Method for testing gold recovery performance of gold-containing material

Abstract

The application provides a kind of gold-containing material gold extraction performance test method, and relates to gold resource dressing technical field.The method comprises the following steps: grinding the gold-containing material to be tested to a specified fineness, and obtaining parallel samples with uniform gold grade by size reduction;an oxygen-free ore pulp system is constructed;the initial concentration of exogenous gold is calculated according to the material grade and the preset leaching rate, and an oxygen-free exogenous gold cyanide solution matching the industrial conditions is prepared;two groups of parallel tests, pure adsorption group and activated carbon synchronous competition group, are set up, and the reaction is carried out synchronously under the same oxygen-free condition until adsorption equilibrium;the gold grade of the original ore sample and the two groups of test ore samples are measured respectively;the total adsorbed gold amount, irreversible gold extraction amount, reversible adsorbed gold amount and irreversible gold extraction rate are calculated according to the test analysis results, and the gold extraction performance test is completed.The systematic interference of gold leaching from the ore itself is eliminated from the root, and the method is suitable for accurate evaluation of gold extraction performance of various gold-containing materials such as gold ore, gold concentrate, roasted slag and oxidized slag.

Description

Technical Field

[0001] This invention relates to the field of gold resource beneficiation and smelting technology, specifically to a test method for the gold-stealing properties of gold-bearing materials, applicable to the evaluation of the gold-stealing properties of gold ore, gold concentrate, roasting slag, oxide slag, and other gold-bearing extraction materials. Background Technology

[0002] Cyanide leaching is the core technology for gold extraction worldwide. Since its industrialization in 1887, it has become the preferred treatment method for various gold-bearing minerals by reacting cyanide solution with gold under aerobic conditions to form stable, soluble gold-cyanide complexes, coupled with solid-liquid separation and enrichment processes. It is divided into heap leaching and stirred cyanide leaching. However, this process suffers from a fatal flaw: preg-robbing. Some gold-bearing components can strongly adsorb the dissolved gold-cyanide complexes, leading to irreversible loss of leached gold and a significant decrease in gold recovery rate. This restricts mine efficiency and resource utilization, and is a core challenge that the gold extraction industry needs to overcome.

[0003] Studies have shown that the causes of gold robbery have a clear mineralogical orientation, mainly falling into two categories: one is naturally occurring carbonaceous materials in the ore (such as activated carbon and humic acid), which have a strong specific adsorption capacity for gold-cyanide complexes and are highly efficient gold-robbing carriers; the other is sulfide and silicate minerals (such as pyrite and feldspar), whose surfaces can fix gold-cyanide complexes through a combination of physical adsorption and chemical reduction. Furthermore, the gold robbery mechanism is differentiated, involving both reversible physical adsorption and irreversible chemical precipitation and reduction fixation, exacerbating the risk of gold loss. Accurately evaluating the gold-robbing performance of gold-bearing materials is of great significance for predicting gold leaching recovery rates, optimizing process parameters, and selecting pretreatment schemes. Currently, the commonly used industrial BGMI and PRP methods have significant technical shortcomings. The BGMI method involves contacting a fixed concentration of exogenous gold solution with the ore for 15 minutes, calculating the gold robbery rate by reducing the gold concentration in the solution. While simple to operate and quick, the exogenous gold concentration is disconnected from the actual leaching concentration, the reaction fails to reach adsorption equilibrium, and the interference of gold leaching from the ore itself is ignored, resulting in distorted test results that cannot guide production. The PRP method uses a standard addition method, employing adsorption experiments at multiple gold concentration points, characterizing the gold robbery potential by the deviation of the adsorption curve slope, and extending the reaction to 24 hours to ensure adsorption equilibrium. While this improves accuracy, the exogenous gold concentration is unrelated to ore grade, the concentration gradient has poor adaptability, the physical meaning of the slope deviation value in characterizing the gold robbery potential is ambiguous, and a unified evaluation benchmark for various types of gold-bearing materials has not been established, resulting in insufficient practicality.

[0004] In addition to the two mainstream methods mentioned above, US Patent No. US20260085379A1 discloses a gold robbery capacity test method based on total carbonaceous material characterization. This method calculates the apparent total adsorption rate of the material through an exogenous gold spike test. However, its core technical defects are: first, it uses an aerobic leaching system, which cannot block the cyanide dissolution of gold in the ore itself. It can only make a rough correction through blank tests and cannot eliminate the systematic error caused by the dissolution of gold itself from the root; second, it can only measure the total amount of gold adsorbed by the material and cannot distinguish between reversible adsorption and irreversible gold robbery. In industrial production, reversibly adsorbed gold can be competitively desorbed and recovered by activated carbon, which will not cause gold loss. Only irreversibly fixed gold is the real permanent loss. Therefore, the test results of this method seriously overestimate the risk of gold robbery and are seriously out of touch with actual production.

