A method of determining sinter mineral phase content

Abstract

The application discloses a method for determining sinter mineral phase content, and the sinter is scanned and analyzed in a mineral analyzer after a light sheet sample is treated by spraying gold, so that the composition and content data of each mineral phase of the sinter are obtained; the light sheet sample with the plating layer removed is placed in a 20wt% hydrofluoric acid or 20wt% sodium hydroxide solution for corrosion, the light sheet sample is placed in an X-ray diffraction analyzer for testing after being corroded and dried, so that the content proportion of three mineral phases of hematite, magnetite and wustite is obtained; the content proportion is brought into the test result of the mineral analyzer, the content of hematite, magnetite and wustite is calculated, and the final result is formed. The method can relatively accurately distinguish the minerals such as hematite and magnetite which are difficult to distinguish under an electron microscope and obtain a better quantitative result, has better feasibility and operability, can give more accurate sinter mineral phase content data, has a positive significance for process improvement, improves the sinter mineral phase quantitative detection precision, reduces the labor intensity and improves the work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, specifically relating to a method for determining the content of sintered mineral phases. Background Technology

[0002] Sinter is a key raw material for blast furnace ironmaking. Accurately determining the mineral phase composition of sinter under different process conditions and material ratios is crucial for guiding process improvement and saving material costs. Currently, the main methods for detecting sinter can be categorized as follows: First, visual estimation—a traditional method for mineral quantification, using an optical microscope for visual estimation. The accuracy of the estimation results is limited by the operator's mineralogical knowledge and experience; the process is cumbersome and inefficient, and the obtained mineral quantitative data is only for reference. Second, diffraction—standardized by national standards, capable of relatively accurately distinguishing the main phases in sinter other than amorphous phases, but it cannot achieve accurate quantification. This is because sinter contains a considerable amount of amorphous phase—glassy material (generally ranging from 5% to 20% by mass). Amorphous material appears as amorphous inclusions in XRD patterns; the higher the amorphous content, the more obvious the amorphous inclusions, rendering the corresponding quantitative data meaningless. The third method is mineral analyzer method—a commonly used mineral detection method in recent years. It can provide a series of relatively accurate basic mineral data such as mineral composition, elemental occurrence, mineral intergrowth relationships, and degree of liberation. It is widely used in mineral processing, metallurgy, and other fields with great success. However, for hematite, magnetite, and fulminate in sintered ore, which have very similar gray values ​​under electron microscopy and indistinct differences in micro-area energy dispersive spectroscopy composition, neither MLA, AMICS, nor other mineral analysis systems can effectively and accurately distinguish them. In actual use, the segmentation effect of these three minerals is very poor, resulting in a large error between the quantitative data of these three minerals and the actual situation. The fourth method is automatic quantitative method of optical microscopy image—that is, using an optical microscope equipped with an automatic sample stage to take large-area pictures of the sample surface, and then using the image software of the equipment to color the stitched pictures to obtain the content of different minerals. However, in actual use, it has been found that the segmentation effect of minerals such as calcium ferrite, perovskite, and magnetite, which appear in complex intergrowth relationships, have fine grain size, and have similar reflectance colors, is not very ideal. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, this invention, based on the premise that XRD meets national standards and provides good quantitative results for crystalline minerals, and combined with the basic conditions that mineral analyzers can obtain high accuracy even with large amounts of data collected, designs a method for determining the phase content of sintered minerals. This method can relatively accurately distinguish minerals such as hematite and magnetite that are difficult to distinguish under electron microscopy and obtain good quantitative results.

[0004] To achieve the above-mentioned objective, the present invention provides a method for determining the content of sintered mineral phases, the method comprising the following steps:

[0005] Step 1: Select a representative sintered ore sample, crush and grind it to about 200 mesh to obtain the corresponding powder sample.

