A method for energy dispersive analysis of low content components

Abstract

The present application relates to a kind of low content component energy spectrum analysis method, belong to metallurgical dust resource utilization and material microanalysis technical field.The method includes: preparation sample exposure center section, obtain full section image by scanning electron microscope image splicing, and different analysis regions are divided;Low multiple energy spectrum area scanning is carried out in each analysis region, and the element distribution and zinc content data of multiple positions are obtained;For each analysis region, the arithmetic mean of residual zinc content is calculated as the regional representative value;Based on the characteristic data image of zinc element distribution, high multiple energy spectrum area scanning and point scanning are carried out on the characteristic micro area of zinc element aggregation to analyze the phase form and element composition of residual zinc.The present application realizes the quantitative, zoned, spatial positioning and multi-scale characterization of residual zinc content distribution and occurrence state in metallized pellet by "overall observation-zoned statistics-micro area analysis" progressive analysis, provides more accurate data support for process optimization.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology in the iron and steel metallurgy industry, and specifically relates to an energy dispersive spectroscopy (EDS) analysis method for low-content components. Background Technology

[0002] Metallurgical dust and sludge are solid wastes generated during steel production, mainly including blast furnace gas ash, converter sludge, and electric furnace dust, containing valuable elements such as iron, carbon, and zinc. Rotary hearth furnace treatment technology is currently one of the mainstream processes in the steel industry for treating metallurgical dust and sludge. Its basic process involves mixing the metallurgical dust and sludge with a reducing agent and binder, pressing it into pellets, and then subjecting it to high-temperature reduction roasting in a rotary hearth furnace. During the reduction roasting process, the zinc in the metallurgical dust and sludge is reduced to metallic zinc, which volatilizes into the flue gas under high-temperature conditions and is recovered and reused. Meanwhile, the iron oxides in the metallurgical dust and sludge are reduced to metallic iron, forming metallized pellets that can be returned to the steel smelting process as raw materials.

[0003] Zinc removal rate is a key technical indicator in rotary hearth furnace processes, directly affecting the quality of metallized pellets. However, in existing rotary hearth furnace processes, a small amount of zinc (approximately 1% by mass) often remains in the metallized pellets, making complete removal difficult. When this residual zinc is returned to the steelmaking process with the metallized pellets, it causes zinc to circulate and accumulate in the steel production system, severely impacting the normal operation of the smelting process. Therefore, in-depth research into the distribution patterns, forms, and retention mechanisms of residual zinc in metallized pellets is of great significance for optimizing rotary hearth furnace process parameters, improving zinc removal efficiency, and ensuring the quality of metallized pellets.

[0004] Existing analytical methods for residual zinc in metallized pellets mainly fall into two categories:

[0005] Existing Solution 1: Chemical Composition Analysis Method. This method involves crushing and grinding the metallized pellets, dissolving a suitable amount of sample powder, and then determining the zinc concentration using inductively coupled plasma atomic emission spectrometry (ICP-AES) or atomic absorption spectrometry (AAS). Finally, the overall average content of residual zinc in the metallized pellets is calculated. This method is currently the most common method for elemental content detection in metallurgical products and is widely used in the compositional analysis of metallized pellets from rotary hearth furnaces.

[0006] The patent “A method for detecting element content in rotary hearth furnace products (application number: 201110151536X)” discloses an inductively coupled plasma atomic emission spectrometry method for detecting element content in rotary hearth furnace products. After dissolving the sample, the concentration of each element in the solution is determined by an inductively coupled plasma atomic emission spectrometer.

[0007] Existing Solution 2: Scanning Electron Microscope - Energy Dispersive Spectrometer (SEM-EDS) analysis. This technique involves cutting, mounting, and polishing metallized pellets, then using a scanning electron microscope combined with an energy dispersive spectrometer to characterize the sample at a microscopic level, analyzing the microstructure, elemental distribution, and phase composition of specific regions within the sample. This technique is a commonly used method for characterizing the microstructure of materials.

