Method for evaluating high-temperature metallurgical performance of sintered ore

Abstract

The invention discloses a method for evaluating the high-temperature metallurgical performance of sintered ore, which comprises the following steps: carrying out a molten drop experiment on the sintered ore, obtaining various soft-melting dropping performance index parameters of the sintered ore in a soft-melting zone, comparing the soft-melting dropping performance index parameters with a reference level, and if the soft-melting dropping performance index parameters of the sintered ore all meet the requirements of the reference level, judging that the sintered ore is in the high-temperature metallurgical performance. If yes, the dripping temperature of the dripping object is obtained, and the corresponding temperature when the dripping object of the soft melting belt reaches the first weight value is obtained and defined as the middle-stage dripping temperature; calculating a difference value between the mid-term dripping temperature and the dripping temperature, comparing the difference value with a first preset value, and judging that the high-temperature metallurgical performance of the sintered ore is suitable for blast furnace production according to a comparison result, or judging that the high-temperature metallurgical performance of the sintered ore is not suitable for blast furnace production according to the comparison result. According to the method for evaluating the high-temperature metallurgical performance of the sinter, the difficulty degree of slag-iron separation of the sinter in the soft melting dripping process can be evaluated, and the application of the detection index of the high-temperature metallurgical performance of the sinter in production is enhanced.

Description

Technical Field

[0001] This application belongs to the technical field of iron and steel smelting, and particularly relates to a method for evaluating the high-temperature metallurgical properties of sinter. Background Art

[0002] In the production of iron and steel smelting, to achieve high yield, low consumption, and long service life, it is necessary to ensure the stable and smooth operation of the blast furnace, that is, "seven parts of raw materials and three parts of operation". To achieve the stable and smooth operation of the blast furnace, it is necessary to ensure that the raw materials have good metallurgical properties. The main indicators used to measure the metallurgical properties of iron ore include low-temperature reduction degradation performance, reduction performance, and high-temperature metallurgical properties (softening and dripping performance). The high-temperature metallurgical properties of iron-bearing burden materials determine the structure, position, and thickness of the softening zone in the blast furnace. Accurately and comprehensively evaluating the high-temperature metallurgical properties of burden materials helps improve the accuracy of blast furnace operators' prediction of the blast furnace operation status and reduce production fluctuations.

[0003] At present, some researchers have done a lot of exploratory research on the high-temperature metallurgical properties of ores, and fully affirmed the important role of high-temperature metallurgical properties in blast furnace production. In the current blast furnace burden distribution, the proportion of sinter is generally between 70% and 85%. The high-temperature metallurgical properties of high-proportion sinter are the most important influencing factors for the high-temperature metallurgical properties of the burden structure. Ensuring that the sinter has good high-temperature metallurgical properties is the basis for ensuring a reasonable burden structure and the stable and smooth operation of the blast furnace.

[0004] Comprehensively and accurately evaluating the high-temperature metallurgical properties of iron ore helps predict the behavior of the softening zone in the blast furnace, which is very important for blast furnace operation and the long-term stable and smooth operation of the blast furnace. The commonly used detection and evaluation indicators for high-temperature metallurgical properties mainly include softening start temperature, softening end temperature, softening range, melting start temperature (or differential pressure steep rise temperature), dripping temperature, dripping range, maximum differential pressure, and total characteristic value of melting performance, etc. The evaluation methods for the high-temperature metallurgical properties of iron ore by different units are relatively messy, and the definitions of the same indicator are also different. There are significant differences in the test results of the same iron ore using different equipment and different methods, which have troubled the industry's internal benchmarking, data analysis, etc. for a long time. "Methods for Determination of High-temperature Load Reduction Softening and Dripping Properties of Iron Ore" - GB / T 34211-2017 standardizes the relevant detection indicators, experimental equipment, and operations, improving the accuracy and reference value of the data. A large number of production experiments and tracking comparisons of actual production have found that the high-temperature metallurgical property detection indicators in "Methods for Determination of High-temperature Load Reduction Softening and Dripping Properties of Iron Ore" - GB / T 34211-2017 still have certain limitations in actual production, and the combination with production is not very good. It cannot well evaluate the difficulty of slag-iron separation during the softening and dripping process of sinter, and has limited reference value for blast furnace operators. Summary of the Invention

[0005] An embodiment of the present application provides a method for evaluating the high-temperature metallurgical properties of sinter, which can be used to evaluate the ease of slag-iron separation during the softening and dripping process of sinter, make up for the deficiencies of "Determination Method for High-temperature Load Reduction Softening and Dripping Properties of Iron Ores" - GB / T 34211-2017 in evaluating the high-temperature metallurgical properties of sinter, and enhance the application of high-temperature metallurgical property detection indicators of sinter in production.

