Method for Measuring Gold Content in Gold Concentrate

Abstract

The present application provides a method for measuring the gold content in gold concentrate, which belongs to the technical field of process mineralogy. The traditional measurement method mainly separates metals by subjecting the sample to acid treatment. Although this can remove silver, it cannot remove metals such as platinum and rhodium, which affects the accuracy. The present application determines the gold content in the gold concentrate by fire assay enrichment and automatic mineralogical analysis. Compared with the traditional measurement method, the present application does not require contact with dangerous drugs such as acids and alkalis, and can remove insoluble impurities and accurately measure the gold content in the gold concentrate. In addition, the test method provided by the present invention has simple operating steps; drying and measurement are carried out simultaneously, saving measurement time; combined with automatic mineralogical analysis, the measurement data is accurate, while saving workload, providing reliable data support for the efficient use of such resources.

Description

Technical Field

[0001] The present invention relates to the technical field of process mineralogy, and particularly relates to a method for measuring the gold content in gold concentrate. Background Art

[0002] The gold content in gold concentrate is one of the important indicators for evaluating the gold ore reserves and value. It directly affects the mining and extraction efficiency of gold ore. By measuring the gold content in gold concentrate, the potential value of the gold ore can be understood, which has guiding significance for formulating reasonable mining and extraction plans, optimizing the production process, improving production efficiency, and increasing the economic benefits of the gold ore. The gold content in gold concentrate is also an important basis for evaluating the quality of gold ore and the risk of gold price fluctuations, because the level of gold content directly affects the market price and competitiveness of gold ore.

[0003] Regarding the determination of the gold content in gold concentrate, there are many methods, such as fire assay gravimetry, fire assay enrichment-flame atomic absorption spectrometry, activated carbon enrichment-flame atomic absorption spectrometry, activated carbon enrichment-iodometry, etc. For the above-mentioned various measurement methods, their operation steps are generally numerous, and the determination of the batching amount is relatively complicated, and corresponding personnel need to be trained to operate.

[0004] In the prior art, the patent with the publication number CN104089798A provides a method for determining the gold content, including: (1) burning the sample to be measured in a muffle furnace to remove sulfur, arsenic, carbon, and organic substances; (2) adding sodium fluoride and aqua regia to the sample to be measured after the burning treatment for dissolution to obtain a dissolution solution; (3) adding foamed plastic to the dissolution solution for adsorption treatment so that the foamed plastic adsorbs the gold in the dissolution solution; (4) taking out the foamed plastic after the adsorption treatment and burning it to ashing to obtain an ashing product; (5) adding aqua regia, water, phosphoric acid-sodium phosphate solution, potassium bromide solution, diphenylthiourea acetone solution, and ethyl acetate to the ashing product in sequence for extraction; (6) separating to obtain an organic phase containing gold; (7) using a flame atomic absorption spectrometer to analyze the organic phase containing gold to determine the gold content of the sample to be measured. However, this method requires multiple additions of strong acids for dissolution, which poses certain occupational health hazards to operators. The patent with the publication number CN109900678A provides an analytical method for determining the gold content in crude silver. The fire assay enrichment-atomic absorption spectrometry is used to determine the gold content in crude silver, which avoids the interference of other elements in crude silver, has high accuracy, good precision, and a wide measurement range, and is suitable for the determination of the gold content in crude silver. The operation steps of this invention are numerous, and acids are also needed for dissolution, which poses certain occupational health hazards to operators. In addition, when using nitric acid to separate gold, for elements such as platinum and rhodium that are insoluble in nitric acid, this method cannot eliminate the influence of interfering elements, which results in errors in the test results for specific samples containing platinum and rhodium elements. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present application provides a method for measuring the gold content in gold concentrate, aiming to solve the problems that the existing methods for testing the gold content in gold concentrate are complex in operation, involve contact with corrosive acids and other substances, pose certain occupational health hazards to personnel, and cannot eliminate some interfering elements, resulting in errors in the test results.

