CA1050766A - Method and means for reducing material containing ferric oxide - Google Patents
Method and means for reducing material containing ferric oxideInfo
- Publication number
- CA1050766A CA1050766A CA221,555A CA221555A CA1050766A CA 1050766 A CA1050766 A CA 1050766A CA 221555 A CA221555 A CA 221555A CA 1050766 A CA1050766 A CA 1050766A
- Authority
- CA
- Canada
- Prior art keywords
- gas
- reaction zone
- solid
- carbonaceous material
- molecular oxygen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000000463 material Substances 0.000 title claims description 39
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims description 31
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 title 1
- 239000003575 carbonaceous material Substances 0.000 claims abstract description 51
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000000571 coke Substances 0.000 claims abstract description 15
- 229910052742 iron Inorganic materials 0.000 claims abstract description 10
- 238000006243 chemical reaction Methods 0.000 claims description 84
- 239000007789 gas Substances 0.000 claims description 83
- 239000011343 solid material Substances 0.000 claims description 32
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 30
- 229910001882 dioxygen Inorganic materials 0.000 claims description 30
- 235000013980 iron oxide Nutrition 0.000 claims description 29
- 239000007787 solid Substances 0.000 claims description 28
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 claims description 25
- 229910001868 water Inorganic materials 0.000 claims description 21
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 20
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 17
- 239000012530 fluid Substances 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 238000001816 cooling Methods 0.000 claims description 11
- 239000001569 carbon dioxide Substances 0.000 claims description 10
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 6
- 238000000926 separation method Methods 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 239000000428 dust Substances 0.000 claims description 4
- 238000007885 magnetic separation Methods 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 230000008030 elimination Effects 0.000 claims description 3
- 238000003379 elimination reaction Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 claims description 2
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 claims 6
- 230000003134 recirculating effect Effects 0.000 claims 1
- 238000004064 recycling Methods 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 8
- 238000005243 fluidization Methods 0.000 abstract description 6
- 230000001771 impaired effect Effects 0.000 abstract 1
- 239000000543 intermediate Substances 0.000 description 13
- 239000003921 oil Substances 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- 239000012141 concentrate Substances 0.000 description 4
- 238000013021 overheating Methods 0.000 description 4
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 3
- 239000003830 anthracite Substances 0.000 description 3
- 229960004424 carbon dioxide Drugs 0.000 description 3
- 239000006148 magnetic separator Substances 0.000 description 3
- 238000009835 boiling Methods 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 235000002918 Fraxinus excelsior Nutrition 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- -1 air Chemical compound 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000002956 ash Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 229910002090 carbon oxide Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000002817 coal dust Substances 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000332 continued effect Effects 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0033—In fluidised bed furnaces or apparatus containing a dispersion of the material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Dispersion Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method and apparatus for reducing pulverulent iron ore with a carbonaceous material in a circulating fluidized bed is described. In such system a known difficulty is that sticking together of the particles in the bed impairs fluidization of the bed. Such impaired fluidization is avoided by controlling the flow of carbonaceous material to the bed so that there is always sufficient coke in the bed to avoid sticking.
A method and apparatus for reducing pulverulent iron ore with a carbonaceous material in a circulating fluidized bed is described. In such system a known difficulty is that sticking together of the particles in the bed impairs fluidization of the bed. Such impaired fluidization is avoided by controlling the flow of carbonaceous material to the bed so that there is always sufficient coke in the bed to avoid sticking.
Description
6~
The present invention relates to a method of completely or partially reducing pulverized material containing iron oxides mixed with finely disintegrated, solid carbonaceous material at a temperature lower than the melting point of the iron. By solid carbonaceous material is meant coke obtained from the fuel and reducing agent containing carbon, such as anthra-cite, coal or oil. By pulverized material containing iron oxides is meant iron ore concentrate, calcined pyrites or other material containing iron oxide, said material having a particle size of up to 1 mm.
It has already been proposed to reduce pulverized material containing iron oxides mixed with pulverized, solid carbonaceous material, for example in rotary furnaces or in fluidized beds of conventional type.
The present invention does not make use of a fluidized bed of conventional type but instead uses a so-called circulating fluidized bed tor conditions of existence for a circulating fluid see L. Reh, Chem.
Engineering Progress, February, 1971, vol. 67, No. 2, p. 58-63).
Most attempts to utilize the fluid bed technique for reducing material containing iron oxides which have been made so far have used the con-ventional fluid bed technique, whereupon the difficulties have been encoun-tered which are caused by the gas being kept in the bed for only a short while.
Endeavours to increase the effect in such a process by increasing the reaction temperature have also resulted in problems of sticking, i.e. the small par--ticles oE material in the bed have agglomerated to form larger particles and aggregates and finally made Eluidization impossible.
The contact time can be increased by using a circulating fluid bed in which the tendency of sticking is also less due to the vigorous inter-nal circulation of the material. Sticking increases with inCreaSing tempera-ture, degree of metallization and fineness of the bed material and decreases with increasing turbulence, gangue content, total pressure and addition of pulverized diluting material, such as coke.
Experiments have been perEormed reducing the puLverized mate-rial containing iron oxides mixed with pulverized, solid, carbonaceous mate-r~ .
~05~766 rial in a circulating fluid bed where the carbonaceous material is partially combusted with a gas containing molecular oxygen, which is introduced as fluidization gas in the bed. Due to the addition of the solid, pulverized carbonaceous material, the risk of sticking has been decreased and it has been possible to increase the temperature, thus increasing the reaction rate.
However, when the gas containing molecular oxvgen is blo~ in through distributors in the bottom of the reactor for fluidization, there is even in this case a certain tendency towards agglomeration at the distributors, probably due to local overheating.
