A hydrogen-based magnetization reduction process for hematite ore

Abstract

The present invention proposes a hydrogen-based magnetization reduction process for hematite ore, belonging to the field of metallurgy technology, comprising: 1) generating saturated high-temperature gas; 2) mixing the temperature within the saturated high-temperature gas; 3) causing the saturated high-temperature gas to collide countercurrently with powdered hematite ore in a rotary kiln, the saturated high-temperature gas transferring heat to the powdered hematite ore and a reducing agent, causing the reducing agent to pyrolyze at high temperature to produce a large amount of reducing hydrogen gas, which penetrates into the powdered hematite ore layer and undergoes a hydrogen-based magnetization reduction reaction with the powdered hematite ore, thereby magnetizing the powdered hematite ore. The present invention provides sufficient time for the temperature to transfer from the surface of the iron ore particles to the core of the iron ore particles, thereby avoiding the phenomenon of "ringing" in the rotary kiln caused by the instantaneous excessive temperature of the iron ore surface and the inability to transfer the temperature to the core of the iron ore particles in a timely manner.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy and relates to a metallurgical combustion technology, in particular to a hydrogen-based magnetization reduction process for hematite iron ore. Background Art

[0002] Specularite, siderite, and limonite are all refractory iron ores. Existing technologies typically use oxidative roasting to convert these refractory ores into magnetic iron ore. Separating the iron-containing materials from the gangue through magnetic separation is an effective method for improving resource utilization of these refractory iron ores. Currently, the most common magnetic roasting technology for iron ore, both domestically and internationally, is the rotary kiln process.

[0003] In the existing rotary kiln process, the material is heated while tumbling inside the rotary kiln. The surface of the material particles simultaneously receives heat from three methods: thermal radiation, thermal convection, and thermal conduction. However, heat is transferred from the surface of the material particles to the center of the material particles only by thermal conduction. In terms of the heating process of the iron ore particles, the surface of the particles is heated first, and then the heat is transferred along the surface of the particles to the center of the particles. As a result, the heating time of particles with small particle size is short, and the heating time of particles with large particle size is long. Under the condition of a relatively stable reducing atmosphere inside the material layer, the higher the temperature, the better the metallurgical dynamic conditions, and the faster the reduction rate. The reduction time required for fine-grained iron ore and the surface of coarse-grained iron ore is very short, while the reduction time required for the core of the coarse-grained iron ore particles (the center of the iron ore) is very long. If the reduction time of coarse-grained iron ore is to be shortened, the heat transfer problem needs to be solved. At present, the only way to shorten the heat transfer time is to increase the internal and external temperature gradient of coarse-grained iron ore, that is, to increase the surface temperature of coarse-grained iron ore. Under higher temperature conditions, the heating rate of the core of the coarse-grained iron ore particles (the center of the iron ore) will increase to a certain extent, but the surface temperature of the coarse-grained iron ore and the temperature of the fine-grained iron ore will be higher. In the local high temperature environment of about 1000°C, Fe3O4 can be easily further reduced to FeO. FeO will undergo a series of complex chemical reactions with SiO2 in the iron ore to generate a variety of low-melting-point compounds, causing "ringing" in the rotary kiln, affecting the roasting quality of the iron ore and resulting in a low recovery rate of the metal ore. Summary of the Invention

[0004] In response to the above-mentioned problem that the existing rotary kiln process has uneven heat transfer temperature, resulting in "ringing" in the rotary kiln, which affects the roasting quality of iron ore and leads to low metal ore recovery rate, the present invention proposes a hydrogen-based magnetization reduction process for hematite iron ore.

[0005] The present invention adopts a heat transfer method of countercurrent collision between saturated high-temperature gas and powdered hematite iron ore, so that the saturated high-temperature gas transfers heat to the powdered hematite iron ore. The countercurrent collision heat transfer process causes the powdered hematite iron ore particles to gradually increase in temperature. In the process of continuous heating of the iron ore, the temperature is continuously transferred from the surface of the iron ore particles to the core of the iron ore particles, giving sufficient time for the temperature to be transferred from the surface of the iron ore particles to the core of the iron ore particles, avoiding the instantaneous excessive temperature of the iron ore particle surface, causing the "ringing" phenomenon of the rotary kiln, and solving the technical problem of "ringing" of the rotary kiln in the prior art.