[0006] The present application provides a method for measuring the gold content in gold concentrate, comprising the following steps:

[0007] S1. Take m1 g of the sample to be tested, dry it, cool it to obtain sample a1, weigh it, record the mass as m2 g, and calculate the weight loss rate w of the sample to be tested, w = m2 / m1;

[0008] S2. Subject the sample a1 to hot inlay sample preparation, curing, grinding and polishing, and carbon spraying treatment to obtain an automatic mineralogical analysis sample, and then conduct automatic mineralogical analysis to measure the mass fraction of sulfur as f1 and the mass fraction of copper as f2;

[0009] S3. Take m3 g of the sample to be tested, grind it to obtain sample a2;

[0010] S4. Mix the sample a2 with potassium nitrate, sodium carbonate, lead oxide, silicon dioxide and borax to obtain sample a3;

[0011] S5. Add silver nitrate solution to the sample a3 and cover the surface with a mixture of sodium carbonate and borax; then melt it, cool it, and separate the precious metals, lead alloy beads and slag;

[0012] S6. Place the precious metals and lead alloy beads in a preheated magnesia ash dish, heat them, cool them to obtain alloy grains;

[0013] S7. Place the alloy grains in ethanol for the first ultrasonic oscillation, then roll the alloy grains into thin slices, and then place them in ethanol for the second ultrasonic oscillation to obtain sample a4, dry it and weigh it, record the mass as N mg;

[0014] S8. Conduct automatic mineralogical analysis and testing on the sample a4 to measure the area data of each element, denoted as Si1; after the test analysis is completed, turn the sample a4 by 180° and conduct automatic mineralogical analysis and testing on the other surface to obtain the area data of each element, denoted as Si2; where Si1 and Si2 are respectively used to represent the area data of element i on two different surfaces, i = 1, 2, 3,......, n, which are respectively used to represent different elements, when i = 1, it represents the gold element, and n is the number of measured element types;

[0015] Then calculate the gold percentage content O of the alloy grains, O = (S11 + S12)ρ1 / M;

[0016] Among them, , ρi is the density of element i;

[0017] S9. Calculate the gold grade H in the gold concentrate, H = N * O / ((m3 * w) * 10 -3 ) g / t.

[0018] In the technical solution of the embodiment of the present application, the present application determines the gold content in the gold concentrate through fire assay enrichment and automatic mineralogical analysis. Compared with the traditional measurement method, the present application does not need to contact dangerous drugs such as acids and alkalis, and can remove insoluble impurities, accurately measuring the gold content in the gold concentrate. In addition, the test method provided by the present invention has simple operation steps; drying and measurement are carried out simultaneously, saving measurement time; combined with automatic mineralogical analysis, the measurement data is accurate, and the workload is saved at the same time, providing reliable data support for the efficient utilization of such resources.

[0019] In some embodiments, in step S1, the drying temperature is 90 - 100 °C, and the drying time is 1.5 - 2.0 h.

[0020] In this embodiment, the dry weight of the sample to be tested can be obtained through drying.

[0021] In some embodiments, in step S3, the mass m3 of the sample to be tested is 20 - 30 g; the grinding fineness is that it all passes through a 320 - mesh sieve.

[0022] In this embodiment, by grinding the sample to be tested to a certain fineness, it is convenient for subsequent processing of the sample.

[0023] In some embodiments, in step S4, the addition amount of sample a2 is 23 - 27 g; the theoretical addition amount of potassium nitrate is 1.0Q - 1.2Q g, where Q = 600 * f1 - 7. If the theoretical addition amount is within the range of 10 - 30 g, then the theoretical addition amount is used as the actual addition amount of potassium nitrate. If the theoretical addition amount < 10 g, then 10 g is used as the actual addition amount of potassium nitrate. If the theoretical addition amount > 30 g, then 30 g is used as the actual addition amount of potassium nitrate; the addition amount of sodium carbonate is 35 - 50 g; the addition amount of lead oxide is 1.0P - 1.2P g, where P = 500 * f1 + 40 * f2 + 30; the addition amount of silicon dioxide is 15 - 30 g; the addition amount of borax is 10 - 20 g.

