Improved determination method of gold content in high-impurity materials based on gray dish improved collaborative optimization

Abstract

The application provides a method for determining gold content in a high-impurity material based on an improved gray dish collaborative optimization, and belongs to the technical field of noble metal analysis and detection. Before fire assaying, the application stirs and uniformly mixes tricalcium phosphate, kaolin, calcium silicate, carbon powder and water according to a certain proportion to obtain a mud material, presses the mud material into a gray dish green body by using a gray dish mold, and processes the gray dish green body through segmented drying and sintering to obtain a gray dish with regular pores, high impurity removal efficiency and stable structure. By using the improved gray dish, impurities can be effectively absorbed by the gray dish in the cupellation stage, the accuracy and stability of the detection result are improved, and the precise detection requirement of a high-impurity and complex matrix sample is met.

Description

Technical Field

[0001] This application relates to the field of precious metal analysis and detection technology, specifically to a method for determining the gold content in high-impurity materials based on improved synergistic optimization using ash pans. Background Technology

[0002] Fire assay gravimetric method is the arbitration method for detecting gold and silver content in ores, metallurgical intermediates, and precious metal concentrates. It has strong resistance to matrix interference and high detection accuracy, making it a core technology for precious metal metrological traceability. The ash blowing process is the core link in fire assay testing. The core principle is that lead oxide melts and penetrates into the ash pan at high temperature, simultaneously removing the lead matrix, adsorbing non-metallic impurities, and eliminating trace associated impurities, ultimately leaving pure gold and silver particles. The thoroughness of impurity removal directly determines the accuracy and reliability of the gold and silver analysis results.

[0003] Currently, magnesia ash dishes are the mainstream consumable in domestic precious metal fire assay testing. However, their inherent material properties and pore structure defects result in a severe deficiency in impurity removal during the ash blowing stage. This is a core technical bottleneck in the industry, causing residual gold and silver granular impurities, distorted test results, and large systematic errors. It cannot meet the accurate testing requirements of high-impurity and complex matrix samples. The specific defects are as follows: 1. Due to its dense pores and poor permeability, the magnesia ash pan is prone to impurity retention and accumulation. Made from magnesia sintered at high temperatures, it has low overall porosity, small pore size, poor connectivity, and weak permeability. During the ash blowing process, impurities such as metal oxides carried by molten lead oxide cannot quickly permeate and be discharged. These impurities easily accumulate and remain on the surface of the ash pan, making effective filtration impossible. A large number of impurities adhere to and coat the surface and crevices of the gold-silver composite particles, resulting in insufficient particle purity and directly leading to poor accuracy and stability of gold detection results.

[0004] 2. Lacks graded filtration and impurity removal capabilities, resulting in poor impurity removal for complex samples. Magnesia ash pans have a simple pore structure and lack graded filtration channels with varying coarseness. They can only achieve simple adsorption of small amounts of pure lead matrix, and their ability to remove impurities from highly impure materials such as copper-lead electrolytic anode mud, metallurgical enriched slag, and highly impure ores is weak. The amount of residual impurities increases significantly with the increase of sample impurity content, continuously amplifying the detection error and failing to meet the detection requirements of highly impure matrix samples.

[0005] 3. Granular impurities are difficult to clean and cannot be eliminated through pretreatment. Surface and crevices of magnesia ash residues, resulting from incomplete impurity removal, have strong adhesion and cannot be completely removed by conventional pretreatment methods such as acid washing, boiling, and wiping.

[0006] In view of this, it is necessary to design a method for improving and optimizing ash pans to solve the problem of weak impurity removal capacity of magnesia ash pans for high-impurity materials. Without changing the detection method and process, this method can improve the stability and accuracy of high-impurity material detection and adapt to the current status of mineral resources. Summary of the Invention

[0007] In view of the technical problems existing in the background art, this application provides a method for determining the gold content in high-impurity materials based on the improved synergistic optimization of ash pans. By constructing a controllable and regular pore structure through precise proportioning, the method can achieve efficient removal of impurities during the ash blowing process, completely make up for the shortcomings of magnesia ash pans in impurity removal, eliminate the detection system error introduced by impurities, and significantly improve the accuracy and reliability of gold content determination in high-impurity materials.

