U.S. patent application number 16/314508 was filed with the patent office on 2019-05-30 for smelting method for metallurgical electric-furnace.
This patent application is currently assigned to BEIJING ZHONGKAIHONGDE TECHNOLOGY CO., LTD.. The applicant listed for this patent is BEIJING ZHONGKAIHONGDE TECHNOLOGY CO., LTD.. Invention is credited to John Tung CHAO, Lei CHEN, Jibin LIU, Wenheng MU, Cunhu WANG, Han WEN.
Application Number | 20190161816 16/314508 |
Document ID | / |
Family ID | 57469155 |
Filed Date | 2019-05-30 |
United States Patent
Application |
20190161816 |
Kind Code |
A1 |
CHAO; John Tung ; et
al. |
May 30, 2019 |
SMELTING METHOD FOR METALLURGICAL ELECTRIC-FURNACE
Abstract
The present disclosure provides a metallurgical electric
furnace, and a smelting method for the metallurgical electric
furnace. The metallurgical electric furnace includes a furnace
body, an oxygen lance and a coal lance, wherein the furnace body is
provided with a furnace chamber; the oxygen lance is located on a
side wall of the furnace chamber and is used for blowing oxygen
into the slag promoting the smelting process, and the outlet of the
oxygen lance is higher than the slag; and the coal lance is located
on the side wall of the furnace chamber beside the oxygen lance and
is used for spraying coal into the slag, and the outlet of the coal
lance is higher than the slag.
Inventors: |
CHAO; John Tung; (Beijing,
CN) ; MU; Wenheng; (Beijing, CN) ; LIU;
Jibin; (Beijing, CN) ; WANG; Cunhu; (Beijing,
CN) ; CHEN; Lei; (Beijing, CN) ; WEN; Han;
(Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BEIJING ZHONGKAIHONGDE TECHNOLOGY CO., LTD. |
Beijing |
|
CN |
|
|
Assignee: |
BEIJING ZHONGKAIHONGDE TECHNOLOGY
CO., LTD.
Beijing
CN
|
Family ID: |
57469155 |
Appl. No.: |
16/314508 |
Filed: |
May 15, 2017 |
PCT Filed: |
May 15, 2017 |
PCT NO: |
PCT/CN2017/084396 |
371 Date: |
December 31, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B 7/18 20130101; C22B
4/08 20130101; C21B 11/10 20130101; C22B 34/22 20130101; F27D 7/06
20130101; F27D 2003/164 20130101; F27D 2003/165 20130101; F27D
2003/168 20130101; F27D 3/18 20130101; C22B 34/12 20130101; H05B
7/22 20130101; F27D 99/0033 20130101; C21C 5/5217 20130101; C22C
1/02 20130101; F27D 3/0026 20130101; C21C 2300/02 20130101; F27D
2003/166 20130101; F27D 3/0033 20130101; C21C 2005/5223 20130101;
F27D 2003/162 20130101 |
International
Class: |
C21B 11/10 20060101
C21B011/10; C22B 4/08 20060101 C22B004/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 2016 |
CN |
201610515542.1 |
Claims
1. A metallurgical electric furnace, comprising: a furnace body
provided with a furnace chamber; an oxygen lance located on a side
wall of the furnace chamber and used for blowing oxygen into slag
promoting the smelting process, wherein the outlet of the oxygen
lance is higher than the slag; and a coal lance located on the side
wall of the furnace chamber beside the oxygen lance and used for
injecting coal particles into the slag, wherein the outlet of the
coal lance is higher than the slag.
2. The metallurgical electric furnace according to claim 1,
comprising: a plurality of oxygen lances that are uniformly
distributed along the side wall of the furnace chamber; and an
equal number of coal lances that are uniformly distributed along
the side wall of the furnace chamber, wherein the oxygen lances are
located below the coal lances, or the oxygen lances and the coal
lances are located at the same height on the side wall of the
furnace chamber.
3. The metallurgical electric furnace according to claim 1, further
comprising: a spray tube located on the side wall of the furnace
chamber and used for spraying a hydrocarbon into a furnace
freeboard, wherein the outlet of the spray tube is higher than the
slag.
4. The metallurgical electric furnace according to claim 3, wherein
the spraying direction of the hydrocarbon into the furnace
freeboard can be (but not limited to) tangential to the side wall
of the furnace chamber.
5. A smelting method for the metallurgical electric furnace
comprising: a furnace body provided with a furnace chamber; an
oxygen lance located on a side wall of the furnace chamber and used
for blowing oxygen into slag promoting the smelting process,
wherein the outlet of the oxygen lance is higher than the slag; and
a coal lance located on the side wall of the furnace chamber beside
the oxygen lance and used for injecting coal particles into the
slag, wherein the outlet of the coal lance is higher than the slag,
wherein the slag comprises a reduced state substance capable of
being oxidized by oxygen, and the smelting method comprises:
blowing oxygen into the slag via an oxygen lance so as to oxidize
the reduced state substance to an oxidization state substance; and
spraying coal into the slag through a coal lance so as to reduce
the oxidized oxidization state substance.
6. The smelting method according to claim 5, wherein the depth of
the oxygen blown into the slag does not exceed one-half of the
thickness of the slag.
7. The smelting method according to claim 6, wherein the depth of
the oxygen blown into the slag is within the range of one-third of
the thickness of the slag to one-half of the thickness of the
slag.
8. The smelting method according to claim 5, wherein the coal is
anthracite or bituminous coal.
9. The smelting method according to claim 5, wherein after spraying
the coal into the slag through the coal lance, the method further
comprises: blowing a hydrocarbon into the furnace freeboard through
a spray tube.
10. The smelting method according to claim 9, wherein the
hydrocarbon comprises natural gas or light oil.