[0005] In summary, existing gold robbery testing methods generally suffer from common technical defects, including the inability to eliminate inherent gold dissolution interference, a disconnect between testing conditions and industrial operating conditions, the inability to distinguish between reversible adsorption and irreversible gold robbery, ambiguous physical meanings of evaluation indicators, and a narrow range of material compatibility. These deficiencies fundamentally fail to meet the demand for accurate and efficient evaluation of gold robbery performance in different gold-bearing materials in industrial production. This directly leads to blind optimization of gold leaching process parameters and inaccurate selection of pretreatment schemes, further amplifying resource losses. Therefore, developing a standardized gold robbery performance testing method that eliminates inherent gold dissolution interference at its source, fully matches industrial production conditions, accurately distinguishes between reversible adsorption and irreversible gold robbery, provides clear physical meanings for evaluation indicators, and is compatible with all types of gold-bearing materials is not only a key breakthrough in overcoming the technical bottlenecks of gold robbery but also has significant practical implications and major engineering application value for improving gold leaching recovery rates, optimizing mineral processing procedures, and achieving efficient recycling of gold resources. Summary of the Invention

[0006] In view of the technical problems existing in the background art, the present invention provides a test method for the gold-robbing performance of gold-bearing materials. By blocking the cyanide dissolution of gold in the ore itself from the thermodynamic source, the system interference of gold leaching is completely eliminated; the synchronous competitive adsorption conditions of industrial carbon leaching are completely replicated, accurately distinguishing between reversible adsorption and irreversible gold robbery; the test conditions are highly matched with industrial production, the evaluation indicators have clear physical meanings, and the permanent gold loss in production can be directly quantified. It is applicable to the standardized gold-robbing performance test of all types of gold-bearing materials.

[0007] This invention provides a method for testing the gold-stealing properties of gold-containing materials, which includes the following steps: S1, Sample preparation: Grind the gold-bearing material to be tested to the specified fineness, and obtain parallel samples with uniform gold grade by fractionation; S2, Anaerobic slurry pretreatment: Two parallel samples were taken to prepare slurry. The slurry was pretreated under reducing conditions in the absence of oxygen to block the cyanide dissolution of gold in the gold-containing material itself. S3, Determination of exogenous gold concentration: The initial concentration of exogenous gold is calculated based on the gold grade of the gold-containing material to be tested and the preset leaching rate, combined with the liquid-solid ratio. S4, comparative leaching: According to the determined liquid-solid ratio, two parallel samples were contacted with an oxygen-free exogenous gold cyanide solution, and were respectively designated as the pure adsorption group and the synchronous competition group; among them, the parallel samples of the pure adsorption group were carried out under the condition that there was no competing adsorbent, and the parallel samples of the synchronous competition group were carried out under the condition that there was a competing adsorbent. Both were reacted synchronously to adsorption equilibrium under the same reaction conditions. S5, Sample post-processing: After the reaction is completed, the competing adsorbents in the synchronous competition group are separated and the slag in both groups is washed to obtain the mineral sample to be tested. S6, Solid phase gold grade determination: The solid phase gold grade of the original gold-bearing material to be tested, the pure adsorption group mineral sample, and the synchronous competition group mineral sample were determined respectively. S7, Calculation of gold robbery performance indicators: Based on the solid phase gold grade determination results, the total adsorbed gold amount, irreversible gold robbery amount, reversible adsorbed gold amount and irreversible gold robbery rate are calculated. Wherein, the total adsorbed gold amount is the difference between the final gold grade of the pure adsorption group ore sample and the gold grade of the original ore sample; the irreversible gold robbery amount is the difference between the final gold grade of the synchronous competition group ore sample and the gold grade of the original ore sample; the reversible adsorbed gold amount is the difference between the total adsorbed gold amount and the irreversible gold robbery amount; and the irreversible gold robbery rate is the ratio of the irreversible gold robbery amount to the total adsorbed gold amount.

[0008] As a further improvement of the present invention, in step S2, the anaerobic slurry pretreatment includes: introducing an inert gas into the slurry to remove dissolved oxygen and oxygen adsorbed in the mineral pores of the system, and / or adding a reducing agent to the slurry to reduce the solid oxidizing minerals in the ore, and keeping the system under anaerobic positive pressure protection.

[0009] As a further improvement of the present invention, in step S4, the competing adsorbent is granular activated carbon with adsorption capacity for gold cyanide complexes; the amount of the competing adsorbent added to the slurry is 10~30g / L; the same reaction conditions include the same anaerobic environment, the same temperature, stirring speed and reaction time.

[0010] As a further improvement of the present invention, in step S3, the formula for calculating the initial concentration of exogenous gold is: Cadd=G×R×L:S; In the formula, G is the gold grade of the material to be tested, R is the preset leaching rate, and L:S is the liquid-solid ratio; The liquid-to-solid ratio is calculated based on the leaching concentration, and the calculation formula is as follows: L:S=(100-Cp) / Cp; In the formula, Cp is the leaching concentration; The preset leaching rate R ranges from 60% to 80%.

[0011] As a further improvement of the present invention, in step S3, the leaching concentration is determined according to the material type: the leaching concentration of gold ore is 40%~45%, and the leaching concentration of gold concentrate is 30%~35%.

[0012] As a further improvement of the present invention, in step S4, the oxygen-free exogenous gold cyanide solution is a sodium cyanide solution, and the reaction leaching time is 24-36 hours.

[0013] As a further improvement of the present invention, in step S4, the concentration of the sodium cyanide solution is determined according to the material type: the concentration of sodium cyanide in the exogenous gold solution of the gold ore sample is 0.2~0.5 g / L, and the concentration of sodium cyanide in the exogenous gold solution of the gold concentrate sample is 0.5~1.0 g / L; and the pH value of the sodium cyanide solution is 10.0~11.0.

