A fluidized bed reaction system and method for phase transformation of refractory iron ore.

Abstract

This invention relates to the field of mineral processing engineering technology, and in particular to a fluidized bed reaction system and method for phase transformation of refractory iron ore. The apparatus includes a feeding system, a spiral plate type multi-chamber fluidized bed reactor, and a gas supply system. The spiral plate type multi-chamber fluidized bed reactor includes a reaction chamber and a gas supply chamber. Several spiral baffles and plate baffles of the same height as the reactor wall are installed in the reaction chamber to divide the shell side of the reactor, prolonging the residence time of the bulk material in the reactor, which is conducive to the complete physicochemical reaction and can also effectively reduce the back mixing phenomenon of bulk material in the reactor. The geometric structure of the spiral plate simplifies the contact between the bulk material and the reactor wall, which is conducive to the complete diffusion of gas in the internal space and reduces the fluidization dead zone. Four baffles are installed in the gas supply chamber to divide the gas supply chamber into five unit gas supply chambers, fluidizing the bed material in different areas and reducing the occurrence of gas short-circuiting.

Description

Technical Field

[0001] This invention relates to the field of mineral processing engineering technology, and in particular to a fluidized bed reaction system and method for the ore phase transformation of refractory iron ore. Background Technology

[0002] Fluidization technology can effectively improve the contact and transfer behavior between fluids and particles, and significantly improve the material and energy utilization rate and production efficiency of heterogeneous processes. As the medium for realizing fluidization technology, fluidized bed reactors are often used for the efficient utilization of complex and difficult-to-process iron ore resources.

[0003] Traditional single-chamber fluidized bed reactors suffer from limited reaction space, insufficient residence time of bulk materials within the reactor, making complete reaction difficult. Furthermore, severe particle backmixing occurs within the single chamber, resulting in uneven and inadequate utilization of matter and energy. Chinese utility model patent with authorization announcement number CN208487882U and authorization announcement date of February 12, 2019, discloses a horizontal multi-chamber fluidized bed reactor. This type of fluidized bed reactor uses baffles to separate the shell side of a single-chamber reactor, resulting in a multi-chamber reactor with several reaction chambers. The residence time of the bulk material in the multi-chamber reactor is extended, the backmixing phenomenon is reduced, and the conditions for physicochemical reaction are strengthened. However, there are some three-dimensional corners in this type of multi-chamber reactor. The bulk material is subjected to three-dimensional forces at these corners, resulting in greater gas diffusion resistance and bed resistance, which eventually forms a fluidization dead zone. The existence of the fluidization dead zone will, on the one hand, deteriorate the bed fluidization, limit heat and mass transfer, and reduce the reaction efficiency. On the other hand, the mass and heat transfer in the fluidization dead zone is not timely, and coking is easily formed at this location, reducing the utilization rate of the internal space of the chamber. On the other hand, in traditional fluidized bed reactors, when gas enters the reaction chamber from the gas supply chamber through the air distribution plate, it is very sensitive to the bed resistance, which can easily cause gas short-circuiting. That is, gas can easily flow out from the position with less bed resistance, which deteriorates the fluidization phenomenon. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a fluidized bed reaction system for phase transformation of refractory iron ore, including a feeding system, a spiral plate type multi-chamber fluidized bed reactor 18, and an air supply system. The feeding system includes a hopper 1, a spiral feeder 2, and a computer 3. The hopper 1 is connected to the spiral feeder 2, and the spiral feeder 2 is connected to the top of the spiral plate type multi-chamber fluidized bed reactor 18. The computer 3 controls the motor speed of the spiral feeder 2 to achieve quantitative feeding of the feeding system. The air supply system is connected to the lower part of the fluidized bed reactor 18 to provide airflow.

[0005] The spiral plate type multi-chamber fluidized bed reactor 18 includes a reaction chamber 5 and a gas supply chamber 7. The reaction chamber 5 is a cylindrical shape with an open bottom, and its bottom is fixedly connected to the gas supply chamber 7. A feed inlet 4 connected to a spiral feeder 2 is provided at the center of the top wall, and the feed inlet 4 connects the inside and outside of the reaction chamber 5. A discharge outlet 8 is provided at the lower part of the side wall, and the discharge outlet 8 connects the inside and outside of the reaction chamber 5. Several spiral baffles 6 of the same height as the reactor wall are provided in the reaction chamber 5. The spiral baffles 6 radiate spirally towards the reactor wall with the center of the reaction chamber 5 as the center, dividing the shell side of the reaction chamber 5 into several spiral strip channels. The strip channels connect the feed inlet 4 and the discharge outlet 8, and the position of the spiral center corresponds to the position of the feed inlet 4.

[0006] The present invention also includes a receiving hopper 15, through which the reduced product after the reaction is completed enters the receiving hopper 15 via the discharge port 8 to achieve product collection.

[0007] The reaction chamber 5 is also equipped with four plate-shaped baffles 16 evenly arranged. The plate-shaped baffles 16 are perpendicular to the strip-shaped channel, and the height of the plate-shaped baffles 16 is 1 / 2 of the height of the vessel wall.

