Iron ore powder reduction device

Abstract

An iron ore powder reduction device belongs to the technical field of direct reduction ironmaking. A reducing gas H2 enters the gas inlet from bottom to top; the reducing gas is pre-distributed in the gas chamber; the reducing gas is uniformly distributed through the gas distribution plate; the vertical section I is used for accommodating iron ore powder, and the iron ore powder is subjected to reduction reaction with reducing gas to generate reduced iron; the vertical section I is provided with an iron ore powder feeding pipe and a reduced iron discharging pipe; the included angle between the wall of the expansion section and the horizontal line is 70-85 degrees; the cyclone powder collector is mounted in the vertical section II; reaction gas separated by the cyclone powder collector is collected in the gas collecting chamber; and the reaction gas in the gas collecting chamber is discharged through the gas outlet pipe. The device has the advantages that the speed of air flow leaving a mineral powder layer is gradually reduced, the amount of fine mineral powder carried by the air flow is reduced, and the fine mineral powder is separated after the air flow carrying the fine mineral powder passes through the cyclone powder collector and then returns to the mineral powder below.

Description

Technical Field

[0001] The utility model discloses an iron ore powder reduction device, belonging to the technical field of direct reduction ironmaking. Background Art

[0002] Iron ore powder reduction uses coal-based rotary kiln technology. For example, New Zealand Steel Plant uses coal-based rotary kiln to reduce vanadium-titanium magnetite. The reduced iron is used for electric furnace smelting. Two 4.6x60m rotary kilns are used, each with a production capacity of about 250,000 tons / year. Due to the low production capacity and high coal consumption (about 900kg / t) of this process, it has now been discontinued.

[0003] Rio Tinto's KWINANA smelting reduction ironworks in Australia uses a circulating fluidized bed to preheat and pre-reduce iron ore powder. The original design was to use the high-temperature coal gas produced by the smelting reduction furnace to preheat and pre-reduce the iron ore powder. However, as the equipment failed to operate normally, natural gas has been used to preheat the iron ore powder, and the high-temperature coal gas produced by the smelting reduction furnace has not been used, and the pre-reduction of the iron ore powder has not been achieved.

[0004] The fixed fluidized bed iron ore powder reduction process is adopted. The fluidized bed is cylindrical. The air flow velocity flowing through the ore powder layer is high. A large amount of fine ore powder leaves the fluidized bed with the air flow. This part of the ore powder accounts for about 30% and is not fully heated and reduced. Summary of the invention

[0005] Technical issues solved

[0006] Reduce the speed of the airflow in the upper space of the fluidized bed to reduce the amount of mineral powder carried away by the airflow; set a cyclone powder collector in the fluidized bed to recover the mineral powder carried in the airflow, and return the separated fine mineral powder to the mineral powder layer at the bottom of the fluidized bed; the combination of multiple iron ore powder reduction devices can reasonably utilize the heat and pressure of the reducing gas.

[0007] Solutions to technical problems

[0008] An iron ore powder reduction device, from bottom to top:

[0009] Air inlet, where reducing gas CO, H2 or a mixture containing CO and H2 enters;

[0010] A gas chamber, in which reducing gas is pre-distributed;

[0011] Gas distribution plate, reducing gas is evenly distributed through the gas distribution plate;

[0012] The vertical section I is cylindrical and contains iron ore powder, where the iron ore powder reacts with the reducing gas to generate reduced iron;

[0013] The vertical section I is provided with a feed pipe for iron ore powder and a discharge pipe for reduced iron;

[0014] An expansion section, wherein the angle between the wall of the expansion section and the horizontal line is 70 to 85°, preferably 78 to 83°;

[0015] The vertical section II is cylindrical, and the cyclone powder collector is installed in the vertical section II;

[0016] Gas collecting chamber, where the reaction gas separated by the cyclone powder collector is collected;

[0017] The reaction gas in the gas collecting chamber is discharged through the gas outlet pipe;

[0018] The air outlet of the cyclone powder collector can also be directly extended to the synthetic air outlet pipe of the iron ore powder reduction device R foreign exchange.