The present invention relates to a method of reduction of pulverized material containing iron oxides mixed with pulverized carbonaceous material in a circulating fluid bed while entirely avoiding sticking between the particles, and a device Eor performing this method.
~ ccording to the invention a circulat:ing ELuid bed of pulver-ized material containing iron oxides mixcd with pulverized carbonaccous material is maintained in a vertically elongated reaction zone. The circulat-ing fluid bed is maintained by supplying it with suitable flows of the pulverized material containing iron oxides, pulverized solid carbonaceous material and possibly liquid carbonaceous material, together with gas contain-ing molecular oxygen. A mixture of gas and solid material leaves the reactionzone and is subjected to separation, after which the solid material is returned to the reaction zone.
This invention seeks to provide a method of reducing a pulver-ized material containing iron oxides mixed with carbonaceous material, comprising: (a) maintaining in a vertically uninterrupted, elongated reaction zone a circulating fluidized bed, said circulating fluid bed being maintained by 1) continually withdrawing a portion of fluidized solids and fluidizing gas and a gas formed by reaction in said reaction zone, 2) separating said gas and solids, 3) continually returning a portion of said solid material to said reaction zone for circulating of said solids in said bed without a solid gas interface in said bed, and 4) continually returning said separation gas to said elongated reaction zone as a fluidizing gas, said reaction zone consist-~ - 2 -~J
~i0766i ing essentially of lower, intermediate, and upper reaction zones; ~b) supply-ing said bed with a suitable quantity of pulverized material containing iron oxides and pulverized solid carbonaceous material as said solid material and liquid carbonaceous material, said liquid carbonaceous material being from 0 .
to 60% by weight of the carbonaceous material and, as a gas for reaction with said solid material, a gas containing molecular oxygen; (c) supplying said pulverized material containing iron oxides, said carbonaceous material and said gas containing molecular oxygen, to the intermediate reaction zone of -said reaction zone, said intermediate reaction zone being at a position of about middle of said elongated reaction zone; ~d) controlling the carbonaceous ~.
ma~erial feed into said reaction zone so that there is always sufficient solid :. ' . ' carbonaceous material in the bed to prevent the defluidization of said bed caused by sticking; (e) withdrawing gas and solid material from the upper reaction zone, said solid material being withdrawn, being separated ~rom the gas and said solid material being continually returned to said intermediate reaction zone of said reaction zone; If) feeding a portion of said withdrawn gas, after dust separation and elimination of substantially all carbon .
dioxide and water, to said lower part of said reaction zone as fluidizing and .
reducing gas, said carbon dioxide being formed by reaction of carbon in said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas and said water being formed by reaction of hydrogen from said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas; and (g) withdrawing a solid material containing completely or partially reduced iron oxides from the lower part of the reaction zone. :.
The pulverized material containing iron oxides supplied to the fluid bed has a particle size of less than 1 mm, preferably less than 0.5 mm.
The disintegrated, solid carbonaceous material supplied may be coke breeze, anthracite dust or coal dust and should have a particle size of less than 3 mm, preferably less than 1 mm.
- 2a -I:~,;, ' ' ~ .
; :
~al 5C~6~
The reaction zone may be thought of as divided into an upper part, a lower part and an intermediate part. In the method according to the invention the pulverized material containing iron oxides, the carbonaceous - 2b -11D5(~76~i :
material and the gas containing molecular oxygen are fed into the inter-mediate section. Partial combustion of the carbonaceous material in this section generates the heat necessary for the process. Coking and degassing of carbonaceous material takes place in ~he upper part of the reaction zone, as well as reduction with carbon or carbon dioxide and water formed during the combustion to form hydrogen gas and carbon monoxide. A certain amount of reduction of the material containing iron oxides also takes place here. This reaction suitably takes place at a temperature of 850 -1000 C. The flow of solid carbonaceous material must be controlled so that there is always suffi-cient in the bed to prevent interference of the fluidization due to agglGmera-tion. Gas produced is discharged from the upper part mixed with the solid material from the bed. This is separated from the gas and returned to the intermediate section.
It has been found that the abili~y of the solid carbonaceous material to prevent sticking is dependent on the temperature and the proper-ties of the material containing iron oxides. At a temperature of 900 C and using normal iron ore concentrate, it has been found that the weight ratio between solid carbonaceous material ~coke) and concentrate in the reaction zone should be at least 0.5:1.
Part of the gas discharged is subjected to additional dust separation, most of its content of C02 and H20 is removed, and it is reintro-duced in the lower part of the reaction zone as fluidization and reducing gas.
A strongly reducing atmosphere is thus maintained in the lower part and con-tinued reduction of the material containing iron oxides takes place.
Solid material is discharged as required from the lower part of the reaction zone, so that the quantity of solid material in the reaction zone is kept constant. Net transport of solid material is thus obtained in countercurrent to the gas introduced into the lower part. The transfer of heat from the intermediate section of the reaction zone to the lower part, however, is maintained mainly through the internal circulation of material in 7~6 the reaction zone. This internal circulation is considerable, thus promoting temperature equalization. The solid material discharged consists of coke and completely or partially reduced iron oxides and is preferably cooled to below the curie point of iron and separated magnetically intO a substantially coke~
free iron fraction and a substantially iron-free coke fraction. The cooling -~
is suitably performed by allowing the material to pass a conventional fluid bed formed by the material itself, with built-in cooling surfaces. The gas containing molecular oxygen is suitably used as coolant and is thereby pre-heated.
It is advisable to control the flow of gas containing molecular oxygen, for example air possibly mixed with C02 and/or H2O, so that the heat requirement for maintaining the desired temperaturc in the circulating bed is covered. The heat is generated by partial combustion of the carbonaceous material. It is also feasible to supply heat, either solely or partially, indirectly from an external source of heat such as a nuclear reactor. In this case heat may be transferred by hot gas to heating surfaces built into the reaction zone.