11. The smelting method according to claim 9, wherein while
spraying the hydrocarbon into the furnace freeboard through the
spray tube, the method further comprises: spraying liquid water
and/or gaseous water into the furnace freeboard through the spray
tube.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the priority of Chinese
Application No. 201610515542.1, filed in the Chinese Patent Office
on Jul. 1, 2016, and entitled "SMELTING METHOD FOR METALLURGICAL
ELECTRIC-FURNACE", the entire contents of which are herein
incorporated by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to the field of metallurgy,
and more particularly to a metallurgical electric furnace and a
smelting method for the metallurgical electric furnace.
BACKGROUND
[0003] Oxygen has been widely used in the metallurgical industry
and has been very successful, wherein the oxygen has been
successfully used in steelmaking converters, has been successfully
applied to the melting of scrap steel in electric arc furnaces, and
is combined with coal injection to produce foaming slags to improve
the efficiency, which are very mature and widely used process
technologies. The oxygen has been successfully applied to the
nonferrous metallurgy since the 1970s. There are two famous types:
firstly, Ausmelt developed by Outotec has been used for smelting
lead, zinc, nickel, copper, tin and other minerals, and secondly,
ISASMELT developed by MIM and CSIRO in Australia has also been
successfully applied to the smelting of non-ferrous metals. For
more than a decade, RIO TINTO has also successfully developed the
HISMELT technology for ironmaking, which has also been
commercialized, but it has not been widely used in the ironmaking
industry. Recently, the Russian company Technologiya Metallov
published its Project Magma on its website to explain the oxygen
blowing and coal spraying technology, which can be applied not only
to the non-ferrous metals, but also can be applied to ferrous
metals
(Ferrous Metallurgy)
[0004] In the current metallurgical electric furnaces (such as a
titanium slag electric furnace), the chemical energy has never been
applied by virtue of the oxygen blowing and coal spraying
technology to reduce the consumption of electric energy and to
improve the efficiency of smelting. The present disclosure aims at
promoting the oxygen blowing and coal spraying technology to such
electric furnaces.
SUMMARY
[0005] To this end, the objective of one aspect of the present
disclosure is to provide a metallurgical electric furnace.
[0006] The objective of another aspect of the present disclosure is
to provide a smelting method for the above metallurgical electric
furnace.
[0007] In order to achieve the above objectives, the embodiment of
one aspect of the present disclosure provides a metallurgical
electric furnace, including: a furnace body provided with a furnace
chamber; an oxygen lance located on a side wall of the furnace
chamber and used for blowing oxygen into slag promoting the
smelting process, wherein the outlet of the oxygen lance is higher
than the slag; and a coal lance located on the side wall of the
furnace chamber and used for spraying coal into the slag, wherein
the outlet of the coal lance is higher than the slag.
[0008] In the metallurgical electric furnace provided by the above
embodiment of the present disclosure, especially in the
metallurgical electric furnace operated by an open arc, the outlet
of the oxygen lance and the outlet of the coal lance are higher
than the upper surface of the slag, the O.sub.2 is blown into the
slag from top to bottom by the oxygen lance, the low-valent reduced
state substance in the slag is oxidized to a high-valent oxidation
state substance, a large amount of chemical energy is released in
the oxidation process, the temperature of the slag is increased,
the released chemical energy can effectively melt the feed,
meanwhile, the coal particles are also injected into the slag from
top to bottom through the coal lance, the carbon in the coal
reduces the high-valent oxidation state substance to a low-valent
reduced state, when the high-valent oxidation state substance is
reduced by the carbon, CO is released, meanwhile, the reduction
reaction is endothermic, and then the energy released by the
oxidation of the reduced state substance is also supplied to the
reduction reaction; in the slag, due to the existence of the
O.sub.2, the O.sub.2 may also cause a combustion reaction with the
CO and C, the heat of combustion which is produced by the
combustion reaction can raise the temperature of the slag so as to
provide heat for the melting of the feed, and can also provide
energy for the reduction reaction, in this way, both the chemical
energy released in the oxidation reaction and the energy released
in the combustion reaction can be used for the smelting of the
feed, so that, in addition to electrical energy, chemical energy
can also provide a large amount of energy for the smelting process,
thereby increasing the total power available for smelting, and thus
improving the productivity and efficiency, and it is especially
effective for the slag with a high melting point, so that the
consumption of electric energy is reduced.
[0009] In the present solution, the oxygen lance and the coal lance
are both arranged above the slag, the O.sub.2 and the coal
particles are blown into the slag from top to bottom, and is away
from the furnace lining, so that the damage to the furnace lining
is reduced, and the service life of the furnace lining is prevented
from being shortened. As the O.sub.2 is blown from top to bottom
and inclines toward a direction away from the installation position
of the oxygen lance on the side wall of the furnace chamber, that
is, the spraying direction of the O.sub.2 faces to the opposite
side of the installation position of the oxygen lance on the side
wall of the furnace chamber, the coal particles is also sprayed
from top to bottom and inclines toward the direction away from the
installation position of the coal lance on the side wall of the
furnace chamber, that is, the spraying direction of the coal
particles faces to the opposite side of the installation position
of the coal lance on the side wall of the furnace chamber, so that
the slag flows toward the opposite side of the installation
positions of the oxygen lance and the coal lance on the side wall
of the furnace chamber, but is very far away from the furnace
lining, in this way, the generated influence is low, and the
integrity of the furnace lining can be protected.