[0006] An embodiment of the present application provides a method for evaluating the high-temperature metallurgical properties of sinter, including:

[0007] Conduct a dripping experiment on the sinter to obtain various softening and dripping property index parameters of the sinter in the softening zone;

[0008] Compare the softening and dripping property index parameters of the sinter with the reference level. If all the softening and dripping property index parameters of the sinter meet the requirements of the reference level, further obtain the dripping temperature of the drippings in the softening zone, and obtain the temperature corresponding to the first weight value of the drippings in the softening zone and define it as the mid-term dripping temperature;

[0009] Calculate the difference between the mid-term dripping temperature and the dripping temperature, and compare the difference with the first preset value. Determine whether the high-temperature metallurgical properties of the sinter are suitable for blast furnace production according to the comparison result, or determine that the high-temperature metallurgical properties of the sinter are not suitable for blast furnace production according to the comparison result.

[0010] According to the embodiment of the first aspect of the present application, the softening and dripping property index parameters include: softening start temperature, softening end temperature, softening range, melting start temperature, dripping temperature, dripping range, maximum pressure difference, and total characteristic value of melting performance.

[0011] According to the embodiment of the first aspect of the present application, the reference level may include the following indicators: softening start temperature: 1120 °C to 1250 °C, softening end temperature: 1230 °C to 1360 °C, softening range: 80 °C to 130 °C, melting start temperature: 1250 °C to 1360 °C, dripping temperature: 1450 °C to 1560 °C, dripping range: 160 °C to 280 °C, softening range: 250 °C to 400 °C, maximum pressure difference: 15 KPa to 40 KPa, total characteristic value of melting performance: 2000 KPa·°C to 6000 KPa·°C.

[0012] According to the embodiment of the first aspect of the present application, calculating the difference between the mid-term dripping temperature and the dripping temperature is calculated according to the following formula:

[0013] Difference = mid-term dripping temperature T m - dripping temperature T d (1),

[0014] In formula (1), the mid-term dripping temperature T mrefers to the temperature corresponding to when the dripping weight of the cohesive zone reaches the first weight value, and the dripping temperature is T d refers to the temperature corresponding to when the first drop of liquid slag and iron drips, and the units of the medium dripping temperature, dripping temperature, and the difference are all °C.

[0015] According to an embodiment of the first aspect of the present application, comparing the difference with a first preset value includes:

[0016] If the difference ≤ the first preset value, it is determined that the difficulty level of slag-iron separation of the sinter is relatively low, and the high-temperature metallurgical properties of the sinter are suitable for blast furnace production;

[0017] If the difference > the first preset value, it is determined that the difficulty level of slag-iron separation of the sinter is relatively high, and the high-temperature metallurgical properties of the sinter are not suitable for blast furnace production.

[0018] According to an embodiment of the first aspect of the present application, the first weight value refers to the temperature corresponding to when the molten slag-iron drippings reach any value in the range of 4 wt.% to 60 wt.% of the total mass of the sinter sample.

[0019] According to an embodiment of the first aspect of the present application, the first weight value refers to the temperature corresponding to when the total mass of the drippings reaches 40 g.

[0020] According to an embodiment of the first aspect of the present application, the first preset value is 20 °C.

[0021] According to an embodiment of the first aspect of the present application, the method for evaluating the high-temperature metallurgical properties of the sinter further includes:

[0022] Based on the difference between the medium dripping temperature and the dripping temperature, determine the difficulty level of slag-iron separation in the high-temperature metallurgical properties of the sinter.

[0023] According to an embodiment of the first aspect of the present application, based on the difference between the medium dripping temperature and the dripping temperature, determining the difficulty level of slag-iron separation in the high-temperature metallurgical properties of the sinter includes:

[0024] If the difference between the medium dripping temperature and the dripping temperature ≤ 20 °C, it is determined that the difficulty level of slag-iron separation of the sinter is relatively low;

[0025] If the difference between the medium dripping temperature and the dripping temperature is greater than 20 °C and ≤ 40 °C, it is determined that the difficulty level of slag-iron separation of the sinter is moderate;

[0026] If the difference between the medium dripping temperature and the dripping temperature > 40 °C, it is determined that the difficulty level of slag-iron separation of the sinter is relatively high.

[0027] The method for evaluating the high-temperature metallurgical properties of sinter ore according to the embodiments of the present application determines the ease of slag-iron separation during the softening and dripping process of sinter ore by comparing the difference between the mid-dripping temperature and the dripping temperature with a first preset value, helping blast furnace operators more accurately predict the behavior of the burden containing sinter ore during the softening and dripping process in the blast furnace, and then taking measures to stabilize the blast furnace production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a flowchart showing the method for evaluating the high-temperature metallurgical properties of sinter ore provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the objectives, technical solutions, and advantages of the present application more clearly understood, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application and not to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present application by showing examples of the present application.

[0031] It should be noted that in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or device. Without further limitation, elements defined by the statement "comprising..." do not preclude the existence of additional identical elements in the process, method, article, or device comprising the said elements.

[0032] During the blast furnace smelting process, the interior of the blast furnace can be divided into a burden zone, a softening-melting zone, a dripping zone, a combustion zone, and a slag-iron storage zone from top to bottom. Among them, the softening characteristics and melting-dripping characteristics of the sinter ore burden play a decisive role in the formation, shape, and position of the softening-melting zone.