[0006] The technical solutions of the present invention are as follows:

[0007] A hydrogen-based magnetization reduction process for hematite iron ore comprises the following steps:

[0008] 1) After the gas is burned, saturated high-temperature gas is produced;

[0009] 2) The saturated high-temperature gas is discharged into the flue along the combustion chamber. In the flue, a portion of the saturated high-temperature gas continuously collides with the flue wall and swirls, forming a vortex flue gas. The vortex flue gas continuously collides and mixes with another portion of the saturated high-temperature gas, and heat is conducted inside the saturated high-temperature gas, making the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber uniform;

[0010] 3) The saturated high-temperature gas in the high-temperature gas buffer chamber flows along the high-temperature gas drainage pipe into the kiln chamber of the rotary kiln. In the kiln chamber of the rotary kiln, the saturated high-temperature gas countercurrently collides with the powdered hematite iron ore and the reducing agent. The saturated high-temperature gas transfers heat to the powdered hematite iron ore and the reducing agent. The reducing agent is pyrolyzed at high temperature to produce a large amount of reducing hydrogen. The reducing hydrogen penetrates into the powdered hematite iron ore layer and undergoes a hydrogen-based magnetic reduction reaction with the powdered hematite iron ore, thereby magnetizing the powdered hematite iron ore.

[0011] Further defined, the step 1) is specifically:

[0012] 1.1) Gas and air are introduced into the combustion nozzle in the combustion chamber through the gas pipeline and the primary combustion air pipeline respectively. The gas and air are burned at the combustion nozzle to produce high-temperature gas to be saturated;

[0013] 1.2) Air is introduced into the combustion chamber through the secondary combustion air pipe. The air is heated by the high-temperature gas to be saturated and mixed with the high-temperature gas to be saturated for secondary combustion, and saturated high-temperature gas is formed through the secondary combustion.

[0014] It is further defined that the flue in step 2) is a corner flue;

[0015] The step 2) is specifically as follows:

[0016] The saturated high-temperature gas is discharged into the flue along the high-temperature gas outlet of the combustion chamber. In the flue, a part of the saturated high-temperature gas collides and swirls with the flue wall at the corner of the flue wall to form vortex flue gas. The vortex flue gas continuously collides and mixes with another part of the saturated high-temperature gas, and heat is conducted inside the saturated high-temperature gas. This cycle makes the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber uniform.

[0017] Further defined, the step 3) is specifically as follows:

[0018] 3.1) The saturated high-temperature gas in the high-temperature gas buffer chamber flows into the kiln chamber of the rotary kiln along the high-temperature gas drainage pipe. The outlet of the high-temperature gas drainage pipe is a flared structure. The high-temperature gas drainage pipe increases the diffusion area of ​​the saturated high-temperature gas, ensuring that the saturated high-temperature gas discharged from the high-temperature gas drainage pipe fully contacts the powdered hematite iron ore flowing in the opposite direction.

[0019] 3.2) The saturated high-temperature gas transfers heat to the powdered hematite ore and the reducing agent, causing the reducing agent to pyrolyze and release hydrogen at high temperature, generating saturated hydrogen in the kiln cavity of the rotary kiln. The saturated hydrogen penetrates and disperses into the powdered hematite ore layer, undergoing a hydrogen-based magnetic reduction reaction with the powdered hematite ore, thereby magnetizing the powdered hematite ore.

[0020] Further defined, the step 3) further comprises:

[0021] 3.3) Powdered hematite iron ore is pyrolyzed during magnetization to produce crystal water, which reacts with part of the reducing agent to produce hydrogen.

[0022] Further defined, the step 3) further comprises:

[0023] 3.4) The tail gas discharged from the kiln cavity of the rotary kiln is physically purified to form purified tail gas, which flows along the combustion-supporting gas pipeline into the combustion cavity, where it is heated and participates in combustion to form saturated high-temperature gas.