[0008] To achieve the above objectives, this application provides a method for determining the gold content in high-impurity materials based on improved synergistic optimization using ash pans. The specific steps are as follows: S1. Mix tricalcium phosphate, kaolin, calcium silicate and carbon powder, stir evenly to obtain a mixture; S2. Mix the mixture with water and stir until homogeneous to prepare mud. S3. Press the clay material into shape using a clay mold, and demold to obtain a clay blank; S4. The first ash dish is obtained by drying the ash dish green blank; S5. The first ash dish is sintered to obtain the second ash dish; S6. The high-impurity material is subjected to a ash blowing operation using the second ash pan to obtain gold-silver granules. The gold-silver granules are separated to obtain gold particles. The gold content in the high-impurity material is calculated based on the mass of the high-impurity material and the mass of the gold particles.

[0009] Furthermore, in step S1, the mass ratio of coarse particles with a particle size of 35-45 μm to fine particles with a particle size of 10-20 μm in the tricalcium phosphate is 65:35 to 75:25.

[0010] Furthermore, in step S1, the mixture comprises, by mass parts, 30-50 parts of tricalcium phosphate, 5-10 parts of carbon powder, 22-33 parts of kaolin, and 22-33 parts of calcium silicate.

[0011] Furthermore, in step S1, the stirring time is 15 to 25 minutes.

[0012] Furthermore, in step S2, the water content in the mud is 8% to 12%.

[0013] Furthermore, in step S3, the pressing and molding are performed using a constant hydraulic pressure method; the constant hydraulic pressure is 40-50 MPa static pressure, and the holding time is 10-30 seconds.

[0014] Furthermore, in step S4, the drying step includes: air-drying the ash pan blank at room temperature for 7 to 10 days, and then drying it at a constant temperature of 110 to 130°C for 4 to 8 hours.

[0015] Furthermore, in step S5, the sintering process includes: placing the first ash dish in a muffle furnace, heating it to 450-550°C for 20-30 minutes; then heating it to 860-880°C for 10-20 minutes; and then cooling it naturally in the furnace.

[0016] Furthermore, in step S5, the first heating rate is 3-5°C / min; the second heating rate is 5-8°C / min.

[0017] Furthermore, in step S6, the temperature of the ash blowing is 860–900°C.

[0018] The beneficial technical effects of this application are as follows: 1. Excellent structural performance: The modified ash pan of this invention has a scientifically proportioned composition, resulting in high refractory resistance and structural strength. It does not soften, crack, or leak lead during the entire ash blowing process at 900-1100℃, and is suitable for conventional and high-temperature enhanced ash blowing processes.

[0019] 2. Comprehensive impurity removal effect: The ash dish used in this invention can efficiently remove various base metal impurities such as bismuth, antimony, arsenic, tin, and copper during the ash blowing process. In particular, it solves the technical problem of poor impurity removal effect of magnesia ash dishes in the industry, eliminating the need for secondary ash blowing and greatly improving detection efficiency.

[0020] 3. High detection accuracy: The ash dish used in this invention balances low gold and silver adsorption loss with high impurity removal capability, overcoming the defect of high precious metal loss in magnesia ash dishes. The accuracy and stability of the detection data are superior to those of magnesia ash dishes.

[0021] 4. Wide applicability: The ash dish used in this invention can be adapted to various high-impact materials such as high bismuth lead ore, copper-lead-bismuth anode mud, and polymetallic symbiotic ore. It has strong versatility and is suitable for industrial batch preparation and laboratory application.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Detailed Implementation

[0023] The following embodiments are only used to illustrate the technical solutions of this application more clearly, and are therefore only examples and should not be used to limit the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0026] The existing mainstream magnesia ash pans have weak high-temperature impurity removal capabilities and poor impurity filtration capabilities, resulting in low accuracy and poor stability of gold and silver analysis results.