[0033] As described in the background art section, the detection indexes in the "Method for Determining the High-temperature Load Reduction Softening Melting and Dripping Properties of Iron Ore" - GB / T 34211-2017 cannot well represent the ease of slag-iron separation during the softening melting and dripping process of sinter. The inventors of this application found through a large number of production practices that the ease of slag-iron separation during the softening melting and dripping process of sinter will affect the interaction reaction between different ore types in the burden structure, and further affect the slag-making process in the softening melting zone of the blast furnace, which is an important aspect of the high-temperature metallurgical properties of sinter. Therefore, it is necessary to study the ease of slag-iron separation during the softening melting and dripping process of sinter in order to further evaluate the high-temperature metallurgical properties of sinter.

[0034] To solve the problems of the prior art, the embodiments of this application provide a method for evaluating the high-temperature metallurgical properties of sinter.

[0035] The method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of this application uses the same equipment as that used in the "Method for Determining the High-temperature Load Reduction Softening Melting and Dripping Properties of Iron Ore" - GB / T 34211-2017.

[0036] First, the method for evaluating the high-temperature metallurgical properties of sinter provided by the embodiments of this application will be introduced below. Figure 1 The flow diagram of the method for evaluating the high-temperature metallurgical properties of sinter provided by an embodiment of this application is shown.

[0037] As Figure 1 shown, the method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of this application includes:

[0038] Conduct a melting and dripping experiment on the sinter to obtain various softening melting and dripping property index parameters of the sinter in the softening melting zone;

[0039] Compare the softening melting and dripping property index parameters of the sinter with the reference level; if the index parameters of the softening melting and dripping properties of the sinter meet the requirements of the reference level, further obtain the dripping temperature of the drippings in the softening melting zone, and obtain the temperature corresponding to the first weight value of the drippings in the softening melting zone and define it as the mid-term dripping temperature;

[0040] Calculate the difference between the mid-term dripping temperature and the dripping temperature, and compare the difference with the first preset value. According to the comparison result, determine whether the high-temperature metallurgical properties of the sinter are suitable for blast furnace production, or, according to the comparison result, determine that the high-temperature metallurgical properties of the sinter are not suitable for blast furnace production.

[0041] The conventional evaluation method for the high-temperature metallurgical properties of sinter only obtains the softening, melting and dripping performance index parameters of sinter through the melting and dripping experiment. When the softening, melting and dripping performance index of sinter meets the requirements of the reference level, it is considered that the sinter meets the requirements of blast furnace production. However, this evaluation method only evaluates the softening, melting and dripping performance of the same kind of sinter, and cannot characterize the ease of slag-iron separation during the softening, melting and dripping process of sinter. And this performance of the ease of slag-iron separation during the softening, melting and dripping process of sinter will affect the interaction reaction between different ore types in the burden structure, and further affect the slag-making process of the softening zone in the blast furnace.

[0042] Based on this, the method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of the present application, on the basis that the softening, melting and dripping performance index parameters of sinter meet the requirements of the reference level, further judges the ease of slag-iron separation during the softening, melting and dripping process of sinter by comparing the difference between the mid-dripping temperature and the dripping temperature with a first preset value, which helps the blast furnace operator more accurately predict the behavior of the burden during the softening process in the blast furnace and take measures to stabilize the blast furnace production. It should be noted that the dripping temperature is the temperature corresponding to the dripping of the first drop of liquid slag and iron, and the mid-dripping temperature is the temperature corresponding to the weight of the dripping in the softening zone reaching a first weight value.

[0043] According to the experimental observations of a large number of sinter by the inventors of the present application, in the softening, melting and dripping process of high-alkali sinter, the liquid iron drips before the slag. The slag and iron inside the sinter are gradually separated under the combined action of factors such as heat, diffusion rate, and gangue viscosity. To a certain extent, the mid-dripping temperature can characterize the ease of slag-iron separation inside the sinter. Combining the temperature difference between the mid-dripping temperature and the dripping temperature can better characterize the ease of slag-iron separation during the softening, melting and dripping process of sinter. Among them, the gangue viscosity refers to the fluidity of the sinter in the molten state and is used to characterize the speed of mass transfer inside the melt.

[0044] In the embodiments of the present application, the mid-dripping temperature during the softening, melting and dripping process of sinter in the softening zone can characterize the ease of slag-iron separation inside the sinter in the blast furnace to a certain extent. The reason is that: compared with the dripping temperature, the lower the mid-dripping temperature, that is, the easier the overall molten iron inside the sinter drips, indicating that the slag and iron inside the sinter in the softening zone are easier to separate. The higher the mid-dripping temperature, the more difficult it is for the overall molten iron inside the sinter to drip, indicating that the slag and iron inside the sinter in the softening zone are more difficult to separate.