[0008] Two adjacent plate-shaped baffles 16 are arranged alternately at different heights along the spiral channel path. The upper edge of the plate-shaped baffle 16 at the higher position is flush with the top of the reaction chamber 5, and the lower edge of the plate-shaped baffle 16 at the lower position is flush with the bottom of the reaction chamber 5.

[0009] The air supply chamber 7 is a closed cylindrical shape with the same radius as the reaction chamber 5. The top is an air distribution plate 17 with several air holes. The air holes of the air distribution plate 17 are evenly arranged. The air distribution plate 17 is fixedly connected to the bottom of the reaction chamber 5. An air inlet 9 is provided at the bottom. The air supply chamber 7 is connected to the air supply system through the air inlet 9.

[0010] The air supply chamber 7 is provided with four partitions 20, which divide the air supply chamber 7 into unit air supply chamber one 21, unit air supply chamber two 22, unit air supply chamber three 23, unit air supply chamber four 24, and unit air supply chamber five 25.

[0011] Three partitions 20 form an equilateral triangle inscribed in the side wall of the air supply chamber 7. The three sides of the triangle form unit air supply chamber 1 21, unit air supply chamber 22, and unit air supply chamber 3 23 respectively. A partition 20 is set on the altitude of the isosceles triangle, dividing the isosceles triangle into unit air supply chamber 4 24 and unit air supply chamber 5 25.

[0012] Each of the three air supply chambers 21, 22, and 3 has an air inlet 9 on its side wall, and each of the three air supply chambers 24 and 5 has an air inlet 9 at its bottom, for a total of five air inlets 9.

[0013] The gas supply system includes a gas storage tank 10, a gas supply pipeline 11, and a flow meter 12. The gas storage tank 10 is connected to the gas supply pipeline 11. Compressed gas in the gas storage tank 10 can be blown into the gas supply chamber 7 through the gas supply pipeline 11 and the air inlet 9. The gas supply chamber 7 blows the airflow into the reaction chamber 5 through the air distribution plate 17. The flow meter 12 is installed on the gas supply pipeline 11 and electrically connected to the computer 3 to detect the air flow rate of the five air inlets 9.

[0014] The present invention also includes a temperature control system, which includes a temperature control cabinet 14 disposed outside the reaction chamber 5 and three heating plates 13 evenly arranged on the inner side of the wall of the reaction chamber 5, and three temperature sensors 19 evenly arranged on the inner side of the wall of the reaction chamber 5; the temperature control cabinet 14 is electrically connected to the heating plates 13 and the temperature sensors 19 for real-time monitoring and control of the temperature inside the reaction chamber 5.

[0015] The present invention also provides a fluidization method for the morphological transformation of refractory iron ore, implemented using the apparatus of the present invention, comprising the following steps:

[0016] Step 1: Place the iron ore bulk material crushed to -0.8mm with a content of more than 90% in the silo 1. The feeding rate of the screw feeder 2 is controlled by the computer 3 to achieve quantitative feeding by the screw feeder 2. The bulk material enters the reaction chamber 5 of the spiral plate fluidized bed reactor through the feed inlet 4.

[0017] Step 2: The air storage tank 10 supplies air to the air supply chamber 7 through the air supply pipe 11, and adjusts the flow rate of the unit air supply chamber 1 21, unit air supply chamber 22, unit air supply chamber 3 23, unit air supply chamber 4 24, and unit air supply chamber 5 25 in sequence to promote the fluidization of the bulk material in different areas and make it flow continuously until it is finally discharged, thus achieving material sealing.

[0018] Step 3: After the material sealing is completed, the feeding system starts to feed the preheated iron ore bulk material. The heating plate 13 and temperature sensor 19 of the reactor are activated at the same time to monitor and control the temperature in the reaction chamber 5 in real time, so that the temperature in the chamber is maintained at 450℃~500℃. At the same time, the gas supply system feeds in reducing gas. The iron ore bulk material is fluidized in the reaction chamber 5 and flows along the strip channel formed by the spiral baffle 6 and is discharged from the outlet 8. During this process, the reduction reaction is completed under fluidization.

[0019] Step 4: The reduced iron ore bulk material finally leaves the reaction chamber 5 through the discharge port 8 and enters the receiving hopper 15, and is sent to the next process.

[0020] Effects of the invention:

[0021] 1. This invention divides the shell side of the reactor in different ways, which prolongs the residence time of the bulk material in the reactor, which is conducive to the complete physicochemical reaction. At the same time, the shell side division can effectively reduce the back mixing phenomenon of bulk material in the reactor, reduce the residence time distribution of bulk material, and finally produce a uniform and good product quality.

[0022] 2. Based on the shell-side segmentation, this invention adopts a spiral plate-type geometric structure, which can effectively simplify the contact between the bulk material and the vessel wall, facilitate the complete diffusion of gas in the vessel space, reduce the fluidization dead zone, improve the material and energy utilization rate, improve the internal space utilization rate of the chamber, and provide good mass and heat transfer performance. The mineral phase transformation process from weakly magnetic minerals to strongly magnetic minerals in iron ore can be completed rapidly.

