Evaluation and determination system and method for pulverization behavior of direct reduction ironmaking raw material

Abstract

The invention relates to a system and a method for evaluating and measuring pulverization behaviors of direct reduction ironmaking raw materials. The system comprises a fluidized bed reactor, a heating furnace and a gas supply device, the fluidized bed reactor comprises a fluidized bed straight pipe section and a settling pipe section connected above the straight pipe section; the straight pipe section is vertically arranged in the heating furnace, and the bottom of the straight pipe section is connected with an external air supply device through an air inlet pipe; a gas distribution plate is arranged in the straight pipe section, and a fluidized raw material is arranged above the gas distribution plate; and the settling pipe section is connected to the dust collection chamber. According to the method, the pulverization degree is quantitatively represented, so that a reference basis is provided for determining the applicability of the raw material for fluidized bed reduction production or further optimizing fluidized reduction ironmaking raw material structure conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and in particular to a system and method for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials. Background Art

[0002] The increasing scarcity of high-quality coking coal resources, the decline in iron ore quality, and the increasingly fine particle size are forcing metallurgists to continuously explore new ironmaking processes with low energy consumption, minimal pollution, and low emissions. Among these, various non-blast furnace ironmaking technologies, such as direct reduction and smelting reduction, are gaining increasing attention.

[0003] As an important branch of gas-based direct reduction technology, fluidized bed technology was introduced to the steel and metallurgical industry very early. It was once regarded as the most promising method in gas-based reduction processes because it can directly use small-particle powder ore, does not require coke, has little environmental pollution, and the fluidized bed reaction has the advantages of large gas-solid contact area and good heat and mass transfer conditions. However, the development of fluidized bed ironmaking technology has been restricted by some shortcomings in actual production. Common problems include particle adhesion leading to transmission blockage and loss of fluidization effect, difficulty in processing fine particles the size of concentrate, elutriation loss, low gas utilization rate, etc., which have greatly reduced the technical advantages of fluidized bed reduction and become the main bottleneck preventing its large-scale industrial application.

[0004] From the perspective of chemical reaction theory, the finer the iron ore powder particle size, the more conducive it is to reduction. However, in the actual production of fluidized bed direct reduction ironmaking, the raw material particle size requirement cannot be too fine. Most types of iron concentrate cannot be directly used in fluidized bed reactors. Too fine particle size often exacerbates the tendency to stick, losing the fluidized state and forming a fixed bed. In addition, too fine iron ore powder particles are more likely to be carried out of the fluidized bed in large quantities by the high-temperature, high-speed reducing gas, clogging the equipment pipeline, thereby affecting the stable operation of the fluidized bed and causing raw material loss, and increasing the burden on the recovery system. Therefore, to ensure stable and smooth production, fluidized gas-based direct reduction ironmaking has certain requirements for raw material particle size. For example, iron ore particles within a certain particle size range can be used as raw material. However, during the fluidized reduction process, the reducing gas and solid raw material particles will generate strong disturbances in the bed, and the iron ore raw material particles will constantly collide and rub against each other, causing physical wear. In addition, during the fluidized reduction process, as process conditions such as the reducing atmosphere, reaction temperature, and reaction time change, the iron ore raw material will also undergo complex chemical reactions. These may cause the iron ore raw material to tend to be powdered, thereby changing the designed material particle size and affecting the stable operation of the fluidized reduction.

[0005] In summary, in addition to requiring certain indicators such as particle size and strength, fluidized bed reduction ironmaking raw materials also need to have certain anti-pulverization properties, but there is currently no targeted research on this in the industry. Summary of the Invention

[0006] In response to the above problems, the purpose of the present invention is to provide a system and method for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials. By appropriately evaluating the pulverization behavior of raw materials for fluidized bed direct reduction ironmaking, the suitability of the raw materials for fluidized bed reduction production can be determined, or a reference basis can be provided for further optimizing the raw material structure conditions.