[0024] It is further defined that the weight ratio of the powdered hematite iron ore to the reducing agent is 100:3-5.

[0025] It is further defined that the reducing agent is coke particles.

[0026] It is further defined that the temperature of the saturated high-temperature gas in step 1) is 800°C to 950°C.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The hydrogen-based magnetization reduction process of hematite ore of the present invention uses countercurrent collision of saturated high-temperature gas with powdered hematite ore to transfer heat. The countercurrent collision heat transfer process causes the powdered hematite ore particles to gradually increase in temperature. As the iron ore continues to heat up, the temperature is continuously transferred from the surface of the iron ore particles to the core of the iron ore particles. This provides sufficient time for the temperature to transfer from the surface of the iron ore particles to the core of the iron ore particles, thereby avoiding the phenomenon of "ringing" in the rotary kiln caused by the instantaneous excessive temperature of the iron ore particle surface and the inability to transfer the temperature to the core of the iron ore particles in a timely manner. At the same time, it also prevents the local temperature in the iron ore material layer from being too high, thereby improving the roasting quality and recovery rate of the powdered hematite ore.

[0029] 2. The present invention heats the powdered hematite ore by burning coal gas after full contact with air to generate saturated high-temperature gas. The temperature of the saturated high-temperature gas formed by combustion can be controlled according to the calorific value of the coal gas after full combustion, which facilitates the temperature control of the saturated high-temperature gas and avoids the problem of "ringing" caused by excessively high local temperature of the saturated high-temperature gas and uneven heating temperature of the powdered hematite ore.

[0030] 3. In the present invention, a portion of the saturated high-temperature gas collides and swirls with the flue wall in the flue to form vortex flue gas. The vortex flue gas continuously collides and mixes with another portion of the saturated high-temperature gas, making the temperature inside the saturated high-temperature gas uniform. There is no temperature gradient inside the saturated high-temperature gas, further avoiding the local temperature of the saturated high-temperature gas being too high.

[0031] 4. The saturated high-temperature gas of the present invention not only transfers heat to the powdered hematite ore but also reacts with the reducing agent to produce saturated hydrogen. The saturated hydrogen penetrates into the powdered hematite ore layer and reacts with the powdered hematite ore to produce a magnetizing reduction reaction, thereby magnetizing the powdered hematite ore. Since hydrogen molecules are small, have strong penetrating power, and react quickly, the magnetizing effect of the powdered hematite ore is enhanced.

[0032] 5. In the present invention, a gas pipeline, a primary combustion-supporting air pipeline and a secondary combustion-supporting air pipeline are connected in the combustion chamber. The gas transported through the gas pipeline and the air transported through the primary combustion-supporting air pipeline are preliminarily burned to form a saturated high-temperature gas. The saturated high-temperature gas is mixed with the air transported through the secondary combustion-supporting air pipeline and burned to form a high-temperature gas. By adding air for the second time, it is ensured that the gas is fully burned and the calorific value is fully released.

[0033] 6. The flue of the present invention is a corner flue, which utilizes the corner portion of the corner flue to cause collision and reflux of the saturated high-temperature gas, thereby achieving better collision and reflux effects of the saturated high-temperature gas.

[0034] 7. The present invention sets the outlet of the high-temperature gas drainage pipe as a flared structure. The flared structure can increase the contact area between the saturated high-temperature gas discharged from the high-temperature gas drainage pipe and the powdered hematite iron ore and the reducing agent, thereby enhancing the heat transfer effect between the saturated high-temperature gas and the powdered hematite iron ore and the reducing agent.