[0023] 3. The present invention divides the gas supply chamber of the reactor, which limits the space for gas movement and allows for the fluidization of the bed material in different areas, thereby reducing the occurrence of gas short-circuiting. Attached Figure Description

[0024] Figure 1 A schematic diagram of a fluidized bed reaction system for phase transformation of refractory iron ore;

[0025] Figure 2 Schematic diagram of a spiral plate fluidized bed reactor;

[0026] Figure 3 Top view of a spiral plate fluidized bed reactor;

[0027] Figure 4 External schematic diagram of the air supply chamber;

[0028] Figure 5 Schematic diagram of the interior of the air supply chamber.

[0029] 1. Hopper; 2. Screw feeder; 3. Computer; 4. Inlet; 5. Reaction chamber; 6. Spiral baffle; 7. Gas supply chamber; 8. Outlet; 9. Inlet; 10. Gas storage tank; 11. Gas supply pipeline; 12. Flow meter; 13. Heating plate; 14. Temperature control cabinet; 15. Receiving hopper; 16. Plate baffle; 17. Air distribution plate; 18. Spiral plate type multi-chamber fluidized bed reactor; 19. Temperature sensor; 20. Baffle; 21. Unit gas supply chamber one; 22. Unit gas supply chamber two; 23. Unit gas supply chamber three; 24. Unit gas supply chamber four; 25. Unit gas supply chamber five. Detailed Implementation

[0030] The technical solution implemented in this patent is clearly and completely described in conjunction with the accompanying drawings.

[0031] See Figure 1The present invention provides a fluidized bed reaction system for the phase transformation of refractory iron ore, including a feeding system, a spiral plate type multi-chamber fluidized bed reactor 18, a gas supply system, a temperature control system, and a receiving hopper 15.

[0032] The feeding system adopts existing technology and includes a silo 1, a screw feeder 2 and a computer 3. The silo 1 is connected to the screw feeder 2, and the screw feeder 2 is connected to the inlet 4 of the spiral plate type multi-chamber fluidized bed reactor 18. The computer 3 controls the motor speed of the screw feeder 2 to realize the quantitative feeding of the feeding system.

[0033] See Figure 2 , Figure 3 The spiral plate type multi-chamber fluidized bed reactor 18 includes a feed inlet 4, a reaction chamber 5, a spiral baffle 6, an air supply chamber 7, a discharge outlet 8, and a plate baffle 16.

[0034] The reaction chamber 5 is a cylindrical shape with an opening at the bottom. A feed inlet 4 is provided at the center of the top wall, which connects the inside and outside of the reaction chamber 5 and is connected to the screw feeder 2. A discharge outlet 8 is provided at the bottom of the side wall, which connects the inside and outside of the reaction chamber 5. The wall of the reaction chamber 5 is curved, which can optimize the contact between the bulk material and the wall and make the gas diffuse evenly in the reaction chamber 5.

[0035] Several spiral baffles 6, at the same height as the vessel wall, are installed inside the reaction chamber 5. These spiral baffles radiate outwards from the center of the reaction chamber 5, dividing the shell side of the chamber into several spiral channel-like sections. The center of the spiral corresponds to the inlet 4, and the channel-like sections connect the inlet 4 and the outlet 8. Four plate-shaped baffles 16 are also evenly arranged inside the reaction chamber 5. These baffles 16 are perpendicular to the channel-like sections, and their height is half the height of the vessel wall. Adjacent plate-shaped baffles 16 are arranged at alternating heights along the spiral channel path. The upper edge of the higher baffle 16 is flush with the top of the reaction chamber 5, while the lower baffle 16... The lower edge of the baffle plate 16 is flush with the bottom of the reaction chamber 5. The baffle plate 16 further divides the shell side of the reaction chamber 5, extending the movement path and residence time of the bulk material in the reaction chamber 5. In addition, when the bulk material flows in the spiral channel, there is less axial mixing in the flow direction, while complete mixing is achieved in the radial direction. This flow pattern can reduce the back mixing phenomenon of bulk material in the reaction chamber 5. The curved structure of the sidewall of the spiral channel makes the bulk material subjected to two-dimensional force, which can uniformly distribute the air resistance at various positions, reduce the fluidization dead zone in the reaction chamber 5, and improve the material and energy utilization rate and the internal space utilization rate of the fluidization process.

