Title of Invention

A DIRECT REDUCTION PROCESS FOR METALLIFEROUS MATERIAL AND APPARATUS THEREFOR

Abstract There is disclosed a direct reduction process for a metalliferous material comprises: supplying a solid carbonaceous material (43) and an oxygen-containing gas (45) into a fluidised bed in a first vessel (3) and generating heat by reactions between the oxygen-containing gas and the solid carbonaceous material and any other oxidisable solids and gases in the fluidised bed and discharging a hot off-gas stream containing entrained solids (7); and supplying the metalliferous material to a fluidised bed in a second vessel (5) and supplying the hot off-gas stream containing entrained solids (7) from the first vessel (3) to the fluidised bed in the second vessel (5) and at least partially reducing the metalliferous feed material in the solid state in the fluidized bed and discharging a product stream of at least partially reduced metalliferous material and an off-gas stream containing entrained solids (61).
Full Text The present invention relates to a direct reduction process and apparatus for a metalli-
ferous feed material, particularly, although by no means exclusively, to a direct reduc-
tion process and apparatus for an iron-containing feed material, such as iron ore.
The present invention also relates to a process for reducing a metalliferous feed mate-
rial that comprises a direct reduction process for partially reducing metalliferous feed
material in the solid state and a smelting process for melting and further reducing the
partially reduced metalliferous feed material to a molten metal.
A known direct reduction technology is the so called "CIRCOFER technology" that is
capable of reducing iron ore in the solid state to a metallisation of 50% or higher.
CIRCOFER technology is based on the use of fluidised beds. The main feed materials
to the fluidised beds are fluidising gas, metal oxides (typically iron ore fines), solid car-
bonaceous material (typically coal) and oxygen-containing gas (typically oxygen gas).
The main product produced in the fluidised beds is metallised metal oxides, ie metal
oxides that have been at least partially reduced.
The applicant has realised that it is possible to effectively and efficiently reduce iron
oxides in the solid state in a two stage process in which heat is generated by reactions
between solid carbonaceous material and oxygen-containing gas in a first fluidised bed
and metalliferous feed material is reduced in a second fluidised bed, with heat being
supplied to the second fluidised bed via a stream of hot off-gas and entrained solids
from the first fluidised bed.
According to the present invention there is provided a direct reduction process for a
metalliferous material which comprises:

supplying a solid carbonaceous material and an oxygen-containing gas into a fluidised
bed in a first vessel and generating heat by reactions between the oxygen-containing
gas and the solid carbonaceous material and any other oxidisable solids and gases in
the fluidised bed and discharging a hot off-gas stream containing entrained solids; and
. supplying the metalliferous material to a fluidised bed in a second vessel and supplying
the hot off-gas stream containing entrained solids from the first vessel to the fluidised
bed in the second vessel and at least partially reducing the metalliferous feed material
in the solid state in the fluidised bed and discharging a product stream of at least par-
tially reduced metalliferous material and an off-gas stream containing entrained solids.
The above-described process separates the heat generation and reduction functions of
the process into two separate vessels and makes it possible to optimise each of these
functions.
In particular, separating the heat generation and reduction functions means that it is
possible to operate the first vessel at a high temperature to generate heat and ensure
destruction of tars and other products of devolatilisation than would be acceptable in a
situation in which heat generation and reduction occur in one vessel. Specifically, in a
situation in which heat generation and reduction occur in one vessel the potential for
accretion problems with metalliferous materials limits the maximum operating tempera-
tures that can be used.
Preferably the process comprises generating temperatures in the first vessel that are
higher than the operating temperatures in the second vessel.
Preferably the process comprises operating the first vessel at temperatures above
1000°C.
Preferably the process comprises operating the second vessel at temperatures below
1000°C.

Preferably the process comprises supplying the oxygen-containing gas into the first
vessel so that there is a downward flow of the gas in the first vessel.
Preferably the process comprises supplying an oxygen-containing gas into the second
vessel.
More preferably the introduction of oxygen-containing gas into the second vessel is
performed under such controlled conditions that a desirable agglomeration of smaller
reduced ore particles with other particles of feed material to form larger reduced ore
particles takes place.
Preferably the process comprises supplying the oxygen-containing gas into the second
vessel so that there is a downward flow of the gas in the second vessel.
Preferably the process comprises injecting the oxygen-containing gas into the first ves-
sel and/or the second vessel via at least one lance having a lance tip with an outlet po-
sitioned in the vessel inwardly of the side wall of the vessel in a central region of the
vessel.
Preferably the lance tip is directed downwardly.
More preferably the lance tip is directed vertically downwardly.
The position of the lance and, more particularly, the height of the outlet of the lance tip,
are determined by reference to factors, such as the oxygen-containing gas injection
velocity, the vessel pressure, the selection and amounts of the other feed materials to
the vessel, and the fluidised bed density.
Preferably the process comprises water-cooling the lance tip to minimise the possibility
of accretions forming on the lance tip that could block the injection of the oxygen-
containing gas.
Preferably the process comprises water-cooling an outer surface of the lance tip.