[0035] 8. The tail gas discharged from the kiln cavity of the rotary kiln is physically purified to form purified tail gas. The purified tail gas flows along the combustion-supporting gas pipeline into the combustion chamber, is heated and participates in combustion to form saturated high-temperature gas, realizing the recycling of tail gas and achieving the purpose of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of the hydrogen-based magnetization reduction process for hematite iron ore of the present invention;

[0037] Figure 2 Schematic diagram of the structure of the hydrogen-based magnetization reduction device for hematite iron ore of the present invention;

[0038] Among them, 1-gas pipeline, 2-primary combustion-supporting air pipeline, 3-combustion-supporting nozzle, 4-combustion-supporting gas pipeline, 5-secondary combustion-supporting air pipeline, 6-high-temperature gas buffer chamber, 7-combustion chamber, 8-combustion gas nozzle, 9-high-temperature gas drainage pipe, 10-rotary kiln, 11-hematite ore reducing agent pipeline, 12-exhaust gas purification device. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further explained below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described below.

[0040] Example 1

[0041] See also Figure 1 The present embodiment provides a hydrogen-based magnetization reduction process for hematite ore, comprising the following steps:

[0042] 1) After the coal gas is burned, saturated high-temperature gas is generated. When the high-temperature gas is burned to a saturated state, the temperature of the saturated high-temperature gas formed by the combustion can be controlled according to the calorific value of the coal gas after full combustion, which facilitates the temperature control of the saturated high-temperature gas and avoids the local temperature of the saturated high-temperature gas from being too high;

[0043] 2) The saturated high-temperature gas is discharged into the flue along the high-temperature gas outlet of the combustion chamber 7. In the flue, a portion of the saturated high-temperature gas continuously collides with the flue wall and swirls, forming a vortex flue gas. The vortex flue gas continuously collides and mixes with another portion of the saturated high-temperature gas, and heat is conducted within the saturated high-temperature gas, making the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber 6 uniform, thereby avoiding excessively high local temperatures of the saturated high-temperature gas.

[0044] 3) The saturated high-temperature gas in the high-temperature gas buffer chamber 6 flows along the high-temperature gas drainage pipe 9 to the kiln chamber of the rotary kiln 10, and the saturated high-temperature gas collides with the powdered hematite iron ore and the reducing agent in the kiln chamber of the rotary kiln 10 in a countercurrent manner. The saturated high-temperature gas transfers heat to the powdered hematite iron ore and the reducing agent. The reducing agent pyrolyzes at high temperature to produce a large amount of reducing hydrogen. The reducing hydrogen penetrates into the powdered hematite iron ore layer and undergoes a hydrogen-based magnetization reduction reaction with the powdered hematite iron ore, thereby magnetizing the powdered hematite iron ore. The countercurrent collision heat transfer process causes the powdered hematite iron ore particles to gradually heat up, and in the process of continuous heating of the iron ore, the temperature is continuously transferred from the surface of the iron ore particles to the core of the iron ore particles, giving sufficient time for the temperature to be transferred from the surface of the iron ore particles to the core of the iron ore particles, thereby avoiding the surface temperature of the iron ore particles being too high when heat is transferred to the core, which causes the "ringing" phenomenon of the rotary kiln.

[0045] Specifically, the temperature of the saturated high-temperature gas in step 1) is 800°C to 950°C, and the temperature of the saturated high-temperature gas is ≥800°C and ≤950°C, specifically 800°C, 850°C, 900°C or 950°C.

[0046] The saturated high-temperature gas in this embodiment refers to the high-temperature gas formed after the coal gas is completely burned.

[0047] Example 2

[0048] The hydrogen-based magnetization reduction process for hematite ore in this embodiment is based on the embodiment 1, and step 1) is specifically as follows:

[0049] 1.1) Gas and air are introduced into the combustion nozzle 8 in the combustion chamber 7 through the gas pipe 1 and the primary combustion air pipe 2, respectively. The gas and air are burned at the combustion nozzle 8 to produce high-temperature gas to be saturated;

[0050] 1.2) Air is introduced into the combustion chamber 7 through the secondary combustion air pipe 5. The air is heated by the high-temperature gas to be saturated and mixed with the high-temperature gas to be saturated for secondary combustion, and saturated high-temperature gas is formed after the secondary combustion.