[0036] See Figure 4 , Figure 5The air supply chamber 7 is a closed cylindrical shape with the same radius as the reaction chamber 5. The top is a distribution plate 17 with several air holes. The air holes on the distribution plate 17 are evenly arranged to ensure uniform air distribution and good fluidization conditions. The distribution plate 17 is fixedly connected to the bottom of the reaction chamber 5. As shown in the figure, four partitions 20 are installed inside the air supply chamber 7, dividing it into unit air supply chamber 1 21, unit air supply chamber 22, unit air supply chamber 3 23, unit air supply chamber 4 24, and unit air supply chamber 5 25. Three of the partitions 20 form an equilateral triangle inscribed in the sidewall of the air supply chamber 7, with the three sides of the triangle forming a unit air supply chamber. Unit air supply chambers 1-21, 22, and 3-23 are divided into unit air supply chambers 4-25 by a partition 20 located on the altitude of an isosceles triangle. Each of the unit air supply chambers 1-23 has an air inlet 9 on its side wall, and each of the unit air supply chambers 4-24 and 5-25 has an air inlet 9 at its bottom, for a total of five air inlets 9. The air inlets 9 are connected to the air supply system. The air flow rate of the five air inlets 9 is detected by a flow meter 12, and the detected signal is sent to a computer 3. The computer 3 or a person can adjust the flow rate of each air inlet 9 individually. When gas enters the reaction chamber 5 from the gas supply chamber 7 through the air distribution plate 17, it is very sensitive to the bed resistance. The gas is very likely to flow out from the position with less bed resistance, causing gas short circuit and deteriorating the fluidization phenomenon. After dividing the gas supply chamber 7 into five unit gas supply chambers, the space for gas movement is limited, and the bed material can be fluidized in different areas to reduce the occurrence of gas short circuit.

[0037] See Figure 1 The gas supply system includes a gas storage tank 10, a gas supply pipeline 11, and a flow meter 12. The gas storage tank 10 is connected to the gas supply pipeline 11. During operation, the compressed gas in the gas storage tank 10 is blown into the gas supply chamber 7 through the gas supply pipeline 11 and the air inlet 9. The gas supply chamber 7 blows the airflow into the reaction chamber 5 through the air distribution plate 17, causing the bulk material to flow outward along the spiral strip channel and finally be discharged through the discharge port 8.

[0038] See Figure 1 The temperature control system includes a temperature control cabinet 14 located outside the reaction chamber 5 and three heating plates 13 evenly arranged on the inner side of the reaction chamber 5 wall. It also includes three temperature sensors 19 arranged on the inner side of the reaction chamber 5 wall. The temperature control cabinet 14 is electrically connected to the heating plates 13 and the temperature sensors 19 to monitor and control the temperature inside the reaction chamber 5 in real time.

[0039] The reduced product after the reaction is complete enters the receiving hopper 15 through the discharge port 8 to achieve product collection.

[0040] A fluidization method for facies transformation of refractory iron ore includes the following steps:

[0041] Step 1: Place the iron ore bulk material crushed to -0.8mm with a content of more than 90% in the silo 1. The feeding rate of the screw feeder 2 is controlled by the computer 3 to achieve quantitative feeding by the screw feeder 2. The bulk material enters the reaction chamber 5 of the spiral plate fluidized bed reactor through the feed port 4.

[0042] Step 2: The air storage tank 10 supplies air to the air supply chamber 7 through the air supply pipe 11, and adjusts the flow rate of the unit air supply chamber 1 21, unit air supply chamber 22, unit air supply chamber 3 23, unit air supply chamber 4 24 and unit air supply chamber 5 25 in sequence to promote the fluidization of the bulk material in different areas and make it flow continuously until it is finally discharged, thus achieving material sealing.

[0043] Step 3: After the material sealing is completed, the feeding system begins to feed in the preheated iron ore bulk material. The heating plate 13 and temperature sensor 19 of the reactor are activated simultaneously to monitor and control the temperature in the reaction chamber 5 in real time, maintaining the temperature in the chamber at 450℃~500℃. At the same time, the gas supply system supplies reducing gas. The iron ore bulk material is fluidized in the reaction chamber 5 and flows along the strip-shaped channel formed by the spiral baffle 6, and is discharged from the outlet 8. During this process, the reduction reaction is completed under fluidization, and the weakly magnetic minerals in the ore are transformed into strongly magnetic minerals. The spiral baffle 6 and the plate baffle 16 separate the shell side of the reaction chamber 5, which prolongs the residence time of the bulk material in the reaction chamber 5, promotes the contact between the reducing gas and the iron ore, and improves the technical indicators of the final product. At the same time, the geometric structure of the spiral baffle 6 optimizes the contact between the bulk material and the reactor wall, facilitates gas diffusion, reduces the fluidization dead zone in the reactor, and improves the utilization rate of materials and energy as well as the utilization rate of chamber space.

[0044] Step 4: The reduced iron ore bulk material finally leaves the reaction chamber 5 through the discharge port 8 and enters the receiving hopper 15, and is sent to the next process.

[0045] Example 1

[0046] The iron ore used in this embodiment comes from a beneficiation plant of Maanshan Iron and Steel Group. The chemical composition analysis results of the ore are shown in Table 1, and the iron phase analysis results are shown in Table 2.