[0014] As a further improvement of the present invention, in step S6, the solid gold grade is determined by fire assay. In step S1, the particle size of the parallel samples meets the requirement that the content of -0.074mm is 80%~95%; the relative deviation of the gold grade of the parallel samples is verified by fire assay ≤2%.

[0015] As a further improvement of the present invention, in step S2, the inert gas is high-purity nitrogen with a purity ≥99.999%, and the stirring time is ≥30 min; the reducing agent is ascorbic acid or ferrous ammonium sulfate, and the amount added is 0.1%~0.5% of the dry basis mass of the gold-bearing mineral sample to be tested; the pressure of the oxygen-free positive pressure protection is 0.01~0.03 MPa.

[0016] As a further improvement of the present invention, the gold-containing material to be tested is selected from at least one of gold ore, gold concentrate, roasting slag, and oxide slag; The test method is applied to the evaluation of gold-stealing performance in gold ore, gold concentrate, roasting slag, oxide slag, or gold-bearing extraction materials.

[0017] Beneficial effects: 1. The method provided by this invention completely eliminates the systemic interference of gold dissolution in the ore itself from a thermodynamic perspective by using an anaerobic system. Through the dual means of isolating gaseous oxygen with high-purity nitrogen and reducing solid-phase oxidizing minerals with a weak reducing agent, the occurrence of cyanide dissolution of gold is completely blocked. This ensures that the test system contains only exogenous gold as the sole source of gold, eliminating the need for any blank correction. This fundamentally solves the problem of inherent gold leaching interference that cannot be eradicated by existing technologies, resulting in zero background error in the test results.

[0018] 2. The method provided by this invention determines the exogenous gold concentration based on the industrial standard slurry concentration, material grade, and preset leaching rate. It truly reflects the range of liquid phase gold concentration for materials of different grades under actual leaching conditions. The test conditions are highly consistent with actual production, thus solving the core defect of existing technologies that fix the exogenous gold concentration and are out of touch with industrial operating conditions.

[0019] 3. The method provided by this invention achieves precise quantitative differentiation between reversible adsorption and irreversible gold loss, with clear physical meaning of the indicators. Through parallel experiments of a pure adsorption group and a synchronous competition group, the actual working conditions of synchronous competitive adsorption in industrial carbon leaching are completely replicated, accurately separating the total adsorbed gold amount, the reversibly adsorbed gold amount, and the irreversibly lost gold amount. The irreversible gold loss amount directly corresponds to the permanent gold loss that cannot be recovered in industrial production, and process engineers can directly use it to predict the amount of gold loss and guide process optimization.

[0020] 4. The method provided by this invention abandons the indirect calculation mode of liquid phase gold concentration in the existing technology, and adopts direct measurement of the gold grade change of the ore sample, which completely eliminates the detection error caused by factors such as decomposition of gold-cyanide complex, fluctuation of free cyanide, and entrainment in ore slurry, and significantly improves the authority and repeatability of test data.

[0021] 5. The method provided by this invention is applicable to a variety of gold-bearing materials such as gold ore, gold concentrate, roasting slag, and oxide slag. It provides differentiated parameter ranges for different material characteristics and establishes a unified evaluation benchmark for all types of gold-bearing materials. This facilitates horizontal comparison of the gold-robbing performance of materials from different sources and of different types, and has strong universality.

[0022] 6. All the operation steps of the method provided by the present invention can be completed in a conventional mineral laboratory without special equipment. The test cycle is moderate (24-36 hours), which ensures both sufficient adsorption equilibrium and test efficiency.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0025] Figure 1 This is a flowchart illustrating the test method for the gold-stealing performance of gold-containing materials provided in this embodiment of the invention. Detailed Implementation

[0026] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0027] 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 invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0028] In the description of the embodiments of this invention, 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 specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0031] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0032] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0033] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0034] To address the technical problems commonly found in existing gold robbery testing methods, such as poor working condition matching, inability to eliminate inherent gold interference, inability to distinguish between reversible and irreversible gold robbery, vague evaluation indicators, and narrow material applicability, this invention provides a testing method for the gold robbery performance of gold-containing materials. First, by blocking the cyanide dissolution of gold in the ore itself through an anaerobic system, the systemic interference of gold leaching on the test results is eliminated at the source, solving the technical problem that existing technologies can only compensate for errors through blank correction. Second, the initial concentration of exogenous gold is correlated with the actual grade of the gold-bearing material to be tested, the preset leaching rate, and the liquid-solid ratio of the process and dynamically calculated, so that the liquid phase gold concentration under laboratory test conditions accurately corresponds to the actual gold concentration level in the industrial leaching process, fundamentally solving the technical problem that the test conditions of traditional methods are out of sync with actual production. Third, a two-group parallel experiment is set up with a pure adsorption group and an activated carbon synchronous competition group, replicating the synchronous competitive adsorption conditions of industrial carbon leaching 1:1, accurately distinguishing between reversible adsorption and irreversible gold robbery, and realizing the accurate quantification of real gold robbery loss. Fourth, the solid phase gold grade is directly determined by the fire assay method, completely eliminating the systematic error of liquid phase detection, and fundamentally improving the authority and accuracy of the test data.