[0024] In this embodiment, adding potassium nitrate, sodium carbonate, lead oxide, silicon dioxide and borax to the gold concentrate for melting can reduce the melting point of the slag, improve the fluidity of the melt, promote metal oxidation and separation, reduce sulfide interference through chemical reactions, and improve the recovery rate of precious metals such as gold and silver and the accuracy of the fire assay method.

[0025] In some embodiments, in step S5, the addition amount of the silver nitrate solution is 0.5 - 1.0 ml, and the concentration is 8 - 12 g / L.

[0026] In this embodiment, by adding the silver nitrate solution, it can react with the silver in the sample to dissolve the silver into a soluble silver nitrate solution. Through this dissolution - precipitation method, gold and silver can be effectively separated.

[0027] In some embodiments, in step S5, the mass ratio of sodium carbonate to borax is 2:1.

[0028] In this embodiment, in the fire assay method, sodium carbonate and borax are used as covering agents to prevent the melt from splashing and dust from spreading, and at the same time protect the equipment from high temperatures.

[0029] In some embodiments, in step S5, the melting temperature is 1150 - 1250 °C, and the melting time is 25 - 30 min.

[0030] In this embodiment, through melting, the precious metals, lead buttons and slag are separated.

[0031] In some embodiments, in step S6, the preheating and heating temperature is 850 - 950 °C, and the heating time is 2 - 3 min.

[0032] In this embodiment, the precious metals and lead buttons are heated to melt them into alloy grains.

[0033] In some embodiments, in step S7, the time of the first ultrasonic oscillation is 18 - 22 min, and the time of the second ultrasonic oscillation is 8 - 12 min.

[0034] In this embodiment, the sample is ultrasonically treated to remove surface impurities.

[0035] In some embodiments, in step S7, the thickness of the thin sheet is 0.01 - 0.03 mm.

[0036] In this embodiment, the sample is pressed into a thin sheet to facilitate subsequent mineralogical analysis and testing.

[0037] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, 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 exemplified below. Brief Description of the Drawings

[0038] To more clearly illustrate the technical solution of this application, the accompanying drawings used in this application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0039] Figure 1 It is a flowchart of the method for measuring the gold content in the gold concentrate in Example 1.

[0040] Figure 2 It is a diagram of the automatic mineralogical analysis results of sample a1 in Example 1.

[0041] Figure 3 It is a physical diagram of the automatic mineralogical analysis sample of sample a4 in Example 1.

[0042] Figure 4 It is a test diagram of the automatic mineralogical analysis of sample a4 in Example 1. Detailed implementation manners

[0043] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to more clearly illustrate the technical solution of this application, so they are only examples and cannot be used to limit the protection scope of this 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 this application. The phrase appears in various positions 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 explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0045] In the description of the embodiments of this 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 indicating the quantity, specific order or primary-secondary relationship of the indicated technical features.

[0046] In the description of the embodiments of this application, the term "and / or" is only 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 associated objects before and after.

[0047] To solve the problems that the existing gold content testing methods for gold concentrate are complex in operation, involve contact with corrosive acids and other substances, pose certain occupational health hazards to personnel, and cannot eliminate some interfering elements, resulting in errors in test results, this application provides a method for testing the gold content in gold concentrate. Traditional measurement methods mainly separate metals by acid-treating samples. Although this can remove silver, it cannot remove metals such as platinum and rhodium, affecting the accuracy. This application determines the gold content in gold concentrate through fire assay enrichment and automatic mineralogical analysis. Compared with traditional measurement methods, this application does not require contact with dangerous drugs such as acids and alkalis, can eliminate insoluble impurities, and accurately measure the gold content in gold concentrate. In addition, the testing method provided by the present invention has simple operation steps; drying and measurement are carried out simultaneously, saving measurement time; combined with automatic mineralogical analysis, the measurement data is accurate, and the workload is saved at the same time, providing reliable data support for the efficient utilization of such resources.