[0047] Table 1. Chemical composition analysis results of the ore / %

[0048]

[0049] Table 2. Iron phase analysis results / %

[0050]

[0051] Table 1 shows that the main valuable element in the sample is iron, with a TFe content of 37.68%; the main impurities are SiO2 and Al2O3, with contents of 31.44% and 5.00%, respectively; the harmful element P has a relatively high content of 0.72%. Table 2 analysis shows that iron mainly exists in the form of hematite, with a content of 36.35% and an iron distribution rate of 96.48%.

[0052] The iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion, with a feed rate of 80 kg / h. Air was introduced into the gas storage tank 10, and the flow rates of unit gas supply chambers 1-21, 22, 3-23, 4-24, and 5-25 were 3 m³ / h and 3 m³ / h, respectively. 3 / h、3m 3 / h、3m 3 / h、2m 3 / h、2m 3 / h, causing the bulk material to flow outward along the spiral channel and finally be discharged through the outlet 8, achieving material sealing; after material sealing, the gas storage tank 10 is adjusted to supply a reducing atmosphere, with the flow rate of each gas supply chamber 7 being the same as above, wherein the composition of the reducing atmosphere is N2:CO:H2=3:1:2; the reducing gas reacts with the iron ore at a temperature of 500℃; after continuous discharge for 15 minutes, the screw feeder 2 is turned off, and the product in the docking hopper 15 is dried, weighed, and sampled, and The material was ground to a fineness of -0.038 mm (70%), and magnetic separation tests were conducted using a magnetic separator under a magnetic field strength of 85 kA / m. The test results are shown in Table 3. It can be seen that with a TFe grade of 37.65% in the raw ore, a feed fineness of -0.8 mm (93%), and a feed rate of 80 kg / h, the flow rates of unit air supply chambers 1-21, 22, 3-23, 4-24, and 5-25 were 3 m³ / h, respectively. 3 / h、3m 3 / h、3m 3 / h、2m 3 / h、2m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 59.86% and a recovery rate of 97.15% can be obtained.

[0053] Under traditional technology, the ore from this region can only achieve a production target of 57% iron grade in concentrate and 75% iron recovery rate.

[0054] Table 3. Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case 1)

[0055]

[0056] Example 2

[0057] The iron ore used in this experiment came from a beneficiation plant of Maanshan Iron and Steel Group. The chemical composition and material composition of the ore were the same as in Example 1.

[0058] The aforementioned iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion, with a feed rate of 80 kg / h. The flow rates of unit gas supply chambers 1-21, 22-23, 3-24, 4-25 were 2.5 m³ / h and 2.5 m³ / h, respectively. 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to supply a reducing atmosphere, wherein the composition of the reducing atmosphere is N2:CO:H2=3:1:2; the hydrogen-rich gas and iron ore undergo a reduction reaction at a reduction temperature of 500℃; after continuous discharge for 15min, the screw feeder 2 is turned off, the product in the reduction product quenching tank is dried, weighed, sampled, and ground to -0.038mm accounting for 70%, and a magnetic separation test is carried out under a magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 37.65%, the feed fineness is -0.8mm accounting for 93%, the feed rate is 80kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2.5m 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 60.95% and a recovery rate of 92.05% can be obtained.

[0059] Table 4. Results of the sorting test for hydrogen-based mineral phase conversion products / % (Case 2)

[0060]

[0061] Example 3

[0062] The iron ore used in this experiment came from a beneficiation plant of Maanshan Iron and Steel Group. The chemical and material composition of the ore was the same as in Example 1.

[0063] The iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion. The feed rate was set at 80 kg / h. The flow rates of unit gas supply chambers 1-21, 22, 3-23, 4-24, and 5-25 were 2 m³ / h. 3 / h、2m 3 / h、2m 3 / h, 1.5m 3 / h, 1.5m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to feed the reducing atmosphere, and the flow rate of each gas supply chamber 7 is the same as above, wherein the composition of the reducing atmosphere is N2:CO:H2=3:1:2; the hydrogen-rich gas and iron ore undergo a reduction reaction at a reduction temperature of 500℃; after continuous discharge for 15min, the screw feeder 2 is closed, the product in the reduction product quenching tank is dried, weighed, sampled, and ground to -0.038mm accounting for 70%, and a magnetic separation test is carried out under the condition of magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 37.65%, the feed fineness is -0.8mm accounting for 93%, and the feed rate is 80kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2m 3 / h、2m 3 / h、2m 3 / h, 1.5m 3 / h, 1.5m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 60.95% and a recovery rate of 92.10% can be obtained.

[0064] Table 5. Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case Study 3)

[0065]

[0066] Example 4

[0067] The iron ore used in this experiment came from a foreign ore processing plant. The chemical composition analysis results of the ore are shown in Table 6, and the iron phase analysis results are shown in Table 7.

[0068] Table 6. Chemical composition analysis results of the ore / %

[0069]

[0070] Table 7. Iron phase analysis results / %

[0071]

[0072]

[0073] Table 6 shows that the element with recovery value in the ore is iron, with a content of 45.45%. The FeO content is very low, only 0.14%, suggesting that the main iron mineral is hematite. The contents of SiO2 and Al2O3 are 13.44% and 5.80%, respectively. Analysis of Table 7 shows that the iron-bearing mineral in the ore is hematite (or goethite), with a distribution rate of 99.10%.