Preferably the process comprises injecting the oxygen-containing gas through a central
pipe of the lance.
Preferably the process comprises injecting the oxygen-containing gas with sufficient
velocity to form a substantially solids-free zone in the region of the lance tip to de-
crease the possibility of accretions forming on the lance tip that could block the injec-
tion of the oxygen-containing gas.
Preferably the process comprises injecting nitrogen and/or steam and/or other suitable
shrouding gas and shrouding a lower end of the central pipe to minimise oxidation of
metal that could result in accretions forming on the lance tip that could block the injec-
tion of the oxygen-containing gas.
Preferably the process comprises separately supplying the metalliferous material and
the hot off-gas stream containing entrained solids from the first vessel into the fluidised
bed in the second vessel.
Preferably the process comprises controlling the temperature difference between the
bulk temperature in the fluidised bed in the second vessel and the average temperature
of the inwardly facing surface of a side wall of the second vessel to be no more than
100°C.
The term "bulk temperature" is understood herein to mean the average temperature
throughout the fluidised bed.
More preferably the temperature difference is no more than 50°C.
In the case of reducing metalliferous feed material in the form of iron ore fines, prefera-
bly the bulk temperature in the fluidised bed in the second vessel is in the range 850°C
to 1000°C.

Preferably the bulk temperature in the fluidised bed in the second vessel is at least
900°C, more preferably at least 950°C.
Preferably the process comprises controlling the temperature variation within the fluid-
ised bed in the second vessel to be less than 50°C.
The temperature difference may be controlled by controlling a number of factors includ-
ing, by way of example, the amounts of the solids and the gases supplied to the second
vessel and the selection of the solids and the gases.
In addition, preferably the process comprises controlling the pressure in at least the
second vessel to be in the range of 1-10 bar absolute and more preferably 4-8 bar ab-
solute.
In the case of reducing metalliferous material in the form of iron ore fines, preferably
the fines are sized to minus 6 mm.
Preferably the fines have an average particle size in the range 0.1-0.8mm.
One of the advantages of the process is that it can accept a substantial amount of met-
alliferous feed material with a particle size of less than 100 microns without a significant
amount of this material exiting the process entrained in off-gas. This is believed to be
due to an agglomeration mechanism operating within the fluidised bed that promotes a
desirable level of agglomeration between particles of feed materials, particularly sub-
100 micron particles, without appearing to promote uncontrolled agglomeration capable
of interrupting operation of the fluidised bed. Similarly, friable ores that have a ten-
dency to break down during processing and to thereby increase the proportion of parti-
cles in the fluidised bed with a size of less than 100 microns may be processed without
significant loss of feed material in process off-gas.
Preferably the solid carbonaceous material is coal. In such a situation, the process
devolatilises the coal to char and at least part of the char reacts with oxygen and forms
CO in the fluidised bed in the first vessel.

The coal may be any suitable coal. By way of example, the coal may be medium-high
volatiles coal crushed to minus 6 mm.
Preferably the fluidising gas comprises a non-oxidising gas.
Preferably the fluidising gas in the second vessel comprises a reducing gas, such as
CO and H2.
Preferably the process comprises selecting the amount of H2 in the fluidising gas in the
second vessel to be at least 10% by volume of the total volume of CO and H2 in the
gas.
Preferably the process comprises separating at least partially reduced metalliferous
feed material and at lest a portion of other solids (for example char) from the product
stream from the second vessel.
Preferably the process comprises returning at least a part of the other solids separated
from the product stream to the first vessel and/or the second vessel.
Preferably the process comprises separating at least a portion of the solids from the
off-gas stream from the second vessel.
Preferably the process comprises supplying the solids separated from the output off-
gas stream to the first vessel.
Preferably the process comprises preheating metalliferous feed material with the off-
gas from the second vessel.
Preferably the process comprises treating the off-gas after the preheating step and re-
turning at least a part of the treated off-gas to the first vessel and/or the second vessel
as fluidising gas.