[0008] The literature (Ouyang Siwen et al. Study on reduction dezincification of zinc-containing double-layer pellets with internal coke powder [J]. Sintering and Pelletizing, 2025, 50(5): 43-52.) studied the microstructure and distribution characteristics of oxygen, iron, calcium and zinc elements of the calcined products of zinc-containing pellets by SEM-EDS analysis.

[0009] While existing chemical composition analysis methods and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) methods are widely used in the field of metallurgical dust reduction roasting research, they both have significant limitations:

[0010] The disadvantages of the existing scheme 1 are: (1) Chemical composition analysis can only obtain the overall average content of residual zinc in metallized pellets, and cannot grasp the differences in residual zinc distribution in different regions (such as the surface and center of the pellets, the upper and lower parts, etc.) within the metallized pellets. Due to the lack of understanding of the distribution law of residual zinc in metallized pellets, researchers cannot optimize key parameters such as pelletizing process and reduction roasting process in a targeted manner, which leads to a bottleneck in further improving the zinc removal rate. (2) Chemical composition analysis cannot provide phase information of residual zinc, which makes it difficult to support the study of zinc removal mechanism, and makes it difficult to grasp the reasons for incomplete zinc removal.

[0011] The disadvantages of the existing scheme 2 are: (1) The low content of residual zinc (only about 1%) in the metallized pellets is very sparsely distributed and difficult to be directly located by conventional SEM-EDS. The microscopic analysis of zinc is "like looking for a needle in a haystack", resulting in low analysis efficiency, long equipment occupation time and high analysis cost. (2) Since the researchers do not know the distribution location and pattern of residual zinc in the pellets in advance, they can only select a few fields of view for exploratory scanning analysis based on experience, resulting in strong subjectivity and randomness in the analysis results. (3) Since the size of the metallized pellets is large and the field of view of the scanning electron microscope is very small, even if residual zinc is detected in a certain field of view, it is impossible to determine the specific location of the metallized pellets corresponding to that field of view (such as near the edge or near the center, upper or lower part, etc.), so that the analysis results cannot establish a spatial correspondence and it is difficult to guide the fine process control. Summary of the Invention

[0012] The purpose of this invention is to solve the problems of the inability to grasp the spatial distribution differences and patterns of residual zinc, the difficulty in obtaining residual zinc phase information, the difficulty in locating and analyzing low-content residual zinc with low efficiency, and the lack of spatial correspondence in microscopic analysis results. Therefore, it provides an energy dispersive spectroscopy (EDS) method for low-content components.

[0013] To achieve the above objectives, the technical solution of the present invention is: an energy dispersive spectroscopy (EDS) method for analyzing low-content components, comprising:

[0014] The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section;

[0015] Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis.

[0016] On the full-section image, divide it into two or more analysis regions;

[0017] For each defined analysis region, a low-magnification energy spectrum surface scan is performed within that region to obtain the elemental distribution surface scan data image and the corresponding zinc content data for each scan position.

[0018] For each defined analysis region, the arithmetic mean of the zinc content data at all scanning locations within the corresponding analysis region is calculated, and this arithmetic mean is used as the representative value of the residual zinc content of the corresponding analysis region.

[0019] Based on the obtained elemental distribution surface scan data images, characteristic micro-regions of zinc element aggregation were identified, and high-magnification energy dispersive spectroscopy analysis was performed on these characteristic micro-regions to determine the phase morphology and elemental composition of residual zinc.

[0020] Furthermore, when capturing adjacent single SEM images, maintain a boundary area overlap of 5% to 15%.

[0021] Furthermore, the analysis area includes an upper region, a middle region, and a lower region divided along the vertical direction of the pellet, and / or includes an inner region and an outer ring region divided along the radial direction of the pellet.

[0022] Furthermore, the low multiplier is 50 to 100 times.

[0023] Furthermore, energy spectrum scans are performed at 4 to 8 scan positions within each analysis region.

