U.S. patent application number 17/295965 was filed with the patent office on 2022-07-07 for ironmaking system and ironmaking process of two-section downdraft bed.
This patent application is currently assigned to SHANDONG UNIVERSITY. The applicant listed for this patent is SHANDONG UNIVERSITY. Invention is credited to Juan CHEN, Chunyuan MA, Tao WANG, Yuan ZHAO, Binxuan ZHOU, Zhenfeng ZHOU.
Application Number | 20220213567 17/295965 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-07 |
United States Patent
Application |
20220213567 |
Kind Code |
A1 |
MA; Chunyuan ; et
al. |
July 7, 2022 |
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.
Inventors: |
MA; Chunyuan; (Jinan,
CN) ; ZHAO; Yuan; (Jinan, CN) ; WANG; Tao;
(Jinan, CN) ; ZHOU; Binxuan; (Jinan, CN) ;
ZHOU; Zhenfeng; (Jinan, CN) ; CHEN; Juan;
(Jinan, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHANDONG UNIVERSITY |
Jinan, Shandong |
|
CN |
|
|
Assignee: |
SHANDONG UNIVERSITY
Jinan, Shandong
CN
|
Appl. No.: |
17/295965 |
Filed: |
December 28, 2019 |
PCT Filed: |
December 28, 2019 |
PCT NO: |
PCT/CN2019/129539 |
371 Date: |
May 21, 2021 |
International
Class: |
C21B 13/14 20060101
C21B013/14; C21B 13/00 20060101 C21B013/00; C21B 13/10 20060101
C21B013/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2019 |
CN |
201910911189.2 |
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.degree. C. to 1700.degree. C.; or
a temperature of the pre-reduction furnace section ranges from
700.degree. C. to 1100.degree. 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
BACKGROUND
Technical Field
[0001] The present invention relates to the field of metal smelting
technologies, and in particular, to an ironmaking process of a
two-section downdraft bed.
Related Art
[0002] Information of the Related Art part is merely disclosed to
increase the understanding of the overall background of the present
invention, but is not necessarily regarded as acknowledging or
suggesting, in any form, that the information constitutes the prior
art known to a person of ordinary skill in the art.
[0003] Currently, blast furnace ironmaking is a main method for
producing steel, and the predominance of the blast furnace
ironmaking is unlikely to be changed in a short term. The method is
a continuous metallurgical process for reducing iron ore into iron
in a blast furnace, and a smelting process is as follows: Iron ore,
coke, and a flux used for slagging are fed from a furnace top
according to a prescribed ratio, and a charge level of a furnace
throat is maintained at a certain height. The coke and the iron ore
form an alternating layer structure in the furnace. The coke
combusts with oxygen in blown hot air to generate carbon monoxide
and hydrogen. Oxygen is removed from the iron ore in a rising
process in the furnace, to obtain iron through reduction, and the
iron becomes a liquid at a searing temperature of more than
2000.degree. C. The refined liquid molten iron flows from a tapping
hole, and forms cast iron ingots through solidification. Impurities
in the iron ore and the flux are combined into slags, and
discharged from a slag discharging hole.
[0004] It can be seen that a large amount of premium coke is
required in the blast furnace ironmaking. However, coke resources
are increasingly deficient, and prices of metallurgical coke are
increasingly higher, but non-coke resources that are abundant in
reserves and that are cheap cannot be fully utilized in ironmaking
production. To change the dependency of ironmaking on the coke
resources, researchers have discovered non-blast furnace ironmaking
in different forms, and a modern non-blast furnace ironmaking
industrial system with direct reduction and melting reduction as
main parts is initially formed. The existing non-blast furnace
ironmaking technologies include a direct reduction method of gas
reduction, a direct reduction method using a solid reducing agent,
and typical melting reduction processes, for example, a Corex
process, a Finex process, and a HIsmelt process. However, the
foregoing processes have different problems respectively, for
example, low reduction efficiency, a low waste heat recovery rate,
and that some metallurgical coke is still needed. An ironmaking
process that has a simple process and low energy consumption is not
achieved.
SUMMARY
[0005] To resolve the technical problem in the prior art, an
objective of the present invention is to provide an ironmaking
system and an ironmaking process of a two-section downdraft
bed.
