. However, if the sample is deemed to meet the requirements solely based on the F-test result, and the subsequent evaluation process is continued before the sample is issued and the proficiency testing plan is implemented, it is highly likely to cause distortion of the test data. The reasons are as follows: After arranging the above data in ascending order of their original numbers, a processing trend analysis was performed, and the results are shown in the table below: Table 42 Analysis of copper processing trends in copper concentrate samples As shown in the table above, the sample values ​​for the copper concentrate proficiency testing vary significantly with the processing sequence, indicating a systematic error between samples with different numbers. However, the F-test alone cannot determine whether there is a problem with the homogeneity of the samples. Under these circumstances, implementing the proficiency testing program may lead to participants failing the proficiency testing program due to sample issues. It should be noted that the above embodiments are only for further elaboration and explanation of the technical solution of the present invention, and are not intended to further limit the technical solution of the present invention. The method of the present invention is only a preferred embodiment and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a mineral proficiency testing sample, characterized in that, The steps include: Determine the types and content ranges of the target elements to be tested in the mineral proficiency testing; Screen mineral raw materials that meet the requirements for the types and content ranges of the target elements; The mineral raw materials are dried to constant weight and then cooled to obtain dried mineral material; The dried mineral material is ground to ensure that 98% of the particles are less than 200 mesh, thus obtaining the ground mineral material. All the ground mineral materials were mixed evenly to obtain a mineral strength test sample.

2. The method for preparing mineral proficiency testing samples according to claim 1, characterized in that, The dried mineral material is ground using a ball mill or a rod mill.

3. The method for preparing mineral proficiency testing samples according to claim 1 or 2, characterized in that, The grinding mineral materials are mixed using a V-type mixer or a three-dimensional mixer.

4. A method for testing mineral proficiency testing samples, characterized in that, The steps include: A mineral proficiency testing sample was prepared according to the preparation method of any one of claims 1 to 3; The homogeneity of the mineral proficiency testing sample was initially tested, and the results of the initial homogeneity test were subjected to an F-test using the one-way variance method to preliminarily determine whether the homogeneity met the preset requirements. If the initial uniformity test meets the preset requirements, a second uniformity test is performed. The second uniformity test includes a suitability assessment of the analytical method, and the assessment formula is as follows: In the formula: n refers to the number of tests, S refers to the standard deviation of the test results, and r refers to the repeatability limit of the national standard method; If the suitability determination result of the analytical method meets the preset requirements, the test results of the detection sequence and processing sequence are analyzed to determine whether the requirements are met; if the suitability determination result of the analytical method does not meet the preset requirements, the obtained analytical results must be discarded and the analytical method must be changed. If the analysis results of the testing sequence or processing sequence do not meet the preset requirements, the mineral proficiency testing sample is deemed unqualified. If the analysis results of the detection sequence or processing sequence meet the preset requirements, the uniformity second inspection is deemed qualified; Perform a stability test to determine whether the stability meets the preset requirements; If the stability test does not meet the preset requirements, the mineral proficiency test sample is deemed unqualified. If the stability test meets the preset requirements, the retained sample will be subjected to a proficiency testing cycle verification test. The t-test method will be used to analyze and determine whether the stability of the sample can cover the entire proficiency testing cycle. If the verification meets the requirements, the mineral proficiency testing sample will be deemed qualified; otherwise, the mineral proficiency testing sample will be deemed unqualified.

5. The testing method for mineral proficiency testing samples according to claim 4, characterized in that, The steps of the initial uniformity detection method are as follows: The mineral proficiency testing sample is laid flat and evenly divided into N regions. Each region is numbered from left to right and top to bottom as region 1 to N. Sufficient mass samples are taken from the surface, middle and lower layers of each region and placed in 3 sample bags. The initial test samples are numbered according to the region number in the order of 1-1, 1-2, 1-3, ..., N-1, N-2, N-3. If N is even and N≥3, the target element content of the initial test sample shall be detected in the following order under the same conditions: 1-1—2-1···—N-1； N-2···2-2—1-2； 1-3—3-3···—(N-1)-3—2-3···—N-3; If N is odd and N≥3, the detection shall be performed in the following order under the same conditions: 1-1—2-1···—N-1； N-2···—2-2—1-2； 1-3—3-3···—N-3—2-3····—(N-1)-3.

6. The testing method for mineral proficiency testing samples according to claim 5, characterized in that, The sampling method in the homogeneity double inspection includes: Samples that pass the initial uniformity test are repackaged into X units, numbered 1 to X according to the packaging order; Y units are randomly selected and numbered 1 to Y, and then sampled and tested again according to the sampling method and testing order of the initial uniformity test.

7. The method for testing mineral proficiency testing samples according to claim 6, characterized in that, The correspondence between the number of extracted units Y and the total number of units X is as follows: If X≤100, then Y takes the maximum value of (3, 10%X). If 100 < X ​​≤ 200, then Y ≥ 11; If 200 < X ​​≤ 500, then Y ≥ 15; If 500 < X ​​≤ 1000, then Y ≥ 25; If X ≥ 1000, then Y = 30.

8. The method for testing mineral proficiency testing samples according to any one of claims 4 to 7, characterized in that, The stability test includes: conducting a 7-day simulated experiment on the sample under shock conditions, taking samples for testing on day 0, day 1, day 3, and day 7, and analyzing the test results using the linear fitting method to determine whether the transportation conditions affect the test results.

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