Method for analyzing the effect of sample roasting

Abstract

The application provides a sample roasting effect analysis method, belongs to the field of process mineralogy and metallurgical test analysis, and realizes grading determination of the sample roasting effect by comparing content changes of metal sulfides and oxides in the sample before and after roasting through automatic mineralogy analysis, combining with microscopic morphology observation to count areas of different state iron oxides, and calculating corrected standard oxidation score and single mineral oxidation rate. The application constructs a set of accurate, comprehensive and reproducible sample roasting effect analysis method by systematically integrating accurate quantitative detection of mineral components before and after roasting, comprehensive characterization of product microscopic pore structure, scientific correction of original inclusion mineral interference and weighted quantitative calculation of multi-dimensional indexes, so that overall roasting efficiency, independent oxidation effect of single mineral and product microscopic oxidation structure are comprehensively and stereoscopically evaluated, and solid technical support is provided for fine regulation and control and standardized management of sulfide ore roasting process.

Description

Technical Field

[0001] This invention relates to the fields of process mineralogy and beneficiation testing and analysis, specifically to an analytical method for the effect of sample roasting. Background Technology

[0002] Roasting is a crucial pretreatment technology in sulfide ore beneficiation and metallurgy, directly determining the dissolution efficiency of valuable metals in subsequent leaching operations and the technical specifications of the final product. However, current evaluations of roasting effectiveness heavily rely on methods such as loss on ignition measurement and elemental chemical analysis. These methods offer limited evaluation dimensions, allowing only rough assessments based on macroscopic mass changes or increases / decreases in the total amount of target elements. They cannot accurately measure the oxidation and transformation effects of sulfides during roasting, nor can they quantitatively characterize the looseness or density of the microstructure of the roasted product.

[0003] The existing technologies have the following main drawbacks: First, traditional detection methods cannot distinguish the individual oxidation efficiency of different types of metal sulfides in sulfide ores, resulting in evaluation results that are holistic but lack specificity, masking the under-burning or over-burning problems of individual minerals. Second, existing methods generally ignore the profound impact of changes in the micropore structure of minerals after roasting on the mass transfer efficiency of subsequent leaching or sorting processes, leading to a technical gap between roasting and subsequent processes. Third, existing evaluation methods have never considered the interference of gangue encapsulation in the original mineral on the roasting effect, causing the detection data to deviate from the actual process state and resulting in errors in evaluation accuracy. Fourth, the industry has long lacked a unified and quantitative comprehensive scoring standard for roasting effect, making it impossible to make horizontal comparisons of roasting data from different sources, which seriously hinders the selection of optimal process parameters.

[0004] In view of this, it is necessary to design an analytical method for the calcination effect of samples to solve the above problems. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides an analytical method for the roasting effect of samples, aiming to solve the technical problems of low accuracy, single dimension and lack of quantitative standards in the existing roasting effect evaluation technology.

[0006] This application provides a method for analyzing the calcination effect of a sample, comprising the following steps: S1. Sample preparation and testing before calcination Multiple samples were taken for analysis, and automated mineralogical analysis samples were prepared for each sample. The first automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.1 The proportion of metal sulfides in an encapsulated state was measured to be e. n Where n is the type number of the metal sulfide; Another batch of raw ore samples from the same batch was roasted. After roasting, the samples were cooled to room temperature, the mass of the roasted samples was weighed, and the roasting yield c was calculated. S2. Sample preparation and testing after calcination Multiple samples, equivalent in weight to the analytical sample from step S1, were taken after roasting and prepared for automated mineralogical analysis. A second automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.2 ; S3. Oxidation Degree Analysis Microscopic morphology of samples before and after calcination was observed, and the original iron oxide area S was statistically analyzed. 原始 , Loose iron oxide area S 疏松 and the area S of dense iron oxide 致密 And calculate the total oxidation area S 总 S 总 =S 疏松 +S 致密 -S 原始 ; S4. Comparison Calculation Calculate the oxidation score W, the inclusion mineral correction factor K, and the corrected standard oxidation score W'; W = (S 疏松 -S 原始 ) / S 总 ×(1-c×∑b n.2 / ∑b n.1 ); K=∑(b n.1 ×e n ); W' = W / (1-K); And calculate the oxidation rate T of a single mineral. n T n =1-c×b n.2 / b n.1 ; S5. Grading of Firing Effect Based on the corrected standard oxidation score W' and single mineral oxidation rate T n The roasting effect of the samples was graded and judged.