[0024] Furthermore, the formula used to calculate the arithmetic mean is:

[0025] =

[0026] in, Let n be the representative value of residual zinc content in a certain analytical region, and n be the number of locations in that analytical region where energy dispersive spectroscopy (EDS) scans were performed. This represents the zinc content measured by energy dispersive spectroscopy at the i-th scanning position within the analytical region.

[0027] Furthermore, the high magnification is 2000 to 5000 times; the energy spectrum analysis at the high magnification includes energy spectrum surface scanning and energy spectrum point scanning.

[0028] This invention also provides an energy dispersive spectroscopy (EDS) method for analyzing low-content components, comprising:

[0029] The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section;

[0030] Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis.

[0031] After obtaining the full cross-sectional image, regions enriched in floatite were identified, and high-magnification energy dispersive spectroscopy analysis was performed to determine the phase morphology and elemental composition of the residual zinc.

[0032] Furthermore, the method for identifying areas of floc enrichment is as follows: by identifying the contrast difference between the metallic iron phase and the floc phase in the backscattered electron image of a scanning electron microscope, the areas of floc enrichment are determined.

[0033] Furthermore, the method is used to analyze the residual zinc content distribution and occurrence state in metallized pellets obtained by rotary hearth furnace reduction roasting process.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) This invention can characterize the residual zinc content of any clearly defined region within the cross-section of a metallized pellet: using a full-section Maps image of the metallized pellet as a location map, any region to be studied can be selected for low-magnification energy spectrum scanning. While obtaining the residual zinc content, it can also clearly determine the spatial location of that region within the metallized pellet (e.g., ...). Figure 4(As shown in the figure). Simultaneously, employing low-magnification energy dispersive spectroscopy (EDS) ensures a sufficiently large analytical field of view, maximizing the sample size and thus improving the accuracy and reliability of zinc content analysis results. In contrast, existing scheme one can only obtain the overall average content of residual zinc in the metallized pellets, failing to capture the differences in residual zinc distribution across different regions (e.g., the surface and center, upper and lower parts of the pellets). While existing scheme two can determine the zinc content of localized areas through SES analysis, the relative spatial location of this analytical region within the metallized pellet is difficult to determine, resulting in a lack of correlation between the distribution pattern and spatial location of residual zinc content.

[0036] (2) This invention can quickly grasp the variation law of residual zinc phase characteristics with spatial location within metallized pellets: using the full-section Maps image of the metallized pellets as a positioning map, and with the help of the zinc element distribution at each location obtained by low-magnification energy dispersive spectroscopy, it can quickly locate the zinc element accumulation area for high-magnification energy dispersive spectroscopy and point scanning to grasp the phase characteristics of residual zinc. At the same time, it can establish a correspondence between the variation law of residual zinc phase characteristics and the spatial location within the metallized pellets (e.g., Figure 5 , Figure 6 (As shown in Tables 3 and 4). Simultaneously, employing high-magnification energy dispersive spectroscopy (EDS) ensures the accuracy of residual zinc phase analysis results. In contrast, Existing Scheme 1 cannot provide phase information for residual zinc; while Existing Scheme 2, although it can determine the zinc phase information within a certain region, struggles to ascertain the relative spatial location of this analytical region within the metallized pellets, resulting in a lack of correlation between the phase characteristic variation patterns of residual zinc and their spatial location. Furthermore, Existing Scheme 2 suffers from a "needle in a haystack" approach to microscopic analysis of low-content zinc elements, leading to low analytical efficiency, long equipment downtime, and high analytical costs.

[0037] (3) This invention enables systematic and objective analysis of low-content residual zinc according to research needs: using the full-section Maps image of metallized pellets as a location map, a number of representative locations can be systematically selected for residual zinc analysis according to research needs, and the selected representative locations can follow objective spatial distribution requirements (such as...). Figure 3 (As shown in (a)). In contrast, the existing scheme 2 does not know the distribution of residual zinc in the pellets in advance, and can only select a few fields of view for scanning analysis based on experience, resulting in highly subjective and random analysis results.