[0010] Specifically, using an example that the reduced state
substance in the slag is Me.sub.2O.sub.3, the chemical reactions
occurred in the slag during the oxygen blowing and coal spraying
include:
Me.sub.2O.sub.3+0.5O.sub.2=2MeO.sub.2 (1)
2MeO.sub.2+C=Me.sub.2O.sub.3+CO (2)
CO+0.5O.sub.2=CO.sub.2 (3)
O.sub.2+C=CO.sub.2 (4)
[0011] After the O.sub.2 is blown in, the reaction (1) occurs, the
O.sub.2 oxidizes the Me.sub.2O.sub.3 into MeO.sub.2, the oxidation
reaction is an exothermic reaction, and a large amount of chemical
energy is released in the reaction for smelting of the feed; after
the coal particles is injected, the reaction (2) occurs, the carbon
reduces the MeO.sub.2 into Me.sub.2O.sub.3, meanwhile, releases CO,
the reaction (2) is an endothermic reaction, and the chemical
energy released in the reaction (1) is further used for providing
energy for the reaction (2) in addition to smelting the feed; and
the O.sub.2 in the slag may also cause the combustion reactions (3)
and (4) with the CO and C, a part of the heat of combustion is
released into the slag for smelting the feed and being supplied to
the reaction (2), as the reaction (1), the reaction (3) and the
reaction (4) are all exothermic reactions, and the chemical energy
released in the reactions is added to the electric energy, thereby
improving the total smelting power and reducing the consumption of
electric energy. At the same time, a large amount of CO is released
in the reaction (2) to form bubbles, which swells the slag into
foam slag, and the formation of the foam slag is favorable for the
blowing of the O.sub.2.
[0012] The electric furnace of the present disclosure is fixed, the
feed is supplied unceasingly, when the molten iron reaches a
certain liquid level, a molten metal outlet is opened to release
the molten metal, the feed is supplied as usual, and the oxygen and
coal are blown and sprayed as usual. After a certain amount of the
molten metal flows out, the molten metal outlet is blocked by a
blocking machine, after a period of time, when the slag level is
too high, a slag opening is opened to discharge the slag, the feed
is supplied as usual, and the oxygen and coal are blown and sprayed
as usual.
[0013] In addition, the metallurgical electric furnace provided by
the above embodiment of the present disclosure further has the
following additional technical features:
[0014] In the above technical solution, preferably, the
metallurgical electric furnace includes a plurality of oxygen
lances that are uniformly distributed along the side wall of the
furnace chamber; and a plurality of coal lances that are uniformly
distributed along the side wall of the furnace chamber; wherein the
oxygen lances are located below the coal lances, or the oxygen
lances and the coal lances are located at the same height on the
side wall of the furnace chamber.
[0015] In a specific embodiment of the present disclosure, the
oxygen lances are located below the coal lances. Preferably, the
number of the oxygen lances is equal to the number of the coal
lances, the coal lances are located right above the oxygen lances,
the coal lances and the oxygen lances are arranged in an
above-and-below pattern.
[0016] In another specific embodiment of the present disclosure,
the oxygen lances and the coal lances are located at the same
height on the side wall 11 of the furnace chamber 1, and are
arranged next to one another in an alternate pattern.
[0017] Preferably, the plurality of oxygen lances are uniformly
distributed along the circumferential direction of the side wall of
the furnace chamber and are located at the same height on the side
wall of the furnace chamber; and the plurality of coal lances are
uniformly distributed along the circumferential direction of the
side wall of the furnace chamber and are located at the same height
on the side wall of the furnace chamber.
[0018] Preferably, a coal lance and an oxygen lance can be placed
in the same cooling jacket, and the distance between the injection
points of the coal lance and the oxygen lance in a molten pool is
not less than 300 mm.
[0019] In the above embodiment, the oxygen lance and the coal lance
are located above the molten pool, and the O.sub.2 and the coal
particles are blown into the furnace chamber 1 from top to bottom,
the injecting velocity of the O.sub.2 is supersonic to penetrate
through the foam slag, the coal can also be injected into the
molten pool, the plurality of oxygen lances are uniformly
distributed on the side wall of the furnace chamber to balance the
mechanical stirring caused by each lance. In such a way, the
chemical energy released by the oxidation of the reduced state
substance in the slag is uniformly distributed, and thus the
uniformity of the feed distribution in the furnace chamber can be
improved; and the plurality of coal lances are uniformly
distributed on the side wall of the furnace chamber, so that the
conversion rate of reducing the high-valent oxidation state
substance into the low-valent reduced state substance is
improved.
[0020] Preferably, the oxygen lance and the coal lance are
installed on the side wall of the furnace chamber, penetrate
through a refractory material and enter the furnace chamber.
[0021] In the above technical solution, preferably, the
metallurgical electric furnace further includes a spray tube, the
spray tube is located on the side wall of the furnace chamber above
the oxygen lances and used for spraying a hydrocarbon into a
furnace freeboard, and the outlet of the spray tube is higher than
the slag.
[0022] In the above embodiment, a part of the electrical energy and
the chemical energy is applied to the reaction (2), the CO produced
by the reaction (2) enters the furnace freeboard, and the CO
carries a large amount of energy, a part of the heat of combustion
released by the reactions (3) and (4) is used for smelting the feed
and the reaction (2), a part of the heat of combustion heats up
gases (CO, CO.sub.2, O.sub.2) and enters the furnace freeboard to
serve as a heat source for the pyrolysis gasification of the
hydrocarbon to generate coal gas, therefore the present disclosure
generates the coal gas while improving the total power of the
smelting, and avoids the waste of energy contained in the flue
gas.
[0023] The furnace freeboard is also known as a freeboard, which
refers to a space above the molten pool and below a furnace
roof.
[0024] Specifically, the hydrocarbon causes the following reactions
in the furnace freeboard:
C.sub.nH.sub.m=nC+m/2H.sub.2 (5)
2C.sub.nH.sub.m+CO.sub.2=2(n+1)CO+mH.sub.2 (6)
C.sub.nH.sub.m+nH.sub.2O=nCO+(n+m/2)H.sub.2 (7)
C+CO.sub.2=2CO (8)
C+H.sub.2O=H.sub.2+CO (9)
As the space of the furnace freeboard is limited, the reactions
(5), (6), (7), (8), (9) may not reach chemical equilibrium, and the
final temperature and gas composition depend on the dynamic balance
of the system.
[0025] Preferably, a plurality of uniformly distributed spray tubes
is arranged on the side wall of the furnace chamber.