[0019] Furthermore, the ratio of the cross-sectional area of ​​the vertical section II to the cross-sectional area of ​​the vertical section I is ≥2.

[0020] Furthermore, there are 1 to 4 cyclone powder collectors; the cyclone powder collectors separate the dust carried in the reaction gas, the reaction gas enters from the air inlet of the cyclone powder collector, and the separated reaction gas is discharged from the air outlet of the cyclone powder collector to the air collecting chamber, and the separated dust is discharged into the iron ore powder in the vertical section I through the discharge pipe of the cyclone powder collector.

[0021] Furthermore, the height of the vertical section I and / or the vertical section II may be 0, and the expansion section connects the upper end of the vertical section I and the lower end of the vertical section II.

[0022] Furthermore, the reducing gas contains CO ≥ 18% or H2 ≥ 10%.

[0023] Furthermore, the reducing gas is heated to 650-1050°C, preferably 700-850°C, and then enters the iron ore powder reduction device R from the air inlet.

[0024] Furthermore, multiple iron ore powder reduction devices R are used in combination, and the iron ore powder enters the iron ore powder reduction device R3, the iron ore powder reduction device R2, and the iron ore powder reduction device R1 in sequence, and the reducing gas enters the iron ore powder reduction device R1, the iron ore powder reduction device R2, and the iron ore powder reduction device R3 in sequence.

[0025] Furthermore, multiple iron ore powder reduction devices R are used in combination, and the iron ore powder enters the iron ore powder reduction device R3, the iron ore powder reduction device R2, and the iron ore powder reduction device R1 in sequence, and the reducing gas enters the iron ore powder reduction device R1, the iron ore powder reduction device R2, and the iron ore powder reduction device R3 respectively.

[0026] Furthermore, the plurality of iron ore powder reduction devices R are used in combination, and the number of the combination is 2 to 4.

[0027] Furthermore, the particle size of the iron ore powder is ≤8mm; and the reduction degree of the reduced iron is 10-90%.

[0028] The shape of the iron ore powder reduction device is small at the bottom and large at the top. The air flow velocity passing through the ore powder is high, which can fluidize well. The air flow velocity leaving the ore powder layer gradually decreases upward, and the amount of fine ore powder carried by the air flow decreases. A cyclone powder collector is installed in the iron ore powder reduction device. After passing through the cyclone powder collector, the fine ore powder carried by the air flow is separated and returned to the ore powder layer below. Multiple iron ore powder reduction devices are used in combination to reasonably utilize the pressure and temperature of the reducing gas to achieve a better iron ore powder reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of an iron ore powder reduction device

[0030] Figure 2 A schematic diagram of an iron ore powder reduction assembly 1

[0031] Figure 3 A schematic diagram of an iron ore powder reduction combined device 2

[0032] Legend Marker

[0033] 1 air inlet, 2 air chamber, 3 gas distribution plate, 4 vertical section I, 5 expansion section, 6 vertical section II, 7 air chamber, 8 air outlet pipe, 9 cyclone powder collector, 91 cyclone powder collector air inlet, 92 cyclone powder collector air outlet, 93 cyclone powder collector feed pipe, 10 feed pipe, 11 discharge pipe, 12 reduction gas heater, 13 iron ore powder bin, 14 reduction iron bin, 15 iron ore powder reduction device R3, 16 iron ore powder reduction device R2, 17 iron ore powder reduction device R 1； 18Iron ore powder reduction device R. Specific embodiments

[0034] Example 1

[0035] The following is attached Figure 1 For reference, the implementation of the utility model patent is described in detail so that ordinary technicians in the field can easily implement it. The implementation of the utility model patent can be embodied in many different forms and is not limited to this description.

