IRONMAKING SYSTEM AND IRONMAKING PROCESS OF TWO-SECTION DOWNDRAFT BED

Abstract

An ironmaking system and process of a two-section downdraft bed, including: a vertical melting furnace, where a basic combustor/gasifier is at the top, first and second inlets evenly along a side wall of the melting furnace below the basic combustor/gasifier, and the first inlet connected to coke powder/pulverized coal, air, and water vapor sources; a slag pool, at a bottom of the melting furnace; a vertical pre-reduction furnace, the top portion connected to the outlet of the melting furnace, third and fourth inlets on an upper portion of the pre-reduction furnace and connected respectively to a temperature-adjusting and tempering medium source and an iron mineral powder source, an outlet at a bottom of the pre-reduction furnace; and a separator, an inlet of the separator connected to the outlet of the pre-reduction furnace, and an outlet at a bottom of the separator connected to the second inlet through a pipeline.

Claims

1. An ironmaking system of a two-section downdraft bed, the system comprising: a melting furnace section, vertically downward disposed, wherein a basic combustor/gasifier is disposed at a top portion thereof, a first inlet and a second inlet are provided below the basic combustor/gasifier, both the first inlet and the second inlet are evenly provided along a side wall of the melting furnace section, and form a tangent circle in the melting furnace section, the second inlet is located below the first inlet, and the first inlet is connected to a coke powder/pulverized coal source, an air source, and a water vapor source; a slag pool, disposed at a bottom portion of the melting furnace section, and equipped with a slag discharging device and a tapping device, wherein an outlet end is downstream of the slag pool; a pre-reduction furnace section, vertically downward disposed, wherein a top portion thereof is connected to the outlet end of the melting furnace section, a third inlet and a fourth inlet are provided on an upper portion of the pre-reduction furnace section, an outlet is disposed at a bottom portion of the pre-reduction furnace section, the third inlet is connected to a temperature-adjusting and tempering medium source, and the fourth inlet is connected to an iron mineral powder source; and a first separator, wherein an inlet of the first separator is connected to the outlet of the pre-reduction furnace section, and an outlet at a bottom portion of the first separator is connected to the second inlet through a conveying pipeline.

2. The ironmaking system of a two-section downdraft bed according to claim 1, wherein a funnel structure is disposed at the bottom portion of the melting furnace section, and the slag pool is disposed at an outlet end of the funnel structure.

3. The ironmaking system of a two-section downdraft bed according to claim 1, wherein the first inlet comprises 2 to 8 inlets, circumferentially arranged along the melting furnace section; or the second inlet comprises 2 to 8 inlets, circumferentially arranged along the melting furnace section.

4. The ironmaking system of a two-section downdraft bed according to claim 1, wherein the pre-reduction furnace section is connected to the melting furnace section through an arc-shaped pipeline.

5. The ironmaking system of a two-section downdraft bed according to claim 1, further comprising a second separator, wherein an inlet of the second separator is connected to a gas outlet of the first separator through a pipeline, a fifth inlet is provided on the pipeline, and the fifth inlet is connected to a cold iron mineral powder source; and further, a solid outlet of the second separator is connected to the fourth inlet through a conveying pipeline, and a gas outlet is connected to a first heat exchanger through a pipeline.

6. The ironmaking system of a two-section downdraft bed according to claim 1, further comprising a pulverized coal coking furnace section and a third separator, wherein the pulverized coal coking furnace section is vertically disposed, a bottom portion of the pulverized coal coking furnace section is connected to the gas outlet of the first separator, a sixth inlet is provided at a lower end of the pulverized coal coking furnace section, the sixth inlet is connected to a pulverized coal source, and a top portion of the pulverized coal coking furnace section is connected to an inlet of the third separator; further, a solid outlet end of the third separator is connected to the first inlet; and further, a gas outlet end of the third separator is connected to a second heat exchanger through a pipeline.

7. An ironmaking process of a two-section downdraft bed, comprising the following steps: entering, by coke powder/pulverized coal carried by air and water vapor, a melting furnace section from a side wall of the melting furnace section, to form a swirling flow in the melting furnace section; jetting, by a basic combustor/gasifier at a top portion of the melting furnace section, a flame inward to ignite or gasify a fluid, to generate reducing gas; jetting pre-reduced iron mineral powder into the melting furnace section, to fully mix the pre-reduced iron mineral powder with a coke powder/pulverized coal gas flow; under the action of high-temperature reduction, reducing an iron oxide in iron mineral powder into an iron element, and melting the iron element into molten iron at a high temperature; and flowing, by a high-temperature reducing gas after the reaction, from the melting furnace section to a pre-reduction furnace section, and pre-reducing iron mineral powder jetted into the pre-reduction furnace section; and conveying the pre-reduced iron mineral powder to the melting furnace section.

8. The ironmaking process of a two-section downdraft bed according to claim 7, further comprising a step of pre-heating cold iron mineral powder by using a high-temperature gas flow flowing out from the pre-reduction furnace section; or further comprising a step of coking pulverized coal by using a high-temperature gas flow flowing out from the pre-reduction furnace section.