[0006] To achieve the objective, the present invention includes the
following technical solutions:
[0007] An ironmaking system of a two-section downdraft bed is
provided, including:
[0008] a melting furnace section, vertically downward disposed,
where 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;
[0009] a slag pool, disposed at a bottom portion of the melting
furnace section, and equipped with a slag discharging device and a
tapping device, where an outlet end is downstream of the slag
pool;
[0010] a pre-reduction furnace section, vertically downward
disposed, where 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
[0011] a first separator, where 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.
[0012] Carried by air and water vapor, coke powder/pulverized coal
enters the melting furnace section from a side wall of the melting
furnace section, to form a swirling flow in the melting furnace
section, and rotationally moves downward. A combustor jets a flame
to the swirling flow, to ignite or gasify the coke
powder/pulverized coal, to generate a high-temperature flame.
Carried by the swirling flow, the high-temperature flame flows
through a pre-reduced mineral powder fluid that enters, and two
strands of fluids with different movement velocities meet, collide,
and further, are rapidly mixed evenly.
[0013] Because the fluids spirally move downward, a time during
which pre-reduced iron mineral powder is in contact with a
high-temperature reducing gas is prolonged, so that a reduction
degree of the iron mineral powder can be effectively improved,
thereby improving an ironmaking yield. In addition, the fluids
spirally move downward, and play a sound role in carrying the iron
mineral powder, to effectively prevent the iron mineral powder from
sedimentation in the melting furnace section, so that the iron
mineral powder and a gas flow are mixed evenly, which is relatively
beneficial to improve an ironmaking rate of the iron mineral
powder.
[0014] An iron oxide in the iron mineral powder is reduced to
generate molten iron, and the molten iron and slags fall into the
slag pool, and are discharged through the tapping device and the
slag discharging device.
[0015] After being cooled to a proper temperature by a tempering
medium that enters through the third inlet, the gas flow flowing
out of the melting furnace section enters the pre-reduction furnace
section, and comes into contact with the iron mineral powder fluid
that enters, to pre-reduce the iron mineral powder. After the
pre-reduction is completed, the iron oxide in the iron mineral
powder mainly becomes FeO, and a part of the iron oxide is directly
reduced into Fe. Separated by a separator, the pre-reduced iron
mineral powder is conveyed to the melting furnace section for
high-temperature reduction. Because a pre-reduction step has been
performed, an ironmaking recovery rate of the iron mineral powder
can be significantly improved.
[0016] In some embodiments, 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. The molten iron
generated in the melting furnace section converges at the funnel
structure, and flows into the slag pool through the funnel
structure, to ensure that the molten iron flows out smoothly.
[0017] In some embodiments, the first inlet includes 2 to 8 inlets,
circumferentially arranged along the melting furnace section.
[0018] In some embodiments, the second inlet includes 2 to 8
inlets, circumferentially arranged along the melting furnace
section.
[0019] In some embodiments, the pre-reduction furnace section is
connected to the melting furnace section through an arc-shaped
pipeline. The arc-shaped pipeline can gently change a flow
direction of a reducing gas, and has relatively small impact on an
inner flow field of the gas flow. Through the arc-shaped pipeline,
when flowing through the pre-reduction furnace section, the gas
flow flowing out of the melting furnace section can play relatively
good role in disturbing and carrying the iron mineral powder added
into the pre-reduction furnace section, to improve a pre-reduction
effect on the iron mineral powder.
[0020] In some embodiments, the ironmaking system of a two-section
downdraft bed further includes a second separator, where 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.
[0021] A gas flow with a relatively high temperature that is
separated from the first separator flows through the fifth inlet,
comes into contact with cold iron mineral powder added from the
fifth inlet, heats the cold iron mineral powder, and carries the
cold iron mineral powder to the second separator for gas-solid
separation in the second separator. The pre-heating of the cold
iron mineral powder is relatively beneficial to subsequent
reduction ironmaking of the iron mineral powder.
[0022] 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.
[0023] Because after the cold iron mineral powder is pre-heated, a
temperature of the gas is still relatively high, waste heat
recovery can be performed at a position of the first heat
exchanger, to avoid heat waste.
[0024] In some embodiments, the ironmaking system of a two-section
downdraft bed further includes a pulverized coal coking furnace
section and a third separator, where 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.
[0025] A hot gas flow separated from the first separator can be
utilized for heating and coking the pulverized coal.