[0045] In some embodiments of the present application, the softening, melting and dripping performance index parameters include:

[0046] Softening start temperature, softening end temperature, softening range, melting start temperature, dripping temperature, dripping range, maximum pressure difference, total characteristic value of melting performance.

[0047] In some embodiments of the present application, the reference level may include the following indicators: softening start temperature: 1120°C to 1250°C, softening end temperature: 1230°C to 1360°C, softening range: 80°C to 130°C, melting start temperature: 1250°C to 1360°C, dripping temperature: 1450°C to 1560°C, dripping range: 160°C to 280°C, softening and melting range: 250°C to 400°C, maximum pressure difference: 15 KPa to 40 KPa, total characteristic value of melting performance: 2000 KPa·°C to 6000 KPa·°C. By setting the values in the above reference level within the above ranges, it is possible to better evaluate whether the softening and dripping performance index parameters of the sinter ore meet the requirements, thereby preliminarily obtaining sinter ore that meets the requirements of blast furnace production.

[0048] In the embodiments of the present application, by obtaining the above-mentioned several softening and dripping performance index parameters of the sinter ore in the softening zone, determining the difference between the softening and dripping performance index parameters and the reference level, and judging whether the sinter ore can be used for blast furnace production. When the softening and dripping performance index parameters of the sinter ore all meet the requirements of the reference level, it preliminarily indicates that the sinter ore is suitable for blast furnace production. It can be understood that in the step of comparing the softening and dripping performance index parameters of the sinter ore with the reference level, if there are index parameters among the softening and dripping performance index parameters of the sinter ore that do not meet the requirements of the reference level, then the sinter ore cannot be used in the process of blast furnace production. When the softening and dripping performance index of the sinter ore does not meet the requirements of the reference level, it is necessary to adjust the raw material ratio or process parameters of the sinter ore in the blast furnace to make the softening and dripping performance index parameters of the sinter ore meet the requirements of the reference level. Then, further by obtaining and defining the temperature corresponding to the first weight value reached by the dripping matter in the softening zone as the mid-term dripping temperature, calculating the difference between the mid-term dripping temperature and the dripping temperature, and comparing it with the first preset value, and then determining the ease of slag-iron separation during the softening and dripping process of the sinter ore.

[0049] In the embodiments of the present application, the difference between the mid-term dripping temperature and the dripping temperature is calculated according to the following formula:

[0050] Difference = Mid-term dripping temperature T m - Dripping temperature T d (1),

[0051] In formula (1), the mid-term dripping temperature refers to the temperature corresponding to the dripping weight in the softening zone reaching the first weight value, the dripping temperature refers to the temperature corresponding to the dripping of the first drop of liquid slag and iron, and the units of the mid-term dripping temperature, the dripping temperature, and the difference are all °C.

[0052] It should be noted that the difference in formula (1) can be negative. When the sinter is smelted in the blast furnace, it is a highly endothermic reaction process. If the heat supply is insufficient, or the temperature field of the reaction is very concentrated and intense, the situation where the mid-term dripping temperature is less than the dripping temperature will occur, that is, the difference between the mid-term dripping temperature and the dripping temperature is negative. The occurrence of a negative difference indicates that the reduction reaction area of the sinter is relatively concentrated, which is theoretically beneficial to the slag-iron separation of the sinter.

[0053] In the embodiments of the present application, in most cases, the mid-term dripping temperature can effectively characterize the ease of slag-iron separation in the softening-melting zone of the sinter. However, for the sinter with a relatively low dripping temperature, only the mid-term dripping temperature cannot well reflect the ease of slag-iron separation. Therefore, the present application further evaluates the ease of slag-iron separation by obtaining and calculating the difference between the dripping temperature and the mid-term dripping temperature.

[0054] In the embodiments of the present application, comparing the difference with a first preset value includes:

[0055] If the difference ≤ the first preset value, it is determined that the ease of slag-iron separation of the sinter is relatively low, and the high-temperature metallurgical properties of the sinter are suitable for blast furnace production;

[0056] If the difference > the first preset value, it is determined that the ease of slag-iron separation of the sinter is relatively high, and the high-temperature metallurgical properties of the sinter are not suitable for blast furnace production.

[0057] The method for evaluating the high-temperature metallurgical properties of the sinter in the embodiments of the present application is based on the following considerations: When the sinter in the blast furnace melts in the softening-melting zone, the smaller the difference between the dripping temperature and the mid-term dripping temperature of the slag-iron, the easier it is for the slag-iron in the sinter melting in the softening-melting zone to separate and drip as a whole, and the lower the ease of slag-iron separation, that is, the better the high-temperature metallurgical properties of the sinter and the more suitable it is for blast furnace production; when the difference between the dripping temperature and the mid-term dripping temperature of the slag-iron is larger, it indicates that the temperature field that the slag-iron in the sinter melting in the softening-melting zone needs to cross is larger, the required time and process are longer, and it is more difficult for the slag-iron to drip as a whole, and the ease of slag-iron separation is higher.