[0027] To address the aforementioned technical problems, this application provides a method for determining the gold content in high-impurity materials based on improved synergistic optimization using ash pans. The specific steps are as follows: S1. Mix tricalcium phosphate, kaolin, calcium silicate and carbon powder, stir evenly to obtain a mixture; S2. Mix the mixture with water and stir evenly to prepare mud. S3. Press the clay material into shape using a clay mold, and demold to obtain a clay blank; S4. After drying the raw ash dish, the first ash dish is obtained; S5. The first ash dish is sintered to obtain the second ash dish; S6. Use a second ash pan to perform ash blowing on the high-impurity material to obtain gold-silver granules. Separate the gold-silver granules to obtain gold particles. Calculate the gold content in the high-impurity material based on the mass of the high-impurity material and the mass of the gold particles.

[0028] In the technical solution of this application, by adding tricalcium phosphate, under high-temperature ash blowing conditions, tricalcium phosphate undergoes a solid-phase reaction with metal oxides to generate a high-melting-point, high-stability phosphate solid phase, which is permanently fixed inside the pores of the ash pan, completely solving the problem that metal oxides cannot be chemically fixed; by adding kaolin, the silica in kaolin can form an infinitely miscible silicate glass phase with metal impurities and lead oxide, greatly improving the solubility of metal impurities in lead melt and eliminating the problem of melt stratification and saturation; by using coarse and fine tricalcium phosphate in combination with carbon powder, a continuous and uniform gradient microporous structure is constructed, which enhances the capillary suction of the ash pan, accelerates the rapid penetration of impurities and lead melt into the interior of the ash pan, and avoids the accumulation of impurities on the surface of the aggregate.

[0029] It can be explained that the steps of the ash blowing operation in step S6 are as follows: Weigh a certain mass of high-impurity material into a clay crucible, add 80-120g of lead oxide, 30-40g of sodium carbonate, 10-15g of borax, and flour / nitrate, mix evenly, and then cover with a 10mm thick covering agent. Transfer the clay crucible to the melting furnace, slowly heat to 1100℃, maintain the temperature for 10 minutes, rotate the crucible steadily several times, and gently tap the bottom of the crucible 2-3 times on an iron plate to ensure that the molten material gathers at the bottom of the crucible. Then pour all the molten material into a preheated cast iron mold. After cooling, separate the lead buckle from the slag, hammer the lead buckle into a cube, and weigh it. Place the lead buckle in the second ash dish, and after the molten lead has been removed from the mold, partially open the furnace door, wait for the lead to be completely blown away, and then take out the gold and silver granules.

[0030] It can be explained that in step S6, the gold separation process is as follows: The gold-silver alloy granules are hammered into thin sheets of 0.2–0.3 mm thickness. These sheets are placed in a colorimetric tube, and 10 mL of (1+7) nitric acid is added. The colorimetric tube is then heated in a water bath. After the reaction between the alloy granules and the acid has ceased, the colorimetric tube is removed, the acid solution is poured out, and 10 mL of gently boiling (1+2) nitric acid is added. Heating continues in a boiling water bath for 40 minutes. The colorimetric tube is removed, the acid solution is poured out, and the gold granules are washed with distilled water. They are then transferred to a porcelain crucible, dried on a hot plate, annealed, and cooled to room temperature. The gold granules are then weighed on a microbalance, and the mass is recorded.

[0031] It can be explained that the steps for calculating the gold content in high-impurity materials are as follows: ω(Au) = m1 / m0 × 1000.

[0032] In the formula, ω(Au) represents the gold content, in g / t; m0 represents the mass of the high-impurity material weighed, in g; and m1 represents the mass of the gold particles, in mg.