[0007] As a further improvement of this application, in step S1, the preparation process of the automated mineralogy analysis sample includes: rolling, mixing, ultrasonic vibration, curing followed by side cutting, secondary embedding, grinding and polishing, and carbon spraying; the solid-liquid ratio of the mixed adhesive is 1:2 to 1:5; the ultrasonic vibration duration is 15 to 30 minutes, and the vibration frequency is 40 kHz; the curing time is 12 hours; the grinding and polishing uses silicon carbide abrasive of 1000 mesh or higher for stepwise grinding, and diamond polishing agent of 0.5 μm or lower for polishing, with a total grinding and polishing time ≥10 minutes; the carbon spraying thickness is 20 to 30 nm.

[0008] As a further improvement of this application, in step S2, during the preparation of the automated mineralogy analysis sample, the solid-liquid ratio of the sample to the resin is c:2 to c:5, where c is the calcination yield.

[0009] As a further improvement of this application, in step S3, the micromorphological observation is carried out using a metallographic microscope at a magnification of 200 to 1000 times, randomly selecting no less than 30 mineral particle fields of view, and using image analysis software to count the area of ​​various iron oxide microstructures.

[0010] As a further improvement of this application, in step S3, the loose state refers to an iron oxide structure in which the pores in the mineral particles are evenly distributed, the pore area accounts for more than 10% of the particle area, and the pore diameter is not less than 0.5 μm; the dense state refers to an iron oxide structure in which the pores in the mineral particles are evenly distributed, the pore area accounts for less than 10% of the particle area, or the pore diameter is less than 0.5 μm.

[0011] As a further improvement to this application, in step S1, the metal sulfide includes at least one of pyrite, arsenopyrite, and chalcopyrite.

[0012] As a further improvement of this application, in steps S1 and S2, the automated mineralogy analysis is performed using an automated mineralogy analysis system; the average value of the measurement results of multiple samples in each step is taken as the final measured value.

[0013] As a further improvement of this application, in step S1, the process parameters of the roasting treatment are matched with the actual production process on site, including roasting temperature, heating rate, holding time, roasting atmosphere, ventilation flow rate and material layer thickness.

[0014] As a further improvement to this application, in step S5, the criterion for grading determination is: When W'≥0.8, and T of all tested metal sulfides n When the content is ≥85%, it is judged as high-quality roasting; When 0.5 ≤ W' < 0.8, and T of all tested metal sulfides nWhen the content is ≥60%, it is considered to be qualified roasting; When W' < 0.5, or T of any type of metal sulfide n If the content is less than 60%, it is considered an unqualified roasting process.

[0015] The beneficial effects of this application are as follows: This application provides an analytical method for the roasting effect of samples. By comparing the changes in the content of metal sulfides and oxides in the samples before and after roasting using automated mineralogical analysis, and combining this with the observation of microscopic morphology to statistically analyze the area of ​​iron oxide in different states, a corrected standard oxidation score and single-mineral oxidation rate are calculated, thereby achieving a graded judgment of the roasting effect of the samples. This application systematically integrates precise quantitative detection of mineral components before and after roasting, comprehensive characterization of the microscopic pore structure of the product, scientific correction of interference from original encapsulated minerals, and weighted quantitative calculation of multi-dimensional indicators. It constructs a precise, comprehensive, and reproducible method for analyzing the roasting effect of samples, thereby achieving a comprehensive and three-dimensional evaluation of overall roasting efficiency, independent oxidation effect of single minerals, and microscopic oxidation structure of the product. This provides solid technical support for the refined control and standardized management of sulfide ore roasting processes.