[0038] (4) The method of the present invention is not only applicable to the characterization of low-content residual zinc in metallized pellets of rotary hearth furnace, but can also be extended to the characterization of the micro-distribution of low-content elements and phase analysis in various materials, and has wide applicability. Attached Figure Description

[0039] Figure 1 Capture and stitch together full-section Maps images.

[0040] Figure 2 Example of dividing a Maps image into regions.

[0041] Figure 3 The diagram shows the progressive energy spectrum analysis process and the surface scanning positions; (a) a representative position diagram of low-exponential energy spectrum surface scanning; (b) low-exponential energy spectrum surface scanning results; and (c) high-exponential energy spectrum surface scanning and point scanning results.

[0042] Figure 4 This represents the zinc content (mass fraction) at each location.

[0043] Figure 5 The phase characteristics of residual zinc in sample 1 are as follows: (1) Phase characteristics of residual zinc in the upper part; (2) Phase characteristics of residual zinc in the middle part; (3) Phase characteristics of residual zinc in the lower part; (a), (b), (c) SEM images and EDS sites of metallized pellets; (d), (e), (f) Surface scan results of zinc element; (g), (h), (i) Surface scan results of sulfur element; (j), (k), (l) Surface scan results of iron element; (m), (n), (o) Surface scan results of oxygen element.

[0044] Figure 6 The phase characteristics of residual zinc in sample 2 are as follows: (1) Phase characteristics of residual zinc in the upper part; (2) Phase characteristics of residual zinc in the middle part; (3) Phase characteristics of residual zinc in the lower part; (a), (b), (c) SEM images and EDS sites of metallized pellets; (d), (e), (f) Surface scan results of zinc element; (g), (h), (i) Surface scan results of sulfur element; (j), (k), (l) Surface scan results of iron element; (m), (n), (o) Surface scan results of oxygen element.

[0045] Figure 7 SEM-EDS analysis of a region within a metallized pellet; (a) SEM image of the metallized pellet; (b) surface scan results of iron; (c) surface scan results of oxygen; (d) surface scan results of zinc.

[0046] Figure 8 The phase characteristics of residual zinc in the floating aggregate region are shown below; (a) SEM image and EDS location of metallized pellets; (b) surface scan results of zinc; (c) surface scan results of sulfur; (d) surface scan results of iron; and (e) surface scan results of oxygen. Detailed Implementation

[0047] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0048] This invention provides an energy dispersive spectroscopy (EDS) method for analyzing low-content components, comprising:

[0049] The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section;

[0050] Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis.

[0051] On the full-section image, divide it into two or more analysis regions;

[0052] For each defined analysis region, a low-magnification energy spectrum surface scan is performed within that region to obtain the elemental distribution surface scan data and the corresponding zinc content data for each scan position.

[0053] For each defined analysis region, the arithmetic mean of the zinc content data at all scanning locations within the corresponding analysis region is calculated, and this arithmetic mean is used as the representative value of the residual zinc content of the corresponding analysis region.

[0054] Based on the obtained elemental distribution surface scanning data, characteristic micro-regions of zinc element aggregation were identified, and high-magnification energy dispersive spectroscopy analysis was performed on the characteristic micro-regions to determine the phase morphology and elemental composition of residual zinc.

[0055] This invention also provides an energy dispersive spectroscopy (EDS) method for analyzing low-content components, comprising:

[0056] The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section;

[0057] Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis.

[0058] After obtaining the full cross-sectional image, regions enriched in floatite were identified, and high-magnification energy dispersive spectroscopy analysis was performed to determine the phase morphology and elemental composition of the residual zinc.

[0059] The following is a detailed implementation process of the present invention.