[0051] In this step, the saturated high-temperature gas is mixed with the air delivered by the secondary combustion air pipe 5 and burned to form high-temperature gas, ensuring that the coal gas is fully burned.

[0052] Example 3

[0053] A hydrogen-based magnetization reduction process for hematite iron ore in this embodiment is based on Example 1 or Example 2, wherein the flue in step 2) is a corner flue;

[0054] Step 2) is specifically as follows:

[0055] The saturated high-temperature gas is discharged into the flue along the high-temperature gas outlet of the combustion chamber 7. In the flue, a part of the saturated high-temperature gas collides and swirls with the flue wall at the corner of the flue wall to form vortex flue gas. The vortex flue gas continuously collides and mixes with another part of the saturated high-temperature gas, and heat is conducted inside the saturated high-temperature gas. This cycle makes the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber 6 uniform.

[0056] In this step, the flue is set as a corner flue, so that the collision and backflow effect of the saturated high-temperature gas and the flue wall are better.

[0057] Example 4

[0058] A hydrogen-based magnetization reduction process for hematite ore of this embodiment, based on embodiment 1, embodiment 2 or embodiment 3, further includes step 3):

[0059] Step 3) is specifically as follows:

[0060] 3.1) The saturated high-temperature gas in the high-temperature gas buffer chamber 6 flows along the high-temperature gas drainage pipe 9 into the kiln chamber of the rotary kiln 10. The outlet of the high-temperature gas drainage pipe 9 is a flared structure. The high-temperature gas drainage pipe 9 increases the diffusion area of ​​the saturated high-temperature gas, thereby increasing the contact area between the saturated high-temperature gas, the powdered hematite iron ore, and the reducing agent, ensuring that the saturated high-temperature gas discharged from the high-temperature gas drainage pipe 9 is in full contact with the counterflowing powdered hematite iron ore.

[0061] 3.2) The saturated high-temperature gas transfers heat to the powdered hematite ore and the reducing agent, causing the reducing agent to be pyrolyzed at high temperature to release hydrogen, generating saturated hydrogen in the kiln cavity of the rotary kiln 10. The saturated hydrogen penetrates and disperses into the powdered hematite ore layer, undergoing a hydrogen-based magnetic reduction reaction with the powdered hematite ore, thereby magnetizing the powdered hematite ore.

[0062] 3.3) Powdered hematite iron ore is pyrolyzed during the magnetization process to produce crystal water, which reacts with part of the reducing agent to produce hydrogen, further increasing the hydrogen saturation.

[0063] 3.4) The exhaust gas discharged from the kiln cavity of the rotary kiln 10 undergoes physical purification to form purified exhaust gas. The purified exhaust gas flows along the combustion-supporting gas pipe 4 into the combustion chamber 7, where it is heated and participates in combustion to form saturated high-temperature gas. This achieves exhaust gas purification and recovery, achieving the goal of energy conservation and emission reduction.

[0064] Preferably, the reducing agent in this embodiment is coke particles.

[0065] The weight ratio of the powdered hematite ore to the reducing agent is 100:3-5. Specifically, 1 kg of the powdered hematite ore corresponds to 0.03 kg, 0.04 kg, or 0.05 kg of the reducing agent.

[0066] The reducing agent and the powdered hematite iron ore are heated together in the kiln cavity of the rotary kiln 10 .

[0067] The hydrogen-based magnetization reduction reaction in the present invention refers to a reduction reaction between powdered hematite ore and saturated hydrogen gas to reduce the hematite ore to iron.

[0068] The powdered hematite iron ore and the reducing agent in the present application are moved toward the saturated high-pressure gas under the rotation of the rotary kiln 10 .

[0069] It should be noted that the corner flue in the present invention means that the outlet of the high-temperature gas on the combustion chamber 7 and the inlet of the high-temperature gas on the high-temperature gas buffer chamber 6 are not on the same straight line, and the central axes of the two form an angle. Preferably, the angle between the central axis corresponding to the outlet of the high-temperature gas on the combustion chamber 7 of this embodiment and the central axis corresponding to the inlet of the high-temperature gas on the high-temperature gas buffer chamber 6 is 90°.