In order to prevent excessive generation of heat per unit volume of the reaction zone, which would cause local over-heating and risk of a certain amount of agglomeration of the bed material, the flow of gas con-taining molecular oxygen is preferably divided into several part-flows which are introduced at separate points in several levels in the intermediate section of the reaction zone.
The solid carbonaceous material is suitably supplied to the intermediate section of the reaction zone in several jets, preferably with the help of reducing and/or neutral gas blown through nozzles. However, with carbonaceous material having a low content of volatile constituents, such as anthracite, it is possible to use gas containing molecular oxygen such as air, in which case this is preferably not preheated in order to avoid the ; 30 risk of local overheating. For this purpose a total flow of gas comprising ~5~766 10 - 30 % of the total flow of the carbonaceous material will be required, depending on the shape of the blowing nozzles. ~
It is also possible to introduce the carbonaceous material via ;
a smaller, auxiliary reaction zone, separate from the reaction zone, in which a fluid bed is maintained with the help of a partial flow of the gas contain-ing molecular oxygen. In this case, gas and material are conducted from the auxiiiary reaction zone through a common pipe into the intermediate section of the reaction zone. A certain amount of the partial combustion of the carbonaceous material takes place in the auxiliary reaction zone and agglomera-tion around the distributor openings can therefore be avoided due to the short ~ :
time which the carbonaceous material spends there, which means that only a ~
few particles ha~e time to be burnt to ashes. With too high concentrations - :
and in the event of local overheating, this may easily result in agglomeration ~:
and crusting.
Some of the solid carbonaceous material may be replaced by liquid carbonaceous material, such as oil. In this case, it is preferably sprayed into ~he intermediate section of the reaction zone through a number of jets. So-called atomization of the oil as done in connection with complete ,`
combustion, is not necessary. The relatively rough dispersion of the oil which is obtained if it is supplied in part-flows through pipes together with a non-oxidizing gas, is sufficient. A volume ratio of 100:1 is suitable for gas and oil used. If an auxiliary reaction zone is used the oil is prefer-ably supplied to this and the level at which it is supplied should be about 0.5 m above the distrîbutor bottom for the gas containing molecular oxygen.
The exhaust from the reaction zone can at least partially be used for preheating the feed material containing iron oxides, by being brought into direct contact with this. Thereafter, this portion of the exhaust is recirculated to the lower part of the reaction zone, after elimination of most of its content of C02 and H20 in a manner known per se, and is used as fluidizing and reducing gas in the lower part of the reaction zone.
. , ., .':
~5~76~
A par~-flow of the exhaust, substantially freed from C02 and H20, is suitably used as fluidizing gas in the cooling and magnetic separation of the material discharged from the lower part of the reaction zone. By performing the entire process above atmospheric pressure, for example 1 -10 atm, the dimensions necessary for the apparatus can be considerably reduc-ed.
The heat content ~physical and chemical) of the exhaust is suit-ably used to generate electric energy with which, for example, the reduced ferrous material can be melted and possibly finally reduced.
The method and means according to the invention will be further explained with reference to the embodiment of the invention shown in the ~igure. This consists of vertically elongated reactor 1, the upper part 2 o which encloses the upper part of the reaction zone, the central part 3 of the reactor enclosing the :intermediate section oE the reaction zone ~nd :its lower part 4 the lower part of the reaction zone. A cyclone 5 is connected to the upper part 2 o the reactor and has a return conduit 6 leading to the central part 3 of the reactor. There are also one or more inlets for carbonaceous material 7 in this zone. The gas containing molecular oxygen is supplied to the central part 3 of the reactor in a number of part-flows through nozzles 8, while the recirculated part-flow of the gas is supplied to the lower part 4 of the reactor through a suitable distributor 9. Treated solid material is discharged through an outlet 10 in the lower part of the reactor, cooled in a cooling device ll and passes a magnetic serparator 12 in which it is separa~ed into a substantially coke-free iron fraction 13 and a substantially iron-free coke fraction 14.
The gas containing molecular oxygen, preferably air, is blown through line 15 through the cooling device 11 where it is preheated, and on through the line 17 to nozzles 8. The cooling device 11 is preferably in the form of a conventional fluid bed with built-in cooling elements thro-ugh which the gas containing molecular oxygen is led for preheating.
~0~7gi~
Some of the exhaust (for instance 50 percent) from the exhaustpipe 18 from the cyclone 5 is led via valve 16 to a ven-turi device 19 where it preheats the pulverized material containing iron oxides, for instance ore concentrate entering via line 20, possibly mixed with return coke from the magnetic separator. The flow of gas and material is then conveyed to a cyclone 21 and then to a fine cleaning cyclone 22 in which the solid material is separated off and returned to the central part of the reactor, preferably through the return conduit 6. The gas, cleaned from solid material, is con-veyed along a conduit 23, possibly being cooled indirectly at 2~ by boiling water, and through a heat exchanger 25 to scrubbers 27 where it is substan-tially freed from C02 and H20. Cooling by boiling water may be necessary to prevent the temperature in the heat exchanger from becoming too high for the materials used. H20 can be removed through direct or indirect cooling.
C2 is washed out, for instance using alkaline solutions, in which case the steam in line 28 from the boiler 24 can be used to regenerate these solutions.
If the pressure in the system is sufficiently high C02 can be washed out with water. Most of the gas coming from the scrubbers, which is driven by a com-pressor 29, is heat-exchanged at 25 with gas entering the scrubbers and is introduced as fluidizing and rieducing gas into the lower part ~ of the reactor.