[0035] Please see Figure 1 As shown in the figure, this invention provides a method for testing the gold-stealing properties of gold-containing materials, which includes the following steps: S1, Sample preparation: Grind the gold-bearing material to be tested to the specified fineness to obtain a material sample with a particle size that meets the test requirements, and then reduce it to obtain multiple parallel samples with uniform gold grade. S2, Anaerobic slurry pretreatment: Two parallel samples were taken to prepare slurry. High-purity nitrogen was introduced to remove dissolved oxygen and oxygen adsorbed in mineral pores. A weak reducing agent was added to reduce the solid oxidizing minerals in the ore. Nitrogen positive pressure protection was maintained throughout the process to prevent the cyanide dissolution of gold in the ore itself. S3, Determination of exogenous gold concentration: Based on the grade of the gold-containing material to be tested and the preset leaching rate, the initial concentration of exogenous gold is calculated in combination with the liquid-solid ratio. The formula for calculating the initial concentration of exogenous gold is as follows: Cadd=G×R×L:S; In the formula, G is the gold grade of the material to be tested, R is the preset leaching rate, and L:S is the liquid-solid ratio; The liquid-to-solid ratio is calculated based on the leaching concentration, and the calculation formula is as follows: L:S=(100-Cp) / Cp; In the formula, Cp is the leaching concentration; S4, comparative leaching: According to the determined liquid-solid ratio, the two parallel samples were contacted with the oxygen-free exogenous gold cyanide solution of the pure adsorption group and the synchronous competition group, respectively, and reacted synchronously until the preset leaching time under the same nitrogen protection, constant temperature and stirring conditions; among them, granular activated carbon for industrial gold extraction was added to the slurry of the synchronous competition group, while no activated carbon was added to the pure adsorption group. S5, Sample post-processing: After the reaction is completed, the slurry of the synchronous competition group is screened to remove all activated carbon. The slag of the two groups is washed with oxygen-free deionized water until no free cyanide and no gold are detected in the washing liquid. After filtration and drying, the mineral sample to be tested is obtained. S6, Gold grade determination: The gold grade of the original ore sample, the pure adsorption group ore sample, and the synchronous competition group ore sample were determined by fire assay. S7, Calculation of gold robbery performance indicators: Based on the fire assay results, the total adsorbed gold amount, irreversible gold robbery amount, reversible adsorbed gold amount, and irreversible gold robbery rate are calculated to complete the gold robbery performance test of gold-containing materials; the calculation formulas for each indicator are as follows: Total adsorbed gold content = final gold grade of pure adsorbed sample - gold grade of original sample; Irreversible gold content = Final gold grade of synchronous competition group ore sample - Gold grade of original ore sample; Reversible adsorption gold amount = Total adsorption gold amount - Irreversible gold amount; Irreversible gold robbery rate = (Irreversible gold robbery amount / Total gold adsorbed) × 100%.

[0036] Preferably, in step S3, the preset leaching rate R ranges from 60% to 80%.

[0037] Preferably, in step S2, the leaching concentration is determined according to the material type: the leaching concentration of gold ore is 40%~45%, and the leaching concentration of gold concentrate is 30%~35%.

[0038] Preferably, in step S4, the leaching agent solution is a sodium cyanide solution, and the reaction leaching time is 24-36 hours.

[0039] Preferably, in step S4, the concentration of the sodium cyanide solution is determined according to the material type: the concentration of sodium cyanide in the exogenous gold solution of the gold ore sample is 0.2~0.5 g / L, and the concentration of sodium cyanide in the exogenous gold solution of the gold concentrate sample is 0.5~1.0 g / L; and the pH value of the sodium cyanide solution is 10.0~11.0.

[0040] Preferably, in step S1, the particle size satisfies that the content of -0.074mm is 80%~95%; the material must not contain coarse or larger gold minerals. If coarse gold minerals are present, they must be recovered by gravity separation before the test is carried out; the parallel samples are verified by fire assay, and the relative deviation of gold grade is ≤2%.

[0041] Preferably, in step S2, the high-purity nitrogen gas has a purity of ≥99.999%, and the deoxygenation stirring time is ≥30 min; the weak reducing agent is ascorbic acid or ferrous ammonium sulfate, and the amount added is 0.1%~0.5% of the dry basis mass of the mineral sample; the positive pressure of nitrogen gas throughout the process is 0.01~0.03 MPa.

[0042] Preferably, in step S4, the granular activated carbon for industrial gold extraction is 6-16 mesh coconut shell activated carbon, and the addition amount is 10-30 g / L slurry; the activated carbon is pretreated by wet grinding to remove sharp edges and then sieved with a 40 mesh standard sieve to remove fine powder.

[0043] Preferably, in step S4, the two sets of experiments are carried out simultaneously in the same magnetic stirring device; the criteria for determining adsorption equilibrium are: the gold concentration is measured by taking the supernatant of the slurry every 2 hours, the relative deviation of the results of 3 consecutive tests is <5%, and the shortest reaction time is not less than 24 hours.

[0044] Preferably, in step S5, the slurry of the synchronous competition group is screened using a 40-mesh standard Taylor sieve, and after screening, it is confirmed that there are no activated carbon particles remaining; the slag is washed no less than 3 times.