[0070] See also Figure 2 , which is a hematite iron ore hydrogen-based magnetization reduction process used in the present invention, comprises a combustion chamber 7 and a gas pipeline 1, a primary combustion air pipeline 2, a combustion gas pipeline 4 and a secondary combustion air pipeline 5 all connected to the combustion chamber 7. Specifically, a combustion nozzle 3 and a combustion gas nozzle 8 are provided in the combustion chamber 7, wherein the gas pipeline 1 and the primary combustion air pipeline 2 are both connected to the combustion gas nozzle 8, and the gas and air transported by the gas pipeline 1 and the primary combustion air pipeline 2 are transported to the combustion chamber 7. Combustion occurs at the gas nozzle 8 to produce high-temperature gas to be saturated; the secondary combustion-supporting air pipe 5 is connected to the kiln cavity of the combustion chamber 7, and the secondary combustion-supporting air pipe 5 is used to introduce air into the kiln cavity of the combustion chamber 7, and the air is mixed with the high-temperature gas to be saturated and burns to form saturated high-temperature gas; the combustion-supporting gas pipe 4 is connected to the combustion-supporting nozzle 3, and the combustion-supporting gas pipe 4 is used to introduce purified exhaust gas into the combustion chamber 7, and the purified exhaust gas is used for combustion and combustion to form saturated high-temperature gas again, which is used to heat powdered hematite iron ore and pyrolysis reducing agent.

[0071] The combustion chamber 7 is connected to the high-temperature gas buffer chamber 6 through the flue. Preferably, the high-temperature gas buffer chamber 6 is arranged above the gas outlet of the combustion chamber 7, which is conducive to more complete collision and swirl of the saturated high-temperature gas with the flue wall during the upward flow.

[0072] The high-temperature gas buffer chamber 6 is connected to the kiln chamber of the rotary kiln 10 through the high-temperature gas drainage pipe 9. The saturated high-temperature gas is buffered and stored in the high-temperature gas buffer chamber 6, and then transmitted to the kiln chamber of the rotary kiln 10 through the high-temperature gas drainage pipe 9. The outlet of the high-temperature gas drainage pipe 9 is a flared structure, which can enable the saturated high-temperature gas discharged from the high-temperature gas drainage pipe 9 to have more sufficient contact and heat exchange with the powdered hematite iron ore.

[0073] A hematite ore reducing agent pipeline 11 is provided on the rotary kiln 10 , and the hematite ore reducing agent pipeline 11 is connected to the feed port of the rotary kiln 10 . The powdered hematite ore layer and the reducing agent enter the kiln cavity of the rotary kiln 10 together along the hematite ore reducing agent pipeline 11 .

[0074] The rotary kiln 10 of the present invention is also connected to an exhaust gas purification device 12, which is connected to the combustion-supporting gas pipeline 4. The exhaust gas purification device 12 is used to continue to pass the gas discharged from the rotary kiln 10 through the combustion-supporting gas pipeline 4 into the combustion chamber 7 for heating, so that the carbon monoxide and hydrogen in the gas discharged from the rotary kiln 10 continue to participate in the magnetization process of the powdered hematite iron ore as reducing gases, thereby achieving the purpose of energy conservation and emission reduction.

Claims

1. A hydrogen-based magnetization reduction process for hematite ore, characterized in that: The following steps are involved: 1) After the gas is burned, saturated high-temperature gas is produced; 2) The saturated high-temperature gas is discharged into the flue along the combustion chamber (7), and a portion of the saturated high-temperature gas continuously collides with the flue wall and swirls in the flue to form vortex flue gas. The vortex flue gas continuously collides with and mixes with another portion of the saturated high-temperature gas, and heat is conducted inside the saturated high-temperature gas, so that the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber (6) is uniform; 3) The saturated high-temperature gas in the high-temperature gas buffer chamber (6) flows along the high-temperature gas drainage pipe (9) into the kiln chamber of the rotary kiln (10). In the kiln chamber of the rotary kiln (10), the saturated high-temperature gas countercurrently collides with the powdered hematite iron ore and the reducing agent. The saturated high-temperature gas transfers heat to the powdered hematite iron ore and the reducing agent. The reducing agent is pyrolyzed at high temperature to produce a large amount of reducing hydrogen. The reducing hydrogen penetrates into the powdered hematite iron ore layer and undergoes a hydrogen-based magnetic reduction reaction with the powdered hematite iron ore, thereby magnetizing the powdered hematite iron ore.