[0026] In the above technical solution, preferably, the spraying
direction of the hydrocarbon into the furnace freeboard is
tangential to the side wall of the furnace chamber. Preferably, the
hydrocarbon is sprayed horizontally into the freeboard.
[0027] The embodiment of the second aspect of the present
disclosure provides a smelting method for the metallurgical
electric furnace according to any one of the above embodiments,
wherein the slag includes a reduced state substance capable of
being oxidized by O.sub.2, and the smelting method includes:
blowing oxygen into the slag via an oxygen lance so as to oxidize
the reduced state substance to an oxidization state substance; and
spraying coal into the slag through a coal lance so as to reduce
the oxidized oxidization state substance.
[0028] According to the smelting method provided by the above
embodiment of the present disclosure, the O.sub.2 is blown into the
slag from top to bottom to oxidize the low-valent reduced state
substance in the slag into a high-valent oxidation state substance,
a large amount of chemical energy is released in the oxidation
process to effectively smelt the slag, meanwhile, the coal
particles are also sprayed into the slag from top to bottom to
reduce the high-valent oxidation state substance to a low-valent
reduced state, CO is released at the same time, the reduction
reaction is an endothermic reaction, the energy released by the
oxidation of the reduced state substance is also supplied to the
reduction reaction; and in the slag, due to the existence of the
O.sub.2, the O.sub.2 may cause a combustion reaction with the CO
and C, the heat of combustion of the combustion reaction can raise
the temperature of the slag so as to provide heat for melting of
the feed, and can also provide energy for the reduction reactions,
in this way, the chemical energy released in the oxidation reaction
and the energy released in the combustion reaction can be used for
melting of the feed, in addition to electrical energy in the
smelting process, the chemical energy can also provide a large
amount of energy for the smelting process, thereby increasing the
total available power for smelting, and improving the productivity
and efficiency, (it is especially effective for the slag with a
high melting point) and the consumption of electric energy is
reduced.
[0029] In the above technical solution, preferably, the depth of
the oxygen blown into the slag does not exceed one-half of the
thickness of the slag.
[0030] In the above technical solution, preferably, the depth of
the oxygen blown into the slag is within the range of one-third of
the thickness of the slag to one-half of the thickness of the
slag.
[0031] In the above embodiment, for different slag systems, the
ratios of the depth of the oxygen blown into the slag to the total
thickness of the slag are different, if the slag system needs to be
controlled at a very low oxygen potential to reduce the metal
oxides to be recovered, the depth of the oxygen blown into the slag
is within the range of one-third of the height of the slag bath to
two-thirds of the height of the slag bath, and the coal particles
can be sprayed deeper, however, not reaching the metal bath
underneath the slag, to ensure the low oxygen potential.
[0032] In the above technical solution, preferably, the coal is
anthracite or bituminous coal.
[0033] In the electric arc furnace steelmaking, only the anthracite
or coke can be used, and the bituminous coal cannot be used.
However, the anthracite or bituminous coal can be used in the
present application. Of course, the coke can also be used in the
present application.
[0034] In the above technical solution, preferably, after injecting
the coal particles into the slag through the coal lance, the method
further includes: blowing a hydrocarbon into the furnace freeboard
through a spray tube.
[0035] In the above embodiment, the hydrocarbon is blown into the
furnace freeboard horizontally, the energy carried by the CO
released by the oxidation reaction, the chemical energy generated
by the combustion reaction of CO and O.sub.2, and the chemical
energy generated by the combustion reaction of C and O.sub.2 can be
used as the heat source for the pyrolysis gasification of the
hydrocarbon, so that a coal gas is generated in the furnace
freeboard. In the above technical solution, preferably, the
hydrocarbon includes natural gas or light oil. Of course, methane
gas and solid bituminous coal and the like sprayed into the furnace
freeboard can be converted into the coal gas, the temperature of
the gases (CO, CO.sub.2, H.sub.2, H.sub.2O) generated in the molten
pool is extremely high (the temperature is greater than
1700.degree. C.), and the gases contain a large amount of heat,
which enters the furnace freeboard, the above hydrocarbon is
sprayed into the freeboard to cause endothermic chemical reactions
with the CO.sub.2 and H.sub.2O so as to be cracked into the coal
gas. In such a way the furnace roof can be cooled by these
endothermic reactions.
[0036] In the above technical solution, preferably, while spraying
the hydrocarbon into the furnace freeboard through the spray tube,
the method further includes: spraying liquid water and/or gaseous
water into the furnace freeboard through the spray tube.
[0037] In the above embodiment, in order to increase the content of
hydrogen in the coal gas, a small amount of water may be sprayed
while spraying the hydrocarbon. Of course, an additional spray tube
can also be arranged on the side wall of the furnace chamber for
spraying the water.
[0038] Additional aspects and advantages of the present disclosure
will become apparent in the following description or are understood
via the practice of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The above and/or additional aspects and advantages of the
present disclosure will become apparent and readily understood from
the following description of embodiments in combination with
drawings, wherein:
[0040] FIG. 1 is a structural schematic diagram of a metallurgical
electric furnace in an embodiment of the present disclosure,
wherein an arrow at a site A represents the blowing direction of
oxygen into slag, and the arrow at a site B represents the spraying
direction of coal particles into the slag;
[0041] FIG. 2 is a schematic diagram of an overlooking structure of
the metallurgical electric furnace as shown in FIG. 1, wherein the
arrow at a site C represents the spraying direction of oxygen and
coal particles into the slag;
[0042] FIG. 3 is a schematic diagram of an overlooking structure of
a metallurgical electric furnace in an embodiment of the present
disclosure, wherein the arrow at a site D represents the blowing
direction of a hydrocarbon into a furnace freeboard.
[0043] The corresponding relationship between reference signs and
component names in FIGS. 1 to 3 is as follows:
[0044] 1 furnace chamber, 11 side wall, 12 electrode, 13 slag, and
14 molten metal.