[0060] An energy dispersive spectroscopy (EDS) method for analyzing low-content components according to an embodiment of the present invention includes the following steps:

[0061] 1. Cold mounting and polishing of metallized pellets: The metallized pellets are mounted and fixed with cold mounting adhesive, and then polished to the center section of the metallized pellets with a polishing machine.

[0062] 2. Capture and stitch together full-section Maps images: Use a scanning electron microscope (SEM) to capture SEM images of the entire central cross-section of the metallized pellet from step 1, and then stitch together the individual SEM images to create a full-section Maps image of the metallized pellet (an image covering the entire central cross-section of the metallized pellet, hereinafter referred to as "Maps image"). For example... Figure 1 As shown, adjacent single SEM images (each yellow square represents one SEM image) maintain a 5% to 15% overlap in boundary area to ensure the accuracy of the full-section Maps image stitching.

[0063] 3. Analysis Area Division: Based on research needs, the full-section Maps image of the metallized pellets from step 2 is divided into different analysis and research areas. For example... Figure 2 As shown, the Maps image can be divided into three regions: upper, middle, and lower, and two regions: inner and outer ring, to study the differences in residual zinc distribution between the upper and lower parts and between the inner and outer rings within the metallized pellets.

[0064] 4. Low-expansion energy spectrum scanning: Based on the full-section Maps image of the metallized pellets from step 2, several representative locations are selected in the upper, middle, lower, inner, and outer rings (e.g., ...). Figure 3 As shown in (a), 13 representative positions can be selected (the number of representative positions can be increased or decreased according to research needs) for low-magnification (e.g., 50-100x) energy spectrum scanning to statistically analyze the residual zinc content at each position and to understand the distribution of zinc at each position (e.g., Figure 3 As shown in (b). Figure 4 As shown in Table 1, the residual zinc content at various locations within the two metallized pellet samples was statistically analyzed, which can intuitively demonstrate the spatial distribution pattern of residual zinc within the metallized pellets, as well as the differences in the spatial distribution of residual zinc under different conditions.

[0065] Table 1. Zinc content (mass fraction) at various locations

[0066]

[0067] 5. Statistical Analysis of Residual Zinc Content in Different Regions within Metallized Pelletizing Clusters: For each region (e.g., upper, middle, lower, internal, and outer ring) included in step 4, the arithmetic mean of the zinc content at multiple analytical locations was calculated. This arithmetic mean was used as the representative value of the residual zinc content for the corresponding region. For each analytical region, 4-8 analytical locations were selected for low-magnification energy dispersive spectroscopy (EDS). Statistical averaging of multiple sample points effectively eliminated the influence of local outliers, ensuring the stability and reliability of the residual zinc content data for each region. The results of this statistical analysis provide fundamental data support for analyzing the spatial distribution of residual zinc and the dezincification patterns under different process conditions (as shown in Table 2).

[0068] Table 2. Arithmetic mean (mass fraction) of zinc content in each region

[0069]

[0070] 6. Analysis of residual zinc phase characteristics within metallized pellets: Based on the zinc element distribution at each location as determined in step 4 (e.g., Figure 3 As shown in (b), high-magnification (e.g., 2000-5000 times) energy-dispersive X-ray spectroscopy (EDS) and point scanning (e.g., 2000-5000 times) were performed on the zinc-rich region. Figure 3 As shown in (c), this allows us to understand the phase characteristics and variation patterns of residual zinc at various locations. Figure 5 As shown in Table 3, the zinc distribution areas in the upper and middle parts of sample 1 mainly overlap with sulfur, while iron is relatively scarce. The remaining zinc mainly forms sphalerite, i.e., the ZnS phase, with sulfur. In the lower part, although the zinc distribution area also overlaps with sulfur, iron content increases, forming zinc-rich iron sphalerite, i.e., a (Zn,Fe)S solid solution with a high zinc content. Meanwhile, as... Figure 6 As shown in the analysis results in Table 4, the distribution and phase characteristics of zinc, iron, and sulfur in the upper and middle parts of sample 2 are similar to those in the lower part of sample 1, but the sample 2 contains more iron and less zinc, forming an iron sphalerite with an equiatomic ratio, i.e., a (Zn,Fe)S solid solution (Zn:Fe atoms ≈ 1:1); while the lower part contains more iron and less zinc, forming an iron-rich iron sphalerite, i.e., a (Zn,Fe)S solid solution with a higher iron content.