[0016] This application combines automated mineralogical analysis with microstructural characterization, significantly improving the accuracy and repeatability of evaluation results through standardized sample preparation, detection, and calculation of parameters throughout the entire process. It addresses the problems of traditional methods relying on chemical analysis, having limited evaluation dimensions, and lacking unified quantitative standards. By introducing a correction coefficient K for inclusion minerals, it eliminates the interference of gangue inclusions in the original minerals on the evaluation of roasting effects, avoiding evaluation distortion caused by differences in sample structure, and significantly improving the authenticity and reliability of the detection data. Simultaneously, this application achieves a two-way evaluation of the overall roasting effect and the oxidation effect of individual minerals. It can determine the overall roasting quality and accurately pinpoint the oxidation shortcomings of individual minerals such as pyrite, arsenopyrite, and chalcopyrite, providing precise data support for optimizing roasting process parameters. Furthermore, this application, for the first time, classifies roasting products into two microscopic oxidation structures: loose and dense. Combining the structural proportion with the oxidation conversion rate for comprehensive scoring aligns with the actual needs of subsequent mineral processing and metallurgical processes, making the evaluation results more suitable for industrial production applications.

[0017] 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. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0019] Figure 1 This is a compositional analysis diagram of the sample before calcination in Example 1 of this application; Figure 2 This is a measurement diagram of pyrite inclusions in step S1 of Embodiment 1 of this application; Figure 3 This is a graph showing the analysis and measurement of iron oxide in step S3 of Example 1 of this application. Detailed Implementation

[0020] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0021] 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, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0022] 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 this application. 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.

[0023] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0024] Currently, the evaluation of roasting effect still relies heavily on methods such as loss on ignition measurement and chemical analysis of elemental content. The evaluation dimensions are singular, and only a rough judgment can be made from macroscopic quality changes or the increase or decrease of the total amount of target elements. It is impossible to accurately measure the oxidation conversion effect of sulfides during roasting, nor can it quantitatively characterize the loose or dense state of the micropore structure of roasted products.

[0025] In existing methods for evaluating roasting effects, traditional detection techniques heavily rely on loss-on-ignition (LOI) measurements and elemental chemical analysis. These methods offer only a single evaluation dimension, allowing for rough judgments based solely on macroscopic mass changes or increases / decreases in the total amount of target elements. They fail to distinguish the independent oxidation efficiencies of different types of metal sulfides in mixed sulfide ores, thus masking under- or over-burning issues in individual minerals. Furthermore, existing methods generally neglect the profound impact of changes in the microstructure of the mineral after roasting on the mass transfer efficiency of subsequent leaching or sorting processes, resulting in a lack of technical integration between roasting and subsequent processes. In addition, existing methods never consider the inherent interference of gangue inclusions in the original mineral on the roasting effect, causing detection data to deviate from the actual process conditions and leading to systematic errors in evaluation accuracy. Therefore, the industry has long lacked a unified, quantitative comprehensive scoring standard for roasting effects, making horizontal comparisons of roasting data from different sources impossible and severely hindering the selection of optimal process parameters and the standardization of process control.