[0033] In some embodiments, in step S1, the mass ratio of coarse particles with a particle size of 34-45 μm to fine particles with a particle size of 10-20 μm in tricalcium phosphate is 65:35 to 75:25.

[0034] In this embodiment, by controlling the mass ratio of tricalcium phosphate, a gradient pore structure can be formed: coarse particles serve as a framework, providing sufficient and permeable large pores to ensure that the lead oxide melt can be absorbed quickly; fine particles fill the spaces between the coarse particles, adjusting the size and distribution of the pores to prevent excessively large pores from causing the loss of precious metals, while also improving the mechanical strength and density of the ash pan.

[0035] In some embodiments, in step S1, the mixture contains, by mass parts, 30-50 parts tricalcium phosphate, 5-10 parts carbon powder, 22-33 parts kaolin, and 22-33 parts calcium silicate.

[0036] In this embodiment, by adding the above-mentioned mass proportions of tricalcium phosphate, kaolin, calcium silicate and carbon powder, with tricalcium phosphate as the main substrate, the core advantages of the ash dish are guaranteed: high temperature resistance, high strength and low gold and silver adsorption loss, thus avoiding the detection defects of magnesia ash dishes.

[0037] In some embodiments, the stirring time in step S1 is 15 to 25 minutes.

[0038] In this embodiment, tricalcium phosphate of different particle sizes is mixed with kaolin, calcium silicate, and carbon powder by stirring to form a completely homogeneous mixture.

[0039] In some embodiments, in step S2, the water content in the mud is 8% to 12%.

[0040] In this embodiment, by controlling the water content in the clay, the molding performance, drying shrinkage behavior, and pore structure and strength of the final ash pan are regulated.

[0041] In some embodiments, in step S3, hydraulic constant pressure is used for pressing and molding; the hydraulic constant pressure is 40-50 MPa static pressure, and the holding time is 10-30 s.

[0042] In this embodiment, a dense and uniform ash pan blank with a regular appearance is obtained by hydraulic constant pressure, ensuring that the pore distribution and filtration channels of each ash pan are consistent.

[0043] In some embodiments, the drying step in step S4 includes: air-drying the raw ash pan at room temperature for 7 to 10 days, and then drying it at a constant temperature of 110 to 130°C for 4 to 8 hours.

[0044] In this embodiment, the surface free water is removed by air-drying the ash dish green at room temperature; and the internal adsorbed water is removed by drying the ash dish green at a constant temperature.

[0045] In some embodiments, in step S5, the sintering process includes: placing the first ash dish in a muffle furnace, heating it to 450-550°C for 20-30 minutes; then heating it to 860-880°C for 10-20 minutes; and then cooling it naturally with the furnace.

[0046] In this embodiment, by step-controlled temperature calcination during sintering, various defects caused by rapid evaporation of moisture, concentrated release of gas, abrupt phase transformation, or local overheating are avoided, and a second ash dish with sufficient strength, suitable porosity, and stable phase is finally obtained.

[0047] In some embodiments, in step S5, the first heating rate is 3-5°C / min; the second heating rate is 5-8°C / min.

[0048] In this embodiment, the heating rate is controlled to avoid low production efficiency due to excessively slow heating and rapid evaporation of moisture due to excessively rapid heating.

[0049] In some embodiments, in step S6, the temperature of the ash blowing is 860–900°C.

[0050] In this embodiment, by controlling the ash blowing temperature, the lead buckle is successfully oxidized and de-leaded, and the lead oxide can be effectively absorbed by the ash dish, thereby ensuring the accurate gold recovery rate.

[0051] The embodiments of this application will be described in further detail below with reference to the examples. The detailed description of the following embodiments is used to illustrate the principles of this application, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0052] I. Experimental Procedure Example 1 This embodiment provides a method for determining the gold content in high-impurity materials based on improved synergistic optimization using ash pans. The grade of the high-impurity material sample used is 87.67 g / t. The specific steps are as follows: S1. Mix 40 parts tricalcium phosphate (coarse particles: fine particles = 70:30), 25 parts kaolin, 25 parts calcium silicate and 10 parts carbon powder, and stir for 20 minutes until completely homogeneous to form a mixture.