[0058] Furthermore, in the method for evaluating the high-temperature metallurgical properties of the sinter in the embodiments of the present application, the difference is compared with the first preset value. If the difference between the dripping temperature and the mid-term dripping temperature of the slag-iron is greater than the first preset value, it indicates that it is difficult for the slag-iron in the sinter melting in the softening-melting zone to drip as a whole, and the ease of slag-iron separation is higher, that is, the high-temperature metallurgical properties of the sinter are worse and it is more unsuitable for blast furnace production. If the difference between the dripping temperature and the mid-term dripping temperature of the slag-iron is less than or equal to the first preset value, it indicates that it is easier for the slag-iron in the sinter melting in the softening-melting zone to drip as a whole, and the ease of slag-iron separation is smaller, that is, the high-temperature metallurgical properties of the sinter are better and it is more suitable for blast furnace production.

[0059] In some embodiments of the present application, the first weight value refers to the temperature corresponding to any value within 4 wt.% to 60 wt.% of the total mass of the sinter ore sample when the molten slag-iron drippings reach that value. The weight of the drippings can be measured by a weighing device, such as a balance, including but not limited to an electronic balance or a mechanical balance, or other weighing instruments capable of measuring the weight of the drippings.

[0060] Optionally, the first weight value may refer to the temperatures corresponding to the molten slag-iron drippings reaching 4 wt.%, 5 wt.%, 8 wt.%, 10 wt.%, 15 wt.%, 18 wt.%, 20 wt.%, 22 wt.%, 25 wt.%, 28 wt.%, 30 wt.%, 35 wt.%, 36 wt.%, 40 wt.%, 42 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 52 wt.%, 57 wt.%, 58 wt.%, 60 wt.% of the total mass of the sinter ore sample.

[0061] Exemplarily, the mid-term dripping temperature is the temperature when the weight of the molten slag-iron drippings in the softening-melting zone reaches the first weight value (40 g), and 40 g is the temperature corresponding to the weight of the molten slag-iron drippings reaching 40 as determined according to GB / T 34211-2017, "Determination Method for High Temperature Load Reduction Softening-Melting Dripping Properties of Iron Ores". It can be understood that the first weight value can also be any value among 20 g, 50 g, 100 g, 150 g, 160 g, 200 g, or a point value between any two values.

[0062] It should be noted that since the molten slag-iron in the sinter ore sample cannot be completely separated and dripped, the total mass of the drippings must be less than the total mass of the sinter ore sample. In the present application, only the temperature corresponding to a part of the molten and dripped slag-iron is selected as the mid-term dripping temperature to calculate the difference from the dripping temperature, and then the ease of separation of the molten and dripped slag-iron in the softening-melting zone is judged based on the mid-term dripping temperature and the difference.

[0063] In some embodiments of the present application, the first preset value is 20°C.

[0064] The method for evaluating the high-temperature metallurgical properties of sinter ore in the embodiments of the present application adds two detection indexes on the basis of the detection and evaluation indexes of "Determination Method for High Temperature Load Reduction Softening-Melting Dripping Properties of Iron Ores" - GB / T 34211-2017: the temperature when the weight of the drippings reaches the first weight value (i.e., the mid-term dripping temperature) and the relative difference (temperature difference) between this mid-term dripping temperature and the dripping temperature. The ease of separation of slag and iron during the softening-melting and dripping process of sinter ore is judged by the mid-term dripping temperature, the temperature difference between the mid-term dripping temperature and the dripping temperature.

[0065] During the blast furnace smelting process of sinter, it is difficult to separate slag and iron, which will increase the gas permeability and liquid permeability in the softening-melting zone and the upper part of the dripping zone of the blast furnace. The fault tolerance ability of the blast furnace becomes worse, and fluctuations are likely to occur, requiring blast furnace operators to be more focused, and the corresponding treatment measures require faster operation. Therefore, the method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of the present application can measure the difficulty of slag-iron separation during the softening-dripping process of sinter, helping blast furnace operators more accurately predict the behavior of the burden containing sinter during the softening-dripping process in the blast furnace, so as to guide blast furnace operators to take measures to stabilize blast furnace production.

[0066] The method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of the present application is mainly applied in blast furnace production to comprehensively measure the high-temperature metallurgical properties of sinter and help blast furnace operators more accurately predict the impact of the burden on the blast furnace.

[0067] The technical solutions and beneficial effects of the present application will be described below through specific examples and comparative examples.

[0068] Examples 1-5 and Comparative Examples 1-3

[0069] Method for Evaluating High-Temperature Metallurgical Properties of Sinter

[0070] Sinter 1, Sinter 2, Sinter 3, and Sinter 4 including the components contained in Table 1 below are provided respectively. Among them, Sinter 2 is used as Example 1, Sinter 3 is used as Example 2, Sinter 1 is used as Comparative Example 1, Sinter 4 is used as Comparative Example 2, and Sinter 7 is used as Comparative Example 3. Sinter 5, Sinter 6, and Sinter 8 are used as Examples 3-5 respectively. Comparative Examples 1-3 do not adopt the index of the mid-dripping temperature, but to distinguish the differences between the method for evaluating the high-temperature metallurgical properties of sinter using the present application and not using the method for evaluating the high-temperature metallurgical properties of sinter using the present application, the mid-dripping temperature of the sinter in Comparative Examples 1-3 is obtained together here and the difference between it and their respective dripping temperatures is calculated, so as to verify the guiding role for sinter in blast furnace production through subsequent further blast furnace smelting hot metal tests.