[0036] The iron ore powder reduction device comprises, from bottom to top:

[0037] Inlet 1, where reducing gas H2 enters;

[0038] Gas chamber 2, where reducing gas is pre-distributed;

[0039] Gas distribution plate 3, reducing gas is evenly distributed through the gas distribution plate;

[0040] The vertical section I4 contains iron ore powder, where the iron ore powder reacts with the reducing gas to generate reduced iron;

[0041] The vertical section I4 is provided with a feed pipe 10 for iron ore powder and a discharge pipe 11 for reduced iron;

[0042] The expansion section 5, the angle between the wall of the expansion section 5 and the horizontal line is 80°;

[0043] Vertical section II6, cyclone powder collector 9 is installed in vertical section II6;

[0044] Gas collecting chamber 7, the reaction gas separated by cyclone powder collector 9 is collected in the gas collecting chamber 7;

[0045] The reaction gas from the gas collecting chamber 7 is discharged through the gas outlet pipe [8].

[0046] In the iron ore powder reduction device, the ratio of the cross-sectional area of ​​the vertical section II6 to the cross-sectional area of ​​the vertical section I4 is 2.25.

[0047] The iron ore powder reduction device is equipped with four cyclone powder collectors 9; the cyclone powder collectors 9 separate the dust entrained in the reaction gas, the reaction gas enters from the cyclone powder collector air inlet 91, and the separated reaction gas is discharged from the cyclone powder collector outlet 92 to the gas collection chamber 7, and the separated dust is discharged into the iron ore powder in the vertical section Ⅰ4 through the cyclone powder collector discharge pipe 93.

[0048] The iron ore powder reduction device adopts reducing gas containing H2≥70%.

[0049] In the iron ore powder reduction device, the reducing gas is heated to 700-850°C and then enters the iron ore powder reduction device R18 from the air inlet 1.

[0050] The iron ore powder reduction device has a particle size of ≤8mm and a reduction degree of reduced iron of >80%.

[0051] Embodiment 2:

[0052] Attach Figure 2 For reference, the embodiments are described as follows:

[0053] H2 is heated to 800°C in the reducing gas heater 12, and then enters the iron ore powder reduction device R117 to heat and reduce the iron ore powder to generate reduced iron and H2O; then leaves the iron ore powder reduction device R117 and enters the iron ore powder reduction device R216 to heat and reduce the iron ore powder to generate reduced iron and H2O; then leaves the iron ore powder reduction device R216 and enters the iron ore powder reduction device R315 to heat the iron ore powder; the reaction gas leaving the iron ore powder reduction device R315 is purified and H2O in the reaction gas is removed, and then pressurized and returned to the reducing gas heater 12, and the reaction gas is recycled. The iron ore powder in the iron ore powder bin 13 is first added to the iron ore powder reduction device R315, and the iron ore powder is discharged from the iron ore powder reduction device R315 after being heated. The discharged iron ore powder is added to the iron ore powder reduction device R216, and the iron ore powder is reduced by H2. The reduced iron ore powder is discharged from the iron ore powder reduction device R216, and the discharged iron ore powder is added to the iron ore powder reduction device R117 for further reduction to generate reduced iron. The reduced iron is discharged from the iron ore powder reduction device R117 and then loaded into the reduced iron bin 14.

[0054] Embodiment 3:

[0055] Attach Figure 3 For reference, the embodiments are described as follows:

[0056] H2 is heated to 800°C in the reducing gas heater 12, and then enters: ① into the iron ore powder reduction device R315, to heat and reduce the iron ore powder to generate reduced iron and H2O; ② into the iron ore powder reduction device R216, to heat and reduce the iron ore powder to generate reduced iron and H2O; ③ into the iron ore powder reduction device R117, to heat the iron ore powder; the reaction gases leaving the iron ore powder reduction device R117, the iron ore powder reduction device R216, and the iron ore powder reduction device R315 are gathered together to purify and remove H2O in the reaction gases, and then pressurized and returned to the reducing gas heater 12, and the reaction gases are recycled. The iron ore powder in the iron ore powder bin 13 is first added to the iron ore powder reduction device R315, and the iron ore powder is discharged from the iron ore powder reduction device R315 after being heated. The discharged iron ore powder is added to the iron ore powder reduction device R216, and the iron ore powder is reduced by H2. The reduced iron ore powder is discharged from the iron ore powder reduction device R216, and the discharged iron ore powder is added to the iron ore powder reduction device R117 for further reduction to generate reduced iron. The reduced iron is discharged from the iron ore powder reduction device R117 and then loaded into the reduced iron bin 14.