[0048] This application provides a method for measuring the gold content in gold concentrate, comprising the following steps:

[0049] S1. Take m1 g of the sample to be tested, dry it, cool it, obtain sample a1, weigh it, record the mass as m2 g, and calculate the weight loss rate w of the sample to be tested, w = m2 / m1;

[0050] S2. Subject the sample a1 to hot mounting, curing, grinding and polishing, and carbon spraying treatments to obtain an automatic mineralogical analysis sample, and then conduct automatic mineralogical analysis to measure the mass fraction of sulfur as f1 and the mass fraction of copper as f2;

[0051] S3. Take m3 g of the sample to be tested, grind it to obtain sample a2;

[0052] S4. Mix the sample a2 with potassium nitrate, sodium carbonate, lead oxide, silicon dioxide and borax to obtain sample a3;

[0053] S5. Add silver nitrate solution to the sample a3 and cover the surface with a mixture of sodium carbonate and borax; then melt it, cool it, and separate the precious metals, lead alloy beads and slag;

[0054] S6. Place the precious metals and lead alloy beads in a preheated magnesia ash pan, heat it, cool it to obtain alloy grains;

[0055] S7. Place the alloy grains in ethanol for the first ultrasonic oscillation, then roll the alloy grains into thin slices, and then place them in ethanol for the second ultrasonic oscillation to obtain sample a4, dry it and weigh it, record the mass as N mg;

[0056] S8. Automatically conduct mineralogical analysis tests on the sample a4, measure the area data of each element, and denote it as Si1; after the test analysis is completed, flip the sample a4 by 180°, conduct automatic mineralogical analysis tests on the other surface, and obtain the area data of each element, denoted as Si2; where Si1 and Si2 are respectively used to represent the area data of element i on two different surfaces, i = 1, 2, 3,......, n, which are respectively used to represent different elements. When i = 1, it represents the gold element, and n is the number of measured element types;

[0057] Then calculate the gold percentage content O in the alloy granule, O = (S11 + S12)ρ1 / M;

[0058] Where, , ρi is the density of element i;

[0059] S9. Calculate the gold grade H in the gold concentrate, H = N*O / ((m3*w)*10 -3 ) g / t.

[0060] In the technical solution of the embodiment of the present application, by means of fire assay enrichment and automatic mineralogical analysis to determine the gold content in the gold concentrate. Compared with the traditional measurement method, it does not require contact with dangerous drugs such as acids and alkalis, and can remove insoluble impurities, accurately measuring the gold content in the gold concentrate. In addition, the operation steps of this test method are simple; drying and measurement are carried out simultaneously, saving measurement time; combined with automatic mineralogical analysis, the measurement data is accurate, and the workload is saved at the same time, providing reliable data support for the efficient utilization of such resources.

[0061] Further, in some embodiments, in step S1, the drying temperature is 90~100°C, and the drying time is 1.5~2.0h.

[0062] In the technical solution of the embodiment of the present application, through drying, the dry weight of the sample to be measured can be obtained.

[0063] Further, in some embodiments, in step S2, the hot embedding means mixing the sample and the embedding material in a specific mass ratio, and then heating and pressing to make a sample; the embedding material is thermosetting phenolic epoxy resin, with a particle size of 5~10μm, and the mass ratio of the sample to the embedding material is 1:2~1:5.

[0064] Further, in some embodiments, in step S3, the mass m3 of the sample to be measured is 20~30g; the grinding fineness is that it all passes through a 320-mesh sieve.

