Analysis method of mineral leaching property

Abstract

The invention provides a mineral leaching property analysis method, which belongs to the field of process mineralogy, and comprises the following steps: crushing and enriching a sample to be detected, and selecting single mineral particles to obtain target mineral particles; the preparation method comprises the following steps: coating a sample preparation grinding tool with epoxy resin glue, adding target mineral particles, and carrying out curing and grinding treatment to obtain a primary sample; cutting the primary sample, placing the grinding surface downwards and the three wear-resistant alloys at the bottom of a sample preparation grinding tool, injecting epoxy resin glue, curing to form a composite sample, accurately grinding, polishing, performing carbon spraying treatment, performing first automatic mineralogical analysis, measuring the area of a target mineral, cleaning, and performing leaching treatment to obtain a treated sample; and after solidification, accurate grinding and polishing and carbon spraying treatment, secondary automatic mineralogical analysis is carried out, the area of the residual target mineral is measured, and the leaching index of the target mineral is calculated. Reliable technical support is provided for mineral processing technology optimization and resource evaluation, and the method is particularly suitable for development of efficient leaching technologies of precious metal, rare earth and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of process mineralogy, and particularly to an analysis method for mineral leachability. Background Art

[0002] As a core technology in the fields of hydrometallurgy and mineral processing, the analysis of mineral leachability plays a key role in aspects such as the development of low-grade ores, the resource utilization of tailings, and the extraction of rare metals through selective dissolution means such as chemical leaching and bioleaching. With the increasing depletion of mineral resources and the continuous improvement of environmental protection requirements, the demand for the accuracy of mineral leachability evaluation has become increasingly prominent.

[0003] Traditional evaluation methods mainly rely on batch leaching tests combined with chemical element analysis techniques. Although overall leaching rate data can be obtained, there are obvious technical limitations in practical applications: Firstly, these methods cannot distinguish the differences in dissolution kinetics between target minerals and associated minerals; Secondly, there is a lack of quantitative characterization means for the influence of the occurrence state of minerals (such as fine-grained inclusions, complex intergrowths, etc.) on leaching efficiency, resulting in a lack of scientific basis at the microscale for process optimization. The main technical bottlenecks faced by current mineral leachability analysis are reflected in multiple aspects: In the sample preparation process, conventional crushing and classification processes are prone to over-crushing or selective loss of target minerals. Especially for ores with uneven dissemination sizes, it is difficult to ensure the representativeness of analysis samples; In terms of characterization techniques, although surface analysis techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM) can provide local morphological information, due to limitations in the observation field of view and statistical sample size, global quantitative analysis of mineral dissolution behavior cannot be achieved. In addition, the resin embedding-polishing process, as a key step for comparative analysis before and after leaching, currently lacks a unified standardized control specification, and fluctuations in factors such as the permeability of embedding agents and polishing parameters will introduce analysis errors.

[0004] In view of this, it is necessary to design an improved analysis method for mineral leachability to solve the above problems. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present application provides an analysis method for mineral leachability, aiming to solve the technical problems of lack of representativeness and low accuracy in traditional mineral leachability analysis methods.

[0006] The present application provides an analysis method for mineral leachability, including the following steps: S1. Take a sample to be tested, perform crushing, enrichment, and single mineral particle selection to obtain target mineral particles; S2. Coat epoxy resin glue in a sample preparation mold, add the target mineral particles, and after curing and grinding treatment, obtain a primary sample; S3. Cut the primary sample, place it face-down on the bottom of the sample preparation mold together with three pieces of wear-resistant alloy, and inject epoxy resin glue to cure and form a composite sample; S4. Precision grind and polish the composite sample until it is flush with the surface of the wear-resistant alloy. After carbon spraying treatment, conduct the first automatic mineralogical analysis and measure the area S of the target mineral n ; n is 1, 2, 3..., representing the types of target minerals; S5. Clean the surface of the sample obtained in step S4, conduct leaching treatment to obtain the treated sample; S6. Coat the epoxy resin glue in the sample preparation mold, add the treated sample, inject epoxy resin glue to cure, precision grind and polish until it is flush with the surface of the wear-resistant alloy. After carbon spraying treatment, conduct the second automatic mineralogical analysis and measure the remaining area S of the target mineral n '; S7. Calculate the leachability index A of the target mineral n , where A n = 1 - S n ' / S n .

[0007] As a further improvement of the present application, in step S2, the coating thickness of the epoxy resin glue is 0.1 - 0.3 mm.