[0045] Example 1 Please see Figure 1 As shown, Embodiment 1 of the present invention provides a method for testing the gold-robbing properties of gold-bearing materials. The material to be tested is a semi-oxidized gold ore with few sulfides, and its process mineralogical characteristics are as follows: The main chemical composition analysis results of the sample are shown in Table 1. The main valuable element in the sample is gold, with a grade of 3.15 g / t.

[0046] Table 1. Results of analysis of major chemical components The mineral composition and relative content results are shown in Table 2. The relative content of metallic sulfides in the raw ore sample was 2.20%, with pyrite accounting for 1.35% and arsenopyrite for 0.79%, while other sulfides were present in smaller quantities. The relative content of metallic oxides was 1.35%, with limonite accounting for 1.15% and magnetite and hematite combined accounting for 0.20%. The relative content of gangue minerals was 96.45%, with quartz accounting for 60.44% and feldspar for 19.71%, while other gangue minerals were present in smaller quantities. The sample oxidation rate was 34.43%, classifying it as a semi-oxidized sample. Analysis showed an average gold grade of 3.15 g / t and a sulfur content of 0.92%. Based on these characteristics, this ore is classified as a low-sulfide, semi-oxidized gold ore.

[0047] Table 2. Results of mineral composition and relative content analysis The specific implementation steps of Example 1 are as follows: S1, Sample Preparation: The gold-bearing material to be tested was ground to the specified fineness to obtain a material sample with a particle size that meets the test requirements. The specific process is as follows: A representative gold ore sample was taken and ground until the content of -0.074mm particles accounted for 90%. Microscopic examination showed that no coarse gold minerals were present in the material. The material was divided into 8 parallel samples using a mechanical divider. Two parallel samples were randomly selected and the original gold grade was determined by fire assay. The gold grades of the two samples were 3.14 g / t and 3.16 g / t, respectively, with a relative deviation of 0.32% ≤ 2%. The sample homogeneity was qualified and met the test requirements, and it could be directly used for subsequent tests.

[0048] S2, Anaerobic Slurry Pretreatment: Two parallel samples were taken, each with a dry basis weight of 1.0 kg. 1.5 L of oxygen-free deionized water was added to each sample to prepare a slurry. High-purity nitrogen gas with a purity of 99.999% was introduced and stirred continuously for 30 min to remove dissolved oxygen and pore-adsorbed oxygen from the system. 0.2 g of ascorbic acid (0.02% of the ore sample weight) was added to each of the two slurries. The mixture was stirred for 20 min under a nitrogen positive pressure of 0.02 MPa to reduce the solid-phase oxidizing minerals in the ore, resulting in two pretreated slurries. The system was kept oxygen-free throughout the process.

[0049] S3, Determination of Exogenous Gold Concentration: Based on the grade of the gold-bearing material to be tested and the preset leaching rate, the initial concentration of exogenous gold is calculated in conjunction with the liquid-solid ratio. Specifically, the material is gold ore, and the leaching concentration is determined to be 40% based on the material type. The corresponding liquid-solid ratio is calculated as: L:S = (100-40):40 = 1.5:1; that is, 1.5 liters of solution need to be added per kilogram of ore. The gold grade of the material is G = 3.15 g / t, and the preset leaching rate is R = 60%. The corresponding initial concentration of exogenous gold is calculated as: Cadd = 3.15 × 0.6 × 1.5 = 2.835 mg / L.

[0050] S4, Comparative Leaching: Following a determined liquid-to-solid ratio, two parallel samples were contacted with anaerobic exogenous gold cyanide solutions from the pure adsorption group and the synchronous competition group, respectively. Under identical nitrogen protection, constant temperature, and stirring conditions, the reactions were carried out synchronously until the preset leaching time. Specifically, two material samples, each with a mass m = 1 kg, were taken and each was added to a sodium cyanide solution with a volume V = 1.5 L. The sodium cyanide concentration was 0.3 g / L, and the pH was adjusted to 10.5 with sodium hydroxide. Nitrogen protection was maintained throughout the process. Pure Adsorption Group A: No activated carbon was added. Under a nitrogen positive pressure of 0.02 MPa and a constant temperature of 25 ± 0.5 °C, the mixture was stirred at 200 r / min for 36 hours to ensure the leaching-adsorption process reached full equilibrium. Synchronous Competition Group B: Pretreated 6-16 mesh coconut shell activated carbon was added simultaneously at a rate of 20 g / L of slurry. The temperature, stirring speed, and nitrogen pressure were maintained identically to Group A throughout the process, with synchronous stirring for 36 hours until adsorption equilibrium was reached.

[0051] S5, Sample processing: After the reaction of the two groups of tests was stopped simultaneously, the slurry of the synchronous competition group B was repeatedly sieved using a 40-mesh standard Taylor sieve to confirm that there were no activated carbon particles remaining. Then, the slag of groups A and B were washed 6 times with oxygen-free deionized water until the washing liquid was free of free cyanide. After filtration and drying at a constant temperature of 105℃, the mineral sample to be tested was obtained.

[0052] S6, Gold grade determination: The gold grade of the original ore sample, the pure adsorption group A ore sample, and the synchronous competition group B ore sample were determined by fire assay. The results are as follows: Gold grade of the original ore sample: 3.15 g / t; final gold grade of the pure adsorption group A ore sample: 3.45 g / t; final gold grade of the synchronous competition group B ore sample: 3.24 g / t.