[0007] The technical solution adopted in the present invention is as follows:

[0008] The present invention proposes an evaluation and measurement system for the pulverization behavior of direct reduction ironmaking raw materials, which includes a fluidized bed reactor, a heating furnace and a gas supply device; the fluidized bed reactor includes a fluidized bed straight pipe section and a sedimentation pipe section connected above the straight pipe section; the straight pipe section is vertically arranged inside the heating furnace, and its bottom is connected to an external gas supply device through an air inlet pipe; a gas distribution plate is provided inside the straight pipe section, and the fluidized raw material is placed above the gas distribution plate; the sedimentation pipe section is connected to a dust collection chamber.

[0009] Furthermore, the straight pipe section and the sedimentation pipe section are detachably connected; and the sedimentation pipe section is provided with an observation window.

[0010] Furthermore, the heating furnace includes a furnace body, a heating element and a temperature measuring couple; the heating element is arranged on the inner wall of the furnace body and located outside the straight pipe section; the temperature measuring couple is arranged between the straight pipe section and the heating element.

[0011] Furthermore, the gas supply device includes a gas cylinder group, a gas mixing chamber, a deionized water injection pump and corresponding connecting pipes, valves and flow meters; the gas cylinder group includes CO gas cylinders, H2 gas cylinders, CO2 gas cylinders and N2 gas cylinders; each gas cylinder is connected to the gas mixing chamber through a group of valves and flow meters; the air inlet pipe is respectively connected to the output end of the gas mixing chamber and the deionized water injection pump.

[0012] A method for evaluating the pulverization behavior of direct reduction ironmaking raw materials comprises the following steps:

[0013] S1. Prepare dry raw materials for fluidized bed direct reduction ironmaking within a certain mass and particle size range;

[0014] S2. The dried raw material is fed into the evaluation and measurement system, and a fluidization test is performed under certain temperature and atmosphere conditions;

[0015] After the test and determination in step S3 and step S2 is completed, the materials in the fluidized bed reactor and the dust collection chamber are taken out, multi-stage screening and weighing are performed, and the mass on the sieve of each sieve level is recorded;

[0016] S4, the total mass of the material taken out of the fluidized bed reactor and the dust collection chamber is m0, and the mass of the material on the target particle size screen after screening is m i , expressed as mass percentage Ri Characterize the pulverization behavior of fluidized reduction ironmaking raw materials, where R i =(m0-m i ) / m0×100, based on which the pulverization degree of fluidized reduction ironmaking raw materials is evaluated.

[0017] Furthermore, in step S1, the mass of the dry raw material is 100g-500g, and the particle size is 0.1mm-3mm.

[0018] Furthermore, in step S1, the ironmaking raw material is natural iron ore obtained by screening or artificial ore prepared by forming and roasting; the chemical composition of the ironmaking raw material has a TFe content of not less than 63.5%, a SiO2 content of not more than 3.0%, and a moisture content of less than 0.5%.

[0019] Furthermore, in step S2, the temperature condition is a constant temperature or a variable temperature range between room temperature and 600°C; the atmosphere condition is at least one of compressed air, CO, H2, CO2, N2, and H2O; and the fluidization test time is controlled within a range of 10 min to 120 min.

[0020] Furthermore, in step S3, the screening process is manual screening or mechanical screening; the multi-stage screening is to select more than two particle sizes within the range of 0.1mm-3mm for screening according to actual conditions.

[0021] Furthermore, in step S4, the mass percentage R i When evaluating the pulverization behavior of fluidized reduction ironmaking raw materials, one or more R values ​​calculated based on different particle size screening are used. i Make an evaluation.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention can appropriately evaluate the pulverization behavior of fluidized bed direct reduction ironmaking raw materials and quantitatively characterize the degree of pulverization, thereby providing a reference basis for determining the applicability of raw materials for fluidized bed reduction production or further optimizing the structural conditions of fluidized reduction ironmaking raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials proposed in the present invention.

[0025] Among them, the figure marks are: 1-gas cylinder group, 2-valve, 3-flow meter, 4-gas mixing chamber, 5-air inlet pipe, 6-fluidized bed sedimentation pipe section, 7-gas distribution plate, 8-fluidized raw material, 9-temperature measuring couple, 10-furnace body, 11-dust collection chamber, 12-deionized water injection pump. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] The present invention proposes a system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials, such as Figure 1 As shown, the system includes a fluidized bed reactor, a heating furnace, and a gas supply device. The fluidized bed reactor comprises a straight fluidized bed section and a settling section 6 connected above the straight section. The straight section is vertically arranged within the heating furnace, and its bottom is connected to the external gas supply device via an air inlet pipe 5. A gas distribution plate 7 is provided in the lower middle region of the straight section, with fluidized feedstock 8 placed above the gas distribution plate 7. One side of the upper portion of the settling section 6 is connected to a dust collection chamber 11.