[0008] As a further improvement of the present application, the grinding treatment uses abrasive with a mesh size of 200 - 600, and the grinding thickness is 0.05 - 0.15 mm.

[0009] As a further improvement of the present application, in step S3, the wear-resistant alloy is tungsten carbide with a hardness ≥ 9 Mohs, its three-dimensional size is 1 - 5 mm, and the lower surfaces of the three alloys are kept horizontal and not on the same straight line.

[0010] As a further improvement of the present application, in step S3, the height of the composite sample is 0.8 - 1.2 cm.

[0011] As a further improvement of the present application, in step S1, the single mineral particles include one or more of the target mineral particles in the monomer state, intergrown state, and encapsulated state.

[0012] As a further improvement of the present application, the crushing uses a jaw crusher to reduce the particle size to 1 - 5 mm or a roll crusher to make the particle size > 0.5 mm.

[0013] As a further improvement of the present application, the precision grinding uses abrasive with a mesh size of 1000 - 1400, the polishing uses abrasive with a particle size ≤ 1 μm, and the polishing time ≥ 5 min.

[0014] The beneficial effects of the present application are: The present application provides an analysis method for the leachability of minerals. By taking a sample to be tested, crushing, enriching, and selecting single mineral particles, target mineral particles are obtained; epoxy resin glue is coated in a sample preparation mold, the target mineral particles are added, and after curing and grinding treatments, a primary sample is obtained; the primary sample is cut, the grinding surface is placed downward together with three wear-resistant alloys at the bottom of the sample preparation mold, and epoxy resin glue is injected and cured to form a composite sample; the composite sample is precisely ground and polished until it is flush with the surface of the wear-resistant alloy, and after carbon spraying treatment, the first automatic mineralogical analysis is carried out to measure the area of the target mineral; the surface of the obtained sample is cleaned, leaching treatment is carried out to obtain a treated sample; epoxy resin glue is coated in a sample preparation mold, the treated sample is added, epoxy resin glue is injected and cured, precisely ground and polished until it is flush with the surface of the wear-resistant alloy, and after carbon spraying treatment, the second automatic mineralogical analysis is carried out to measure the area of the remaining target mineral; the leachability index of the target mineral is calculated based on the areas of the target mineral measured before and after the leaching treatment. The present application provides reliable technical support for the optimization of mineral processing technologies and resource evaluation, and is particularly applicable to the development of high-efficiency leaching processes for precious metals, rare earths, etc.

[0015] The present application eliminates the grinding and polishing depth error through a wear-resistant alloy reference and two resin fixations. The wear-resistant alloy (tungsten carbide) is used as an indication of the termination of grinding and polishing. Combining with the thin-layer resin glue technology, it ensures the consistency of the exposure of the target mineral. By high-resolution scanning combined with area ratio calculation, the dissolution loss error of the traditional gravimetric method is avoided. By automatically scanning the change in the mineral area through mineralogy (such as MLA or QEMSCAN), the interference of impurities in traditional chemical analysis is avoided, and the results are more reliable.

[0016] The present application can analyze minerals in different occurrence states (monomer / paragenesis / inclusion), and is applicable to various mineral types such as sulfide ore and oxide ore.

[0017] 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 in accordance with the content of the description. 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. Description of the Drawings

[0018] In order to more clearly illustrate the technical solution of the present application, the drawings used in the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a flow chart of the analysis method for the leachability of minerals provided by the embodiment of the present application; Figure 2 It is a comparison result diagram of chalcopyrite before and after treatment in the embodiment of the present application; Figure 3 This is the comparison result diagram before and after the treatment of chalcopyrite in the embodiments of this application. Specific implementation manners

[0020] Next, embodiments of the technical solution of this application will be described in detail with reference to the accompanying drawings. 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.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0022] 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.

[0023] Traditional mineral leachability analysis methods cannot accurately distinguish the dissolution kinetic differences between target minerals and associated minerals, it is difficult to quantitatively characterize the influence of mineral occurrence states on leaching efficiency, and there are limitations in sample preparation and characterization techniques, resulting in the lack of representativeness and accuracy of analysis results.

[0024] To solve the technical problems of the lack of representativeness and low accuracy of traditional mineral leachability analysis methods, this application provides an analysis method for mineral leachability. Among them, through a comprehensive method combining special sample preparation and treatment, further chemical leaching treatment, and automatic mineralogical quantitative analysis, accurately and quantitatively evaluate the leachable ratio of target minerals, realize the quantitative statistics of mineral composition and dissemination characteristics, track the mineral dissolution behavior during the leaching process in situ, and establish a quantitative correlation model for the surface changes of minerals before and after leaching.