Preferably the off-gas treatment comprises one or more of (a) solids removal, (b) cool-
ing, (c) H2O removal; (d) CO2 removal, (e) compression, and (f) reheating.
Preferably the off-gas treatment comprises returning at least a portion of the separated
solids to the first vessel and/or the second vessel.
The oxygen-containing gas may be any suitable gas.
Preferably the oxygen-containing gas comprises at least 90% by volume oxygen.
According to the present invention there is also provided a direct reduction apparatus
for a metalliferous material which comprises:
(a) a first vessel for generating a hot off-gas stream containing entrained solids, the
first vessel comprising an inlet means for supplying a solid carbonaceous material, a
fluidising gas, and an oxygen-containing gas into the first vessel and maintaining a
fluidised bed in the vessel and producing the hot off-gas stream containing entrained
solids, and an outlet means for discharging the hot off-gas stream containing entrained
solids from the vessel; and
(b) a second vessel for at least partially reducing metalliferous material in a solid
state in a fluidised bed in the second vessel, the second vessel comprising an inlet
means for supplying the metalliferous material, the hot off-gas stream containing en-
trained solids from the first vessel, and a fluidising gas into the second vessel and
maintaining the fluidised bed in the vessel, an outlet means for discharging a predomi-
nantly solids stream of at least partially reduced metalliferous feed material from the
second vessel, and an outlet means for discharging a stream of an off-gas and en-
trained solids from the second vessel.
Preferably the first vessel comprises separate inlet means for supplying each of the
solid carbonaceous material, the fluidising gas, and the oxygen-containing gas into the
first vessel.

Preferably the inlet means for supplying oxygen-containing gas into the first vessel
comprises a lance having a lance tip with an outlet positioned in the vessel inwardly of
the side wall of the vessel in a central region of the vessel.
Preferably the lance tip is directed downwardly in a central region of the vessel for in-
jecting the oxygen-containing gas in a downward flow.
Preferably the lance tip is directed vertically downwardly.
Preferably the second vessel comprises separate inlet means for supplying each of the
metalliferous feed material, the hot off-gas stream containing entrained solids from the
first vessel, and the fluidising gas into the second vessel.
Preferably the second vessel comprises an inlet means for supplying oxygen-
containing gas into the second vessel.
Preferably the inlet means for supplying oxygen-containing gas into the second vessel
comprises a lance having a lance tip with an outlet positioned in the vessel inwardly of
the side wall of the vessel in a central region of the vessel.
Preferably the lance tip is directed downwardly in a central region of the second vessel
for injecting the oxygen-containing gas in a downward flow.
Preferably the lance tip is directed vertically downwardly.
Preferably the apparatus comprises a means for separating entrained solids from the
off-gas stream from the second vessel.
Preferably the first vessel further comprises an inlet means for supplying separated
solids from the off-gas separation means into the first vessel.

Preferably the apparatus comprises a means for processing the off-gas stream from the
second vessel and producing at least part of the fluidising gas for the first vessel and/or
the second vessel.
According to the present invention there is also provided a process for reducing a met-
alliferous material that comprises (a) a direct reduction process for partially reducing
metalliferous material in the solid state as described above and (b) a smelting process
for melting and further reducing the partially reduced metalliferous material to molten
metal.
The present invention is described further with reference to the accompany drawings,
of which:
Figure 1 is a diagram of an embodiment of an apparatus for direct reduction of a
metalliferous feed material in accordance with the present invention; and
Figure 2 is a diagram of another embodiment of an apparatus for direct reduction
of a metalliferous feed material in accordance with the present invention.
The following description is in the context of direct reduction of a metalliferous material
in the form of iron ore in a solid state. The present invention is not so limited and ex-
tends to direct reduction of other iron-containing materials (such as ilmenite) and more
generally to other metalliferous materials.
The following description is also in the context of direct reduction of iron ore with coal
as a solid carbonaceous material, oxygen as an oxygen-containing gas, and recycled
off-gas containing a mixture of CO and H2 as a fluidising gas. The present invention is
not so limited and extends to the use of any other suitable solid carbonaceous material,
oxygen-containing gas, and fluidising gas.
With reference to Figure 1, the apparatus comprises a first vessel 3 that contains a
fluidised bed of gas and entrained solids and a second vessel 5 that contains a fluid-
ised bed of gas and entrained solids.