[0006] Step 2: Using epoxy resin and a curing agent, 3-5g of uniformly mixed sintered ore powder sample is prepared into a qualified optical section through steps such as consolidation, grinding, and polishing. The standard for a qualified optical section is: thickness 1.0-1.2cm, flat observation surface and bottom surface, smooth and scratch-free observation surface, and mineral particles clearly visible under a light microscope.

[0007] Step 3: Spray gold onto the prepared light sheet sample, only onto the observation surface of the light sheet sample; and place it in a mineral analyzer for scanning and analysis to obtain the composition and content data of each phase of the sintered ore. The total number of particles in the sample is greater than 150,000. Hematite, magnetite and fulminate are grouped into one category and represented by FeOx.

[0008] Step 4: Take out the light sheet sample, polish it with water using a 1μm polishing cloth for 20-30 seconds to remove the coating on the observation surface of the light sheet sample, and wipe it dry carefully.

[0009] Step 5: Immerse the observation surface of the plate sample with the coating removed in a 20% (mass fraction) hydrofluoric acid or a 20% (mass fraction) sodium hydroxide solution for 10-30 seconds, then rinse the observation surface with clean water and dry it to remove the amorphous glassy phase from the sample.

[0010] Step 6: Place the etched and dried optical sample into an X-ray diffraction analyzer for testing to obtain the content ratio of the three mineral phases: hematite, magnetite, and fulminate.

[0011] Step 7: Input the content ratios of hematite, magnetite, and fulminate obtained from the X-ray diffraction analysis into the test results of the mineral analyzer, calculate the content of hematite, magnetite, and fulminate, and form the final result.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] This invention presents a method for determining the content of sintered mineral phases, which can relatively accurately distinguish minerals such as hematite and magnetite that are difficult to differentiate under an electron microscope and obtain good quantitative results. This method is feasible and easy to operate, providing relatively accurate data on the content of sintered mineral phases, which is of positive significance for guiding process improvement; it can improve the accuracy of quantitative detection of sintered mineral phases, reduce labor intensity, and increase work efficiency. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments, but this does not limit the invention in any way. To avoid redundancy, unless otherwise specified, the raw materials used in the following embodiments are all commercially available products, and the methods used are all conventional methods unless otherwise specified.

[0015] Example 1

[0016] A method for determining the mineral phase content in sintered metals, the specific operating steps of which are as follows:

[0017] Step 1: Select a representative sintered ore sample, crush and grind it to a 200-mesh pass rate of 95%, and obtain the corresponding powder sample.

[0018] Step 2: Using epoxy resin and curing agent, 3g of uniformly mixed sintered ore powder sample is consolidated, ground, and polished to prepare a qualified light plate sample (the light plate sample is 1cm thick, the observation surface and the bottom surface are flat, the observation surface is clean and free of scratches, and the mineral particles are clearly visible under a light microscope).

[0019] Step 3: Spray gold onto the prepared light sheet sample (spray coating the observation surface) and scan it in the MLA650 mineral analyzer to obtain the composition and content data of each phase of the sintered ore. The actual total number of particles in the sample is close to 200,000. Among them, hematite, magnetite and fulminate are classified into one category and represented by FeOx, as shown in Table 1.

[0020] Step 4: Take out the light sheet sample, polish it with water using a 1μm polishing cloth for 30 seconds to remove the coating on the observation surface and wipe it dry carefully.

[0021] Step 5: Immerse the observation surface of the plate sample with the coating removed in a 20% (mass fraction) hydrofluoric acid solution for 30 seconds, then rinse the observation surface with clean water and dry it to remove the amorphous glassy phase from the sample.

[0022] Step 6: Place the etched and dried optical sample into an X-ray diffraction analyzer for testing to obtain the content ratio of the three mineral phases: hematite, magnetite, and fulminate.

[0023] Step 7: The proportions of hematite, magnetite, and fulminate obtained from X-ray diffraction analysis are input into the mineral analyzer test results to calculate the contents of hematite, magnetite, and fulminate, forming the final results. The final sintered mineral phase content data are shown in Table 1. This method has a fast detection speed, produces a large amount of data with strong statistical properties, and has high reliability. The quantitative results meet expectations.