[0028] The straight pipe section and the settling pipe section 6 are detachably connected, such as by threaded connection, etc. An observation window is provided on one side of the settling pipe section 6 to observe the fluidization state of the raw materials in the reactor.

[0029] The heating furnace includes a furnace body 10, a heating element 13 and a temperature measuring couple 9; the heating element 13 is correspondingly arranged on the inner wall of the furnace body 10 and located outside the straight pipe section; the temperature measuring couple 9 is arranged between the straight pipe section and the heating element 13.

[0030] The gas supply device includes a gas cylinder group 1, a gas mixing chamber 4, a deionized water injection pump 12 and corresponding connecting pipes, valves 2 and flow meters 3, etc.; the gas cylinder group 1 includes compressed air cylinders, CO cylinders, H2 cylinders, CO2 cylinders and N2 cylinders equipped according to actual conditions; each gas cylinder is connected to the gas mixing chamber 4 through a group of valves 2 and flow meters 3; the input end of the air inlet pipe 5 is respectively connected to the output end of the gas mixing chamber 4 and the deionized water injection pump 12.

[0031] A method for evaluating the pulverization behavior of direct reduction ironmaking raw materials comprises the following steps:

[0032] S1. Prepare dry raw materials for fluidized bed direct reduction ironmaking within a certain mass and particle size range for standby use; wherein the mass of the dry raw materials is 100g-500g and the particle size is 0.1mm-3mm; the ironmaking raw materials are natural iron ore obtained by screening or artificial ore prepared by forming and roasting; the chemical composition of the ironmaking raw materials includes a TFe content of not less than 63.5%, a SiO2 content of not more than 3.0%, and a moisture content of not more than 0.5%.

[0033] S2. The dried raw material is fed into the evaluation and measurement system, and a fluidization test is conducted for a certain time under certain temperature and atmosphere conditions; wherein the temperature condition is a constant temperature or a variable temperature range between room temperature and 600°C; the atmosphere condition is at least one of compressed air, CO, H2, CO2, N2, and H2O; and the fluidization test time is controlled within a range of 10 minutes to 120 minutes.

[0034] The fluidization test controls the raw material to reach a stable fluidized state by regulating the gas velocity. As an optional solution, corundum balls of no more than 5% by mass of the raw material can be added to the test to enhance the raw material's anti-pulverization ability test process. The particle size of the corundum balls used is larger than the particle size of the test raw material.

[0035] After the test and measurement in step S3 and step S2 are completed, the materials in the fluidized bed reactor and the dust collection chamber are taken out, multi-stage screening and weighing are performed, and the mass on the sieve of each sieve level is recorded; wherein the screening process is manual screening or mechanical screening; the multi-stage screening is to select more than two particle sizes in the range of 0.1mm-3mm for screening according to actual conditions.

[0036] S4, the total mass of the material taken out of the fluidized bed reactor and the dust collection chamber is m0, and the mass of the material on the target particle size screen after screening is m i , expressed as mass percentage R i Characterize the pulverization behavior of fluidized reduction ironmaking raw materials, where R i =(m0-m i ) / m0×100, based on which the degree of pulverization of fluidized reduction ironmaking raw materials is evaluated; wherein, in the case of the mass percentage R i When evaluating the pulverization behavior of fluidized reduction ironmaking raw materials, one or more R values ​​calculated based on different particle size screening can be used. i Make an evaluation.