[0074] The aforementioned iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion, with a feed rate of 80 kg / h. The flow rates of unit gas supply chambers 1-21, 22-23, 3-24, 4-25 were 2.5 m³ / h and 2.5 m³ / h, respectively. 3 / h, 2.5m 3 / h, 2.5m 3 / h, 1.5m 3 / h, 1.5m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to supply reducing atmosphere, the flow rate of each gas supply chamber 7 is the same as above, the composition of the reducing atmosphere is N2:CO:H2=3:1:2; hydrogen-rich gas and iron ore undergo reduction reaction at a reduction temperature of 500℃; after continuous discharge for 15min, close the screw feeder 2, dry, weigh, and sample the product in the reduction product quenching tank, and grind it to -0.038mm accounting for 70%, and conduct magnetic separation test under the condition of magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 45.45%, the feed fineness is -0.8mm accounting for 93%, and the feed rate is 80kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2.5m 3 / h, 2.5m 3 / h, 2.5m 3 / h, 1.5m 3 / h, 1.5m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 62.11% and a recovery rate of 81.25% can be obtained.

[0075] Under traditional technology, the ore from this region can only achieve a production target of 53% iron grade in concentrate and 72% iron recovery rate.

[0076] Table 8. Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case Study 4)

[0077]

[0078] Example 5

[0079] The iron ore used in this experiment came from a foreign ore processing plant, and its chemical and material composition was the same as in Case 4.

[0080] The aforementioned iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion, with a feed rate of 100 kg / h. The flow rates of unit gas supply chambers 1-21, 22-23, 3-24, 4-25 were 2.5 m³ / h and 2.5 m³ / h, respectively. 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to supply reducing atmosphere, the flow rate of each gas supply chamber 7 is the same as above, the composition of the reducing atmosphere is N2:CO:H2=3:1:2; hydrogen-rich gas and iron ore undergo reduction reaction at a reduction temperature of 500℃; after continuous discharge for 15min, close the screw feeder 2, dry and weigh the product in the reduction product quenching tank, take samples, and grind it to -0.038mm accounting for 70%, and conduct magnetic separation test under the condition of magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 45.45%, the feed fineness is -0.8mm accounting for 93%, the feed rate is 100kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2.5m 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 61.19% and a recovery rate of 80.71% can be obtained.

[0081] Table 9. Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case Study 5)

[0082]

[0083] Example 6

[0084] The iron ore used in this experiment came from a foreign ore processing plant, and its chemical and material composition was the same as in Case 4.

[0085] The iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion. The feed rate was set at 80 kg / h. The flow rates of unit gas supply chambers 1-21, 22, 3-23, 4-24, and 5-25 were 2 m³ / h. 3 / h、2m 3 / h、2m 3 / h, 1.5m 3 / h, 1.5m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to feed the reducing atmosphere, the flow rate of each gas supply chamber 7 is the same as above, the composition of the reducing atmosphere is N2:CO:H2=3:1:2; the hydrogen-rich gas and iron ore undergo a reduction reaction at a reduction temperature of 530℃; after continuous discharge for 15min, the screw feeder 2 is closed, the product in the reduction product quenching tank is dried, weighed, sampled, and ground to -0.038mm accounting for 70%, and a magnetic separation test is carried out under the condition of magnetic field strength of 85.5kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 45.45%, the feed fineness is -0.8mm accounting for 93%, and the feed rate is 80kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2m 3 / h、2m 3 / h、2m 3 / h, 1.5m 3 / h, 1.5m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85.5kA / m, a magnetically separated iron concentrate product with a TFe grade of 63.06% and a recovery rate of 82.53% can be obtained.

[0086] Table 10 Results of Sorting Tests for Hydrogen-Based Mineral Phase Conversion Products / % (Case 6)

[0087]

[0088] Example 7

[0089] The raw material used in this experiment came from flotation tailings of an iron ore beneficiation plant in China. The chemical composition analysis results of the ore are shown in Table 11, and the iron phase analysis results are shown in Table 12.

[0090] Table 11 Chemical composition analysis results of the ore / %

[0091]

[0092] Table 12 Iron phase analysis results / %

[0093]

[0094] Table 11 shows that the main recoverable component in the sample is iron, with a grade of 30.63%. The main impurity, SiO2, has a content of 40.78%, while other impurities, such as Al2O3, CaO, and MgO, have lower contents, at 0.92%, 2.13%, and 1.88%, respectively. The main harmful components, phosphorus and sulfur, have lower contents. Table 12 shows that the main iron mineral in the sample is hematite, with a distribution rate of 62.79%. Iron carbonate minerals have a relatively high iron content, with a distribution rate of 18.02%, followed by magnetite, with a distribution rate of 17.14%. Iron sulfide minerals and iron silicate minerals have relatively low iron content, with distribution rates of 1.01% and 1.04%, respectively. This portion of iron is difficult to enrich and recover.