This produces a strongly reducing zone through which the solid material passes before being discharged. In view of the smaller gas flow, this part of the reactor is suitably given a smaller diameter than the upper part. A part-flow of the gas in line 31 freed from C02 and H20 is used without heat-exchanging as fluidizing gas in the cooling device 11 for discharged solid material and in the magnetic separator 12 and is then con-veyed via 32 and 33 ;; into the lower part of the reactor. The remainder of the exhaust in line 34 from the cyclone 5, possibly together with a part-flow of the coke fraction from the magnetic separation, is preferably used as fuel in a ther~l power station while the rest of the coke flow is recirculated to the reactor, _7_ :lOSa~76G
possibly mixed with the feed containing iron oxides, and/or used as reducing agent in a melt reduction step for the iron fraction from the magnetic separator. --
The present invention relates to a method of completely or partially reducing pulverized material containing iron oxides mixed with finely disintegrated, solid carbonaceous material at a temperature lower than the melting point of the iron. By solid carbonaceous material is meant coke obtained from the fuel and reducing agent containing carbon, such as anthra-cite, coal or oil. By pulverized material containing iron oxides is meant iron ore concentrate, calcined pyrites or other material containing iron oxide, said material having a particle size of up to 1 mm.
It has already been proposed to reduce pulverized material containing iron oxides mixed with pulverized, solid carbonaceous material, for example in rotary furnaces or in fluidized beds of conventional type.
The present invention does not make use of a fluidized bed of conventional type but instead uses a so-called circulating fluidized bed tor conditions of existence for a circulating fluid see L. Reh, Chem.
Engineering Progress, February, 1971, vol. 67, No. 2, p. 58-63).
Most attempts to utilize the fluid bed technique for reducing material containing iron oxides which have been made so far have used the con-ventional fluid bed technique, whereupon the difficulties have been encoun-tered which are caused by the gas being kept in the bed for only a short while.
Endeavours to increase the effect in such a process by increasing the reaction temperature have also resulted in problems of sticking, i.e. the small par--ticles oE material in the bed have agglomerated to form larger particles and aggregates and finally made Eluidization impossible.
The contact time can be increased by using a circulating fluid bed in which the tendency of sticking is also less due to the vigorous inter-nal circulation of the material. Sticking increases with inCreaSing tempera-ture, degree of metallization and fineness of the bed material and decreases with increasing turbulence, gangue content, total pressure and addition of pulverized diluting material, such as coke.
Experiments have been perEormed reducing the puLverized mate-rial containing iron oxides mixed with pulverized, solid, carbonaceous mate-r~ .
~05~766 rial in a circulating fluid bed where the carbonaceous material is partially combusted with a gas containing molecular oxygen, which is introduced as fluidization gas in the bed. Due to the addition of the solid, pulverized carbonaceous material, the risk of sticking has been decreased and it has been possible to increase the temperature, thus increasing the reaction rate.
However, when the gas containing molecular oxvgen is blo~ in through distributors in the bottom of the reactor for fluidization, there is even in this case a certain tendency towards agglomeration at the distributors, probably due to local overheating.
The present invention relates to a method of reduction of pulverized material containing iron oxides mixed with pulverized carbonaceous material in a circulating fluid bed while entirely avoiding sticking between the particles, and a device Eor performing this method.
~ ccording to the invention a circulat:ing ELuid bed of pulver-ized material containing iron oxides mixcd with pulverized carbonaccous material is maintained in a vertically elongated reaction zone. The circulat-ing fluid bed is maintained by supplying it with suitable flows of the pulverized material containing iron oxides, pulverized solid carbonaceous material and possibly liquid carbonaceous material, together with gas contain-ing molecular oxygen. A mixture of gas and solid material leaves the reactionzone and is subjected to separation, after which the solid material is returned to the reaction zone.
This invention seeks to provide a method of reducing a pulver-ized material containing iron oxides mixed with carbonaceous material, comprising: (a) maintaining in a vertically uninterrupted, elongated reaction zone a circulating fluidized bed, said circulating fluid bed being maintained by 1) continually withdrawing a portion of fluidized solids and fluidizing gas and a gas formed by reaction in said reaction zone, 2) separating said gas and solids, 3) continually returning a portion of said solid material to said reaction zone for circulating of said solids in said bed without a solid gas interface in said bed, and 4) continually returning said separation gas to said elongated reaction zone as a fluidizing gas, said reaction zone consist-~ - 2 -~J
~i0766i ing essentially of lower, intermediate, and upper reaction zones; ~b) supply-ing said bed with a suitable quantity of pulverized material containing iron oxides and pulverized solid carbonaceous material as said solid material and liquid carbonaceous material, said liquid carbonaceous material being from 0 .
to 60% by weight of the carbonaceous material and, as a gas for reaction with said solid material, a gas containing molecular oxygen; (c) supplying said pulverized material containing iron oxides, said carbonaceous material and said gas containing molecular oxygen, to the intermediate reaction zone of -said reaction zone, said intermediate reaction zone being at a position of about middle of said elongated reaction zone; ~d) controlling the carbonaceous ~.
ma~erial feed into said reaction zone so that there is always sufficient solid :. ' . ' carbonaceous material in the bed to prevent the defluidization of said bed caused by sticking; (e) withdrawing gas and solid material from the upper reaction zone, said solid material being withdrawn, being separated ~rom the gas and said solid material being continually returned to said intermediate reaction zone of said reaction zone; If) feeding a portion of said withdrawn gas, after dust separation and elimination of substantially all carbon .
dioxide and water, to said lower part of said reaction zone as fluidizing and .
reducing gas, said carbon dioxide being formed by reaction of carbon in said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas and said water being formed by reaction of hydrogen from said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas; and (g) withdrawing a solid material containing completely or partially reduced iron oxides from the lower part of the reaction zone. :.
The pulverized material containing iron oxides supplied to the fluid bed has a particle size of less than 1 mm, preferably less than 0.5 mm.