[0071] Table 1 Composition of Sinter 1-8

[0072] Example / Composition FeO TFe CaO <![CDATA[SiO2]]> MgO <![CDATA[Al2O3]]> <![CDATA[R2]]> Sinter 1 9.10 57.02 10.28 4.89 1.76 1.77 2.102 Sinter 2 8.15 57.23 10.15 5.07 1.83 1.93 2.002 Sinter 3 8.90 57.32 10.11 4.93 1.78 1.74 2.051 Sinter 4 8.50 57.20 10.12 4.78 1.68 1.85 2.117 Sinter 5 8.35 56.79 10.22 5.24 1.78 1.94 1.95 Sinter 6 9.10 56.71 10.40 5.47 1.62 2.00 1.90 Sinter 7 9.00 56.34 10.93 5.02 1.97 1.83 2.18 Sinter 8 7.95 56.65 10.61 5.15 1.91 1.88 2.06

[0073] In Table 1, TFe represents the total iron content in the sinter, and R2 represents the basicity of the sinter, that is, the mass ratio of CaO to SiO2.

[0074] (1) Take four consecutive sinter samples in Table 1 as Sinter 1, Sinter 2, Sinter 3, and Sinter 4 respectively, and take sinter samples with different component compositions as Sinter 5, Sinter 6, Sinter 7, and Sinter 8 respectively. Then, conduct the sinter melting and dripping experiments according to GB / T 34211-2017 - "Determination Method for High-temperature Load Reduction Softening Melting Dripping Performance of Iron Ores", and record the experimental measurement results of the softening melting dripping performance indexes of the sinter.

[0075] (2) Compare the softening melting dripping performance indexes of the sinter with the reference levels. Among them, the reference levels include: softening start temperature: 1120°C - 1250°C, softening end temperature: 1230°C - 1360°C, softening range: 80°C - 130°C, melting start temperature: 1250°C - 1360°C, dripping temperature: 1450°C - 1560°C, melting and dripping range: 160°C - 280°C, softening and melting range: 250°C - 400°C, maximum pressure difference: 15 KPa - 40 KPa, total characteristic value of melting performance: 2000 KPa·°C - 6000 KPa·°C.

[0076] (3) If the softening melting dripping performance indexes of Sinter 1, Sinter 2, Sinter 3, and Sinter 4, as well as Sinter 5 - 8, all meet the requirements of the reference levels, then further obtain the temperature when the dripping matter of each softening zone of Sinter 1 - 4 reaches 40 g, which is defined as the mid-term dripping temperature T m ;

[0077] (4) Calculate the difference between the mid-term dripping temperature T m and the dripping temperature T d of Examples 1 - 5 and Comparative Examples 1 - 3 respectively. Set the first preset value to 20°C, and compare each difference with the first preset value.

[0078] The test results show that: the difference between the mid-term dripping temperature T m and the dripping temperature T d of Sinter 1 is 21°C, which is greater than the first preset value of 20°C, indicating that the slag and iron are relatively not easy to separate during the softening melting dripping process of the sinter. The difference between the mid-term dripping temperature T m and the dripping temperature T d of Sinter 2 is -2°C, which is much less than the first preset value of 20°C, indicating that the slag and iron are relatively easy to separate during the softening melting dripping process of the sinter. The difference between the mid-term dripping temperature T m and the dripping temperature T d of Sinter 3 is 8°C, which is less than the first preset value of 20°C, indicating that the slag and iron are relatively easy to separate during the softening melting dripping process of the sinter. The difference between the mid-term dripping temperature T m and the dripping temperature T dThe temperature difference is 42 °C, which is significantly greater than the first preset value of 20 °C, indicating that it is not easy for slag and iron to separate during the softening, melting and dripping process of sinter. The mid-term dripping temperature T of sinter 5 m and the dripping temperature T d The temperature difference is -6 °C, which is less than the first preset value of 20 °C, indicating that it is relatively easy for slag and iron to separate during the softening, melting and dripping process of sinter. The mid-term dripping temperature T of sinter 6 m and the dripping temperature T d The temperature difference is -2 °C, which is less than the first preset value of 20 °C, indicating that it is relatively easy for slag and iron to separate during the softening, melting and dripping process of sinter. The mid-term dripping temperature T of sinter 7 m and the dripping temperature T d The temperature difference is 28 °C, which is greater than the first preset value of 20 °C, indicating that it is relatively not easy for slag and iron to separate during the softening, melting and dripping process of sinter. The mid-term dripping temperature T of sinter 8 m and the dripping temperature T d The temperature difference is 15 °C, which is less than the first preset value of 20 °C, indicating that it is relatively easy for slag and iron to separate during the softening, melting and dripping process of sinter.