[0026] This application provides a method for analyzing the calcination effect of a sample, comprising the following steps: S1. Sample preparation and testing before calcination Multiple samples were taken for analysis, and automated mineralogical analysis samples were prepared for each sample. The first automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.1 The proportion of metal sulfides in an encapsulated state was measured to be e. n Where n is the type number of the metal sulfide, n is 1, 2, 3..., representing metal sulfide types such as pyrite, arsenopyrite, and chalcopyrite; e n This refers to the percentage of the total mass of a type n metal sulfide that is encased in gangue minerals or other metal oxides and cannot come into contact with oxygen. The preparation process for automated mineralogy analysis samples includes: taking multiple 4.0~6.0g samples, crushing, mixing, ultrasonic vibration, curing, side-cutting, secondary embedding, grinding and polishing, and carbon spraying; specifically, the sample to be tested is uniformly mixed with epoxy resin, with a solid-liquid ratio of 1:2~1:5; ultrasonic vibration time is 15~30min, preferably 20min, with a vibration frequency of 40kHz to ensure that the sample and colloid are fully mixed and free of agglomerates and bubbles; after curing at room temperature for 12h, side-cutting and flattening are performed; secondary embedding and glue filling are completed to eliminate gaps on the sample surface; grinding is performed using silicon carbide abrasive of 1000 mesh or higher, grinding step by step until the sample surface is free of scratches and smooth and flat; polishing is performed using diamond polishing agent of 0.5μm or lower, with a total grinding and polishing time of ≥10min, preferably 10~15min; finally, the sample is vacuum carbon sprayed with a carbon spraying thickness of 20~30nm to ensure the sample conductivity and meet the requirements of automated mineralogy analysis. Another sample of the same batch of raw ore to be tested was roasted using actual on-site production process parameters. The roasting temperature, heating rate, holding time, roasting atmosphere, ventilation flow rate, and material layer thickness parameters were strictly matched to those of the actual process to eliminate process deviations. After roasting, the sample was cooled to room temperature, and the mass of the roasted sample was weighed. The roasting yield c was calculated as c = mass of roasted sample / mass of sample before roasting × 100%. S2. Sample preparation and testing after calcination Multiple samples, equivalent in weight to the analytical sample from step S1, were taken after roasting and prepared for automated mineralogical analysis. A second automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.2 The mass of the calcined sample is c times the mass of the analytical sample in step S1. In the preparation of the sample for automated mineralogy analysis, the solid-liquid ratio of the sample to the resin is c:2 to c:5, where c is the calcination yield. Other sample preparation and testing conditions are the same as in step S1. The measurement area of ​​a single sample is the same. The average value of the measurement results of multiple samples in each step is taken as the final measured value. S3. Oxidation Degree Analysis Microscopic morphology of samples before and after calcination was observed, and the original iron oxide area S was statistically analyzed. 