The disintegrated, solid carbonaceous material supplied may be coke breeze, anthracite dust or coal dust and should have a particle size of less than 3 mm, preferably less than 1 mm.
- 2a -I:~,;, ' ' ~ .
; :
~al 5C~6~
The reaction zone may be thought of as divided into an upper part, a lower part and an intermediate part. In the method according to the invention the pulverized material containing iron oxides, the carbonaceous - 2b -11D5(~76~i :
material and the gas containing molecular oxygen are fed into the inter-mediate section. Partial combustion of the carbonaceous material in this section generates the heat necessary for the process. Coking and degassing of carbonaceous material takes place in ~he upper part of the reaction zone, as well as reduction with carbon or carbon dioxide and water formed during the combustion to form hydrogen gas and carbon monoxide. A certain amount of reduction of the material containing iron oxides also takes place here. This reaction suitably takes place at a temperature of 850 -1000 C. The flow of solid carbonaceous material must be controlled so that there is always suffi-cient in the bed to prevent interference of the fluidization due to agglGmera-tion. Gas produced is discharged from the upper part mixed with the solid material from the bed. This is separated from the gas and returned to the intermediate section.
It has been found that the abili~y of the solid carbonaceous material to prevent sticking is dependent on the temperature and the proper-ties of the material containing iron oxides. At a temperature of 900 C and using normal iron ore concentrate, it has been found that the weight ratio between solid carbonaceous material ~coke) and concentrate in the reaction zone should be at least 0.5:1.
Part of the gas discharged is subjected to additional dust separation, most of its content of C02 and H20 is removed, and it is reintro-duced in the lower part of the reaction zone as fluidization and reducing gas.
A strongly reducing atmosphere is thus maintained in the lower part and con-tinued reduction of the material containing iron oxides takes place.
Solid material is discharged as required from the lower part of the reaction zone, so that the quantity of solid material in the reaction zone is kept constant. Net transport of solid material is thus obtained in countercurrent to the gas introduced into the lower part. The transfer of heat from the intermediate section of the reaction zone to the lower part, however, is maintained mainly through the internal circulation of material in 7~6 the reaction zone. This internal circulation is considerable, thus promoting temperature equalization. The solid material discharged consists of coke and completely or partially reduced iron oxides and is preferably cooled to below the curie point of iron and separated magnetically intO a substantially coke~
free iron fraction and a substantially iron-free coke fraction. The cooling -~
is suitably performed by allowing the material to pass a conventional fluid bed formed by the material itself, with built-in cooling surfaces. The gas containing molecular oxygen is suitably used as coolant and is thereby pre-heated.
It is advisable to control the flow of gas containing molecular oxygen, for example air possibly mixed with C02 and/or H2O, so that the heat requirement for maintaining the desired temperaturc in the circulating bed is covered. The heat is generated by partial combustion of the carbonaceous material. It is also feasible to supply heat, either solely or partially, indirectly from an external source of heat such as a nuclear reactor. In this case heat may be transferred by hot gas to heating surfaces built into the reaction zone.
In order to prevent excessive generation of heat per unit volume of the reaction zone, which would cause local over-heating and risk of a certain amount of agglomeration of the bed material, the flow of gas con-taining molecular oxygen is preferably divided into several part-flows which are introduced at separate points in several levels in the intermediate section of the reaction zone.
The solid carbonaceous material is suitably supplied to the intermediate section of the reaction zone in several jets, preferably with the help of reducing and/or neutral gas blown through nozzles. However, with carbonaceous material having a low content of volatile constituents, such as anthracite, it is possible to use gas containing molecular oxygen such as air, in which case this is preferably not preheated in order to avoid the ; 30 risk of local overheating. For this purpose a total flow of gas comprising ~5~766 10 - 30 % of the total flow of the carbonaceous material will be required, depending on the shape of the blowing nozzles. ~
It is also possible to introduce the carbonaceous material via ;
a smaller, auxiliary reaction zone, separate from the reaction zone, in which a fluid bed is maintained with the help of a partial flow of the gas contain-ing molecular oxygen. In this case, gas and material are conducted from the auxiiiary reaction zone through a common pipe into the intermediate section of the reaction zone. A certain amount of the partial combustion of the carbonaceous material takes place in the auxiliary reaction zone and agglomera-tion around the distributor openings can therefore be avoided due to the short ~ :
time which the carbonaceous material spends there, which means that only a ~
few particles ha~e time to be burnt to ashes. With too high concentrations - :
and in the event of local overheating, this may easily result in agglomeration ~:
and crusting.
Some of the solid carbonaceous material may be replaced by liquid carbonaceous material, such as oil. In this case, it is preferably sprayed into ~he intermediate section of the reaction zone through a number of jets. So-called atomization of the oil as done in connection with complete ,`
combustion, is not necessary. The relatively rough dispersion of the oil which is obtained if it is supplied in part-flows through pipes together with a non-oxidizing gas, is sufficient. A volume ratio of 100:1 is suitable for gas and oil used. If an auxiliary reaction zone is used the oil is prefer-ably supplied to this and the level at which it is supplied should be about 0.5 m above the distrîbutor bottom for the gas containing molecular oxygen.
The exhaust from the reaction zone can at least partially be used for preheating the feed material containing iron oxides, by being brought into direct contact with this. Thereafter, this portion of the exhaust is recirculated to the lower part of the reaction zone, after elimination of most of its content of C02 and H20 in a manner known per se, and is used as fluidizing and reducing gas in the lower part of the reaction zone.
. , ., .':
~5~76~
A par~-flow of the exhaust, substantially freed from C02 and H20, is suitably used as fluidizing gas in the cooling and magnetic separation of the material discharged from the lower part of the reaction zone. By performing the entire process above atmospheric pressure, for example 1 -10 atm, the dimensions necessary for the apparatus can be considerably reduc-ed.