[0079] Table 2 also includes the experimental determination results of the softening, melting and dripping performance indexes of the sinter samples of Comparative Examples 1-3. The sinter samples of Comparative Examples 1-3 only involve the determination of ordinary softening, melting and dripping performance indexes, and do not include the data of the difference between the mid-term dripping temperature and the dripping temperature.

[0080] Table 2 Softening, melting and dripping performance index parameters of the sinter samples of Examples 1-5 and Comparative Examples 1-3

[0081]

[0082]

[0083] It should be noted that the smaller the dripping interval is, the better. There is a certain correlation between the dripping interval and the mid-term dripping temperature, but the linear correlation is not strong and it cannot effectively characterize the ease of slag-iron separation. Therefore, this application adds the mid-term dripping temperature and the difference value to improve the evaluation of the high-temperature metallurgical performance of sinter.

[0084] Here, the total mass of the slag-iron drippings of sintered ores 1-8 during the test when the sample dripping temperature reaches 1560°C is used as a reference benchmark. The more the total mass of the drippings at this temperature, the lower the difficulty level of slag-iron separation, which is one of the high-temperature metallurgical properties of the sintered ore sample in the softening-melting zone, that is, the easier the slag-iron separation and dripping; the less the total mass of the drippings, the higher the difficulty level of slag-iron separation, which is one of the high-temperature metallurgical properties of the sintered ore sample in the softening-melting zone, that is, the more difficult the slag-iron separation and dripping. This is used to verify whether it is accurate and effective to use the mid-term dripping temperature and the difference value to characterize the difficulty level of slag-iron separation of the sintered ore in the softening-melting zone in this application. The total mass of the drippings of sintered ores 1-8 at 1560°C in the melting-dripping experiment is shown in Table 3 below.

[0085] Table 3 Total mass of slag-iron low drippings of sintered ores 1-4 when the softening-melting zone reaches 1560°C

[0086] Sinter Specimen Weight / g Sinter Specimen Weight / g Sinter 1 145 Sinter 5 172 Sinter 2 176 Sinter 6 181 Sinter 3 199 Sinter 7 121 Sinter 4 91 Sinter 8 165

[0087] According to the softening-melting dripping performance index parameters of the sintered ore samples in Table 2 in the softening-melting zone, from the perspective of the softening-melting dripping performance of the melting-dripping interval, the high-temperature metallurgical performance of sintered ore 1 is the best, the high-temperature metallurgical performance of sintered ores 2 and 3 is second, and the high-temperature metallurgical performance of sintered ore 4 is the worst. However, using the softening-melting dripping performance index of the melting-dripping interval cannot better distinguish the advantages and disadvantages between sintered ore 2 and sintered ore 3, that is, the difficulty level of slag-iron separation.

[0088] By using the method for evaluating the high-temperature metallurgical performance of the sintered ore in this application, that is, evaluating through the mid-term dripping temperature and the difference between the mid-term dripping temperature and the dripping temperature, as shown in Table 3, it can be concluded that the high-temperature metallurgical performance of sintered ore 3 in Example 2 is the best; the high-temperature metallurgical performance of sintered ore 2 in Example 1 is second; that is, the slag-iron of sintered ore 3 is easier to separate, which is better than that of sintered ore 2 with a more difficult slag-iron separation degree in Example 1 and sintered ore 1 with a higher slag-iron separation difficulty level in Comparative Example 1; it is even better than sintered ore 4 with the highest slag-iron separation difficulty level in Comparative Example 2.

[0089] The differences between the mid-term dripping temperatures and the dripping temperatures corresponding to Example 1, Example 2, and Examples 3-5 are -2°C, 8°C, -6°C, -2°C, and 15°C respectively, all of which are less than the first preset value of 20°C. The masses of the slag-iron drippings corresponding to them at 1560°C are also relatively large, reaching 176 g, 199 g, 172 g, 181 g, and 165 g respectively, indicating that the slag and iron in the softening-melting zone of the sinter with a difference less than 20°C are more likely to be separated. For Comparative Example 1, Comparative Example 2, and Comparative Example 3, the differences between the mid-term dripping temperatures and the dripping temperatures are 21°C, 42°C, and 28°C respectively, all of which are greater than the first preset value of 20°C. The masses of the slag-iron drippings corresponding to them at 1560°C are also relatively small, reaching 145 g, 91 g, and 121 g respectively, indicating that the slag and iron in the softening-melting zone of the sinter with a difference greater than 20°C are less likely to be separated. The above test results show that the method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of the present application can effectively measure the ease of slag-iron separation during the softening-dripping process of sinter, helping blast furnace operators more accurately predict the behavior of the burden containing sinter during the softening-dripping process in the blast furnace, so as to guide blast furnace operators to take measures to stabilize the blast furnace production.