DETAILED DESCRIPTION
[0045] In order that the above objectives, features and advantages
of the present disclosure can be understood more clearly, the
present disclosure will be further described in detail below with
reference to the drawings and specific embodiments. It should be
noted that the embodiments in the present application and the
features in the embodiments may be combined with each other without
conflict.
[0046] In the following description, numerous specific details are
set forth in order to provide a thorough understanding of the
present disclosure, but the present disclosure may be practiced
otherwise than as described herein, therefore the protection scope
of the present disclosure is not limited by the specific
embodiments disclosed below.
[0047] A metallurgical electric furnace and a smelting method for
the metallurgical electric furnace according to some embodiments of
the present disclosure are described below with reference to the
drawings.
[0048] As shown in FIGS. 1 and 2, a metallurgical electric furnace
provided according to some embodiments of the present disclosure
includes a furnace body, an oxygen lance and a coal lance. The
furnace body is provided with a furnace chamber 1; the oxygen lance
located on a side wall 11 of the furnace chamber 1 and used for
blowing oxygen into slag 3 promoting the smelting process, wherein
the outlet of the oxygen lance is higher than the slag 3; and the
coal lance is located on the side wall 11 of the furnace chamber 1
beside the oxygen lance and used for injecting coal particles into
the slag 3, wherein the outlet of the coal lance is higher than the
slag 3.
[0049] In the metallurgical electric furnace provided by the above
embodiment of the present disclosure, especially in a continuously
operated metallurgical electric furnace, and particularly a
metallurgical electric furnace operated by an open arc, the outlet
of the oxygen lance and the outlet of the coal lance are higher
than the upper surface of the slag 3, the O.sub.2 is blown into the
slag 3 from top to bottom (along the direction of an arrow A in
FIG. 1 and the direction of an arrow C in FIG. 2) by the oxygen
lance, the low-valent reduced state substance in the slag 3 is
oxidized to a high-valent oxidation state substance, a large amount
of chemical energy is released in the oxidation process, the
temperature of the slag 3 is increased, the released chemical
energy can effectively smelt the feed, the coal particles is also
sprayed into the slag 3 from top to bottom (along the direction of
an arrow B in FIG. 1 and the direction of an arrow C in FIG. 2)
through the coal lance, the carbon in the coal particles reduces
the high-valent oxidation state substance to a low-valent reduced
state, when the high-valent oxidation state substance is reduced by
the carbon, CO is released, meanwhile, the reduction reaction needs
to absorb the heat, and then the energy released by the oxidation
of the reduced state substance is also supplied to the reduction
reaction; in the slag 3, due to the existence of the O.sub.2, the
O.sub.2 may also cause a combustion reaction with the CO and C, the
heat of combustion of the combustion reaction can raise the
temperature of the slag 3 so as to provide heat for the smelting of
the feed, and can also provide energy for the reduction reaction,
in this way, the chemical energy released in the oxidation reaction
and the energy released in the combustion reaction can be used for
the smelting of the feed, so that in addition to electrical energy
in the smelting process, the chemical energy can also provide a
large amount of energy for the smelting process, thereby improving
the total power of smelting, and improving the productivity and
efficiency, and it is especially effective for the slag 3 with a
high melting point, so that the consumption of electric energy is
reduced.
[0050] In the present solution, the oxygen lance and the coal lance
are both arranged above the slag 3, the O.sub.2 and the coal
particles are blown into the slag 3 from top to bottom, which are
away from the furnace lining, so that the damage to the furnace
lining is reduced, and the service life of the furnace lining is
prevented from being shortened. As shown by the arrow A in FIG. 1,
as the O.sub.2 is from top to bottom and inclines toward a
direction away from the installation position of the oxygen lance
on the side wall 11 of the furnace chamber 1, that is, the spraying
direction of the O.sub.2 faces to the opposite side of the
installation position of the oxygen lance on the side wall 11 of
the furnace chamber 1, as shown by the arrow B in FIG. 1, the coal
particles is also from top to bottom and inclines toward the
direction away from the installation position of the coal lance on
the side wall 11 of the furnace chamber 1, that is, the spraying
direction of the coal particles faces to the opposite side of the
installation position of the coal lance on the side wall 11 of the
furnace chamber 1, so that the slag flows toward the opposite side
of the installation positions of the oxygen lance and the coal
lance on the side wall 11 of the furnace chamber 1, but is very far
away from the furnace lining, in this way, the generated turbulence
is low or somewhat cancelled by one another, and the integrity of
the furnace lining can be protected.
[0051] Specifically, using an example that the reduced state
substance in the slag 3 is Me.sub.2O.sub.3, the chemical reactions
occurring in the slag 3 in the oxygen blowing and coal spraying
including:
Me.sub.2O.sub.3+0.5O.sub.2=2MeO.sub.2 (1)
2MeO.sub.2+C=Me.sub.2O.sub.3+CO (2)
CO+0.5O.sub.2=CO.sub.2 (3)
O.sub.2+C=CO.sub.2 (4)
[0052] After the O.sub.2 is blown, the reaction (1) occurs, the
O.sub.2 oxidizes the Me.sub.2O.sub.3 into MeO.sub.2, the oxidation
reaction is an exothermic reaction, and a large amount of chemical
energy is released in the reaction for smelting of the feed; after
the coal particles is injected, the reaction (2) occurs, the carbon
reduces the MeO.sub.2 into Me.sub.2O.sub.3, meanwhile, releases CO,
the reaction (2) is an endothermic reaction, and the chemical
energy released in the reaction (1) is further used for providing
energy for the reaction (2) in addition to smelting the feed; and
the O.sub.2 in the slag 3 can also cause the combustion reactions
(3) and (4) with the CO and C, a part of the heat of combustion is
released into the slag 3 for smelting the feed and being supplied
to the reaction (2), as the reaction (1), the reaction (3) and the
reaction (4) are all exothermic reactions, the chemical energy
released in the reactions improves the total smelting power and
reduces the consumption of electric energy. At the same time, a
large amount of CO is released in the reaction (2) to form bubbles,
which swells the slag 3 into foam slag, and the formation of the
foam slag 3 is favorable for the blowing of the O.sub.2.