[0053] S2. Add deionized water to the mixture in batches to make the moisture content about 10%, stir evenly, and prepare a mud material with no layering, no lumps, and uniform plasticity.

[0054] S3. Press the clay material using a standard ash pan mold with constant hydraulic pressure, hold at 45MPa for 10s, and demold to obtain a dense, uniform, and regular-looking ash pan green body.

[0055] S4. Air-dry the raw ash dish at room temperature for 7 days to remove free water from the surface; then place it in an electric constant temperature drying oven and dry it at a constant temperature for 6 hours to completely remove the internal adsorbed water, thus obtaining the first ash dish.

[0056] S5. Place the first ash dish in a muffle furnace and heat it to 450℃ at 3℃ / min, hold it for 30min; then heat it to 880℃ at 5℃ / min, hold it for 20min; let it cool naturally in the furnace to obtain the second ash dish.

[0057] S6. Weigh 10.00g of the high-impurity material sample, accurate to 0.01g, place it in a clay crucible, add 120g of lead oxide, 40g of sodium carbonate, 15g of borax, and flour / nitrate, mix well, and then cover with a 10mm thick covering agent.

[0058] S7. Transfer the clay crucible to the melting furnace, heat it to 1100℃ at 20℃ / min, hold the temperature for 10 minutes, rotate the crucible steadily several times, and gently tap the bottom of the crucible 2-3 times on an iron plate to ensure that the molten material gathers at the bottom of the crucible. Then pour all the molten material into a preheated cast iron mold. After cooling, separate the lead buckle from the slag, hammer the lead buckle into a cube, and weigh it.

[0059] S8. Place the lead buckle into the second ash dish. After the molten lead is removed from the mold, partially open the furnace door and perform ash blowing at 880℃. After the lead is completely blown away, take out the gold and silver granules.

[0060] S9. Use a hammer to break the gold-silver granules into thin sheets of 0.2–0.3 mm thickness. Place the sheet in a colorimetric tube, add 10 mL of (1+7) nitric acid, and heat the colorimetric tube in a water bath. After the granules and acid stop reacting, remove the colorimetric tube, pour out the acid solution, add 10 mL of gently boiling (1+2) nitric acid, and continue heating in a boiling water bath for 40 min. Remove the colorimetric tube, pour out the acid solution, wash the gold granules with distilled water, transfer them to a porcelain crucible, dry them on a hot plate, anneal them, cool them to room temperature, weigh them on a microbalance, and record the mass.

[0061] Examples 2-3 Examples 2 and 3 respectively provide a method for determining the gold content in high-impurity materials based on synergistic optimization of gray dish. The difference between these methods and Example 1 is that the high-impurity material samples used are different. The remaining steps and experimental parameters are basically the same as in Example 1, and will not be repeated here.

[0062] The grade (Au content) and impurity content of the high-impurity material samples used in Examples 1-3 are shown in Table 1.

[0063] Table 1. Grade and impurity content (%) of high-impurity material samples from Examples 1-3 Example 4 This embodiment provides an improved and synergistically optimized method for determining the gold content in highly impure materials based on ash dishes. The difference from Embodiment 1 is that, in step S8, the ash dish pressed according to this patent is not used; instead, a magnesia ash dish is selected. The remaining steps and experimental parameters are basically the same as in Embodiment 1 and will not be repeated here.

[0064] Examples 5-8 Examples 5-8 provide a method for determining the gold content in high-impurity materials based on synergistic optimization using ash pans. The difference from Example 1 is that different pressures are used in the pressing stage of step S3, and the specific pressures are shown in Table 2. The remaining steps and experimental parameters are basically the same as in Example 1, and will not be repeated here.