[0090] The method for evaluating the high-temperature metallurgical properties of sinter in the embodiments of the present application improves the deficiencies in the evaluation of the high-temperature metallurgical properties of sinter in "Determination Method for High-temperature Load Reduction Softening-dripping Properties of Iron Ores" - GB / T 34211-2017.

[0091] As described above, the above is only the specific implementation manner of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process described above can refer to the corresponding process in the foregoing method embodiments and will not be repeated here. It should be understood that the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present application.

Claims

1. A method for evaluating the high temperature metallurgical properties of sintered ore, characterized in that: include: Conduct molten drop experiments on sintered ore to obtain various soft melting drop performance index parameters of sintered ore in the soft melting zone; The soft melting dripping performance index parameters of the sintered ore are compared with the reference level. If the soft melting dripping performance index parameters of the sintered ore meet the requirements of the reference level, the dripping temperature of the dripping material is further obtained, and the temperature corresponding to when the dripping material of the soft melting zone reaches the first weight value is obtained and defined as the mid-term dripping temperature; The difference between the mid-term dripping temperature and the dripping temperature is calculated, and the difference is compared with the first preset value. According to the comparison result, it is determined that the high-temperature metallurgical properties of the sintered ore are suitable for blast furnace production, or, according to the comparison result, it is determined that the high-temperature metallurgical properties of the sintered ore are not suitable for blast furnace production.

2. The method for evaluating the high temperature metallurgical properties of sintered ore according to claim 1, characterized in that: The soft melting dripping performance index parameters include: Softening start temperature, softening end temperature, softening range, melting start temperature, dripping temperature, dripping range, maximum pressure difference, and total characteristic value of melting performance.

3. The method for evaluating the high temperature metallurgical properties of sintered ore according to claim 1, characterized in that: The reference level includes the following indicators: softening start temperature: 1120℃~1250℃, softening end temperature: 1230℃~1360℃, softening range: 80℃~130℃, melting start temperature: 1250℃~1360℃, dripping temperature: 1450℃~1560℃, dripping range: 160℃~280℃, soft melting range: 250℃~400℃, maximum pressure difference: 15KPa~40KPa, total characteristic value of melting performance: 2000KPa﹒℃~6000KPa﹒℃.

4. The method for evaluating the high temperature metallurgical properties of sintered ore according to claim 1, characterized in that: The difference between the mid-term dripping temperature and the dripping temperature is calculated according to the following formula: Difference = mid-term dripping temperature T m -Dripping temperature T d (1) In formula (1), the mid-term dripping temperature T m It refers to the temperature corresponding to when the dripping weight of the soft melting tape reaches the first weight value. The dripping temperature T d It refers to the temperature corresponding to the first drop of liquid slag iron dripping, and the mid-term dripping temperature T m , dripping temperature T d The unit of the value and the difference is °C.

5. The method for evaluating high temperature metallurgical properties of sintered ore according to claim 1, characterized in that: The comparing the difference with the first preset value comprises: If the difference is less than or equal to the first preset value, it is determined that the slag-iron separation difficulty of the sintered ore is relatively low, and the high-temperature metallurgical properties of the sintered ore are suitable for blast furnace production; If the difference is greater than the first preset value, it is determined that the slag-iron separation difficulty of the sintered ore is relatively high, and the high-temperature metallurgical properties of the sintered ore are not suitable for blast furnace production.

6. The method for evaluating the high temperature metallurgical properties of sintered ore according to any one of claims 1 to 5, characterized in that: The first weight value refers to the temperature corresponding to when the molten slag iron drops reach any value between 4wt.% and 60wt.% of the total mass of the sintered ore sample.

7. The method for evaluating the high temperature metallurgical properties of sintered ore according to any one of claims 1 to 5, characterized in that: The first weight value refers to the temperature corresponding to when the total mass of the dripping material reaches 40g.

8. The method for evaluating the high-temperature metallurgical properties of sintered ore according to any one of claims 1 to 5, characterized in that: The first preset value is 20°C.

9. The method for evaluating high temperature metallurgical properties of sintered ore according to claim 1, characterized in that: Also includes: Based on the difference between the mid-term dripping temperature and the dripping temperature, the difficulty level of slag-iron separation in the high-temperature metallurgical properties of the sintered ore is determined.

10. The method for evaluating high temperature metallurgical properties of sintered ore according to claim 9, characterized in that: The difficulty level of slag-iron separation in the high-temperature metallurgical properties of the sintered ore is determined based on the difference between the mid-term dripping temperature and the dripping temperature, including: If the difference between the mid-term dripping temperature and the dripping temperature is ≤20°C, it is judged that the difficulty of slag-iron separation of the sintered ore is relatively low; If the difference between the mid-term dripping temperature and the dripping temperature is greater than 20°C and ≤40°C, it is determined that the difficulty of slag-iron separation of the sintered ore is moderate; If the difference between the mid-term dripping temperature and the dripping temperature is greater than 40°C, it is determined that the slag-iron separation of the sintered ore is difficult.

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