[0024] Table 1. Composition and content of sintered mineral phases (%)

[0025]

[0026] Example 2

[0027] A method for determining the mineral phase content in sintered metals, the specific operating steps of which are as follows:

[0028] Step 1: Select a representative sintered ore sample, crush and grind it to a 200-mesh pass rate of 95%, and obtain the corresponding powder sample.

[0029] Step 2: Using epoxy resin and curing agent, 3g of uniformly mixed sintered ore powder sample is consolidated, ground, and polished to prepare a qualified light plate sample (the light plate sample is 1cm thick, the observation surface and the bottom surface are flat, the observation surface is clean and free of scratches, and the mineral particles are clearly visible under a light microscope).

[0030] Step 3: Spray gold onto the prepared light sheet sample (spray coating the observation surface) and scan it in the MLA650 mineral analyzer to obtain the composition and content data of each phase of the sintered ore. The actual total number of particles in the sample is close to 200,000. Among them, hematite, magnetite and fulminate are classified into one category and represented by FeOx, as shown in Table 1.

[0031] Step 4: Take out the light sheet sample, polish it with water using a 1μm polishing cloth for 30 seconds to remove the coating on the observation surface and wipe it dry carefully.

[0032] Step 5: Immerse the observation surface of the plate sample with the coating removed in a 10% (mass fraction) hydrofluoric acid solution for 30 seconds, then rinse the observation surface with clean water and wipe it dry.

[0033] Step 6: Place the etched and dried optical sample into an X-ray diffraction analyzer for testing to obtain the content ratio of the three mineral phases: hematite, magnetite, and fulminate.

[0034] Compared with Example 1, the concentration of hydrofluoric acid in step five of Example 2 was insufficient, resulting in incomplete etching of the glassy phase in the sample. Because of the presence of amorphous glassy phase, XRD could not accurately quantify phases such as hematite, magnetite, and fulminate. In other words, XRD had no quantitative test results, and therefore could not give the ratio between hematite, magnetite, and fulminate, ultimately resulting in the inability to accurately give the quantitative results as in Example 1.

[0035] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A method for determining the content of sintered mineral phases, characterized in that, The method includes the following steps: Step 1: Select a representative sintered ore sample, crush and grind it to 200 mesh to obtain the corresponding powder sample; Step 2: Using epoxy resin and curing agent, 3-5g of uniformly mixed sintered ore powder sample is prepared into qualified smooth sheet sample through consolidation, grinding and polishing steps. Step 3: Spray gold onto the prepared light sheet sample, only spraying the observation surface of the light sheet sample; and place it in a mineral analyzer for scanning and analysis to obtain the composition and content data of each phase of the sintered ore; among them, the total number of particles in the sample is greater than 150,000, and the three minerals of hematite, magnetite and fulminate are classified into one category and represented by FeOx; Step 4: Take out the light sheet sample, polish it with water using a 1μm polishing cloth for 20-30 seconds to remove the coating on the observation surface of the light sheet sample and wipe it dry; Step 5: Immerse the observation surface of the plate sample with the coating removed in a 20% hydrofluoric acid solution or a 20% sodium hydroxide solution for 10-30 seconds, then rinse the observation surface with clean water and dry it. Step 6: Place the etched and dried optical sample into an X-ray diffraction analyzer for testing to obtain the content ratio of the three mineral phases: hematite, magnetite, and fulminate. Step 7: Input the content ratios of hematite, magnetite, and fulminate obtained from the X-ray diffraction analysis into the test results of the mineral analyzer, calculate the content of hematite, magnetite, and fulminate, and form the final result.

2. The method according to claim 1, characterized in that, The standard for qualified light section samples mentioned in step two is: thickness 1.0-1.2cm, flat observation surface and bottom surface, smooth observation surface without scratches, and mineral particles clearly visible under a light microscope.

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