The heat content ~physical and chemical) of the exhaust is suit-ably used to generate electric energy with which, for example, the reduced ferrous material can be melted and possibly finally reduced.
The method and means according to the invention will be further explained with reference to the embodiment of the invention shown in the ~igure. This consists of vertically elongated reactor 1, the upper part 2 o which encloses the upper part of the reaction zone, the central part 3 of the reactor enclosing the :intermediate section oE the reaction zone ~nd :its lower part 4 the lower part of the reaction zone. A cyclone 5 is connected to the upper part 2 o the reactor and has a return conduit 6 leading to the central part 3 of the reactor. There are also one or more inlets for carbonaceous material 7 in this zone. The gas containing molecular oxygen is supplied to the central part 3 of the reactor in a number of part-flows through nozzles 8, while the recirculated part-flow of the gas is supplied to the lower part 4 of the reactor through a suitable distributor 9. Treated solid material is discharged through an outlet 10 in the lower part of the reactor, cooled in a cooling device ll and passes a magnetic serparator 12 in which it is separa~ed into a substantially coke-free iron fraction 13 and a substantially iron-free coke fraction 14.
The gas containing molecular oxygen, preferably air, is blown through line 15 through the cooling device 11 where it is preheated, and on through the line 17 to nozzles 8. The cooling device 11 is preferably in the form of a conventional fluid bed with built-in cooling elements thro-ugh which the gas containing molecular oxygen is led for preheating.
~0~7gi~
Some of the exhaust (for instance 50 percent) from the exhaustpipe 18 from the cyclone 5 is led via valve 16 to a ven-turi device 19 where it preheats the pulverized material containing iron oxides, for instance ore concentrate entering via line 20, possibly mixed with return coke from the magnetic separator. The flow of gas and material is then conveyed to a cyclone 21 and then to a fine cleaning cyclone 22 in which the solid material is separated off and returned to the central part of the reactor, preferably through the return conduit 6. The gas, cleaned from solid material, is con-veyed along a conduit 23, possibly being cooled indirectly at 2~ by boiling water, and through a heat exchanger 25 to scrubbers 27 where it is substan-tially freed from C02 and H20. Cooling by boiling water may be necessary to prevent the temperature in the heat exchanger from becoming too high for the materials used. H20 can be removed through direct or indirect cooling.
C2 is washed out, for instance using alkaline solutions, in which case the steam in line 28 from the boiler 24 can be used to regenerate these solutions.
If the pressure in the system is sufficiently high C02 can be washed out with water. Most of the gas coming from the scrubbers, which is driven by a com-pressor 29, is heat-exchanged at 25 with gas entering the scrubbers and is introduced as fluidizing and rieducing gas into the lower part ~ of the reactor.
This produces a strongly reducing zone through which the solid material passes before being discharged. In view of the smaller gas flow, this part of the reactor is suitably given a smaller diameter than the upper part. A part-flow of the gas in line 31 freed from C02 and H20 is used without heat-exchanging as fluidizing gas in the cooling device 11 for discharged solid material and in the magnetic separator 12 and is then con-veyed via 32 and 33 ;; into the lower part of the reactor. The remainder of the exhaust in line 34 from the cyclone 5, possibly together with a part-flow of the coke fraction from the magnetic separation, is preferably used as fuel in a ther~l power station while the rest of the coke flow is recirculated to the reactor, _7_ :lOSa~76G
possibly mixed with the feed containing iron oxides, and/or used as reducing agent in a melt reduction step for the iron fraction from the magnetic separator. --
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of reducing a pulverized material containing iron oxides mixed with carbonaceous material, comprising:
(a) maintaining in a vertically uninterrupted, elongated reaction zone a circulating fluidized bed, said circulating fluid bed being maintained by 1) continually withdrawing a portion of fluidized solids and fluidizing gas and a gas formed by reaction in said reaction zone, 2) separating said gas and solids, 3) continually returning a portion of said solid material to said reaction zone for circulating of said solids in said bed without a solid gas interface in said bed, and 4) continually returning said separation gas to said elongated reaction zone as a fluidizing gas, said reaction zone consisting essentially of lower, intermediate, and upper reaction zones;
(b) supplying said bed with a suitable quantity of pulverized material containing iron oxides and pulverized solid carbonaceous material as said solid material and liquid carbonaceous material, said liquid carbonaceous material being from 0 to 60% by weight of the carbonaceous material and, as a gas for reaction with said solid material, a gas containing molecular oxygen;
(c) supplying said pulverized material containing iron oxides, said carbonaceous material and said gas containing molecular oxygen, to the intermediate reaction zone of said reaction zone, said intermediate reaction zone being at a position of about middle of said elongated reaction zone;
(d) controlling the carbonaceous material feed into said reaction zone so that there is always sufficient solid carbonaceous material in the bed to prevent the defluidization of said bed caused by sticking;
(e) withdrawing gas and solid material from the upper reaction zone, said solid material being withdrawn, being separated from the gas and said solid material being continually returned to said intermediate reaction zone of said reaction zone;
(f) feeding a portion of said withdrawn gas, after dust separation and elimination of substantially all carbon dioxide and water, to said lower part of said reaction zone as fluidizing and reducing gas, said carbon dioxide being formed by reaction of carbon in said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen contain-ing gas and said water being formed by reaction of hydrogen from said carbon-aceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas; and (g) withdrawing a solid material containing completely or partially rcduced iron oxides from the lower part of the reaction zone.