[0065] Table 2 Pressure values ​​in Examples 1, 5-8 Examples 9-11 Examples 9-11 respectively provide a method for determining the gold content in high-impurity materials based on synergistic optimization using ash pans. The difference from Example 1 is that different calcination temperatures are used in the second heating stage of step S5. The specific calcination temperatures are shown in Table 3. The remaining steps and experimental parameters are basically the same as in Example 1, and will not be repeated here.

[0066] Table 3 Calcination temperatures of Examples 1, 9-11 Examples 12-15 and Comparative Examples 1-3 Examples 12-15 and Comparative Examples 1-3 each provide a method for determining the gold content in high-impurity materials based on improved synergistic optimization using ash pans. The difference from Example 1 is that the mass fractions of each component in the mixture are different; specific parameters are shown in Table 4. The remaining steps and experimental parameters are basically the same as in Example 1 and will not be repeated here. It should be noted that the total mass of the mixture is the same in Examples 1, 12-15, and Comparative Examples 1-3.

[0067] Table 4. Mass fractions of each component in the mixtures of Examples 1, 12-15 and Comparative Examples 1-3 II. Detection Methods 1. Gold content: The gold content in the sample is calculated using the following formula: ω(Au) = m1 / m0 × 1000 In the formula, ω(Au) represents the gold content, in g / t; m1 represents the mass of the high-impurity material weighed, in g; and m0 represents the mass of the gold particles, in mg.

[0068] Precision is the relative standard deviation of the gold content determination value.

[0069] 2. Spike recovery rate: The spike recovery rate is calculated using the following formula: R(%) = (m 测 -m 本底 ) / m 加标 × 100% In the formula, R represents the spiked recovery rate; m 测 This represents the mass of gold measured in the spiked sample, in mg; m 本底 The mass of gold was measured in mg (unspecified sample); m 加标 This represents the actual mass of the gold standard added, expressed in mg.

[0070] III. Test Results Precision tests were conducted on Examples 1-15 and Comparative Examples 1-3 to verify the stability of the experiments. The specific test results are shown in Table 5.

[0071] Table 5. Average and relative standard deviation of gold content in Examples 1-15 and Comparative Examples 1-3. As can be seen from Table 5, the precision of Examples 1 to 3 is between 0.08% and 0.90%, which proves that the determination method provided in this example has high stability.

[0072] Comparing Example 4 with Example 1, the gold content detected in Example 4 was 83.15 g / t, which deviated significantly from the true value of Example 1; the precision was 1.44%, indicating poor stability. This example used a magnesia ash-blowing dish. During the final stage of ash blowing, impurities could not be completely absorbed by the dish, resulting in gold loss and a lower result; furthermore, impurities remained on the surface of the aggregates, causing gold particle breakage during the gold separation stage, leading to significant fluctuations in the results. This demonstrates that for highly impure materials, the improved ash-blowing dish of this patent can improve the accuracy and stability of the determination results for such materials.

[0073] Comparing Examples 5-8 with Example 1, when the pressure is 35 MPa, the ash pan is unstable due to the low pressure, and cracks and collapses occur, making it impossible to obtain accurate results. When the pressure is 40-50 MPa, the pressure is suitable, and the pore structure and stability of the ash pan are better, resulting in better accuracy and stability of the results. When the pressure is 55 MPa, the ash pan is too compacted due to the excessive pressure, resulting in a small pore ratio, weakened impurity absorption capacity, gold loss at the end of the ash blowing stage, and gold particle breakage during the gold separation stage, resulting in poor stability of the results.

[0074] Comparing Examples 9-11 with Example 1, when the calcination temperature was 840℃, the carbon powder (pore-forming agent) could not be fully released due to the low calcination temperature, resulting in incomplete pore structure construction. At the same time, due to the low temperature, the pores were not fully sintered, leading to insufficient skeleton strength. During the ash blowing stage, the skeleton collapsed, causing loss of precious metals. When the calcination temperature was 860-880℃, the temperature was suitable, the pore skeleton strength was suitable, and a stable impurity removal channel was constructed, which could effectively retain precious metals and remove impurities. When the calcination temperature was 900℃, due to the excessively high temperature, tricalcium phosphate underwent a phase transformation, pore collapse, and structural distortion, resulting in weakened impurity removal ability and gold loss, leading to lower results and poor stability.