9. The ironmaking process of a two-section downdraft bed according to claim 7, wherein a temperature of a reaction in the melting furnace section ranges from 1300° C. to 1700° C.; or a temperature of the pre-reduction furnace section ranges from 700° C. to 1100° C.

10. The ironmaking process of a two-section downdraft bed according to claim 7, wherein a circulating coal gas or a mixture of pulverized coal and a circulating coal gas is added into the pre-reduction furnace section as a cooling and temperature-adjusting medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary examples of the present invention and descriptions thereof are used to explain the present invention, and do not constitute an improper limitation of the present invention.

[0046] FIG. 1 is a structural schematic diagram of an ironmaking system of a two-section downdraft bed according to a first embodiment of the present invention; and

[0047] FIG. 2 is a structural schematic diagram of an ironmaking system of a two-section downdraft bed according to a second embodiment of the present invention.

[0048] In the figures: 1. basic combustor/gasifier; 2. first inlet; 3. second inlet; 4. melting furnace section; 5. slag pool; 6. third inlet; 7. fourth inlet; 8. pre-reduction furnace section; 9. first separator; 10. fifth inlet; 11. second separator; 12. first heat exchanger; 13. coal gas outlet pipeline; 14. sixth inlet; 15. pulverized coal coking furnace section; 16. third separator; and 17. second heat exchanger.

DETAILED DESCRIPTION

[0049] It should be noted that, the following detailed descriptions are all exemplary, and are intended to provide further descriptions of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those usually understood by a person of ordinary skill in the art to which the present disclosure belongs.

[0050] It should be noted that the terms used herein are merely used for describing specific implementations, and are not intended to limit exemplary implementations of the present disclosure. As used herein, the singular form is also intended to include the plural form unless the context clearly dictates otherwise. In addition, it should further be understood that, terms “comprise” and/or “include” used in this specification indicate that there are features, steps, operations, devices, components, and/or combinations thereof.

Embodiment 1

[0051] As shown in FIG. 1, a structure of a device (arrangement manner 1) of an ironmaking process of a two-section downdraft bed includes a melting furnace section 4, where the melting furnace section 4 is a downdraft bed, a basic combustor/gasifier 1 is disposed at a top portion of the melting furnace section 4, a first inlet 2 of coke powder (pulverized coal) (air and water vapor) is provided on a side surface of an upper portion of the melting furnace section 4, and a pre-reduced mineral powder inlet, that is, a second inlet 3, is provided at a specific distance below the first inlet 2; and a mineral powder pre-reduction furnace section 8, which is a downdraft bed, where a pre-heated mineral powder inlet, that is, a fourth inlet 7, is provided on a side surface of an upper portion of the pre-reduction furnace section 8, and a lower portion of the pre-reduction furnace section 8 is connected to an inlet of a pre-reduced mineral powder separator, that is, a first separator 9. The melting furnace section 4 is connected to the mineral powder pre-reduction furnace section 8 through a slag pool 5. A cooling, temperature-adjusting, and tempering medium inlet, that is, a third inlet 6, is provided on a pipeline connecting the slag pool 5 and the mineral powder pre-reduction furnace section 8. An upper outlet the first separator 9 is connected to an inlet of a pre-heating swirling flow separator, that is, a second separator 11. A lower outlet of the first separator 9 is connected to the pre-reduced mineral powder inlet, that is, the second inlet 3. A cold mineral powder inlet, that is, a fifth inlet 10, is provided at the upper outlet of the pre-reduced mineral powder separator, that is, the first separator 9. A lower outlet of the pre-heating swirling flow separator, that is, the second separator 11, is connected to the pre-heated mineral powder inlet, that is, the fourth inlet 7, and an upper outlet is connected to a coal gas heat exchanger, that is, a first heat exchanger 12 and a coal gas outlet pipeline 13 sequentially.

[0052] The foregoing method of the ironmaking process of a two-section downdraft bed (arrangement manner 1) includes the following specific steps:

1) High-Temperature Melting Reduction

[0053] A basic combustor/gasifier combusts/gasifies coke powder (pulverized coal) (air and water vapor) that is fed, generates a high temperature of around 1600° C. and a reducing atmosphere, pre-reduced iron mineral powder is mainly subject to a reaction in which FeO becomes molten iron in a melting reduction furnace, and the molten iron falls into a slag pool. The coke powder (pulverized coal) (air and water vapor) and the pre-reduced iron mineral powder are jetted in a four-corner tangential or a six-corner tangential manner, which is beneficial to even mixing.

2) Mineral Powder Pre-Reduction

[0054] A high-temperature coal gas generated in the melting furnace section enters the mineral powder pre-reduction furnace section after being cooled or tempered by a cooling/tempering medium, pre-heated mineral powder is fed from above the furnace section, and the coal gas and the pre-heated mineral powder are mainly subject to a pre-reduction reaction for generating FeO and a part of Fe from mineral powder. The cooling/tempering medium is a circulating coal gas, or a circulating coal gas together with pulverized coal. Both of the two sections are downdraft beds, which is beneficial to maintain a uniform suspension state for mineral powder particles, and improving reduction efficiency.