[0025] Please refer to Figure 1 , the embodiments of this application provide an analysis method for mineral leachability, including the following steps: S1. Take the sample to be tested, perform crushing, enrichment, and single mineral particle selection to obtain target mineral particles; S2. Coat epoxy resin glue in the sample preparation mold, add the target mineral particles, and after curing and grinding treatment, obtain the primary sample; Specifically, according to the types of target minerals, primary samples of different mineral types are prepared respectively; S3. Cut the primary samples, place the ground surface downward together with three wear-resistant alloys at the bottom of the sample preparation mold, and inject epoxy resin glue to cure and form a composite sample; Specifically, multiple primary samples can be placed in the same sample preparation mold. If the number of samples is large, multiple composite samples can be prepared; S4. Precision grind and polish the composite sample until it is flush with the surface of the wear-resistant alloy, perform carbon spraying treatment, and then conduct the first automatic mineralogical analysis to measure the area S of the target mineral n ; n is 1, 2, 3..., representing the types of target minerals; S5. Clean the surface of the sample obtained in step S4, perform leaching treatment to obtain a treated sample; S6. Coat the epoxy resin glue in the sample preparation mold, add the treated sample, inject epoxy resin glue to cure, precision grind and polish until it is flush with the surface of the wear-resistant alloy, perform carbon spraying treatment, and then conduct the second automatic mineralogical analysis to measure the remaining area S of the target mineral n '; S7. Calculate the leachability index A of the target mineral n , where A n = 1 - S n ' / S n .

[0026] In the technical solution of the embodiment of the present application, the sample to be tested is crushed, enriched, and single mineral particles are selected to separate the target mineral particles and reduce the interference of other minerals; the mineral particles are fixed by epoxy resin glue to facilitate subsequent cutting and grinding treatments; the height after two precision grindings is controlled to be consistent by wear-resistant alloys to ensure the accuracy of data; the leaching treatment simulates the leaching conditions in actual hydrometallurgy or mineral processing processes to observe the dissolution of the target mineral; according to the results of two automatic mineralogical analyses, the leachability index of the target mineral is calculated, and this index reflects the dissolution degree of the target mineral under specific leaching conditions. The larger the value, the better the leachability of the target mineral.

[0027] Further, in some embodiments, in step S2, the coating thickness of the epoxy resin glue is 0.1 - 0.3 mm.

[0028] In the technical solution of the embodiment of the present application, the thickness of the epoxy resin glue needs to be sufficient to ensure that the target mineral particles can be firmly fixed. If it is too thick, it may affect the subsequent grinding and polishing accuracy and the exposure of the target mineral. If the resin layer is too thin, it may not provide sufficient support force, resulting in the movement or damage of the mineral particles during the grinding process. After adding the epoxy resin glue to the sample preparation mold, it is left stationary for 2 - 5 minutes, and then the target mineral particles are placed. Preferably, the target mineral particles are laid flat on the surface of the epoxy resin glue to avoid overlap or inclination. Then, vacuum is applied to remove air bubbles, and it is left to cure at room temperature (20 - 30°C).

[0029] Further, in some embodiments, the grinding treatment uses abrasive with a mesh size of 200 - 600, and the grinding thickness is 0.05 - 0.15 mm.

[0030] In the technical solution of the embodiment of the present application, abrasive paper or abrasive with a mesh size of 200 - 600 is preferably used. When grinding, in order to expose the mineral surface, the force needs to be controlled to avoid the detachment of the mineral. During grinding, the exposure degree of the mineral can be observed and confirmed under a microscope. The thickness ground off is controlled at 0.05 - 0.15 mm, preferably 0.5 times the thickness of the thin-layer resin glue.

[0031] Further, in some embodiments, in step S3, the wear-resistant alloy is tungsten carbide with a hardness ≥ 9 Mohs, its three-dimensional size is 1 - 5 mm, and the lower surfaces of the three alloys are kept horizontal and not on the same straight line.

[0032] In the technical solution of the embodiment of the present application, the purpose of cutting the sample is to place multiple target mineral samples in the same sample preparation mold; after cutting, the sample is placed at the bottom of the sample preparation mold. Preferably, the bottom is at the same height as the lower surface of the wear-resistant alloy; the three wear-resistant alloys are preferably tungsten carbide. The alloys serve as the height reference and the indication of the termination of grinding and polishing. The lower surfaces of the three wear-resistant alloys are horizontal and not on the same straight line, and the three-dimensional size is within the range of 1 - 5 mm.