The first vessel 3 functions as at a heat generator and generates a stream of hot off-
gas containing entrained solids, predominantly char, that is transferred to the second
vessel 5 via a line 7. The purpose of the hot off-gas stream is to provide at least part of
the heat required for reactions in the second vessel.
The second vessel 5 functions as a direct reduction reactor and at least partially re-
duces iron ore fines in the solid state.
The second vessel produces two output streams.
One output stream, which is discharged from the second vessel 5 via an outlet 9 in the
base of the second vessel 5, comprises a predominantly solids stream of at least par-
tially reduced iron ore fines and other solids, typically char.
The soiids stream may be processed by separating the at least partially reduced iron
ore fines and at least a portion of the other solids. The other solids, predominantly
char, separated from the product steam may be returned to the first vessel and/or the
second vessel as a part of the solids feed for the vessels. The at least partially re-
duced iron ore is further processed as required. By way of example, the at least par-
tially reduced iron ore may be supplied to a molten bath-based smelting vessel and
smelted to molten iron, for example by a process such as the so called "Hlsmelt proc-
ess".
The other output stream from the second vessel 5, which is discharged via an outlet 61
in an upper section of the second vessel 5, comprises hot off-gas and entrained solids.
The off-gas stream is transferred to a cyclone 13 via a line 11. The cyclone 13 sepa-
rates at least part of the entrained solids from the off-gas stream. The separated solids
flow downwardly from the cyclone 13 via a line 15 into the first vessel 3. The off-gas
stream flows upwardly from the cyclone 13 into a mixing chamber 17.

The off-gas from cyclone 13 mixes with and heats solids passed to the mixing chamber
17 from a further cyclone 21 via a line 23. The majority of solids in mixing chamber 17
are entrained in off-gas and pass to cyclone 27 via line 25.
There is solids/gas separation in the cyclone 27. Separated solids flow downwardly
from the cyclone 27 via a line 29 into the second vessel 5. Off-gas from the cyclone 27
along with any remaining solids flows upwardly from the cyclone 27 into a further mix-
ing chamber 31.
The off-gas stream from the cyclone 27 mixes with and heats iron ore in the mixing
chamber 31. Iron ore is supplied to the mixing chamber 31 via a lock hopper assembly
33. The majority of the material in the mixing chamber 31 is carried over into the cy-
clone 21 via a line 35. As detailed above, a majority of the material passed to cyclone
21 passes to mixing chamber 17, from where it passes to cyclone 27 and the second
vessel 5 via line 29.
The off-gas from the cyclone 21 is transferred via a line 37 to an off-gas processing unit
39 and is treated in the unit as described hereinafter. Specifically, the off-gas is treated
by a series of steps including (a) solids removal, (b) cooling the off-gas, (c) H20 re-
moval, (d) C02 removal, (e) compression, and (f reheating.
The treated off-gas from the off-gas processing unit 39 becomes a fluidising gas for the
vessels 3 and 5 and is transferred to the vessels via a transfer line 41. The fluidising
gas is injected into the base of each vessel 3 and 5.
Medium-high volatile coal having a particle size of minus 6 mm is supplied into a lower
section of the first vessel 3 via a solids feed device such as a screw feed or a lance 43
that extends through a side wall of the first vessel 3.
In addition, oxygen is supplied into the first vessel 3 via a lance 45 that has a down-
wardly extending lance tip 47 with an outlet that directs the oxygen downwardly in a
centre region of the first vessel 3.

As is described above, preheated iron ore is supplied into the second vessel 5 via the
line 29 and the hot off-gas stream containing entrained solids from the first vessel 3 is
supplied into the second vessel via the line 7.
In addition, oxygen is injected into the second vessel 5 via a lance 49 that has a down-
wardly extending lance tip 51 with an outlet that directs the oxygen downwardly in a
central region of the second vessel 5.
The above-described supply of coal, returned solids and fluidising gas into the first ves-
sel 3 produces an upward flow of fluidising gas and entrained coal and other returned
solids in a central region of the first vessel 3. Increasingly, as the coal particles and
other retained solids move upwardly, the particles disengage from the upward stream
of fluidising gas and flow downwardly predominantly in an annular region between the
central region and the side wall of the first vessel 3. Ultimately, these retained solids
are entrained again in the upward stream of the fluidising gas.
The upward stream of fluidising gas and entrained solids in the central region of the
first vessel 3 is countercurrent to the downward flow of oxygen gas. Some solids near
the flow of oxygen containing gas may become entrained in the oxygen containing gas
and as a result become sticky. The interaction of the counter current flows of fluidising
gas and oxygen containing gas is believed to limit the extent to which solids that have
become entrained in or that have passed through the oxygen flow can contact vessel
surfaces and cause accretions. The formation of accretions is believed to be further
limited due to the central location of the flow of oxygen gas within the vessel.
In the first vessel the coal fines are devolatilised to form char and the coal volatiles de-
compose to gaseous products (such as CO and H2). At least part of the char and the
volatiles react with oxygen and form CO and reaction products of the volatiles. These
reactions generate substantial heat and, as is described above, the heat is transferred
into the second vessel 5 by the hot output off-gas stream containing entrained solids
that flows into the second vessel via the line 7.