原始 , Loose iron oxide area S 疏松 and the area S of dense iron oxide 致密 And calculate the total oxidation area S 总 S 总 =S 疏松 +S 致密 -S 原始 , representing the total cross-sectional area of ​​newly formed iron oxide minerals in the roasted sample, excluding interference from the original inherent iron oxide; The Olympus metallographic microscope is preferably used to observe the micromorphology of the samples before and after roasting at a magnification of 200 to 1000 times. No less than 30 mineral particles are randomly selected, and the area of ​​the microstructure of various iron oxides is statistically analyzed using image analysis software to accurately obtain three sets of core data. Among them, the loose state refers to the iron oxide structure in which the pores are evenly distributed in the mineral particles, the pore area accounts for more than 10% of the particle area and the pore diameter is not less than 0.5μm; this structure is an ideal roasting structure with well-developed pores, which is conducive to subsequent reagent penetration, metal leaching and sorting. The dense state refers to an iron oxide structure in which pores are evenly distributed in mineral particles, the pore area accounts for less than 10% of the particle area, or the pore diameter is less than 0.5 μm; this structure is a deteriorated roasting structure, the mineral reaction is incomplete, and the subsequent processing performance is poor. S4. Comparison Calculation Calculate the oxidation score W, the mineral inclusion correction coefficient K, and the corrected standard oxidation score W' to achieve a quantitative rating of the overall roasting effect; W = (S 疏松 -S 原始 ) / S 总 ×(1-c×∑b n.2 / ∑b n.1 ); K=∑(b n.1 ×e n ); W' = W / (1-K); And calculate the oxidation rate T of a single mineral. n T n =1-c×b n.2 / b n.1 ; S 疏松 S represents the total surface area of ​​the porous iron oxide after calcination; 原始 S represents the original total area of ​​iron oxide before calcination; 总 ∑b represents the total cross-sectional area of ​​newly formed iron oxide after calcination; c represents the calcination yield of the sample; n.1 This represents the total mass percentage of all tested metal sulfides before roasting; ∑b n.2 This represents the total mass percentage of all tested metal sulfides after calcination; (1-c×∑b) n.2 / ∑b n.1 The overall oxidation conversion rate of sulfides represents the total sulfide oxidation rate. A higher value indicates more complete oxidation of the overall sulfides. To eliminate the interference of unreacted mineral inclusions in the original state on the evaluation results, a correction coefficient K is introduced for data correction. The correction coefficient K = ∑(b n.1 ×e n ), where e n The percentage of each metal sulfide encapsulation before calcination, ∑(b n.1 ×e n The percentage of encapsulated sulfides in the original sample that cannot participate in the roasting and oxidation reaction is used to avoid evaluation bias caused by inherent mineral defects. T n T represents the calcination oxidation rate of the nth type of metal sulfide. n The numerical range is 0 to 100%, with higher values ​​indicating more complete oxidation and transformation of the corresponding minerals. S5. Grading of Firing Effect Based on the corrected standard oxidation score W' and single mineral oxidation rate T n The calcination effect of the sample is graded and judged. The larger the W' value, the better the overall calcination oxidation effect, the better the microstructure, and the higher the effective oxidation conversion rate of the sample. When W'≥0.8, and T of all tested metal sulfides n When the content is ≥85%, it is judged as high-quality roasting; the minerals are fully oxidized, the proportion of loose oxidized structure is high, and there is no obvious under-burning or over-burning phenomenon; When 0.5 ≤ W' < 0.8, and T of all tested metal sulfides n When the oxidation rate is ≥60%, it is considered a qualified roasting; the overall oxidation effect meets the standard, and there is slight under-oxidation of individual minerals, which does not affect subsequent production. When W' < 0.5, or T of any type of metal sulfide n If the content is less than 60%, it is considered an unqualified roasting process; if there are serious under-burning, insufficient oxidation, or structural densification defects, the roasting process parameters need to be adjusted.