[0033] Further, in some embodiments, in step S3, the height of the composite sample is 0.8 - 1.2 cm.

[0034] In the technical solution of the embodiment of the present application, the height of the composite sample needs to be appropriate to facilitate the operation in the subsequent grinding and polishing processes.

[0035] Further, in some embodiments, in step S1, the single mineral particles include one or more of the target mineral particles in the monomer state, the intergrown state, and the encapsulated state.

[0036] In the technical solution of the embodiment of the present application, the single mineral particles are preferably the target mineral particles in the monomer state, and can also be the target mineral particles in the intergrown state or the encapsulated state.

[0037] Further, in some embodiments, jaw crushers are used for crushing to reduce the particle size to 1 - 5 mm, or roll crushers are used for crushing to make the particle size > 0.5 mm.

[0038] In the technical solution of the embodiment of the present application, it is preferred to use a jaw crusher for coarse crushing to reduce the particle size to 1 - 5 mm; or use a roll crusher for fine crushing to make the particle size > 0.5 mm; over-crushing that may cause loss of target minerals should be avoided; for enriching the target minerals, gravity separation (shaking table, centrifugal separation), flotation and other means can be used to increase the content of the target minerals; manual separation can be used to select single mineral particles of the target minerals.

[0039] Further, in some embodiments, 1000 - 1400 mesh abrasive is used for fine grinding, abrasive with a particle size ≤ 1 μm is used for polishing, and the polishing time is ≥ 5 min.

[0040] In the technical solution of the embodiment of the present application, 1200 - mesh sandpaper or abrasive is preferably used for fine grinding, abrasive with a particle size below 1 μm is preferably used for polishing, and the polishing time is more than 5 min. Grind and polish until the target mineral is flush with the alloy block to ensure a flat surface. The first grinding and polishing depth of the processed sample should be the same as that of the composite sample (error < ±0.02 mm). For leaching treatment, acid / alkali leaching agents are selected according to the mineral properties, and the concentration, temperature and time are controlled.

[0041] Some specific embodiments are listed below. 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 to the present application. For those not specifying specific technologies or conditions in the embodiments, the technologies or conditions described in the literature in the field or the product instructions are followed. For reagents or instruments not indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0042] Embodiment This embodiment provides an analysis method for mineral leachability, which is used for analyzing the leachability of copper minerals in a certain copper deposit: S1. According to the ore properties (querying relevant geological data), the copper minerals in this copper ore are mainly chalcopyrite and chalcocite, with very small amounts of bornite and copper oxide minerals. The leachability of chalcopyrite and chalcocite is to be analyzed; Take 1.0 kg of the sample to be tested, use a jaw crusher for coarse crushing to reduce the particle size to less than 5 mm; use gravity separation (centrifugal separation) to increase the content of the target minerals chalcopyrite and chalcocite; use manual separation to select single mineral particles of the target minerals; select single mineral particles of chalcopyrite and chalcocite, mainly selecting mineral particles in the monomer state; S2. First fixation: Add a thin layer of epoxy resin glue to two sample preparation molds, with the thickness controlled at 0.1 mm. Let it stand for 2 min, then place the target mineral particles. The particles should be laid flat on the resin surface to avoid overlap or inclination. Evacuate to remove air bubbles, and let it cure at room temperature to obtain samples a1 and a2, where 1 represents chalcopyrite and 2 represents chalcocite. Grind a1 and a2 preliminarily with 300-mesh sandpaper to expose the target minerals, and grind off a thickness of 0.05 mm to obtain samples b1 and b2 respectively. S3. Cut samples b1 and b2, with the grinding surface facing down, and place them together with three wear-resistant alloys at the bottom of the sample preparation mold. The wear-resistant alloy is specifically a tungsten carbide cube with three-dimensional dimensions of 2 mm. Press the lower surfaces of the three alloys to keep them horizontal and at the same height as the cut samples placed at the bottom of the sample preparation mold. The three wear-resistant alloys are not on the same straight line. Add epoxy resin glue to a height of 1.10 cm, evacuate to remove air bubbles, and let it cure to obtain sample c. S4. Re-grind, fine-grind, and spray carbon on sample c. Select 1200-mesh abrasive until the target mineral is flush with the alloy block, ensuring a flat surface. Then perform polishing using abrasive below 1 micron for 5 min to obtain sample d. Grind and polish until the height of the tungsten carbide block is reached. Conduct automatic mineralogical analysis on sample d, and scan the areas of chalcopyrite and chalcocite. S1 = 130245 mm 2 ; S2 = 17761 mm 2 ; S5. Clean the surface with alcohol for measurement, and then conduct a leaching test. Leaching conditions: Select the acidic leaching agent H2SO4 according to the mineral properties, with a concentration of 2 mol / L. React at room temperature for 6 hours. Wash the sample again, shake the sample with ethanol to remove the surface adsorbates to obtain sample e. S6. Second fixation and comparative test: Inject a thin layer of resin glue into the sample preparation mold, add sample e, and inject glue again to cure to obtain sample f. Re-grind, fine-grind, and spray carbon on sample f. Preferably select 1200-mesh abrasive until the target mineral is flush with the alloy block, ensuring a flat surface. Then perform polishing, preferably using abrasive below 1 micron for more than 5 min to obtain sample g. Conduct automatic mineralogical analysis on sample g, and analyze and scan to obtain the target mineral areas S1’ and S2’. S1’ = 32507 mm 2 , S2’ = 874 mm 2 ; As Figures 2 to 3 shown, the single mineral particles of chalcopyrite and chalcocite become significantly smaller after leaching treatment. S7. Calculate the mineral leachability index. A1 = 1 - S1’ / S1 = 1 - 32507 / 130245 = 0.7504; A2 = 1 - S2’ / S2 = 1 - 874 / 17761 = 0.9508; It shows that the leachability of chalcopyrite is medium and the leachability of chalcocite is good.