[0053] S7, Calculation of gold robbery performance indicators: Based on the fire assay results, the total adsorbed gold amount, irreversible gold robbery amount, reversible adsorbed gold amount, and irreversible gold robbery rate are calculated to complete the gold robbery performance test of gold-containing materials; the specific calculation process is as follows: Total adsorbed gold amount = 3.45 - 3.15 = 0.30 g / t; Irreversible amount of gold stolen = 3.24 - 3.15 = 0.09 g / t; Reversible gold adsorption capacity = 0.30 - 0.09 = 0.21 g / t; Irreversible robbery rate = (0.09 / 0.30) × 100% = 30.00%.

[0054] Comparative Example 1 The difference from Example 1 is that the experimental conditions (under normal aerobic conditions, without nitrogen protection and without weak reducing agents) are completely consistent with those of Example 1. The specific experimental steps are as follows: S1, Sample preparation, reduction, and uniformity verification are the same as in Example 1; S2, Slurry pretreatment: Ordinary deionized water is directly added to prepare slurry, and the mixture is stirred for 30 minutes in an aerobic environment without nitrogen deoxygenation or the addition of ascorbic acid; S3, preparation of exogenous gold solution: same as in Example 1, prepared under an aerobic environment; S4, Parallel test: The pure adsorption group and the synchronous competition group were tested simultaneously under aerobic conditions, with other conditions the same as in Example 1; S5 Sample processing, S6 Gold grade determination, and S7 Calculation methods are the same as in Example 1.

[0055] The test results showed that the gold grade of the original ore sample was 3.15 g / t; the gold grade of the pure adsorption group was 3.62 g / t; and the gold grade of the synchronous competition group was 3.38 g / t.

[0056] Total adsorbed gold = 3.62 - 3.15 = 0.47 g / t; Irreversible amount of gold stolen = 3.38 - 3.15 = 0.23 g / t; Irreversible robbery rate = (0.23 / 0.47) × 100% = 48.94%.

[0057] As shown in Comparative Example 1, under aerobic conditions, the elemental gold in the ore continues to dissolve and is re-adsorbed by gold-robbing substances, resulting in inflated test results and a serious overestimation of the risk of gold robbery from the ore.

[0058] Comparative Example 2 The experiment was conducted using a conventional leaching process, with 90% of the ore being ground to a fineness of -0.074 mm, pH=10.5, a leaching concentration of 40%, a free sodium cyanide concentration of 0.3 g / L, and aerobic stirring leaching for 36 hours. The specific experimental steps are as follows: S1, take 1.0 kg of the same batch of homogeneous mineral sample as in Example 1, adjust the slurry to a leaching concentration of 40% and a liquid-to-solid ratio of 1.5:1; S2, adjust the pH to 10.5 with sodium hydroxide, and add sodium cyanide to a free concentration of 0.3 g / L; S3, aerobic stirring leaching at 25℃ and 200r / min for 36h; S4, solid-liquid separation, leaching residue washing and drying, and the gold grade of leaching residue determined by fire assay; S5, calculate the actual gold leaching rate.

[0059] Gold grade in leaching residue: 1.94 g / t; actual leaching rate = (3.15 - 1.94) / 3.15 × 100% = 38.52%. The test results show that the gold leaching effect is poor.

[0060] Comparative Example 3 The experiment employed a carbon leaching process, adding 15 g / L of industrial coconut shell activated carbon to the mixture of Comparative Example 2. All other parameters, including grinding fineness, pH value, leaching concentration, free sodium cyanide concentration, leaching time, temperature, and stirring speed, remained identical to simulate the industrial CIP carbon leaching process. The specific experimental steps are as follows: S1, mineral sample slurry preparation, pH adjustment, and sodium cyanide addition are the same as in comparative example 2; S2, add 15g / L of pretreated coconut shell activated carbon, and leach with aerobic stirring for 36h; S3, activated carbon was removed by sieving with a 40-mesh standard sieve, the leaching residue was washed and dried, and the gold grade of the leaching residue was determined by fire assay. S4, calculate the actual gold leaching rate.

[0061] Gold grade in leaching residue: 1.61 g / t; actual leaching rate = (3.15-1.61) / 3.15×100% = 48.76%. The test results show that after adding activated carbon, the reversibly adsorbed gold was effectively recovered, and the leaching rate increased by 10.24 percentage points compared with Comparative Example 2. However, 23.59% of the leaching rate was still lost and could not be recovered.

[0062] Conventional CIP processes cannot determine that this loss is irreversible gold robbery. The test results are in complete agreement with the 30.00% irreversible gold robbery rate measured in Example 1 of this invention, verifying the accuracy of the data in this invention.

[0063] Comparative Example 4 The BGMI test method was used for the experiment, and the experimental conditions were performed according to the BGMI standard method: 5.0 g ore sample, 90% grinding fineness of -0.074 mm, NaCN concentration of 2.0 g / L, exogenous gold concentration fixed at 3 mg / L, stirring at room temperature for 15 min, and then measuring the gold concentration in the liquid phase after filtration. The specific experimental steps are as follows: S1, Weigh 5.0g of the same batch of mineral sample as in Example 1 and place it in a 250mL beaker; S2, add 10 mL of sodium cyanide solution with a mass concentration of 2.0 g / L, and adjust the concentration of exogenous gold to 3 mg / L; S3, stir at 200 r / min for 15 min at room temperature, and immediately filter to separate the solid and liquid using qualitative filter paper; S4, the gold concentration in the supernatant was determined by atomic absorption spectrophotometry; S5 calculates the robbery rate.