3) Pre-Reduced Mineral Powder Separation

[0055] The coal gas and the pre-reduced mineral powder enter an inlet of a pre-reduced mineral powder separator, the pre-reduced mineral powder is separated from below the separator, and enters the melting furnace section through a pre-reduced mineral powder inlet; and the coal gas is separated from above the separator.

4) Cold Mineral Powder Pre-Heating

[0056] The coal gas discharged from above the pre-reduced mineral powder separator carrying cold mineral powder enters an inlet of a pre-heating swirling flow separator, the coal gas exchanges heat with the cold mineral powder, and a temperature of the cold mineral powder is increased, which is beneficial to improve a pre-reduction level. The pre-heated mineral powder is separated from below the separator, and enters the mineral powder pre-reduction furnace section. The coal gas is discharged from above the separator, and is discharged from a coal gas outlet pipeline through a coal gas heat exchanger.

Embodiment 2

[0057] FIG. 2 is another implementation of this application. A structure of a device (arrangement manner 2) of an ironmaking process of a two-section downdraft bed includes a melting furnace section 4, the melting furnace section 4 is a downdraft bed, a basic combustor/gasifier 1 is disposed at a top portion of the melting furnace section 4, a coke powder (air and water vapor) inlet, that is, a first inlet 2, is provided on a side surface of an upper portion of the melting furnace section 4, and a pre-reduced mineral powder inlet, that is, a second inlet 3, is provided at a certain distance below the first inlet 2; and a mineral powder pre-reduction furnace section 8, which is a downdraft bed, where a mineral powder inlet, that is, a fourth inlet 7, is provided on a side surface of an upper portion of the pre-reduction furnace section 8, and a lower portion of the pre-reduction furnace section 8 is connected to an inlet of a pre-reduced mineral powder separator, that is, a first separator 9. The melting furnace section 4 is connected to the mineral powder pre-reduction furnace section 8 through a slag pool 5. A cooling, temperature-adjusting, and tempering medium inlet, that is, a third inlet 6, is provided on a pipeline connecting the slag pool 5 and the mineral powder pre-reduction furnace section 8. An upper outlet of the pre-reduced mineral powder separator, that is, the first separator 9, is connected to a pulverized coal coking furnace section 15, and a lower outlet of the first separator 9 is connected to the pre-reduced mineral powder inlet, that is, the second inlet 3. A pulverized coal inlet, that is, a sixth inlet 14, is provided on a lower portion of the pulverized coal coking furnace section 15, and an upper portion of the pulverized coal coking furnace section 15 is connected to an inlet of a coke powder separator, that is, a third separator 16. A lower outlet of the coke powder separator, that is, the third separator 16, is connected to the coke powder (air and water vapor) inlet, that is, the first inlet 2, and an upper outlet is connected to a coal gas outlet pipeline 13 and a second heat exchanger 17 sequentially.

[0058] The method of another ironmaking process of a two-section downdraft bed (arrangement manner 2) in this application includes the following specific steps:

1) High-Temperature Melting Reduction

[0059] A basic combustor/gasifier combusts/gasifies coke powder (air and water vapor) that is fed, generates a high temperature of around 1600° C. and a reducing atmosphere, pre-reduced iron mineral powder is mainly subject to a reaction in which FeO becomes molten iron in a melting reduction furnace, and the molten iron falls into a slag pool. The coke powder (air and water vapor) and the pre-reduced iron mineral powder are jetted in a four-corner tangential or a six-corner tangential manner, which is beneficial to even mixing.

2) Mineral Powder Pre-Reduction

[0060] A high-temperature coal gas generated in the melting furnace section enters the mineral powder pre-reduction furnace section after being cooled or tempered by a cooling/tempering medium, mineral powder is fed from above the furnace section, and the coal gas and the mineral powder are mainly subject to a pre-reduction reaction for generating FeO and a part of Fe from mineral powder. Both of the two sections are downdraft beds, which is beneficial to maintain a uniform suspension state for mineral powder particles, and improve reduction efficiency.

3) Pre-Reduced Mineral Powder Separation

[0061] The coal gas and the pre-reduced mineral powder enter an inlet of a pre-reduced mineral powder separator, the pre-reduced mineral powder is separated from below the separator, and enters the melting furnace section through a pre-reduced mineral powder inlet; and the coal gas is separated from above the separator.

4) Pulverized Coal Coking

[0062] The coal gas that is discharged from the upper portion of the pre-reduced mineral powder separator and that carries pulverized coal enters a pulverized coal coking furnace section, at a temperature and an atmosphere provided by the coal gas, coke powder is produced by using the pulverized coal, a pyrolysis gas and the coke powder move upward into a coke powder separator. Coking of the pulverized coal is set, to enhance adaptivity to coal types, and is particularly adapted to lignite or bituminous coal with high moisture. The coke powder is separated from below the separator, and enters the melting furnace section. The coal gas is discharged from above the separator, and enters a coal gas heat exchanger after flowing through a coal gas outlet pipeline.

[0063] The foregoing descriptions are merely preferred embodiments of the present invention, but are not intended to limit the present invention. A person skilled in the art may make various alterations and variations to the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.