[0043] It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having the same constitution in essence as the technical idea and achieving the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, within the scope not departing from the gist of the present application, various modifications that can be conceived by those skilled in the art to the embodiments, and other modes constructed by combining some constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An analysis method for the leachability of minerals, characterized in that It includes the following steps: S1. Take the sample to be tested, perform crushing, enrichment, and selection of single mineral particles to obtain target mineral particles; S2. Coat the epoxy resin glue in the sample preparation mold, add the target mineral particles, and after curing and grinding treatment, obtain a primary sample; S3. Cut the primary sample, place the grinding surface downward together with three wear-resistant alloys at the bottom of the sample preparation mold, and inject epoxy resin glue to cure to form a composite sample; S4. Precision grind and polish the composite sample until it is flush with the surface of the wear-resistant alloy. After carbon spraying treatment, conduct the first automatic mineralogical analysis to measure the area S of the target mineral n ; n is 1, 2, 3..., representing the types of target minerals; S5. Clean the surface of the sample obtained in step S4, perform leaching treatment to obtain a treated sample; S6. Coating the epoxy resin glue in the sample preparation mold, adding the treated sample, injecting the epoxy resin glue to cure, finely grinding and polishing until it is flush with the surface of the wear-resistant alloy, performing carbon spraying treatment and then conducting the second automatic mineralogical analysis to measure the area S of the residual target mineral n '; S7. Calculate the leachability index A of the target mineral n , where A n = 1 - S n ' / S n .

2. The analysis method for the leachability of minerals according to claim 1, characterized in that In step S2, the coating thickness of the epoxy resin glue is 0.1~0.3 mm.

3. The analysis method of mineral leachability according to claim 2, characterized in that, The grinding treatment uses abrasive with 200~600 mesh, and the grinding thickness is 0.05~0.15 mm.

4. The analysis method for mineral leachability according to claim 1, characterized in that, In step S3, the wear-resistant alloy is tungsten carbide with a hardness ≥ 9 Mohs, its three-dimensional size is 1~5 mm, and the lower surfaces of the three alloys are kept horizontal and not on the same straight line.

5. The analysis method for mineral leachability according to claim 1, characterized in that In step S3, the height of the composite sample is 0.8~1.2 cm.

6. The analysis method for mineral leachability according to claim 1, characterized in that, In step S1, the single mineral particles include one or more of the target mineral particles in the monomer state, intergrown state, and encapsulated state.

7. The analysis method of mineral leachability according to claim 6, characterized in that, The crushing uses a jaw crusher to reduce the particle size to 1~5 mm or a pair-roll crusher to make the particle size > 0.5 mm.

8. The analytical method for the leachability of minerals according to claim 1, characterized in that, The fine grinding uses abrasive with 1000~1400 mesh, the polishing uses abrasive with a particle size ≤ 1 μm, and the polishing time ≥ 5 min.

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