[0095] The aforementioned iron ore was ground to -0.8mm (95% purity) and used as raw material for hydrogen-based mineral phase conversion, with a feed rate of 80 kg / h. The flow rates of unit gas supply chambers 1-21, 22-23, 3-24, 4-25 were 2.5 m³ / h and 2.5 m³ / h, respectively. 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to supply reducing atmosphere, the flow rate of each gas supply chamber 7 is the same as above, the composition of the reducing atmosphere is N2:CO:H2=3:1:2; hydrogen-rich gas and iron ore undergo reduction reaction at a reduction temperature of 500℃; after continuous discharge for 15min, close the screw feeder 2, dry, weigh, and sample the product in the reduction product quenching tank, and grind it to -0.038mm accounting for 70%, and conduct magnetic separation test under the condition of magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 30.63%, the feed fineness is -0.8mm accounting for 95%, and the feed rate is 80kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2.5m 3 / h, 2.5m 3 / h, 2.5m 3 / h、2m 3 / h、2m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 500℃, and a magnetic separation fineness of -0.038mm accounting for 70%, and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 59.98% and a recovery rate of 95.24% can be obtained.

[0096] The ore in this region is flotation tailings, with fine particle size. Under traditional technology, only a 47% iron grade concentrate and an iron recovery rate of 65% can be obtained.

[0097] Table 13 Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case 7)

[0098]

[0099] Example 8

[0100] The raw material used in this experiment came from the flotation tailings of a domestic iron ore beneficiation plant. The chemical composition and material composition of this ore are the same as those in Case 7.

[0101] The iron ore was ground to -0.8mm (93% purity) and used as raw material for hydrogen-based mineral phase conversion. The feed rate was set at 75 kg / h. The flow rates of unit gas supply chambers 1-21, 22-22, 3-23, 4-24, and 5-25 were 2 m³ / h. 3 / h、2m 3 / h、2m 3 / h, 1.5m 3 / h, 1.5m 3 / h, to promote the discharge of bulk material and achieve material sealing; adjust the gas storage tank 10 to supply reducing atmosphere, the flow rate of each gas supply chamber 7 is the same as above, the composition of the reducing atmosphere is N2:CO:H2=3:1:2; hydrogen-rich gas and iron ore undergo reduction reaction at a reduction temperature of 550℃; after continuous discharge for 15min, close the screw feeder 2, dry and weigh the product in the reduction product quenching tank, take samples, and grind it to -0.038mm accounting for 80%, and conduct magnetic separation test under the condition of magnetic field strength of 85kA / m. The test results are shown in Table 4. It can be seen that the TFe grade of the raw ore is 30.63%, the feed fineness is -0.8mm accounting for 93%, and the feed rate is 75kg / h; the flow rates of unit gas supply chamber 1 21, unit gas supply chamber 22, unit gas supply chamber 3 23, unit gas supply chamber 4 24, and unit gas supply chamber 5 25 are 2m 3 / h、2m 3 / h、2m3 / h, 1.5m 3 / h, 1.5m 3 Under the following conditions: a reducing atmosphere with H2:CO = 2:1, a reduction temperature of 550℃, and a magnetic separation fineness of -0.038mm accounting for 80% and a magnetic field strength of 85kA / m, a magnetically separated iron concentrate product with a TFe grade of 60.74% and a recovery rate of 97.06% can be obtained.

[0102] Table 14 Results of Sorting Tests on Hydrogen-Based Mineral Phase Conversion Products / % (Case 8)

[0103]

Claims

1. A fluidized bed reaction system for phase transformation of refractory iron ore, characterized in that: The system includes a feeding system, a spiral plate type multi-chamber fluidized bed reactor (18), and an air supply system. The feeding system includes a hopper (1), a spiral feeder (2), and a computer (3). The hopper (1) is connected to the spiral feeder (2), and the spiral feeder (2) is connected to the top of the spiral plate type multi-chamber fluidized bed reactor (18). The computer (3) controls the motor speed of the spiral feeder (2) to achieve quantitative feeding of the feeding system. The air supply system is connected to the lower part of the fluidized bed reactor (18) to provide airflow. The spiral plate type multi-chamber fluidized bed reactor (18) includes a reaction chamber (5) and a gas supply chamber (7); the reaction chamber (5) is a cylindrical shape with an open bottom, and the bottom is fixedly connected to the gas supply chamber (7). The center of the top wall is provided with a feed inlet (4) connected to the spiral feeder (2). The feed inlet (4) connects the inside and outside of the reaction chamber (5); the lower part of the side wall is provided with a discharge port (8), which connects the inside and outside of the reaction chamber (5); a number of spiral baffles (6) of the same height as the reactor wall are provided in the reaction chamber (5). The spiral baffles (6) radiate spirally towards the reactor wall with the center of the reaction chamber (5) as the center, dividing the shell side of the reaction chamber (5) into a number of spiral strip channels. The strip channels connect the feed inlet (4) and the discharge port (8). The position of the spiral center corresponds to the position of the feed inlet (4). It also includes a receiving hopper (15), through which the reduced product after the reaction is completed enters the receiving hopper (15) via the discharge port (8) to achieve product collection; The reaction chamber (5) is also uniformly arranged with four plate-shaped baffles (16). The plate-shaped baffles (16) are perpendicular to the strip channel and the height of the plate-shaped baffles (16) is 1 / 2 of the height of the vessel wall. Two adjacent plate-shaped baffles (16) are arranged alternately at different heights along the spiral strip channel path. The upper edge of the plate-shaped baffle (16) at the higher position is flush with the top of the reaction chamber (5), and the lower edge of the plate-shaped baffle (16) at the lower position is flush with the bottom of the reaction chamber (5). The air supply chamber (7) is a closed cylindrical shape with the same radius as the reaction chamber (5). The top is a distribution plate (17) with several air holes. The air holes of the distribution plate (17) are evenly arranged. The distribution plate (17) is fixedly connected to the bottom of the reaction chamber (5). An air inlet (9) is provided at the bottom. The air supply chamber (7) is connected to the air supply system through the air inlet (9). The air supply chamber (7) is provided with four partitions (20) to divide the air supply chamber (7) into unit air supply chamber one (21), unit air supply chamber two (22), unit air supply chamber three (23), unit air supply chamber four (24), and unit air supply chamber five (25).