[0064] Experimental results: Gold concentration in the supernatant: 2.945 mg / L; Gold robbery rate = (3 - 2.945) / 3 × 100% = 1.83%. Because the BGMI method reaction time is only 15 min, it is far from reaching adsorption thermodynamic equilibrium; the external gold concentration is fixed, which is seriously inconsistent with the actual industrial liquid phase gold concentration; there is no oxygen-free protection or activated carbon competition, and the measured gold robbery rate is only 1.83%, which is seriously inconsistent with the actual leaching indicators and cannot reflect the true gold robbery performance of the ore.

[0065] Comparative Example 5 The experiment was conducted using the method described in US Patent Publication No. US20260085379A1. The experimental conditions were: an aerobic system, an exogenous gold concentration of 3.43 mg / L (0.10 oz / ton), a liquid-to-solid ratio of 1.5:1, and a stirring time of 24 h. A blank control group was set to correct for the dissolution of the gold itself, and the total gold-stealing capacity was calculated. The specific experimental steps are as follows: S1, Sample preparation and grinding are the same as in Example 1; S2, prepare a 3.43 mg / L exogenous gold cyanide solution with a liquid-to-solid ratio of 1.5:1; S3, set up a blank group (without exogenous gold) and an experimental group (with exogenous gold), and stir for 24 hours at 25℃ and 200r / min under aerobic conditions; S4. The gold concentrations of the two solutions were measured separately, and the gold-stealing capacity was calculated according to the US patent formula: Gold-stealing capacity = (initial concentration of exogenous gold + leaching concentration of blank group - equilibrium gold concentration of experimental group) / (initial concentration of exogenous gold + leaching concentration of blank group) × 100%.

[0066] Experimental results: The gold concentration that can be leached in the blank group was 0.848 mg / L; the equilibrium gold concentration in the experimental group was 2.79 mg / L; the gold leaching capacity was (3.43 + 0.848 - 2.79) / (3.43 + 0.848) × 100% = 42.15%.

[0067] This method only measures the apparent total adsorption rate and cannot distinguish between reversible adsorption and irreversible gold robbery; the aerobic system itself has serious interference with gold dissolution, and cannot accurately guide the evaluation of gold robbery performance of ore in actual production.

[0068] The method provided by this invention utilizes a dual approach (anaerobic pretreatment) of isolating gaseous oxygen with high-purity nitrogen and reducing solid-phase oxidizing minerals with a weak reducing agent to fundamentally block the cyanide dissolution of gold in the ore itself, completely eliminating the interference of the gold leaching system that traditional methods cannot avoid. Simultaneously, it dynamically correlates the initial concentration of exogenous gold with the actual gold grade of the test material, the preset leaching rate, and the liquid-solid ratio of the process, ensuring that the laboratory liquid-phase gold concentration accurately matches the real working conditions of the industrial carbon leaching process. Based on this, a dual-track parallel experiment is set up with a pure adsorption group and a synchronously competing activated carbon group. Utilizing the competitive desorption of reversibly adsorbed gold by activated carbon, the total adsorption capacity of the material for gold is precisely separated into two parts: "reversible adsorption" and "irreversible gold robbery." The change in the solid-phase gold grade of the ore sample after the reaction is directly measured using the fire assay method, and the irreversible gold robbery rate is output through a clear mathematical model.

[0069] In summary, this invention provides a method for testing the gold-stealing performance of gold-bearing materials, relating to the field of gold resource beneficiation and smelting technology. The method includes the following steps: grinding the gold-bearing material to be tested to a specified fineness, and reducing it to obtain parallel samples with uniform gold grade; constructing an anaerobic slurry system through high-purity nitrogen protection and reduction with a weak reducing agent to block the cyanide dissolution of gold in the ore itself; calculating the initial concentration of exogenous gold based on the material grade and a preset leaching rate, and preparing an anaerobic exogenous gold cyanide solution matching industrial operating conditions; setting up two parallel experiments: a pure adsorption group and an activated carbon synchronous competition group, reacting synchronously under the same anaerobic conditions until adsorption equilibrium; after the reaction, separating the activated carbon and washing the slag, and measuring the gold grade of the original ore sample and the two experimental ore samples respectively; calculating the total adsorbed gold amount, irreversible gold-stealing amount, reversible adsorbed gold amount, and irreversible gold-stealing rate based on the analysis results, thus completing the gold-stealing performance test. By constructing an anaerobic system to block the cyanide dissolution of gold in the ore itself, the systemic interference of gold leaching is completely eliminated. Through dynamic correlation between exogenous gold concentration and material grade, preset leaching rate, and liquid-solid ratio, the test conditions are highly matched to industrial operating conditions. Double-parallel experiments accurately distinguish between reversible adsorption and irreversible gold robbery. The solid-phase gold grade is directly determined using a fire assay, eliminating errors in liquid-phase detection. This invention provides accurate test results with clear physical meaning, and is applicable to the accurate evaluation of gold robbery performance in various gold-bearing materials such as gold ore, gold concentrate, roasting slag, and oxide slag.