[0027] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0028] Example 1 This embodiment provides a method for analyzing the roasting effect of a sample. The sample is a gold-containing ferrous ore concentrate produced by the flotation process of a gold smelter. Figure 1 As shown, the main metallic sulfide in this sulfur concentrate is pyrite, accounting for 15%, with a small amount of arsenopyrite as a minor sulfide. The gangue minerals are mainly quartz and feldspar minerals. In the raw ore, gold exists in the form of fine-grained inclusions in the pyrite lattice and fractures. The conventional direct cyanide leaching gold leaching rate is 28-30% (more than 90% with fine grinding to -0.045mm). It is necessary to pre-treat by roasting to destroy the pyrite crystal structure and expose the gold inclusions in order to improve the subsequent cyanide leaching effect. Specifically, the following steps are included: S1. Sample preparation and testing before calcination Take 5.0g of the sulfur concentrate in 6 portions, mix it with epoxy resin at a solid-liquid ratio of 1:3, ultrasonically vibrate for 20min (frequency 40kHz), cure at room temperature for 12h, then side cut, re-inserte and fill with resin, grind with 1000-mesh and 2000-mesh silicon carbide sandpaper in sequence, polish with 0.5μm diamond polishing agent for 12min, vacuum carbon spray 25nm, and prepare 6 automated mineralogical analysis samples A1~A6; The first analysis was conducted using an automated mineralogical analysis system (MLA). The average value of the results from six samples was taken, and the pyrite content by mass was calculated as b. 1.1 =15.39%, arsenopyrite content b (by mass) 2.1 =5.64%; Pyrite inclusions account for e1=4.42%, arsenopyrite inclusions account for e2=5.31%; Original iron oxide (limonite) area S 原始 =0.13μm 2 (30 field-of-view measurements); Another 500g of the same batch of raw ore was roasted in a laboratory muffle furnace under conditions strictly matching the on-site process: grinding fineness of -0.074mm accounted for 97%, heating rate of 10℃ / min, roasting temperature of 650℃, holding time of 2h, air flow rate of 2.0L / min, and material layer thickness of 2cm. After roasting, the sample was naturally cooled to room temperature. The mass of the roasted sample was 442.75g. The roasting yield was calculated as c = 442.75 / 500 = 88.55%. S2. Sample preparation and testing after calcination Take 4.4275g of the roasted sample (i.e., 5.0g of the original mass before roasting × yield 88.55%), mix it with epoxy resin at a solid-liquid ratio of 0.8855:3 (i.e., c:3), and prepare 6 automated mineralogical analysis samples D1~D6 using the same method; take the average value of the MLA test results, and the percentage of residual pyrite by mass after roasting b. 1.2 =1.16%, residual arsine content by mass b 2.2 =0.33%; S3. Oxidation Degree Analysis After roasting, samples were prepared for metallographic microscopy. Thirty mineral grain fields were randomly selected at 500x magnification, and Image-Pro Plus image analysis software was used to statistically analyze the area S of the loosely packed iron oxide. 疏松 =420.11μm 2 The area of ​​dense iron oxide S 致密 =50.16μm 2 Then S 总 =S 疏松 +S 致密 -S 原始 =470.14μm 2 ; S4. Comparison Calculation Calculate the oxidation score W, the inclusion mineral correction factor K, and the corrected standard oxidation score W'; W = (S 疏松 -S 原始 ) / S 总 ×(1-c×∑b n.2 / ∑b n.1 = (420.11-0.13) / 470.14×(1-88.55%×(1.16%+0.33%) / (15.39%+5.64%))=0.8934 × 0.9373 =0.8374; K=∑(b n.1 ×e n = 15.39% × 4.42% + 5.64% × 5.31% = 0.98%; W'=W / (1-K)=0.8374 / (1-0.98%)=0.8457; Calculate the oxidation rate T of a single mineral n T n =1-c×b n.2 / b n.1 ; T1 (pyrite) = 1 - c × b 1.2 / b 1.1 =1 - 88.55% × 1.16% / 15.39% = 1 - 0.06674 = 93.33%; T2 (agar) = 1 - c × b 2.2 / b 2.1 =1 - 88.55% × 0.33% / 5.64% = 1 - 0.0518 = 94.82%; S5. Grading of Firing Effect Based on the corrected standard oxidation score W' and single mineral oxidation rate T n The calcination effect of the samples was graded and judged. W'≥0.8, and T for all tested metal sulfides n ≥85% is considered high-quality roasting.