[0065] 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 subsequent processing of the sample.

[0066] Further, in some embodiments, in step S4, the addition amount of the sample a2 is 23 - 27 g; the theoretical addition amount of potassium nitrate is 1.0Q - 1.2Q g, where Q = 600*f1 - 7. If the theoretical addition amount is within the range of 10 - 30 g, then the theoretical addition amount is used as the actual addition amount of potassium nitrate. If the theoretical addition amount < 10 g, then 10 g is used as the actual addition amount of potassium nitrate. If the theoretical addition amount > 30 g, then 30 g is used as the actual addition amount of potassium nitrate; the addition amount of sodium carbonate is 35 - 50 g; the addition amount of lead oxide is 1.0P - 1.2P g, where P = 500*f1 + 40*f2 + 30; the addition amount of silicon dioxide is 15 - 30 g; the addition amount of borax is 10 - 20 g.

[0067] In the technical solution of the embodiment of the present application, potassium nitrate, sodium carbonate, lead oxide, silicon dioxide and borax are added to the gold concentrate for melting. The melting point of the slag can be reduced through chemical reactions, the fluidity of the melt can be improved, metal oxidation and separation can be promoted, the interference of sulfides can be reduced, and the recovery rate of precious metals such as gold and silver and the accuracy of the fire assay method are improved.

[0068] Further, in some embodiments, in step S5, the addition amount of the silver nitrate solution is 0.5 - 1.0 ml, and the concentration is 8 - 12 g / L.

[0069] In the technical solution of the embodiment of the present application, by adding the silver nitrate solution, it can react with the silver in the sample to dissolve the silver into a soluble silver nitrate solution. Through this dissolution - precipitation method, gold and silver can be effectively separated.

[0070] Further, in some embodiments, in step S5, the mass ratio of sodium carbonate to borax is 2:1.

[0071] In the technical solution of the embodiment of the present application, in the fire assay method, sodium carbonate and borax are used as covering agents to prevent the melt from splashing and dust from spreading, and at the same time protect the equipment from high temperatures.

[0072] Further, in some embodiments, in step S5, the melting temperature is 1150 - 1250 °C, and the melting time is 25 - 30 min.

[0073] In the technical solution of the embodiment of the present application, through melting, the precious metals, lead buttons and slag are separated.

[0074] Further, in some embodiments, in step S6, the preheating and heating temperature is 850 - 950 °C, and the heating time is 2 - 3 min.

[0075] In the technical solution of the embodiment of the present application, the precious metals and lead buttons are heated to melt them into alloy grains.

[0076] Further, in some embodiments, in step S6, the magnesite ash dish is obtained by uniformly stirring and pressing 425 - grade cement, magnesite with a particle size ≤ 0.18 mm, and water in a mass ratio of 15:85:10.

[0077] Further, in some embodiments, in step S7, the time of the first ultrasonic oscillation is 18 - 22 min, and the time of the second ultrasonic oscillation is 8 - 12 min.

[0078] In the technical solution of the embodiment of the present application, ultrasonic treatment of the sample can remove surface impurities.

[0079] Further, in some embodiments, in step S7, the thickness of the thin sheet is 0.01 - 0.03 mm.

[0080] In the technical solution of the embodiment of the present application, pressing the sample into a thin sheet facilitates subsequent mineralogical analysis and testing.

[0081] The following are 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 where specific techniques or conditions are not indicated in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in the field or according to the product specifications. For reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.

[0082] Example 1

[0083] This embodiment provides a method for testing the gold content in gold concentrate, as Figure 1 shown, which specifically includes the following steps:

[0084] (1) Weigh 1000 g of the first sample to be tested, and dry it in an oven at 90 °C for 1.5 h; after drying, cool it to room temperature to obtain sample a1, and weigh its mass as 991 g. The weight loss rate w is w = m3 / m2 = 991 / 1000 = 0.991.