[0037] The reduction device commonly used in fluidized direct reduction ironmaking technology is a gas-solid fluidized bed. The ironmaking raw materials are strongly disturbed by the reducing gas, and the iron ore raw materials are washed by the gas. At the same time, the particles constantly collide and rub with each other, causing particle wear. During the fluidized reduction process, especially at 400℃-600℃, the hematite undergoes a crystal transformation and volume change, generating internal stress. These also lead to the powdering tendency of the iron ore raw materials. Particle size refinement often exacerbates the sticking tendency. At the same time, a large amount of powder carried out by the airflow will also block the equipment pipe section, affecting the stable operation of the fluidized bed and causing the loss of raw materials, and increasing the burden on the recovery system. In order to ensure stable and smooth production, fluidized gas-based direct reduction ironmaking not only has certain requirements on the raw material particle size, but also requires the raw materials to have certain anti-powdering properties. To this end, the present invention proposes a system and method for evaluating the pulverization behavior of direct reduction ironmaking raw materials, which can appropriately evaluate the pulverization behavior of fluidized bed direct reduction ironmaking raw materials, providing a basis for determining the applicability of raw materials for fluidized bed reduction production or further optimizing the raw material structure conditions.

[0038] The evaluation effect of the present invention will be further described below by means of specific examples:

[0039] Example 1

[0040] Prepare 500g of fluidized bed direct reduction ironmaking dry raw material with a particle size of 0.5mm-2mm. The raw material is obtained by granulation and roasting of iron ore concentrate, and its TFe content is 67% and SiO2 content is 2.3%. Send it into the fluidized bed reactor of the evaluation and measurement system, introduce 5L / min of N2 gas from the air inlet pipe, increase the temperature to 500℃ at 10℃ / min and keep it constant for 30 minutes, then switch the introduced gas to H2, control the gas flow and gas velocity, so that the test material remains in a fluidized state in the reactor for reduction for 60 minutes, and then switch to 5L / min of N2 gas to cool to room temperature. Take out the materials from the fluidized bed reactor and the dust collection chamber, measure their total mass and record it as m0, manually screen them with 0.5mm, 1.0mm and 1.5mm round hole sieves, measure the mass of the sample on each particle size sieve, and record the mass on each sieve size m 0.5 、m 1.0 、m 1.5 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 0.5 、R 1.0 、R 1.5 , R i The larger the value, the more serious the raw material pulverization is under the process conditions.

[0041] Example 2

[0042] Prepare 100g of fluidized bed direct reduction ironmaking dry raw material with a particle size of 0.1mm-1.5mm. The raw material is obtained by screening natural iron ore, and its TFe content is 63.6% and SiO2 content is 2.9%. Send it into the fluidized bed reactor of the evaluation and measurement system, and introduce compressed air or nitrogen from the air inlet pipe. Control the gas flow and gas velocity at room temperature to keep the test material in a fluidized state in the reactor for 120 minutes. After the test, take out the materials in the fluidized bed reactor and the dust collection chamber, measure their total mass and record it as m0, and use 0.1mm, 0.5mm, and 1.0mm round hole sieves for mechanical screening. Measure the mass of the sample on the sieve of each particle size and record the mass on the sieve of each sieve size m 0.1 、m 0.5 、m 1.0 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 0.1 、R 0.5 、R 1.0 , with R 0.1 Characterize the particle pulverization of the raw material after fluidization for 120 minutes at room temperature.

[0043] Example 3

[0044] Prepare 200g of fluidized bed direct reduction ironmaking dry raw material with a particle size of 1mm-3mm. The raw material is obtained by granulation and roasting of iron ore concentrate, and its TFe content is 66.1% and SiO2 content is 2.2%. Send it into the fluidized bed reactor of the evaluation and measurement system, and introduce 5L / min of N2 gas from the air inlet pipe. After the temperature is increased to 600℃ at 10℃ / min and stabilized, the introduced gas is switched to a mixture of CO and H2, wherein the H2 / CO ratio is 4.0. The gas flow rate and gas velocity are controlled to keep the test material in the fluidized state in the reactor for reduction for 10 minutes, and then switch to 5L / min of N2 gas to cool to room temperature. Take out the material from the fluidized bed reactor and the dust collection chamber, measure its total mass and record it as m0, and manually screen it with 1.0mm, 1.5mm, 2.0mm, and 2.5mm round hole sieves to measure the mass of the sample on the sieve of each particle size, and record the mass on the sieve of each sieve size m 1.0 、m 1.5 、m 2.0 、m 2.5 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 1.0 、R 1.5 、R 2.0 、R 2.5 The corresponding numerical value can be used to characterize the powdering of raw materials under the process conditions, and the anti-powdering performance of different materials can also be compared.