[0029] Verification experiment: 500g of roasted sample was taken without grinding. The slurry concentration was adjusted to 33%, and lime was added to adjust the pH to 11.5. The sodium cyanide dosage was 4.0kg / t, and the leaching time was 48h. After leaching, the gold leaching rate was calculated. The experimental results showed that the gold leaching rate increased from 30% in direct cyanidation of the raw ore to 81.62%, indicating a significant improvement in gold leaching effect. This verifies the accuracy and process guidance value of the evaluation method of this application in judging the roasting effect of gold-sulfur concentrate. In Example 1, the loose iron oxide area accounted for about 90%, with few dense structures. This formed a good structure-performance correspondence with the high leaching rate obtained in the leaching test, fully demonstrating the scientific nature and practicality of incorporating micropore structure into the core evaluation dimension of roasting effect in this application.

[0030] Example 2 This embodiment provides a method for analyzing the roasting effect of a sample, which is a gravity concentrate from a gold smelter, and includes the following steps: S1. Sample preparation and testing before calcination Take 5.0g of the gravity concentrate in 6 portions, mix it with epoxy resin at a solid-liquid ratio of 1:3, ultrasonically vibrate for 20min (frequency 40kHz), cure at room temperature for 12h, then side cut, re-inserte and fill with resin, grind with 1000-mesh and 2000-mesh silicon carbide sandpaper in sequence, polish with 0.5μm diamond polishing agent for 12min, vacuum carbon spray 25nm, and prepare 6 automated mineralogical analysis samples A1~A6; The first analysis was conducted using an automated mineralogical analysis system (MLA). The average value of the results from six samples was taken, and the pyrite content by mass was calculated as b. 1.1 =92.52%, arsenopyrite content b (by mass) 2.1 =0.83%; Pyrite inclusions account for e1=2.25%, arsenopyrite inclusions account for e2=4.01%; Original iron oxide (limonite) area S 原始 =0.02μm 2 (35 field-of-view measurements); Another 500g of the same batch of raw ore was roasted in a laboratory muffle furnace under conditions strictly matching the on-site process: heating rate 10℃ / min, roasting temperature 650℃, holding time 2h, air flow rate 2.0L / min, and material layer thickness 2cm. After roasting, the sample was allowed to cool naturally to room temperature. The mass of the roasted sample was measured to be 415.00g. The roasting yield was calculated as c = 415.00 / 500 = 83.0%. S2. Sample preparation and testing after calcination Take 4.15g of the roasted sample (i.e., 5.0g of the original mass before roasting × 83% yield), mix it with epoxy resin at a solid-liquid ratio of 0.83:3 (i.e., c:3), and prepare 6 automated mineralogical analysis samples D1~D6 using the same method; take the average value of the MLA test results, and the percentage of residual pyrite by mass after roasting b. 1.2 =1.34%, residual arsine content b 2.2 =0.02%; S3. Oxidation Degree Analysis After roasting, samples were prepared for metallographic microscopy. Thirty-five mineral grain fields were randomly selected at 500x magnification, and Image-Pro Plus image analysis software was used to statistically analyze the area S of loose iron oxide. 疏松 =445.64μm 2 The area of ​​dense iron oxide S 致密 =36.23μm 2 Then S 总 =S 疏松 +S 致密 -S 原始 =481.85μm 2 ; S4. Comparison Calculation Calculate the oxidation score W, the inclusion mineral correction factor K, and the corrected standard oxidation score W'; W = (S 疏松 -S 原始 ) / S 总 ×(1-c×∑b n.2 / ∑b n.1 = (445.64 - 0.02) / 481.85 × (1 - 83.00% × 1.36% / 93.35%) = 0.9248 × 0.9879 = 0.9135; K=∑(b n.1 ×e n = 92.52% × 2.25% + 0.83% × 4.01% = 2.11%; W'=W / (1-K)=0.9135 / (1-2.11%)=0.9333; Calculate the oxidation rate T of a single mineral n T n =1-c×b n.2 / b n.1 ; T1 (pyrite) = 1 - c × b 1.2 / b 1.1 =1 - 83% × 1.34% / 92.52% = 1 - 0.012 = 98.80%; T2 (agar) = 1 - c × b 2.2 / b 2.1 =1 - 83% × 0.02% / 0.83% = 1 - 0.020 = 98.00%; S5. Grading of Firing Effect Based on the corrected standard oxidation score W' and single mineral oxidation rate T n The calcination effect of the samples was graded and judged. W'≥0.8, and T for all tested metal sulfides n ≥85% is considered high-quality roasting.

[0031] Verification experiment: The gold in this sample was extremely fine, resulting in poor direct leaching performance, with a gold leaching rate below 5.00%. 500g of the roasted sample was taken and finely ground. With 90% of the sample being -0.045mm, the pulp concentration was adjusted to 33%, lime was added to adjust the pH to 11.5, sodium cyanide was used at 4.0kg / t, and the leaching time was 48h. After leaching, the gold leaching rate increased from less than 5.00% with direct cyanidation to 90.34%, demonstrating a significant improvement in gold leaching performance. This verifies the accuracy and process guidance value of the evaluation method proposed in this application for judging the roasting effect of gold-sulfur concentrate.

[0032] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. 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 this application, are also included in the scope of this application.

