An iron ore powder pre-reduction device with a dryer and a rotary kiln in series

Abstract

The invention discloses an iron ore powder pre-reduction device in which a dryer and a rotary kiln are connected in series, belonging to the field of iron ore reduction technology. The device includes a combustion-supporting blower, a burner, a hot air furnace, a supplementary air blower, a rotary kiln, a sealed quantitative feeder, a mixing silo, a chimney, an induced draft fan, a cylindrical dryer, a dust collector, a humidifier, an inertial dust collector, and a cold air valve. The cylindrical dryer and the rotary kiln are arranged in series, and a hot air furnace is provided at the kiln head of the rotary kiln and a supplementary air blower is provided on the rotary kiln cylinder, so as to solve the problems that the prior art is easy to stick and the reduction degree does not meet the requirements. The advantages are that the production operation is simple, it is not easy to form a ring, and the reduction degree is easy to control.

Description

Technical Field

[0001] The invention belongs to the technical field of iron ore reduction, and in particular relates to an iron ore powder pre-reduction device connected in series with a dryer and a rotary kiln. Background Art

[0002] At present, there are two processes for pre-reduction of iron ore powder in the HISMELT process. One is the circulating fluidized bed process, which has the problems of easy adhesion in the device and the reduction degree not meeting the requirements; the other is the process in which the drum dryer and the rotary kiln are arranged separately, which has the problems of easy ring formation in the rotary kiln and the reduction degree not meeting the requirements. Summary of the invention

[0003] The purpose of the present invention is to provide an iron ore powder pre-reduction device with a dryer and a rotary kiln connected in series, which solves the problems of easy adhesion and insufficient reduction degree.

[0004] The present invention comprises a combustion-supporting blower 1, a burner 2, a hot air furnace 3, an air supply blower 4, a rotary kiln 5, a sealed quantitative feeder 6, a mixing bin 7, a chimney 8, an induced draft fan 9, a cylindrical dryer 10, a dust collector 11, a humidifier 12, an inertial dust collector 13 and a cold air valve 14; a hot air furnace 3 is arranged at the kiln head of the rotary kiln 5 to provide hot air for pre-reduction and drying; an air supply blower 4 is arranged on the cylinder of the rotary kiln 5; an inertial dust collector 13 is arranged at the high end of the cylindrical dryer 10; a humidifier 12 is arranged under the dust collector 11 to humidify the dust collected and feed it into the cylindrical dryer 10; a cold air valve 14 is arranged at the inlet pipe of the dust collector 11.

[0005] The combustion-supporting fan 1 is connected to the hot blast stove 3, the burner 2 is installed on the hot blast stove 3, the lower part of the mixing bin 7 is connected to the sealed quantitative feeder 6, the sealed quantitative feeder 6 is connected to the drum dryer 10, the dust collector 11 is connected to the induced draft fan 9, and the induced draft fan 9 is connected to the chimney 8.

[0006] The steps of using the iron ore powder pre-reduction device with a dryer and a rotary kiln in series according to the present invention are as follows:

[0007] (1) The iron ore powder mixture is quantitatively fed into the drum dryer 10 from the sealed quantitative feeder 6 at the bottom of the mixing bin 7.

[0008] (2) The iron ore powder mixture is dehydrated by the hot air from the rotary kiln 5 in the drum dryer 10 and heated up, and then enters the rotary kiln 5 through the rotation of the drum dryer 10 .

[0009] (3) The hot air in the drum dryer 10 is driven by the induced draft fan 9 and passes through the inertial dust collector 13 to remove coarse particles. The hot air is then removed by the dust collector 11 to meet the emission requirements and discharged into the atmosphere through the chimney 8. When the hot air temperature is higher than the set temperature, the opening of the cold air valve 14 is automatically controlled to keep the hot air temperature within the set range.

[0010] (4) The coarse particles removed by the inertial dust collector 13 fall directly back into the cylindrical dryer 10, and the dust collected by the dust collector 11 falls back into the cylindrical dryer 10 after being humidified by the humidifier.

[0011] (5) The iron ore powder mixture in the rotary kiln 5 is further heated and partially reduced by the reducing agent of the iron ore powder mixture before entering the next process.