(a) maintaining in a vertically uninterrupted, elongated reaction zone a circulating fluidized bed, said circulating fluid bed being maintained by 1) continually withdrawing a portion of fluidized solids and fluidizing gas and a gas formed by reaction in said reaction zone, 2) separating said gas and solids, 3) continually returning a portion of said solid material to said reaction zone for circulating of said solids in said bed without a solid gas interface in said bed, and 4) continually returning said separation gas to said elongated reaction zone as a fluidizing gas, said reaction zone consisting essentially of lower, intermediate, and upper reaction zones;
(b) supplying said bed with a suitable quantity of pulverized material containing iron oxides and pulverized solid carbonaceous material as said solid material and liquid carbonaceous material, said liquid carbonaceous material being from 0 to 60% by weight of the carbonaceous material and, as a gas for reaction with said solid material, a gas containing molecular oxygen;
(c) supplying said pulverized material containing iron oxides, said carbonaceous material and said gas containing molecular oxygen, to the intermediate reaction zone of said reaction zone, said intermediate reaction zone being at a position of about middle of said elongated reaction zone;
(d) controlling the carbonaceous material feed into said reaction zone so that there is always sufficient solid carbonaceous material in the bed to prevent the defluidization of said bed caused by sticking;
(e) withdrawing gas and solid material from the upper reaction zone, said solid material being withdrawn, being separated from the gas and said solid material being continually returned to said intermediate reaction zone of said reaction zone;
(f) feeding a portion of said withdrawn gas, after dust separation and elimination of substantially all carbon dioxide and water, to said lower part of said reaction zone as fluidizing and reducing gas, said carbon dioxide being formed by reaction of carbon in said carbonaceous material with oxygen in said ore or molecular oxygen in said molecular oxygen contain-ing gas and said water being formed by reaction of hydrogen from said carbon-aceous material with oxygen in said ore or molecular oxygen in said molecular oxygen containing gas; and (g) withdrawing a solid material containing completely or partially rcduced iron oxides from the lower part of the reaction zone.
2. The method as defined in claim 1 including introducing in said elongated reaction zone a stream of the molecular oxygen containing gas which is admixed with carbon dioxide and water, wherein said carbon dioxide is from 0% to 10% and water is from 0% to 10% by volume based on said stream, and controlling the introduced amount thereof so as to provide the heat requirement for maintaining the desired temperature in elongated reaction zone by combustion of carbonaceous material.
3. The method as defined in claim 1 wherein the solid material with-drawn from the lower part of the reaction zone is cooled to below the Curie point of iron in the solid material, containing completely or partially reduced iron oxides, and thereafter, separating magnetically said cooled solid material into a substantially coke-free iron fraction and a substantial-ly iron-free coke fraction, said coke having been formed in said reaction zone from said solid carbonaceous material.
4. Method according to claim 3, wherein a portion of the recirculated gas, substantially freed from carbon dioxide and water, is used as fluidizing gas in the magnetic separation.
5. The method as defined in claim 1 including introducing the solid carbonaceous material into an auxiliary reaction zone, wherein said auxiliary reaction zone is separated from said elongated reaction zone, fluidizing and partially combusting said solid carbonaceous material with part of the gas containing molecular oxygen, after which a formed gas, the gas containing molecular oxygen, and said partially reacted solid material are introduced into said intermediate section of the reaction zone.
6. Method according to claim 1, wherein carbonaceous material, optionally divided into several flows, is blown into the intermediate section of the reaction zone by means of non-oxidizing gas.
7. Method according to claim 1, wherein the gas containing molecular oxygen is introduced into the intermediate section of the reaction zone, divided into a number of smaller partial flows.
8. Method according to claim 1, wherein solid material drawn from the lower part of the reaction zone is cooled by being fluidized by a partial flow of the recirculated gas, which has been substantially freed from carbon dioxide and water, in contact with one or more heat exchanger means.
9. Method according to claim 8 wherein the gas containing molecular oxygen is passed through the heat exchanger means to effect cooling of the bed.
10. The method as defined in claim 1 including directly contacting a portion of the withdrawn stream of solid and gas from the circulating fluid bed with a feed containing iron oxides for preheating said feed and there-after recirculating said gas to the lower part of the reaction zone after removal of substantially all of carbon dioxide and water therefrom.
11. Method according to claim 1, characterized in that the entire process is performed above atmospheric pressure.
12. Method according to claim 4, wherein a partial flow of the coke fraction from the magnetic separation is recirculated to the reaction zone.