[0053] The distribution of electrodes 2 in the furnace chamber is
as shown in FIGS. 1 and 2, and preferably, three electrodes are
arranged in a triangle.
[0054] The electric furnace of the present disclosure is fixed, the
feed is supplied unceasingly, when the molten iron reaches a
certain liquid level, a molten metal outlet is opened to release
the molten metal 4, the feed is supplied as usual, and the oxygen
and coal are blown and sprayed as usual. After a certain amount of
the molten metal 4 flows out, the molten metal outlet is blocked by
a blocking machine, after a period of time, when the slag level is
too high, a slag opening is opened to discharge the slag, the feed
is supplied as usual, and the oxygen and coal are blown and sprayed
as usual.
[0055] Preferably, as shown in FIGS. 1 and 3, the continuously
operated metallurgical electric furnace includes a plurality of
oxygen lances and plurality of coal lances, the plurality of oxygen
lances are uniformly distributed along the side wall 11 of the
furnace chamber 1; and the plurality of coal lances are uniformly
distributed along the side wall 11 of the furnace chamber 1.
[0056] In a specific embodiment of the present disclosure, the
oxygen lances are located below the coal lances. Preferably, the
number of the oxygen lances is equal to the number of the coal
lances, the coal lances are located right above the oxygen lances,
and the two lances are arranged up and down.
[0057] In another specific embodiment of the present disclosure,
the oxygen lance and the coal lance are located at the same height
on the side wall 11 of the furnace chamber 1 and are arranged on
the left and right sides.
[0058] Preferably, as shown in FIG. 2, the plurality of oxygen
lances are uniformly distributed at the same height on the side
wall 11 of the furnace chamber 1 along the circumferential
direction, and the plurality of coal lances are uniformly
distributed at the same height on the side wall 11 of the furnace
chamber 1 along the circumferential direction.
[0059] Preferably, a coal lance and an oxygen lance can be placed
in the same cooling jacket, and the distance between the injection
points of the coal lance and the oxygen lance in a molten pool is
not less than 300 mm.
[0060] In the above embodiment, the oxygen lance and the coal lance
are located above the molten pool, and the O.sub.2 and the coal
particles are blown into the furnace chamber 1 from top to bottom,
the flow rate of the O.sub.2 is a supersonic speed to penetrate
through the foam slag, and the coal can also be injected into the
molten pool. The plurality of oxygen lances are uniformly
distributed on the side wall 11 of the furnace chamber 1, so that
the uniformity of blowing the O.sub.2 into the slag 3 can be
improved, in this way, the distribution uniformity of the chemical
energy released by the reduced state substance in the oxidation
process in the slag 3 is improved, and the smelting uniformity of
the feed in the furnace chamber 1 is improved; and the plurality of
coal lances are uniformly distributed on the side wall 11 of the
furnace chamber 1, so that the uniformity of spraying the coal
particles into the slag 3 is improved, and the conversion rate of
reducing the high-valent oxidation state substance into the
low-valent reduced state substance is improved.
[0061] Preferably, the oxygen lance and the coal lance are
installed on the side wall 11 of the furnace chamber 1 and
penetrate through a refractory material to enter the furnace
chamber 1.
[0062] Preferably, as shown in FIG. 3, the continuously operated
metallurgical electric furnace further includes a spray tube, the
spray tube is located on the side wall 11 of the furnace chamber 1
and used for spraying a hydrocarbon into a furnace freeboard,
wherein the outlet of the spray tube is higher than the slag 3.
[0063] In the above embodiment, a part of the electrical energy and
the chemical energy is applied to the reaction (2), the CO produced
by the reaction (2) enters the furnace freeboard, and the CO
carries a large amount of energy, a part of the heat of combustion
released by the reactions (3) and (4) is used for smelting the feed
and the reaction (2), a part of the heat of combustion heats up
gases (CO, CO.sub.2, O.sub.2) and enters the furnace freeboard to
serve as a heat source for the pyrolysis gasification of the
hydrocarbon to generate coal gas, therefore the present disclosure
improves the total power of the smelting, and meanwhile, generates
the coal gas, and avoids the waste of energy contained in the flue
gas.
[0064] The furnace freeboard is also known as a freeboard, which
refers to a space above the molten pool and below a furnace
roof.
[0065] Specifically, the hydrocarbon causes the following reactions
in the furnace freeboard:
C.sub.nH.sub.m=nC+m/2H.sub.2 (5)
2C.sub.nH.sub.m+CO.sub.2=2(n+1)CO+mH.sub.2 (6)
C.sub.nH.sub.m+nH.sub.2O=nCO+(n+m/2)H.sub.2 (7)
C+CO.sub.2=2CO (8)
C+H.sub.2O=H.sub.2+CO (9)
[0066] As the space of the furnace freeboard is limited, the
reactions (5), (6), (7), (8), (9) may not reach chemical
equilibrium, and the final temperature and gas composition depend
on the dynamic balance of the system.
[0067] Preferably, as shown in FIG. 3, the spraying direction of
the hydrocarbon into the furnace freeboard can be (but not limited
to) tangential to the side wall 11 of the furnace chamber 1.
Preferably, the hydrocarbon is sprayed from top to bottom (along
the direction of an arrow D in FIG. 3). The spraying direction of
the hydrocarbon into the furnace freeboard is tangential to the
side wall 11 of the furnace chamber 1, so that the time of the gas
to staying in the furnace chamber 1 is prolonged to cause more
reactions. But if the location occupied by the spray tube is too
large, the design is affected, the spray tube can also be vertical
to the side wall 11 of the furnace chamber 1, that is, the spraying
direction of the hydrocarbon into the furnace freeboard is vertical
to the side wall 11 of the furnace chamber 1.