[0012] (6) A hot blast furnace 3 is provided at the head of the rotary kiln 5 to provide heat for heating and reducing the iron ore powder mixture in the rotary kiln 5. The hot blast temperature at the outlet of the hot blast furnace 3 is controlled at 1000-1100°C, and the oxygen content is controlled below 6%.

[0013] (7) A supplementary air blower 4 is provided on the cylinder of the rotary kiln 5 to provide oxygen for the fuel of the reducing agent of the iron ore powder mixture in the rotary kiln 5 .

[0014] The iron ore powder mixture is composed of iron ore powder, reducing agent (anthracite, coke powder, carbon-containing dust ash, etc.), flux (dolomite, limestone, etc.), etc.

[0015] The drum dryer 10 and the rotary kiln 5 are arranged in series, and the drying and pre-reduction of the iron ore powder mixture are completed in the drum dryer 10 and the rotary kiln 5 connected in series.

[0016] A hot air furnace 3 is provided at the kiln head of the rotary kiln 5 to provide hot air for pre-reduction and drying.

[0017] An air supply fan 4 is provided on the cylinder of the rotary kiln 5 .

[0018] The iron ore powder mixed raw material is quantitatively fed into the drum dryer 10 through the sealed quantitative feeder 6 under the mixing silo 7.

[0019] An inertial dust collector 13 is provided at the high end of the drum dryer 10 .

[0020] A humidifier 12 is provided under the dust collector 11 to humidify the dust and then feed it into the drum dryer 10.

[0021] The inlet duct of the dust collector 11 is provided with a cold air valve 14 .

[0022] The advantages of the present invention are:

[0023] (1) The drying and pre-reduction of the iron ore powder mixture are completed in the series-connected drum dryer 10 and the rotary kiln 5, eliminating the need for material transfer equipment between the two devices, and the operation is simple.

[0024] (2) The hot air furnace installed at the kiln head provides hot air to the kiln, so the temperature in the kiln is uniform, there is no high-temperature area of ​​the flame, and the ring formation in the kiln is reduced.

[0025] (3) The rotary kiln cylinder is equipped with an air supply fan to meet the oxygen needs of coal powder combustion in the kiln, and can control the kiln in a reducing atmosphere to achieve the pre-reduction requirements.

[0026] (4) The dust ash is humidified by a humidifier to increase the material diameter and then returned to the drum dryer to reduce the circulation volume of the dust ash. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The invention discloses an iron ore powder pre-reduction device with a dryer and a rotary kiln in series, wherein the device comprises a combustion-supporting fan 1, a burner 2, a hot air furnace 3, an air supply fan 4, a rotary kiln 5, a sealed quantitative feeder 6, a mixing bin 7, a chimney 8, an induced draft fan 9, a drum dryer 10, a dust collector 11, a humidifier 12, an inertial dust collector 13 and a cold air valve 14. DETAILED DESCRIPTION

[0028] The following further describes the embodiments of the present invention in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0029] The present invention comprises a combustion-supporting blower 1, a burner 2, a hot air furnace 3, an air supply blower 4, a rotary kiln 5, a sealed quantitative feeder 6, a mixing bin 7, a chimney 8, an induced draft fan 9, a cylindrical dryer 10, a dust collector 11, a humidifier 12, an inertial dust collector 13 and a cold air valve 14; a hot air furnace 3 is arranged at the kiln head of the rotary kiln 5 to provide hot air for pre-reduction and drying; an air supply blower 4 is arranged on the cylinder of the rotary kiln 5; an inertial dust collector 13 is arranged at the high end of the cylindrical dryer 10; a humidifier 12 is arranged under the dust collector 11 to humidify the dust collected and feed it into the cylindrical dryer 10; a cold air valve 14 is arranged at the inlet pipe of the dust collector 11.

[0030] The combustion-supporting fan 1 is connected to the hot blast stove 3, the burner 2 is installed on the hot blast stove 3, the lower part of the mixing bin 7 is connected to the sealed quantitative feeder 6, the sealed quantitative feeder 6 is connected to the drum dryer 10, the dust collector 11 is connected to the induced draft fan 9, and the induced draft fan 9 is connected to the chimney 8.

[0031] The iron ore powder mixture consists of iron ore powder, reducing agent (anthracite, SRV ash, etc.), flux (dolomite), etc.