13. Apparatus for performing the method according to claim 1, characterized by a vertically elongated reactor having a cyclone connected to the upper part of the reactor, with return-conduit leading from the cyclone to the central part of the reactor, inlets for iron oxides, carbon-aceous material and for gas containing molecular oxygen in the central part of the reactor, a conduit to convey exhaust from the cyclone to scrubbers for the removal of carbon dioxide and water from the gas, a conduit for recycling of the scrubbed gas to the lower part of the reactor, and an outlet for solid material from the lower part of the reactor.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE7403145A SE384225B (en) | 1974-03-08 | 1974-03-08 | METHOD AND DEVICE FOR REDUCTION OF FINELY DISTRIBUTED IRON-CONTAINING MATERIAL |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1050766A true CA1050766A (en) | 1979-03-20 |
Family
ID=20320462
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA221,555A Expired CA1050766A (en) | 1974-03-08 | 1975-03-07 | Method and means for reducing material containing ferric oxide |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5844722B2 (en) |
| BE (1) | BE826501A (en) |
| CA (1) | CA1050766A (en) |
| DE (1) | DE2510116C2 (en) |
| FR (1) | FR2263305B1 (en) |
| GB (1) | GB1506170A (en) |
| IT (1) | IT1032263B (en) |
| LU (1) | LU72012A1 (en) |
| NL (1) | NL181670C (en) |
| SE (1) | SE384225B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4094665A (en) * | 1977-05-13 | 1978-06-13 | Stora Kopparbergs Bergslags Ab | Method for simultaneous combined production of electrical energy and crude iron |
| JPS54152615A (en) * | 1978-05-24 | 1979-12-01 | Ishikawajima Harima Heavy Ind Co Ltd | Suspended layer type direct reduction iron making process |
| GB2034679B (en) * | 1978-11-14 | 1982-05-19 | Coal Industry Patents Ltd | Heating slurries |
| SE419100B (en) * | 1979-03-01 | 1981-07-13 | Lindstroem O | SET FOR REDUCING FINALLY DISTRIBUTED IRON OXIDE-CONTAINING MATERIAL |
| SE419129B (en) * | 1979-05-29 | 1981-07-13 | Stora Kopparbergs Bergslags Ab | DEVICE FOR REDUCING FINE DISTRIBUTED IRON OXIDE-CONTAINING MATERIAL IN A CIRCULATING FLOAT BED |
| FR2683830B1 (en) * | 1991-11-19 | 1994-04-08 | Irsid | INSTALLATION FOR REDUCING THE IRON ORE IN A FLUIDIZED BED CIRCULATING. |
| FI92223C (en) * | 1992-01-24 | 1994-10-10 | Ahlstroem Oy | Process for the reduction of solid phase metal oxide-containing material |
| CN100371086C (en) * | 2006-01-24 | 2008-02-27 | 庞德明 | Dry-type centrifugal ore dressing machine |
| DE102010022773B4 (en) * | 2010-06-04 | 2012-10-04 | Outotec Oyj | Process and plant for the production of pig iron |
| CN105271164B (en) * | 2014-07-17 | 2019-08-20 | 山东大展纳米材料有限公司 | A kind of device and method of continuously preparing nm carbon tubes |
| EP3418309A1 (en) | 2017-06-20 | 2018-12-26 | Borealis AG | A method, an arrangement and use of an arrangement of preparing polymer |
-
1974
- 1974-03-08 SE SE7403145A patent/SE384225B/en not_active IP Right Cessation
-
1975
- 1975-03-07 DE DE2510116A patent/DE2510116C2/en not_active Expired
- 1975-03-07 FR FR7507186A patent/FR2263305B1/fr not_active Expired
- 1975-03-07 CA CA221,555A patent/CA1050766A/en not_active Expired
- 1975-03-08 JP JP50028568A patent/JPS5844722B2/en not_active Expired
- 1975-03-10 NL NL7502826A patent/NL181670C/en not_active IP Right Cessation
- 1975-03-10 LU LU72012A patent/LU72012A1/xx unknown
- 1975-03-10 GB GB991975A patent/GB1506170A/en not_active Expired
- 1975-03-10 IT IT4853875A patent/IT1032263B/en active
- 1975-03-10 BE BE154192A patent/BE826501A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| LU72012A1 (en) | 1977-01-31 |
| SE384225B (en) | 1976-04-26 |
| AU7891975A (en) | 1976-09-16 |
| DE2510116C2 (en) | 1987-02-26 |
| BE826501A (en) | 1975-09-10 |
| GB1506170A (en) | 1978-04-05 |
| NL181670C (en) | 1987-10-01 |
| JPS5110115A (en) | 1976-01-27 |
| DE2510116A1 (en) | 1975-09-11 |
| NL7502826A (en) | 1975-09-10 |
| SE7403145L (en) | 1975-09-25 |
| IT1032263B (en) | 1979-05-30 |
| JPS5844722B2 (en) | 1983-10-05 |
| NL181670B (en) | 1987-05-04 |
| FR2263305B1 (en) | 1978-10-06 |
| FR2263305A1 (en) | 1975-10-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4073642A (en) | Method for reducing material containing iron oxides | |
| US4806158A (en) | Process of reducing fine-grained iron-containing material by means of solid carbonaceous reducing agents | |
| CN100529118C (en) | Method and plant for the heat treatment of solids containing iron oxide using a fluidized bed reactor | |
| US9181594B2 (en) | Process and device for producing pig iron or liquid steel precursors | |
| CA1050766A (en) | Method and means for reducing material containing ferric oxide | |
| RU2070936C1 (en) | Method and device for treatment of gases and solid particles in fluidized bed | |
| US5674308A (en) | Spouted bed circulating fluidized bed direct reduction system and method | |
| WO1989009290A1 (en) | Method and apparatus for reduction of material containing metal oxide | |
| US5198019A (en) | Manufacture of iron and steel in a duplex smelter and solid state oxide suspension prereducer | |
| US3928021A (en) | Process of reducing iron ores | |
| JP3543837B2 (en) | Method for directly reducing iron oxide-containing raw materials using a solid carbon-containing reducing agent | |
| GB2068769A (en) | Method and apparatus for reducing an iron oxide material in a fluidized bed | |
| US4094665A (en) | Method for simultaneous combined production of electrical energy and crude iron | |
| CA2566157C (en) | A direct reduction process and apparatus | |
| CA2175742A1 (en) | Method of reprocessing zinc- and iron oxide-containing residual material | |
| WO2004056941A1 (en) | Method and plant for producing low-temperature coke | |
| US3909244A (en) | Process for directly reducing iron ores in the solid state under pressure | |
| AU680117B2 (en) | A circulating fluidized bed direct reduction system | |
| CA2136692A1 (en) | Method and apparatus for producing iron | |
| US4207093A (en) | Process for reducing metal oxide containing ores | |
| EP0545387A1 (en) | Method and apparatus for gasifying or combusting solid carbonaceous material | |
| US3190744A (en) | Process for magnetic reduction of iron ore | |
| CA1185432A (en) | System for coal blowing in iron oxide reducing kilns | |
| KR850001505B1 (en) | System for recycling char in iron oxide reducing kilns | |
| US5227116A (en) | Manufacture of iron and steel in a duplex smelter and solid state oxide suspension prereducer |