[0070] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for testing the gold-stealing properties of gold-containing materials, characterized in that, Includes the following steps: S1, Sample preparation: Grind the gold-bearing material to be tested to the specified fineness, and obtain parallel samples with uniform gold grade by fractionation; S2, Anaerobic slurry pretreatment: Two parallel samples were taken to prepare slurry. The slurry was pretreated under reducing conditions in the absence of oxygen to block the cyanide dissolution of gold in the gold-containing material itself. S3, Determination of exogenous gold concentration: The initial concentration of exogenous gold is calculated based on the gold grade of the gold-containing material to be tested and the preset leaching rate, combined with the liquid-solid ratio. S4, comparative leaching: According to the determined liquid-solid ratio, two parallel samples were contacted with an oxygen-free exogenous gold cyanide solution, and were respectively designated as the pure adsorption group and the synchronous competition group; among them, the parallel samples of the pure adsorption group were carried out under the condition that there was no competing adsorbent, and the parallel samples of the synchronous competition group were carried out under the condition that there was a competing adsorbent. Both were reacted synchronously to adsorption equilibrium under the same reaction conditions. S5, Sample post-processing: After the reaction is completed, the competing adsorbents in the synchronous competition group are separated and the slag in both groups is washed to obtain the mineral sample to be tested. S6, Solid phase gold grade determination: The solid phase gold grade of the original gold-bearing material to be tested, the pure adsorption group mineral sample, and the synchronous competition group mineral sample were determined respectively. S7, Calculation of gold robbery performance indicators: Based on the solid phase gold grade determination results, the total adsorbed gold amount, irreversible gold robbery amount, reversible adsorbed gold amount and irreversible gold robbery rate are calculated. Wherein, the total adsorbed gold amount is the difference between the final gold grade of the pure adsorption group ore sample and the gold grade of the original ore sample; the irreversible gold robbery amount is the difference between the final gold grade of the synchronous competition group ore sample and the gold grade of the original ore sample; the reversible adsorbed gold amount is the difference between the total adsorbed gold amount and the irreversible gold robbery amount; and the irreversible gold robbery rate is the ratio of the irreversible gold robbery amount to the total adsorbed gold amount.

2. The method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, In step S2, the anaerobic slurry pretreatment includes: introducing an inert gas into the slurry to remove dissolved oxygen and oxygen adsorbed in the mineral pores, and / or adding a reducing agent to the slurry to reduce solid oxidizing minerals in the ore, while maintaining the system under anaerobic positive pressure protection.

3. The method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, In step S4, the competing adsorbent is granular activated carbon with adsorption capacity for gold cyanide complexes; the amount of the competing adsorbent added to the slurry is 10~30g / L; the same reaction conditions include the same anaerobic environment, the same temperature, stirring speed and reaction time.

4. The method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, In step S3, the formula for calculating the initial concentration of exogenous gold is: Cadd=G×R×L:S; In the formula, G is the gold grade of the material to be tested, R is the preset leaching rate, and L:S is the liquid-solid ratio; The liquid-to-solid ratio is calculated based on the leaching concentration, and the calculation formula is as follows: L:S=(100-Cp) / Cp; In the formula, Cp is the leaching concentration; The preset leaching rate R ranges from 60% to 80%.

5. The method for testing the gold-stealing properties of gold-containing materials according to claim 4, characterized in that, In step S3, the leaching concentration is determined according to the material type: the leaching concentration of gold ore is 40%~45%, and the leaching concentration of gold concentrate is 30%~35%.

6. The method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, In step S4, the oxygen-free exogenous gold cyanide solution is a sodium cyanide solution, and the reaction leaching time is 24-36 hours.

7. The method for testing the gold-stealing properties of gold-containing materials according to claim 6, characterized in that, In step S4, the concentration of the sodium cyanide solution is determined according to the material type: the concentration of sodium cyanide in the exogenous gold solution of the gold ore sample is 0.2~0.5 g / L, and the concentration of sodium cyanide in the exogenous gold solution of the gold concentrate sample is 0.5~1.0 g / L; and the pH value of the sodium cyanide solution is 10.0~11.

0.

8. The method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, In step S6, the solid gold grade is determined using the fire assay method; In step S1, the particle size of the parallel samples meets the requirement that the content of -0.074mm is 80%~95%; the gold grade of the parallel samples is verified by fire assay, and the relative deviation is ≤2%.

9. A method for testing the gold-stealing properties of gold-containing materials according to claim 2, characterized in that, In step S2, the inert gas is high-purity nitrogen with a purity ≥99.999%, and the stirring time is ≥30 min; the reducing agent is ascorbic acid or ferrous ammonium sulfate, and the amount added is 0.1%~0.5% of the dry basis mass of the gold-bearing mineral sample to be tested; the pressure of the oxygen-free positive pressure protection is 0.01~0.03 MPa.

10. A method for testing the gold-stealing properties of gold-containing materials according to claim 1, characterized in that, The gold-containing material to be tested is selected from at least one of gold ore, gold concentrate, roasting slag, and oxide slag; The test method is applied to the evaluation of gold-stealing performance in gold ore, gold concentrate, roasting slag, oxide slag, or gold-bearing extraction materials.

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