[0075] Comparing Examples 12-15, Comparative Examples 1-3, and Example 1, with a total mass of 100 parts of the mixture, when tricalcium phosphate accounts for 30-50 parts, kaolin for 22-30 parts, calcium silicate for 22-30 parts, and carbon powder for 5-10 parts, the resulting ash pan exhibits better pore structure and stability, leading to better accuracy and stability of the results. The specific amounts of each raw material can be appropriately adjusted within the above range according to actual needs. However, significantly changing the amounts of the above raw materials will affect the pore structure and stability of the ash pan, resulting in a decrease in the accuracy and stability of the detection results when measuring high-impurity materials based on the corresponding ash pan.

[0076] The spiked recovery rate was used to verify the results of Examples 1-3. The specific test results are shown in Table 6.

[0077] Table 6 Spike recovery tests of Examples 1-3 As shown in Table 6, the spiked recovery rate of Example 1 was 96.22%–100.3%, demonstrating that the determination method provided in this example has high accuracy. The spiked recovery rates of Examples 2 and 3 were 99.15%–99.85%, further demonstrating the accuracy of the determination method provided in this example.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans, characterized in that, The specific steps are as follows: S1. Mix tricalcium phosphate, kaolin, calcium silicate and carbon powder, stir evenly to obtain a mixture; S2. Mix the mixture with water and stir until homogeneous to prepare mud. S3. Press the clay material into shape using a clay mold, and demold to obtain a clay blank; S4. The first ash dish is obtained by drying the ash dish green blank; S5. The first ash dish is sintered to obtain the second ash dish; S6. The high-impurity material is subjected to a ash blowing operation using the second ash pan to obtain gold-silver granules. The gold-silver granules are separated to obtain gold particles. The gold content in the high-impurity material is calculated based on the mass of the high-impurity material and the mass of the gold particles.

2. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans as described in claim 1, characterized in that, In step S1, the mass ratio of coarse particles with a particle size of 35-45 μm to fine particles with a particle size of 10-20 μm in the tricalcium phosphate is 65:35 to 75:

25.

3. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans as described in claim 1, characterized in that... In step S1, the mixture comprises, by mass parts, 30-50 parts of tricalcium phosphate, 5-10 parts of carbon powder, 22-33 parts of kaolin, and 22-33 parts of calcium silicate.

4. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 1, characterized in that, In step S1, the stirring time is 15 to 25 minutes.

5. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 1, characterized in that, In step S2, the water content in the mud is 8% to 12%.

6. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 1, characterized in that, In step S3, the pressing and molding are performed using a constant hydraulic pressure method; the constant hydraulic pressure is 40-50 MPa static pressure, and the holding time is 10-30 s.

7. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 1, characterized in that, In step S4, the drying step includes: The green clay blank is air-dried at room temperature for 7-10 days, and then dried at a constant temperature of 110-130℃ for 4-8 hours.

8. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 1, characterized in that, In step S5, the sintering process includes: The first ash dish is placed in a muffle furnace and heated to 450–550°C for 20–30 minutes; then heated to 860–880°C for 10–20 minutes; and then cooled naturally with the furnace.

9. The method for determining gold content in high-impurity materials based on improved synergistic optimization using ash pans according to claim 8, characterized in that, In step S5, the first heating rate is 3-5°C / min; the second heating rate is 5-8°C / min.

10. The method for determining gold content in high-impurity materials based on improved synergistic optimization using gray dish as described in claim 1, characterized in that, In step S6, the temperature of the ash blowing is 860-900°C.

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