[0068] Preferably, a plurality of uniformly distributed spray tubes
is arranged on the side wall 11 of the furnace chamber 1.
[0069] The embodiment of the second aspect of the present
disclosure provides a smelting method for the metallurgical
electric furnace according to any one of the above embodiments,
wherein the slag 3 includes a reduced state substance capable of
being oxidized by O.sub.2, and the smelting method includes:
blowing oxygen into the slag 3 via an oxygen lance so as to oxidize
the reduced state substance to an oxidization state substance; and
spraying coal into the slag 3 through a coal lance so as to reduce
the oxidized oxidization state substance.
[0070] According to the smelting method provided by the above
embodiment of the present disclosure, the O.sub.2 is blown into the
slag 3 from top to bottom (along the direction of the arrow A in
FIG. 1 and the direction of the arrow C in FIG. 2) to oxidize the
low-valent reduced state substance in the slag 3 into a high-valent
oxidation state substance, a large amount of chemical energy is
released in the oxidation process to effectively smelt the slag,
meanwhile, the coal particles is also sprayed into the slag 3 from
top to bottom (along the direction of the arrow B in FIG. 1 and the
direction of the arrow C in FIG. 2) to reduce the high-valent
oxidation state substance to a low-valent reduced state, CO is
released at the same time, the reduction reaction is an endothermic
reaction, the energy released by the oxidation of the reduced state
substance is also supplied to the reduction reaction; and in the
slag 3, the O.sub.2 has a combustion reaction with the CO and C,
the heat of combustion of the combustion reaction can raise the
temperature of the slag 3 so as to provide heat for the smelting of
the feed, and can also provide energy for the reduction reaction,
in this way, the chemical energy released in the oxidation reaction
and the energy released in the combustion reaction can be used for
the smelting of the feed, in addition to electrical energy in the
smelting process, the chemical energy can also provide a large
amount of energy for the smelting process, thereby improving the
total power of smelting, and improving the productivity and
efficiency, it is especially effective for the slag 3 with a high
melting point, and the consumption of electric energy is
reduced.
[0071] Preferably, the depth of the oxygen blown into the slag 3
does not exceed one-half of the thickness of the slag 3. Thus, a
high oxidation area, namely, a high reaction area, is located at
the upper part of the slag 3, the lower part is not affected by the
blowing and spraying and is still a high reduction area, so that
the recovery of the metal is not affected.
[0072] Of course, the oxygen can be firstly blown and then the coal
is sprayed, and the oxygen blowing and coal spraying can be
performed at the same time.
[0073] In the above technical solution, preferably, the depth of
the oxygen blown into the slag 3 is within the range of one-third
of the thickness of the slag 3 to one-half of the thickness of the
slag 3.
[0074] In the above embodiment, for different slag 3 systems, the
ratios of the depth of O.sub.2 blown into the slag 3 to the total
thickness of the slag 3 are different, if the slag 3 system needs
to be controlled at a very low oxygen potential to reduce the metal
oxides to be recycled, the depth of the oxygen blown into the slag
3 is within the range of one-third of the longitudinal thickness of
the slag 3 to two-thirds of the longitudinal thickness of the slag
3, and the coal particles can be sprayed deeper to ensure the low
oxygen potential.
[0075] Preferably, the coal is anthracite or bituminous coal.
[0076] In the electric arc furnace steelmaking, only the anthracite
or coke can be used, and the bituminous coal cannot be used.
However, the anthracite or bituminous coal can be used in the
present application. Of course, the coke can also be used in the
present application. Because in the steelmaking furnace, the
purpose is to generate enough gas (CO) to cause foam slag, but to
avoid generating too much gas, which leads to the consumption of
excessive oxygen, and the excessive gas generated cannot be
recycled at the same time, resulting in waste, so the use of
bituminous coal in the steelmaking furnace is avoided. However, in
the present disclosure, the gas yield is increased and the gas is
completely recycled, so bituminous coal is another choice, and
accordingly, the production cost can be reduced.
[0077] Preferably, after spraying the coal into the slag 3 through
the coal lance, the method further includes: blowing a hydrocarbon
into the furnace freeboard through a spray tube.
[0078] In the above embodiment, the hydrocarbon is blown into the
furnace freeboard horizontally into the furnace freeboard (along
the direction of the arrow D or straight to the center in FIG. 3),
the energy carried by the CO released by the oxidation reaction,
the chemical energy generated by the combustion reaction of CO and
O.sub.2, and the chemical energy generated by the combustion
reaction of C and O.sub.2 can be used as the heat source for the
pyrolysis gasification of the hydrocarbon, so that a coal gas is
generated in the furnace freeboard.
[0079] Preferably, the hydrocarbon includes natural gas or light
oil. Of course, methane gas and solid bituminous coal and the like
sprayed into the furnace freeboard can be converted into the coal
gas, the temperature of the gases (CO+CO.sub.2+H.sub.2+H.sub.2O)
generated in the molten pool is extremely high (the temperature is
greater than 1700.degree. C.), and the gases contain a large amount
of heat, which enters the furnace freeboard, the above hydrocarbon
is sprayed into the furnace freeboard to cause an endothermic
chemical reaction with the CO.sub.2 and H.sub.2O so as to cracked
into the coal gas.
[0080] Of course, the hydrocarbon can also be blown into the
furnace freeboard while the coal is sprayed.
[0081] Preferably, while spraying the hydrocarbon into the furnace
freeboard through the spray tube, the method further includes:
spraying liquid water and/or gaseous water into the furnace
freeboard through the spray tube.
[0082] In the above embodiment, in order to increase the content of
hydrogen in the coal gas, a small amount of water may be sprayed
while spraying the hydrocarbon. Of course, an additional spray tube
can also be arranged on the side wall of the furnace chamber for
spraying the water. With respect to the spraying sequence of the
liquid water and/or the gaseous water and the hydrocarbon, the
water can be sprayed while blowing the hydrocarbon, or can be
sprayed successively. Specifically, the hydrocarbon can be sprayed
at first and the water can also be sprayed at first.