[0085] (2) Weigh 4 g of the dried sample, mix the sample with 8 g of thermosetting phenolic epoxy resin with a particle size of 5 μm, and then carry out sample pressing at 125 °C and 220 Bar pressure. After curing, grind, polish, and carbon spray treatment, and then conduct automatic mineralogical analysis. The test diagram is as Figure 2 shown, and the measured mass fraction of sulfur is 26.00%, and the mass fraction of copper is 1.40%.

[0086] (3) Weigh 25 g of the first sample to be tested, carry out grinding, and the grinding fineness is that all passes through a 320 - mesh sieve to obtain sample a2.

[0087] (4) Add 30 g of potassium nitrate, 35 g of sodium carbonate, 170 g of lead oxide, 15 g of silicon dioxide, and 10 g of borax to sample a2, and mix them to obtain sample a3.

[0088] (5) Place sample a3 in a clay crucible, add 0.5 ml of silver nitrate solution with a concentration of 10 g / L, and cover the surface with an 8 g mixture of sodium carbonate and borax with a mass ratio of 2:1. Place it in an electric furnace, set the temperature to 1200 °C, and after the temperature reaches the preset temperature, continue melting for 25 min. Take out the clay crucible, rotate and shake it 5 times to make the lead and precious metal alloy beads sink, pour out the melt, and after cooling, tap to separate the precious metal, lead alloy beads and slag.

[0089] (6) Preheat the magnesia ash dish at 900 °C for 20 min, then place the precious metal and lead alloy beads in it, continue heating for 3 min, and then cool to obtain alloy grains.

[0090] (7) Take out the alloy grains, place them in ethanol and ultrasonically vibrate for 20 min, then roll the alloy grains into a thin sheet with a thickness of 0.02 mm, and then place them in ethanol and ultrasonically vibrate for 10 min to obtain sample a4. Dry and weigh it, and its mass is 0.87 mg.

[0091] (8) As Figure 3 shown, place the sample a4 on the conductive adhesive and perform test analysis in an automatic mineralogical analysis instrument. The test diagram is as Figure 4 shown. Measure the area data of each element and record it as Si1; after the test analysis is completed, turn the sample a4 over 180° and perform automatic mineralogical analysis test on its other surface to obtain the area data of each element, which is recorded as Si2; among them, Si1 and Si2 are respectively used to represent the area data of element i on two different surfaces, i = 1, 2, which are respectively used to represent gold element and silver element;

[0092] Then calculate the gold percentage content O of the alloy grains, O = (S11 + S12)ρ1 / M;

[0093] Among them, , ρi is the density of element i; for example Figure 4 in the sample description, the analysis and calculation results are shown in Table 1 specifically.

[0094] Table 1 Automatic Mineralogical Analysis and Calculation Results of the First Sample to be Measured

[0095]

[0096] (9) Calculate the gold grade H of the gold concentrate, H = N*O / ((m3*w)*10 -3 ) g / t = 0.87 * 95.56% / 25 / 0.991 / 10 -3g / t = 33.56 g / t.

[0097] Example 2

[0098] This example provides a method for testing the gold content in gold concentrate. As Figure 1 shown, it specifically includes the following steps:

[0099] (1) Weigh 500 g of the sample to be tested and dry it in an oven at 95 °C for 1.5 h. After drying, cool it to room temperature to obtain sample a1, and weigh its mass as 496 g. The weight loss rate of the sample is w, then w = m3 / m2 = 496 / 500 = 0.992.

[0100] (2) Weigh 3.5 g of the dried sample, mix the sample with 7 g of thermosetting phenolic epoxy resin with a particle size of 5 μm, then press and sample at 130 °C and 230 Bar pressure. After curing, grind, polish, and carbon spray the sample, and then perform automatic mineralogical analysis. The measured mass fraction of sulfur is 23.55%, and the mass fraction of copper is 2.10%.