[0071] Table 3. EDS elemental analysis (mass fraction) and phase composition results of residual zinc in Sample 1

[0072]

[0073] Table 4. EDS elemental analysis (mass fraction) and phase composition results of residual zinc in Sample 2

[0074]

[0075] Another embodiment of the present invention provides an energy dispersive spectroscopy (EDS) method for analyzing low-content components, comprising the following steps:

[0076] 1. Cold mounting and polishing of metallized pellets: The metallized pellets are mounted and fixed with cold mounting adhesive, and then polished to the center section of the metallized pellets with a polishing machine.

[0077] 2. Capture and stitch together full-section Maps images: Use a scanning electron microscope (SEM) to capture SEM images of the entire central cross-section of the metallized pellet from step 1, and then stitch together the individual SEM images to create a full-section Maps image of the metallized pellet (an image covering the entire central cross-section of the metallized pellet, hereinafter referred to as "Maps image"). For example... Figure 1 As shown, adjacent single SEM images (each yellow square represents one SEM image) maintain a 5% to 15% overlap in boundary area to ensure the accuracy of the full-section Maps image stitching.

[0078] 3. After obtaining the full cross-sectional image, identify the areas enriched in putrescite and perform high-magnification energy dispersive spectroscopy analysis to determine the phase morphology and elemental composition of the residual zinc.

[0079] A rapid screening method for residual zinc in metallized pellets: utilizing the distribution of residual zinc in metallized pellets and the relationship between the residual zinc and the Fe content. x To establish a rapid targeted screening method by identifying the correspondence between the O) distributions.

[0080] The corresponding relationship is as follows: in areas with higher martensite content (i.e., lower metallic iron content), the residual zinc content is significantly higher; in areas with higher metallic iron content, the residual zinc content is lower. For example... Figure 7 As shown in the SEM image, the upper left of this area is dominated by metallic iron (bright white particles), while the lower right is dominated by putrescite (light gray particles); the distribution characteristics of zinc are... Figure 7 As shown in (d), the content is lower in the upper left and higher in the lower right. The mechanism of this correspondence is that the reduction degree in the iron-rich area is higher, which is conducive to the reduction and volatilization of zinc; the reduction degree in the stearite-rich area is lower, and the removal of zinc is insufficient.

[0081] Given the high iron content (over 60% TFe) in the metallized pellets, metallic iron and flourite exhibit a significant contrast difference in backscattered electron images under a scanning electron microscope due to their atomic number differences (metallic iron appears bright white, while flourite appears light gray), making them easy to distinguish visually; however, the residual zinc content is very low (only about 1%), making it difficult to locate directly using conventional energy dispersive spectroscopy.

[0082] Based on the above principles, the method of this invention focuses the analysis area on the distribution region of flostenite for energy dispersive spectroscopy analysis, avoiding invalid scanning in the iron-rich region, thereby greatly improving the analysis efficiency and positioning accuracy.

[0083] Figure 8 Table 5 shows the results of 2500-fold energy dispersive spectroscopy analysis of the floating body aggregation region within the metallized pellets. In this region, the distribution of zinc mainly overlaps with that of sulfur and iron, with zinc being relatively more abundant and iron relatively less abundant, forming zinc-rich sphalerite, i.e., (Zn,Fe)S solid solution with high zinc content.

[0084] Table 5. EDS elemental analysis (mass fraction) and phase composition results of residual zinc.