[0083] Using the smelting of titanium vanadium magnetite as an
example, the oxygen blowing and coal spraying is carried out in a
pilot electric furnace, and the operating parameters are different
according to the conditions of the raw materials. The table below
lists some operation parameters of two different smelting manners
and the obtained iron output, coal gas output and coal gas
components.
TABLE-US-00001 Embodiment -- First Second embodiment embodiment Raw
material -- Direct cold Prereduction hot feeding feeding
Metallization rate % 0 85 Inlet temperature .degree. C. 25 650 Iron
output tph 1.2 2.9 Slag output tph 0.8 1.9 Electric power MW 2.4
1.9 Chemical energy power MW 4.1 4.6 Total power MW 6.5 6.5 Oxygen
blowing amount Nm.sup.3/h 1435 1607 Natural gas spraying amount
Nm.sup.3/h 323 354 Bituminous coal spraying tph 2.0 2.2 amount
Anthracite adding amount tph 0.59 0.35 Nitrogen consumption
Nm.sup.3/h 198 222 Electric furnace flue gas flow Nm.sup.3/h 6302
6394 CO Vol % 59 57 H.sub.2 Vol % 29 30 N.sub.2 Vol % 7 7 CO.sub.2
Vol % 3 4 H.sub.2O Vol % 2 2
[0084] The first embodiment differs from the second embodiment in
that, in the first embodiment, the cold material is directly added
into the metallurgical electric furnace, and in the second
embodiment, the vanadium titano-magnetite is pre-reduced to a high
metallization rate, and then the hot material is added into the
metallurgical electric furnace.
[0085] It can be seen from the parameters of the first embodiment
and the second embodiment that after the oxygen blowing and coal
spraying technology is adopted in the metallurgical electric
furnace, the electric power accounts for 37% of the total power in
the first embodiment, and the electric power accounts for 30% of
the total power in the second embodiment, therefore, after the
oxygen blowing and coal spraying technology is adopted, the
consumption of electric energy is reduced in the smelting.
[0086] In the first embodiment and the second embodiment, the total
power is the same, and the coal gas output and the components
generated are also substantially the same, but the iron output
produced in the second embodiment is 2.4 times greater than that of
the first embodiment. In the first embodiment, the cold material is
directly added and is not pre-reduced, so that the equipment is
simple, and the investment is small, but the total energy
consumption per ton of finished product is large, and the dosage of
the anthracite used as a reducing agent is large. In the second
embodiment, the pre-reduced hot material requires the investment of
pre-reduction equipment, but the cheap bituminous coal can be used
as a fuel and the reducing agent to reduce the dosage of the
anthracite, and the smelting energy consumption is small. In the
actual using process, the choice of direct addition of the cold
material or the addition of the pre-reduced hot material can depend
on the energy price.
[0087] It should be noted that the solution is mainly for the
smelting of vanadium, titanium and iron ore. At this time, the
oxidation state substance in the reactions (1) and (2) is
TiO.sub.2, and the reduced state substance is Ti.sub.2O.sub.3, but
it can also be applied to the smelting of FeO/Fe.sub.3O.sub.4
systems with the presence of copper sulfide and nickel sulfide
ores.
[0088] In summary, the continuously operated metallurgical electric
furnace provided by the embodiment of the present disclosure adopts
the oxygen blowing and coal spraying technology, the O.sub.2
oxidizes the low-valent reduced state substance in the slag 3 into
the high-valent oxidation state substance, the chemical energy
released in the oxidation process can effectively smelt the feed,
and meanwhile, the coal particles is also sprayed into the slag 3
from top to bottom to reduce the high-valent oxidation state
substance into the low-valent reduced state; the O.sub.2 in the
slag 3 causes the combustion reaction with the CO and C to further
provide heat for the smelting of the feed, so that in addition to
the electrical energy in the smelting process, the chemical energy
can also provide a large amount of energy for the smelting process,
thereby improving the total power of smelting, and improving the
productivity and efficiency, it is especially effective for the
slag 3 with a high melting point, and the consumption of electric
energy is reduced.
[0089] In the description of the present disclosure, the term
"plurality" means two or more unless specifically stated or defined
otherwise; unless otherwise specified or stated, the terms
"connection", "fixation" and the like are understood generally, for
example, the "connection" may be a fixed connection, a detachable
connection, or an integral connection, or an electrical connection;
and it may be directly connected or indirectly connected through an
intermediate medium. The specific meanings of the above terms in
the present disclosure may be understood by those of ordinary in
the art according to the specific conditions.
[0090] In the description of the present specification, it should
be understood that the orientation or positional relationships
indicated by the terms "upper", "lower", "front", "rear", "left",
"right" and the like are orientation or positional relationships
shown in the drawings, are merely for the convenience of describing
the present disclosure and simplifying the description, and are not
intended to imply that the devices or units referred to have
specific orientations, are constructed and operated in specific
orientations, and therefore are not to be construed as limiting the
present disclosure.
[0091] In the description of the present specification, the
description of the terms "one embodiment", "some embodiments",
"specific embodiments" and the like mean that the specific
features, structures, materials or characteristics described in
combination with the embodiments or examples are included in at
least one embodiment or example of the present disclosure. In the
present specification, the schematic expressions of the above terms
do not necessarily refer to the same embodiment or example.
Furthermore, the particular features, structures, materials or
characteristics described may be combined in a suitable manner in
any one or more embodiments or examples.
[0092] The above descriptions are only preferred embodiments of the
present disclosure, and are not intended to limit the present
disclosure, and various modifications and changes can be made to
the present disclosure for those skilled in the art. Any
modifications, equivalent substitutions, improvements and the like
made within the spirit and principle of the present disclosure
shall fall within the protection scope of the present
disclosure.
* * * * *