[0101] (3) Weigh 25 g of the sample to be tested and grind it. The grinding fineness is that it all passes through a 320-mesh sieve to obtain sample a2.

[0102] (4) Add 30 g of potassium nitrate, 35 g of sodium carbonate, 170 g of lead oxide, 15 g of silicon dioxide, and 10 g of borax to sample a2 and mix them to obtain sample a3.

[0103] (5) Place sample a3 in a clay crucible, add 0.5 ml of silver nitrate solution with a concentration of 10 g / L, and cover the surface with 10 g of a mixture of sodium carbonate and borax with a mass ratio of 2:1. Place it in an electric furnace, set the temperature to 1200 °C, and continue melting for 25 min after the temperature reaches the preset temperature. Take out the clay crucible, rotate and shake it 5 times to make the lead and precious metal alloy beads sink, pour out the melt, cool it, and tap to separate the precious metal from the lead alloy beads and the slag.

[0104] (6) Preheat the magnesia ash dish at 900 °C for 20 min, then place the precious metal and lead alloy beads in it, continue heating for 3 min, and then cool to obtain alloy grains.

[0105] (7) Take out the alloy grains, place them in ethanol and ultrasonically vibrate for 20 min, then roll the alloy grains into a thin sheet with a thickness of 0.02 mm, and then place it in ethanol and ultrasonically vibrate for 10 min to obtain sample a4. Dry and weigh it, and its mass is 0.45 mg.

[0106] (8) placing the sample a4 on a conductive adhesive, and performing a test and analysis in an automatic mineralogical analysis instrument to obtain the area data of each element, which is recorded as Si1; after the test and analysis, turning the sample a4 180°, and performing an automatic mineralogical analysis test on the other surface to obtain the area data of each element, which is recorded as Si2; wherein Si1 and Si2 are respectively used to represent the area data of element i on two different surfaces, and i=1, 2, 3 are respectively used to represent gold, silver, and platinum;

[0107] Then calculate the gold percentage O in the alloy particles, O=(S11+S12)ρ1 / M;

[0108] in, , ρi is the density of element i; the analysis and calculation results are shown in Table 2.

[0109] Table 2 Calculation results of automatic mineralogical analysis of sample 2

[0110]

[0111] (10) Calculate the gold grade H in gold concentrate, H = N*O / ((m3*w)*10 -3 )g / t=0.45*93.03% / 25 / 0.992 / 10 -3 g / t=16.88 g / t.

[0112] According to GB / T20899.1-20149 “Chemical Analysis Methods for Gold Ore”, the gold content in the samples in Example 1 and Example 2 was tested, and the test results were 33.60 g / t and 17.65 g / t, respectively.

[0113] By comparing the test results of the gold content of the samples in Example 1 and Example 2 obtained according to the present application scheme and the national standard test method, it can be seen that the test results of the gold content according to the national standard test method are all on the high side. This is because when treated with acid, the acid-insoluble elements such as platinum and rhodium in the samples are not separated, and a small amount of impurities such as unprocessed silver exist, which makes the test results high.

[0114] In summary, the present application provides a method for testing the gold content in gold concentrate. The traditional measurement method mainly separates metals by acid-treating the sample. Although this can remove silver, it cannot remove metals such as platinum and rhodium, which affects the accuracy. The present application determines the gold content in gold concentrate through fire assay enrichment and automated mineralogy analysis. Compared with the traditional measurement method, the present application does not require contact with dangerous drugs such as acids and alkalis, and can remove insoluble impurities, accurately measuring the gold content in gold concentrate. In addition, the test method provided by the present invention has simple operation steps; drying and measurement are carried out simultaneously, saving measurement time; combined with automated mineralogy analysis, the measurement data is accurate, while saving workload, providing reliable data support for the efficient utilization of such resources.