[0045] Example 4

[0046] Prepare 100g of fluidized bed direct reduction ironmaking dry raw material with a particle size of 1mm-3mm. The raw material is obtained by screening natural iron ore, and its TFe content is 64.1% and SiO2 content is 2.9%. Send it into the fluidized bed reactor of the evaluation and measurement system, introduce 5L / min of N2 gas from the air inlet pipe, increase the temperature to 450℃ at 10℃ / min and keep it at this temperature for 30 minutes, then switch the introduced gas to H2. At the same time, use a deionized water injection pump to inject deionized water into the system to make the reaction atmosphere meet the H2 / H2O ratio of 7 / 3. Control the gas flow rate and gas velocity to keep the test material in the fluidized state in the reactor for reduction for 30 minutes, then switch to 5L / min of N2 gas and cool it to room temperature. Take out the material from the fluidized bed reactor and the dust collection chamber, measure its total mass and record it as m0, manually screen it with 1.0mm, 1.5mm, 2.0mm, and 2.5mm round hole sieves, measure the mass of the sample on the sieve of each particle size, and record the mass on the sieve of each sieve size m 1.0 、m 1.5 、m 2.0 、m 2.5 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 1.0 、R 1.5 、R 2.0 、R 2.5 , in order to characterize the anti-powdering situation of the raw material under these test conditions.

[0047] Example 5

[0048] 400g of dry raw material for fluidized bed direct reduction ironmaking with a particle size of 0.5mm-2mm was prepared. This raw material, obtained by granulating and roasting iron ore concentrate, contained 67% TFe and 2.0% SiO2. 20g of 2.2mm corundum balls were added to enhance the raw material's anti-pulverization test process. The material was then fed into the fluidized bed reactor of the evaluation and measurement system. N2 gas was introduced through the inlet pipe at a rate of 5L / min. The temperature was raised at 10°C / min to 400°C and held constant for 30 minutes. The gas was then switched to a mixture of CO and CO2 with a CO / CO2 ratio of 3:1. The gas flow and velocity were controlled to maintain the test material in a fluidized state within the reactor for 40 minutes. The material was then cooled to room temperature by switching to N2 gas at 5L / min. The materials in the fluidized bed reactor and the dust collection chamber were taken out, and after the corundum balls were sieved out, the total mass was measured and recorded as m0. The materials were manually sieved using 0.5 mm, 1.0 mm, and 1.5 mm round hole sieves, and the mass of the samples on the sieves of each particle size was measured. The mass on the sieves of each sieve size was recorded as m0. 0.5 、m1.0 、m 1.5 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 0.5 、R 1.0 、R 1.5 , R i The larger the value, the more serious the raw material pulverization is under the process conditions.

[0049] Example 6

[0050] Prepare 300g of fluidized bed direct reduction ironmaking dry raw material with a particle size of 0.5mm-2mm. The raw material is obtained by granulation and roasting of iron ore concentrate, and its TFe content is 67% and SiO2 content is 2.0%. Send it into the fluidized bed reactor of the evaluation and measurement system, introduce 5L / min of N2 gas from the air inlet pipe, increase the temperature to 400℃ at 10℃ / min and keep it constant for 30 minutes, then switch the introduced gas to a mixture of H2, CO, and CO2, where H2 / CO / CO2 is 7 / 2 / 1, control the gas flow and gas velocity, so that the test material remains in a fluidized state in the reactor for reduction for 30 minutes, and then switch to 5L / min of N2 gas to cool to room temperature. Take out the material from the fluidized bed reactor and the dust collection chamber, measure its total mass and record it as m0, manually sieve it with 0.5mm, 1.0mm, and 1.5mm round hole sieves, measure the mass of the sample on the sieve of each particle size, and record the mass on the sieve of each sieve size m 0.5 、m 1.0 、m 1.5 Calculate the mass percentage R based on the mass on each sieve level i =(m0-m i ) / m0×100, calculate R 0.5 、R 1.0 、R 1.5 The anti-pulverization performance of the raw materials used under the process conditions is evaluated based on the Ri value.