Claims

1. A method for analyzing the calcination effect of a sample, characterized in that, Includes the following steps: S1. Sample preparation and testing before calcination Multiple samples were taken for analysis, and automated mineralogical analysis samples were prepared for each sample. The first automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.1 The proportion of metal sulfides in an encapsulated state was measured to be e. n Where n is the type number of the metal sulfide; Another batch of raw ore samples from the same batch was roasted. After roasting, the samples were cooled to room temperature, the mass of the roasted samples was weighed, and the roasting yield c was calculated. S2. Sample preparation and testing after calcination Multiple samples, equivalent in weight to the analytical sample from step S1, were taken after roasting and prepared for automated mineralogical analysis. A second automated mineralogical analysis was performed, and the mass percentage of the main metal sulfides was determined to be b. n.2 ; S3. Oxidation Degree Analysis Microscopic morphology of samples before and after calcination was observed, and the original iron oxide area S was statistically analyzed. 原始 , Loose iron oxide area S 疏松 and the area S of dense iron oxide 致密 And calculate the total oxidation area S 总 S 总 =S 疏松 +S 致密 -S 原始 ; S4. Comparison Calculation Calculate the oxidation score W, the inclusion mineral correction factor K, and the corrected standard oxidation score W'; W=(S 疏松 -S 原始 ) / S 总 ×(1-c×∑b n.2 / ∑b n.1 ); K=∑(b n.1 ×e n ); W' = W / (1-K); And calculate the oxidation rate T of a single mineral. n T n =1-c×b n.2 / b n.1 ; S5. Grading of Firing Effect Based on the corrected standard oxidation score W' and single mineral oxidation rate T n The roasting effect of the samples was graded and judged.

2. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S1, the preparation process of the automated mineralogical analysis sample includes: rolling, mixing, ultrasonic vibration, curing followed by side cutting, secondary embedding, grinding and polishing, and carbon spraying; the solid-liquid ratio of the mixed adhesive is 1:2 to 1:5; the ultrasonic vibration duration is 15 to 30 minutes, and the vibration frequency is 40 kHz; the curing time is 12 hours; the grinding and polishing uses silicon carbide abrasive of 1000 mesh or higher for stepwise grinding, and diamond polishing agent of 0.5 μm or lower for polishing, with a total grinding and polishing time ≥10 minutes; the carbon spraying thickness is 20 to 30 nm.

3. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S2, during the preparation of the automated mineralogy analysis sample, the solid-liquid ratio of the sample to the resin adhesive is c:2 to c:5, where c is the calcination yield.

4. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S3, the microscopic morphology observation is performed using a metallographic microscope at a magnification of 200 to 1000 times. At least 30 mineral particles are randomly selected from the field of view, and the area of ​​various iron oxide microstructures is statistically analyzed using image analysis software.

5. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S3, the loose state refers to an iron oxide structure in which the pores in the mineral particles are evenly distributed, the pore area accounts for more than 10% of the particle area, and the pore diameter is not less than 0.5 μm; the dense state refers to an iron oxide structure in which the pores in the mineral particles are evenly distributed, the pore area accounts for less than 10% of the particle area, or the pore diameter is less than 0.5 μm.

6. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S1, the metal sulfide includes at least one of pyrite, arsenopyrite, and chalcopyrite.

7. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In steps S1 and S2, the automated mineralogy analysis is performed using an automated mineralogy analysis system; the average value of the measurement results of multiple samples in each step is taken as the final measured value.

8. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S1, the process parameters of the roasting treatment are matched with the actual production process on site, including roasting temperature, heating rate, holding time, roasting atmosphere, ventilation flow rate and material layer thickness.

9. The method for analyzing the calcination effect of samples according to claim 1, characterized in that, In step S5, the criteria for grading are as follows: When W'≥0.8, and T of all tested metal sulfides n When the content is ≥85%, it is judged as high-quality roasting; When 0.5 ≤ W' < 0.8, and T of all tested metal sulfides n When the content is ≥60%, it is considered to be qualified roasting; When W' < 0.5, or T of any type of metal sulfide n If the content is less than 60%, it is considered an unqualified roasting process.

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