2. The hematite ore hydrogen-based magnetization reduction process according to claim 1, wherein: The step 1) is specifically as follows: 1.1) Gas and air are introduced into the combustion nozzle (8) in the combustion chamber (7) through the gas pipeline (1) and the primary combustion air pipeline (2), respectively. The gas and air are burned at the combustion nozzle (8) to generate high-temperature gas to be saturated; 1.2) Air is introduced into the combustion chamber (7) through the secondary combustion air pipe (5). The air is heated by the high-temperature gas to be saturated and mixed with the high-temperature gas to be saturated to perform secondary combustion, and saturated high-temperature gas is formed after the secondary combustion.

3. The hematite ore hydrogen-based magnetization reduction process according to claim 1, wherein: The flue in step 2) is a corner flue; The step 2) is specifically as follows: The saturated high-temperature gas is discharged into the flue along the high-temperature gas outlet of the combustion chamber (7). In the flue, a portion of the saturated high-temperature gas collides with and swirls against the flue wall at the corner of the flue wall, forming vortex flue gas. The vortex flue gas continuously collides with and mixes with another portion of the saturated high-temperature gas, and heat is conducted inside the saturated high-temperature gas. This cycle makes the temperature of the saturated high-temperature gas entering the high-temperature gas buffer chamber (6) uniform.

4. The hematite ore hydrogen-based magnetization reduction process according to claim 1, wherein: The step 3) is specifically as follows: 3.1) The saturated high-temperature gas in the high-temperature gas buffer chamber (6) flows along the high-temperature gas drainage pipe (9) into the kiln chamber of the rotary kiln (10). The outlet of the high-temperature gas drainage pipe (9) is a flared structure. The high-temperature gas drainage pipe (9) increases the diffusion area of ​​the saturated high-temperature gas, ensuring that the saturated high-temperature gas discharged from the high-temperature gas drainage pipe (9) is in full contact with the powdered hematite iron ore flowing in the opposite direction. 3.2) The saturated high-temperature gas transfers heat to the powdered hematite ore and the reducing agent, causing the reducing agent to be pyrolyzed at high temperature to release hydrogen, generating saturated hydrogen in the kiln cavity of the rotary kiln (10). The saturated hydrogen penetrates and disperses into the powdered hematite ore layer to react with the powdered hematite ore to produce a hydrogen-based magnetic reduction reaction, thereby magnetizing the powdered hematite ore.

5. The hydrogen-based magnetization reduction process for hematite ore according to claim 4, characterized in that: The step 3) further comprises: 3.3) Powdered hematite iron ore is pyrolyzed during magnetization to produce crystal water, which reacts with part of the reducing agent to produce hydrogen.

6. The hydrogen-based magnetization reduction process for hematite iron ore according to claim 5, characterized in that: The step 3) further comprises: 3.4) The tail gas discharged from the kiln cavity of the rotary kiln (10) is physically purified to form purified tail gas, which flows along the combustion-supporting gas pipe (4) into the combustion cavity (7), where it is heated and participates in combustion to form saturated high-temperature gas.

7. The hydrogen-based magnetization reduction process for hematite iron ore according to claim 4, characterized in that: The weight ratio of the powdered hematite ore to the reducing agent is 100:3-5.

8. The hydrogen-based magnetization reduction process for hematite iron ore according to claim 4, wherein: The reducing agent is coke particles.

9. The hydrogen-based magnetization reduction process for hematite ore according to claim 1, wherein: The temperature of the saturated high-temperature gas in step 1) is 800°C to 950°C.

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