[0032] The drying and pre-reduction of the iron ore powder mixture are completed in the drum dryer 10 and the rotary kiln 5 connected in series.

[0033] A hot air furnace 3 is provided at the kiln head of the rotary kiln 5 to provide hot air for pre-reduction and drying.

[0034] The rotary kiln 5 cylinder is provided with air supply fans 4, 3 of which are distributed in the length direction of the kiln body.

[0035] The iron ore powder mixed raw material is quantitatively fed into the drum dryer 10 through the sealed quantitative feeder 6 under the mixing silo 7.

[0036] An inertial dust collector 13 is provided at the high end of the drum dryer 10 .

[0037] A humidifier 12 is provided under the dust collector 11 to humidify the dust and then feed it into the drum dryer 10. A cold air valve 14 is provided at the inlet pipe of the dust collector 11.

Claims

1. An iron ore powder pre-reduction device with a dryer and a rotary kiln in series, characterized in that: The invention comprises a combustion-supporting blower (1), a burner (2), a hot air furnace (3), an air supply blower (4), a rotary kiln (5), a sealed quantitative feeder (6), a mixing bin (7), a chimney (8), an induced draft fan (9), a cylindrical dryer (10), a dust collector (11), a humidifier (12), an inertial dust collector (13), and a cold air valve (14); a hot air furnace (3) is arranged at the kiln head of the rotary kiln (5) to provide hot air for pre-reduction and drying; an air supply blower (4) is arranged on the cylinder of the rotary kiln (5); an inertial dust collector (13) is arranged at the upper end of the cylindrical dryer (10); a humidifier (12) is arranged below the dust collector (11) to humidify the dust collected and then feed it into the cylindrical dryer (10); a cold air valve (14) is arranged at the inlet pipe of the dust collector (11); The combustion-supporting fan (1) is connected to the hot blast furnace (3), the burner (2) is installed on the hot blast furnace (3), the lower part of the mixing bin (7) is connected to the sealed quantitative feeder (6), the sealed quantitative feeder (6) is connected to the drum dryer (10), the dust collector (11) is connected to the induced draft fan (9), and the induced draft fan (9) is connected to the chimney (8); The cylindrical dryer (10) and the rotary kiln (5) are arranged in series; the drying and pre-reduction of the iron ore powder mixture are completed in the cylindrical dryer (10) and the rotary kiln (5) connected in series; The iron ore powder mixture includes iron ore powder, reducing agent and flux.

2. The iron ore powder pre-reduction device with a dryer and a rotary kiln in series according to claim 1 is characterized in that: The steps for using the device are as follows: (1) The iron ore powder mixture is quantitatively fed into the drum dryer (10) from the sealed quantitative feeder (6) at the bottom of the mixing bin (7); (2) The iron ore powder mixture is dehydrated by the hot air from the rotary kiln (5) in the drum dryer (10), and after the temperature is increased, the mixture enters the rotary kiln (5) through the rotation of the drum dryer (10); (3) The hot air in the drum dryer (10) is driven by the induced draft fan (9) to pass through the inertial dust collector (13) to remove coarse particles, and then is removed by the dust collector (11) to meet the emission requirements and discharged into the atmosphere through the chimney (8); when the hot air temperature is higher than the set temperature, the opening of the cold air valve (14) is automatically controlled to keep the hot air temperature within the set range; (4) The coarse particles removed by the inertial dust collector (13) fall directly back into the cylindrical dryer (10), and the dust collected by the dust collector (11) falls back into the cylindrical dryer (10) after being humidified by the humidifier; (5) The iron ore powder mixture in the rotary kiln (5) is further heated and partially reduced by the reducing agent of the iron ore powder mixture before entering the next process; (6) A hot blast furnace (3) is provided at the head of the rotary kiln (5) to provide heat for heating and reducing the iron ore powder mixture in the rotary kiln (5); the hot blast temperature at the outlet of the hot blast furnace (3) is controlled at 1000-1100° C., and the oxygen content is controlled at less than 6%; (7) A supplementary air fan (4) is provided on the cylinder of the rotary kiln (5) to provide oxygen for the fuel of the reducing agent of the iron ore powder mixture in the rotary kiln (5).

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