Claims

1. An iron ore powder reduction device, characterized in that: From bottom to top: An air inlet (1) through which reducing gas CO, H2 or a mixed gas containing CO and H2 enters; A gas chamber (2) in which reducing gas is pre-distributed; A gas distribution plate (3), through which the reducing gas is evenly distributed; The vertical section I (4) is cylindrical and contains iron ore powder, where the iron ore powder reacts with the reducing gas to generate reduced iron; The vertical section I (4) is provided with a feed pipe (10) for iron ore powder and a discharge pipe (11) for reduced iron; The expansion section (5) has a wall of the expansion section (5) and a horizontal line with an angle of 70 to 85 degrees; A vertical section II (6) is cylindrical, and a cyclone powder collector (9) is installed in the vertical section II (6); A gas collecting chamber (7), wherein the reaction gas separated by the cyclone powder collector (9) is collected in the gas collecting chamber (7); An outlet pipe (8), through which the reaction gas in the gas collecting chamber (7) is discharged; The cyclone powder collector air outlet (92) of the cyclone powder collector (9) directly extends to the foreign exchange synthesis air outlet pipe (8) of the iron ore powder reduction device R.

2. The iron ore powder reduction device according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the vertical section II (6) to the cross-sectional area of ​​the vertical section I (4) is ≥2.

3. The iron ore powder reduction device according to claim 1, characterized in that: There are 1 to 4 cyclone powder collectors (9); the cyclone powder collectors (9) separate the dust entrained in the reaction gas. The reaction gas enters from the cyclone powder collector air inlet (91), and the separated reaction gas is discharged from the cyclone powder collector air outlet (92) to the gas collection chamber (7). The separated dust is discharged into the iron ore powder in the vertical section I (4) through the cyclone powder collector discharge pipe (93).

4. The iron ore powder reduction device according to claim 1, characterized in that: The straight section height of the vertical section I (4) and / or the vertical section II (6) may be 0, and the expansion section connects the upper end of the vertical section I and the lower end of the vertical section II.

5. The iron ore powder reduction device according to claim 1, characterized in that: The reducing gas contains CO≥18% or H2≥10%.

6. The iron ore powder reduction device according to claim 1, characterized in that: The reducing gas is heated to 650-1050° C. and then enters the iron ore powder reduction device R (18) from the air inlet (1).

7. The iron ore powder reduction device according to claim 1, characterized in that: A plurality of iron ore powder reduction devices R are used in combination, the iron ore powder sequentially enters the iron ore powder reduction device R3 (15), the iron ore powder reduction device R2 (16), and the iron ore powder reduction device R1 (17), and the reducing gas sequentially enters the iron ore powder reduction device R1 (17), the iron ore powder reduction device R2 (16), and the iron ore powder reduction device R3 (15).

8. The iron ore powder reduction device according to claim 1, characterized in that: A plurality of iron ore powder reduction devices R (18) are used in combination, and the iron ore powder enters the iron ore powder reduction device R3 (15), the iron ore powder reduction device R2 (16), and the iron ore powder reduction device R1 (17) in sequence, and the reducing gas enters the iron ore powder reduction device R1 (17), the iron ore powder reduction device R2 (16), and the iron ore powder reduction device R3 (15) respectively.

9. An iron ore powder reduction device according to claim 7 or 8, characterized in that: The plurality of iron ore powder reduction devices R (18) are used in combination, with the number of the combination being 2 to 4.

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