[0026] Further, a solid outlet end of the third separator is
connected to the first inlet. The separated coke powder is conveyed
to the melting furnace section to participate in a reaction.
[0027] Further, a gas outlet end of the third separator is
connected to a second heat exchanger through a pipeline.
[0028] Waste heat recovery is performed through the second heat
exchanger on the hot gas flow separated from the third separator,
to avoid heat waste.
[0029] An ironmaking process of a two-section downdraft bed is
provided, including the following steps:
[0030] 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;
[0031] 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 a reducing gas;
[0032] 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;
[0033] 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
[0034] 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.
[0035] In some embodiments, the ironmaking process of a two-section
downdraft bed further includes a step of pre-heating cold iron
mineral powder by using a high-temperature gas flow flowing out
from the pre-reduction furnace section.
[0036] In some embodiments, the ironmaking process of a two-section
downdraft bed further includes a step of coking pulverized coal by
using a high-temperature gas flow flowing out from the
pre-reduction furnace section.
[0037] In some embodiments, a temperature of a reaction in the
melting furnace section ranges from 1300.degree. C. to 1700.degree.
C.
[0038] In some embodiments, a temperature of the pre-reduction
furnace section ranges from 700.degree. C. to 1100.degree. C.
[0039] In some embodiments, 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, and a proportion of a reducing gas in
tempered gases is increased.
[0040] A mineral powder pre-reduction furnace section cooperates
with pulverized coal coking/gasification, and a pulverized
coal/water vapor vaporization medium or a circulating coal gas,
together with the pulverized coal/water vapor, adjusts a
temperature and is gasified simultaneously. Cooling and pulverized
coal gasification/coking are performed simultaneously, to achieve
tempering of the coal gas, and provide more appropriate reduction
conditions for subsequent mineral powder pre-reduction. In this
case, the coke powder and the mineral powder are separated
simultaneously, and are fed into the melting furnace section
together.
[0041] The present invention has the following beneficial
effects:
[0042] The present invention provides an ironmaking process of a
two-section downdraft bed, applicable to a melting furnace section
and a mineral powder pre-reduction furnace section. According to
conditions required for reducing iron mineral powder into molten
iron, temperature distribution in a two-section reactor is
controlled, a high-temperature melting reduction reaction occurs in
the melting furnace section, and molten iron is mainly generated
from FeO. A pre-reduction reaction occurs in the mineral powder
pre-reduction furnace section, FeO or a part of Fe is mainly
generated from iron mineral powder. The process achieves
pre-reduction and melting reduction of mineral powder. Both of the
two reactions are achieved in the downdraft bed, which is
beneficial to maintain a uniform suspension state for mineral
powder particles, and is beneficial to improve reduction
efficiency. A process that iron ore is transformed into molten iron
is completed within a same set of devices, complexity of the system
is decreased, and an occupied area is decreased.
[0043] Two temperature adjusting manners are provided for cooling
and temperature adjusting of a coal gas at an inlet of the
pre-reduction section. By using a circulating coal gas, the coal
gas at an outlet of the melting furnace section enters the mineral
powder pre-reduction furnace section after being cooled by a
cooling medium. Pulverized coal, or together with a circulation
coal gas, is used as a cooling and temperature-adjusting medium. A
mineral powder pre-reduction furnace section cooperates with
pulverized coal coking/gasification, and a pulverized coal/water
vapor vaporization medium or a circulating coal gas, together with
the pulverized coal/water vapor, adjusts a temperature and is
gasified simultaneously. Cooling and pulverized coal
gasification/coking are performed simultaneously, to provide more
appropriate reduction conditions for subsequent mineral powder
pre-reduction. In this case, the coke powder and the mineral powder
are separated simultaneously, and are fed into the melting furnace
section together.
[0044] Two distribution manners are provided for the coal gas after
the pre-reduction. One is setting heat exchange of mineral powder
in a pre-heating swirling flow separator, to increase a mineral
powder temperature, which is beneficial to improve a pre-reduction
level; and the other is setting coking of pulverized coal, to
enhance adaptivity to coal types, and is particularly adapted to
lignite or bituminous coal with high moisture. Short-process
smelting of steel can be achieved, leading to a broad application
prospect.
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.degree. 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.degree. 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.
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