[0051] Matters not described in detail in this invention are all known technologies.

[0052] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials, characterized by: The system includes a fluidized bed reactor, a heating furnace and a gas supply device; the fluidized bed reactor includes a fluidized bed straight pipe section and a sedimentation pipe section connected above the straight pipe section; the straight pipe section is vertically arranged inside the heating furnace, and its bottom is connected to the external gas supply device through an air inlet pipe; a gas distribution plate is provided inside the straight pipe section, and the fluidized raw material is placed above the gas distribution plate; the sedimentation pipe section is connected to a dust collection chamber.

2. The system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials according to claim 1, characterized in that: The straight pipe section and the sedimentation pipe section are detachably connected; and the sedimentation pipe section is provided with an observation window.

3. The system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials according to claim 1, characterized in that: The heating furnace comprises a furnace body, a heating element and a temperature measuring couple; the heating element is arranged on the inner wall of the furnace body and outside the straight pipe section; the temperature measuring couple is arranged between the straight pipe section and the heating element.

4. The system for evaluating and measuring the pulverization behavior of direct reduction ironmaking raw materials according to claim 3, characterized in that: The gas supply device includes a gas cylinder group, a gas mixing chamber, a deionized water injection pump and corresponding connecting pipes, valves and flow meters; the gas cylinder group includes CO gas cylinders, H2 gas cylinders, CO2 gas cylinders and N2 gas cylinders; each gas cylinder is connected to the gas mixing chamber through a group of valves and flow meters; the air inlet pipe is respectively connected to the gas mixing chamber and the output end of the deionized water injection pump.

5. A method for evaluating the pulverization behavior of direct reduction ironmaking raw materials, implemented based on the evaluation and measurement system according to claim 4, characterized in that: The method comprises the following steps: S1. Prepare dry raw materials for fluidized bed direct reduction ironmaking within a certain mass and particle size range; S2. The dried raw material is fed into the evaluation and measurement system, and a fluidization test is performed under certain temperature and atmosphere conditions; After the test and determination in step S3 and step S2 is completed, the materials in the fluidized bed reactor and the dust collection chamber are taken out, multi-stage screening and weighing are performed, and the mass on the sieve of each sieve level is recorded; S4, the total mass of the material taken out of the fluidized bed reactor and the dust collection chamber is m0, and the mass of the material on the target particle size screen after screening is m i , expressed as mass percentage R i Characterize the pulverization behavior of fluidized reduction ironmaking raw materials, where R i =(m0-m i ) / m0×100, based on which the pulverization degree of fluidized reduction ironmaking raw materials is evaluated.

6. The method for evaluating the pulverization behavior of direct reduction ironmaking raw materials according to claim 5, characterized in that: In step S1, the mass of the dry raw material is 100g-500g, and the particle size is 0.1mm-3mm.

7. The method for evaluating the pulverization behavior of direct reduction ironmaking raw materials according to claim 5, characterized in that: In step S1, the ironmaking raw material is natural iron ore obtained by screening or artificial ore prepared by forming and roasting; the chemical composition of the ironmaking raw material has a TFe content of not less than 63.5%, a SiO2 content of not more than 3.0%, and a moisture content of less than 0.5%.

8. The method for evaluating the pulverization behavior of direct reduction ironmaking raw materials according to claim 5, characterized in that: In step S2, the temperature condition is a constant temperature or a variable temperature range between room temperature and 600°C; the atmosphere condition is at least one of compressed air, CO, H2, CO2, N2, and H2O; and the fluidization test time is controlled within a range of 10 min to 120 min.

9. The method for evaluating the pulverization behavior of direct reduction ironmaking raw materials according to claim 5, characterized in that: In the step S3, the screening process is manual screening or mechanical screening; the multi-stage screening is to select more than two particle sizes in the range of 0.1mm-3mm for screening according to actual conditions.

10. The method for evaluating the pulverization behavior of direct reduction ironmaking raw materials according to claim 5, characterized in that: In step S4, the mass percentage R i When evaluating the pulverization behavior of fluidized reduction ironmaking raw materials, one or more R values ​​calculated based on different particle size screening are used. i Make an evaluation.

Images