[0085]

[0086] In this invention:

[0087] (1) Both low-magnification energy spectrum scanning and high-magnification energy spectrum scanning use the full-section Maps image of metallized pellets as the positioning map, so that the distribution law of residual zinc content and the distribution law of phase characteristics have a clear spatial correspondence, which can provide a basis for systematic residual zinc analysis and research.

[0088] (2) Based on the full-section Maps images of the metallized pellets, a series of representative locations were systematically selected for low-magnification energy spectrum scanning to visually demonstrate the spatial distribution pattern of residual zinc within the metallized pellets (e.g., Figure 4 (as shown in Table 1).

[0089] (3) Based on the zinc element distribution pattern provided by low-magnification energy spectrum surface scanning, the zinc element accumulation area is located quickly and efficiently, and then the phase characteristics of residual zinc at each representative position are grasped by high-magnification energy spectrum surface scanning and point scanning.

[0090] (4) Utilizing the distribution of residual zinc in metallized pellets and the relationship between Fe and other minerals. x By establishing the correspondence between the distributions of O, a rapid targeted screening method can be developed, which can quickly identify key analytical research areas for preliminary and exploratory analysis of residual zinc.

[0091] The above are preferred embodiments of the present invention. Any changes made to the technical solution of the present invention that do not exceed the scope of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for energy dispersive spectroscopy analysis of low-content components, characterized in that, include: The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section; Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis. On the full-section image, divide it into two or more analysis regions; For each defined analysis region, a low-magnification energy spectrum surface scan is performed within that region to obtain the elemental distribution surface scan data image and the corresponding zinc content data for each scan position. For each defined analysis region, the arithmetic mean of the zinc content data at all scanning locations within the corresponding analysis region is calculated, and this arithmetic mean is used as the representative value of the residual zinc content of the corresponding analysis region. Based on the obtained elemental distribution surface scan data images, characteristic micro-regions of zinc element aggregation were identified, and high-magnification energy dispersive spectroscopy analysis was performed on these characteristic micro-regions to determine the phase morphology and elemental composition of residual zinc.

2. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, When capturing adjacent single SEM images, maintain a 5% to 15% overlap in boundary area.

3. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, The analysis area includes an upper region, a middle region, and a lower region divided along the vertical direction of the pellet, and / or includes an inner region and an outer ring region divided along the radial direction of the pellet.

4. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, The low multiplier is 50 to 100 times.

5. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, Within each analysis region, energy spectrum scans are performed at 4 to 8 scan positions.

6. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, The formula used to calculate the arithmetic mean is: = in, Let n be the representative value of residual zinc content in a certain analytical region, and n be the number of locations in that analytical region where energy dispersive spectroscopy (EDS) scans were performed. This represents the zinc content measured by energy dispersive spectroscopy at the i-th scanning position within the analytical region.

7. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, The high magnification is 2000x to 5000x; the energy spectrum analysis at the high magnification includes energy spectrum surface scanning and energy spectrum point scanning.

8. An energy dispersive spectroscopy (EDS) method for analyzing low-content components, characterized in that, include: The metallized pellets to be tested were cold-mounted and polished to expose their central cross-section; Scanning electron microscopes (SEM) were used to capture SEM images of the entire central section one by one, and the individual SEM images were stitched together to form a full cross-sectional image covering the entire central section, i.e., a Maps image; the full cross-sectional image serves as a location map for subsequent analysis. After obtaining the full cross-sectional image, regions enriched in floatite were identified, and high-magnification energy dispersive spectroscopy analysis was performed to determine the phase morphology and elemental composition of the residual zinc.

9. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 8, characterized in that, The method for identifying areas of floc enrichment is as follows: by identifying the contrast difference between the metallic iron phase and the floc phase in the backscattered electron image of a scanning electron microscope, the areas of floc enrichment are determined.

10. The energy dispersive spectroscopy (EDS) method for analyzing low-content components according to claim 1, characterized in that, The method is used to analyze the residual zinc content distribution and occurrence state in metallized pellets obtained by rotary hearth furnace reduction roasting process.

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