[0115] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same composition and the same effect as the technical idea within the technical solution scope of the present application are included in the technical scope of the present application. In addition, within the scope of not departing from the gist of the present application, various modifications that those skilled in the art can think of applied to the embodiments, and other ways constructed by combining some constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for measuring the gold content in a gold concentrate, characterized in that: The following steps are involved: S1. Take m1 g of the sample to be tested, dry it, cool it, and obtain sample a1. Weigh it, record the mass as m2 g, and calculate the weight loss rate w of the sample to be tested, w=m2 / m1; S2. The sample a1 is subjected to hot mounting, curing, grinding and polishing, and carbon spraying to obtain an automatic mineralogical analysis sample, and then an automatic mineralogical analysis is performed to measure the mass fraction of sulfur to be f1 and the mass fraction of copper to be f2; S3. Take the sample m3 g to be tested and grind it to obtain sample a2; S4. The sample a2 is mixed with potassium nitrate, sodium carbonate, lead oxide, silicon dioxide and borax to obtain a sample a3; S5. The sample a3 is added with a silver nitrate solution and covered with a mixture of sodium carbonate and borax on the surface; then melted, cooled, and the precious metal, lead beads and slag are separated; S6. placing the precious metal and lead alloy beads in a preheated magnesia ash dish, heating, cooling, and obtaining alloy particles; S7. The alloy particles are placed in ethanol for a first ultrasonic oscillation, the alloy particles are rolled into thin sheets, and then placed in ethanol for a second ultrasonic oscillation to obtain sample a4, which is dried and weighed, and the mass is recorded as N mg; S8. The sample a4 is subjected to automatic mineralogical analysis and testing to obtain the area data of each element, recorded as Si1; After the test and analysis, the sample a4 is turned 180°, and the other surface is subjected to automatic mineralogical analysis test to obtain the area data of each element, which is recorded as Si2; wherein Si1 and Si2 are respectively used to represent the area data of element i on two different surfaces, i=1, 2, 3, ..., n, respectively used to represent different elements, i=1 represents the gold element, and n is the number of elements measured; Then calculate the gold percentage O in the alloy particles, O=(S11+S12)ρ1 / M; in, , ρi is the density of element i; S9. Calculate the gold grade H in the gold concentrate, H=N*O / ((m3*w)*10 -3 ) g / t; Wherein, in step S4, the added amount of the sample a2 is 23~27g; the theoretical added amount of potassium nitrate is 1.0Q~1.2Q g, wherein Q=600*f1-7, if the theoretical added amount is in the range of 10~30g, the theoretical added amount is used as the actual added amount of potassium nitrate, if the theoretical added amount is <10g, 10g is used as the actual added amount of potassium nitrate, if the theoretical added amount is >30g, 30g is used as the actual added amount of potassium nitrate; the added amount of sodium carbonate is 35~50g; the added amount of lead oxide is 1.0P~1.2P g, wherein P=500*f1+40*f2+30; the added amount of silicon dioxide is 15~30g; the added amount of borax is 10~20g.

2. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S1, the drying temperature is 90-100° C., and the drying time is 1.5-2.0 h.

3. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S3, the mass m3 of the sample to be tested is 20-30 g; the grinding fineness is that the sample can pass through a 320-mesh sieve.

4. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S5, the amount of silver nitrate solution added is 0.5-1.0 ml, and the concentration is 8-12 g / L.

5. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S5, the mass ratio of sodium carbonate to borax is 2:

1.

6. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S5, the melting temperature is 1150-1250° C., and the melting time is 25-30 min.

7. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S6, the preheating and heating temperatures are 850-950° C., and the heating time is 2-3 min.

8. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S7, the first ultrasonic oscillation time is 18-22 minutes, and the second ultrasonic oscillation time is 8-12 minutes.

9. The method for measuring the gold content in gold concentrate according to claim 1, characterized in that: In step S7, the thickness of the sheet is 0.01-0.03 mm.

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