2. The fluidized bed reaction system for phase transformation of refractory iron ore according to claim 1, characterized in that: Three partitions (20) form an equilateral triangle inscribed in the side wall of the air supply chamber (7). The three sides of the triangle form unit air supply chamber one (21), unit air supply chamber two (22), and unit air supply chamber three (23) respectively. A partition (20) is set on the altitude of the isosceles triangle, dividing the isosceles triangle into unit air supply chamber four (24) and unit air supply chamber five (25).

3. A fluidized bed reaction system for phase transformation of refractory iron ore according to claim 2, characterized in that: Each of the three air supply chambers (21, 22, and 3) has an air inlet (9) on its side wall, and each of the three air supply chambers (25) has an air inlet (9) at its bottom, for a total of five air inlets (9).

4. A fluidized bed reaction system for phase transformation of refractory iron ore according to claim 2, characterized in that: The gas supply system includes a gas storage tank (10), a gas supply pipeline (11), and a flow meter (12). The gas storage tank (10) is connected to the gas storage tank (10) through the gas supply pipeline (11). The compressed gas in the gas storage tank (10) can be blown into the gas supply chamber (7) through the gas supply pipeline (11) and the air inlet (9). The gas supply chamber (7) blows the airflow into the reaction chamber (5) through the air distribution plate (17). The flow meter (12) is installed on the gas supply pipeline (11) and electrically connected to the computer (3) to detect the air flow of the five air inlets (9).

5. A fluidized bed reaction system for phase transformation of refractory iron ore according to claim 4, characterized in that: It also includes a temperature control system, which includes a temperature control cabinet (14) located outside the reaction chamber (5) and three heating plates (13) evenly arranged on the inner side of the reaction chamber (5) wall. It also includes three temperature sensors (19) evenly arranged on the inner side of the reaction chamber (5) wall. The temperature control cabinet (14) is electrically connected to the heating plates (13) and the temperature sensors (19) to monitor and control the temperature inside the reaction chamber (5) in real time.

6. A fluidization method for the morphological transformation of refractory iron ore, implemented using the fluidized bed reaction system for morphological transformation of refractory iron ore as described in claim 5, comprising the following steps: Step 1: Place the iron ore bulk material crushed to -0.8mm with a content of more than 90% in the silo (1), and control the feeding rate of the screw feeder (2) through the computer (3) to realize the quantitative feeding of the screw feeder (2). The bulk material enters the reaction chamber (5) of the spiral plate fluidized bed reactor through the feed inlet (4). Step 2: The air storage tank (10) supplies air to the air supply chamber (7) through the air supply pipe (11), and adjusts the flow rate of unit air supply chamber one (21), unit air supply chamber two (22), unit air supply chamber three (23), unit air supply chamber four (24), and unit air supply chamber five (25) in sequence to promote the fluidization of the bulk material in different areas and make it flow continuously until it is finally discharged, thus achieving material sealing; Step 3: After the material sealing is completed, the feeding system starts to feed the preheated iron ore bulk material. The heating plate (13) and temperature sensor (19) of the reactor are started at the same time to monitor and control the temperature in the reaction chamber (5) in real time, so that the temperature in the chamber is maintained at 450℃~500℃. At the same time, the gas supply system feeds in reducing gas. The iron ore bulk material is fluidized in the reaction chamber (5) and flows along the strip channel formed by the spiral baffle (6) and is discharged from the outlet (8). During this period, the reduction reaction is completed under fluidization. Step 4: The reduced iron ore bulk material finally leaves the reaction chamber (5) through the discharge port (8) and enters the receiving hopper (15) for the next process.

Images