The above-described supply of the preheated iron ore fines, the hot off-gas stream con-
taining entrained solids from the first vessel 3, the oxygen-containing gas, and the fluid-
ising gas into the second vessel produces an upward flow of gas and entrained solids
in a central region of the second vessel 5. Increasingly, as the solid particles move
upwardly, the solid particles disengage from the upward stream of gas and flow down-
wardly predominantly in an annular region between the central region and the side wall
of the second vessel 5. Such recirculated solids are either entrained again in the up-
ward stream of the fluidizing gas or are discharged from the vessel.
The fluidising gas and upwards flow of solids fluidised by the fluidising gas in the sec-
ond vessel 5 is counter current to the downward flow of oxygen containing gas. As
described above in relation to the first vessel, this counter current flow of fludising gas
and oxygen containing gas is believed to assist with reducing the extent to which solids
that have become entrained in or passed through the flow of oxygen contact vessel
surfaces and form accretions.
The above-described supply of the preheated iron ore fines, the hot off-gas stream con-
taining entrained solids from the first vessel 3, the oxygen-containing gas, and the fluid-
ising gas into the second vessel 5 produces the following reactions in the second ves-
sel.
Reaction of at least part of the CO2 (formed during reduction of iron ore) with carbon to
form CO (Boudouard reaction).
Direct reduction of iron ore fines to at least partially reduced iron by CO, and H2, which
reactions form CO2 and H2O.
Oxidation of solids and gases such as char and particles of partially reduced metallifer-
ous feed material, coal volatiles carried over from the first vessel 3, H2 and CO in an
upper section of the second vessel 5 which generates heat and promotes controlled
agglomeration of smaller partially reduced ore particles with other particles within the
fluidised bed to form larger reduced ore particles.

The applicant does not have a totally clear understanding at this stage of the mecha-
nism or mechanisms that enable controlled agglomeration of metalliferous material
mentioned in the last dot point above to be achieved. Nevertheless, without wishing to
be bound by the following comments, in a research project the applicant observed that
the agglomerates that formed comprise smaller particles, particularly fines that adhere
to each other and to larger particles. The applicant speculates that the conditions in
the upper section of the vessel are such that (a) micron sized partially and completely
reduced, i.e. metallised, iron ore particles react with oxygen and generate heat and the
resultant oxidised particles become sticky (b) fine coal particles react with oxygen and
oxidise and the resultant ash becomes sticky ; and (c) fine iron ore particles become
sticky as a consequence of being heated. The applicant also speculates that these
smaller sticky particles adhere to larger particles that have a higher heat sink capacity,
with the overall beneficial result that there is a reduction in the proportion of smaller
particles in the vessel that can adhere to apparatus surfaces and be carried out from
the vessel in an off-gas stream.
The apparatus shown in Figure 2 is substantially identical to that shown in Figure 1 and
the same reference numerals are used to describe the same features.
The main difference between the two arrangements is that the apparatus shown in Fig-
ure 2 does not have an oxygen injection lance in the second vessel 5.
The reasons for omitting the oxygen lance in the second vessel 5 could be that (a) suf-
ficient controlled agglomeration can be achieved by oxygen injection solely into the first
vessel 3 or (b) the feed iron ore does not contain a large amount of ultra fine particles.
Many modifications may be made to the embodiments of the present invention shown
in Figures 1 and 2 without departing from the spirit and scope of the invention.
By way of example, whilst the first vessel 3 of each of the embodiments comprises a
lance 45 that has a downwardly extending lance tip 47 that injects oxygen downwardly
countercurrent to an upward flow of solids and fluidising gas, the present invention is
not so limited and extends to other arrangements. Specifically, the present invention is

not limited to injecting oxygen downwardly via one or more than one lance 45 that has
a downwardly extending lance tip 47.
In addition, the present invention is not limited to countercurrent flows of oxygen and
solids and fluidising gas.

WE CLAIM:
1. A direct reduction process for a metalliferous material which comprises:
supplying a solid carbonaceous material and an oxygen-containing gas into a fluidised bed in a first
vessel and generating heat by reactions between the oxygen-containing gas and the solid
carbonaceous material and any other oxidisable solids and gases in the fluidised bed and
discharging a hot off-gas stream containing entrained solids; and
supplying the metalliferous material to a fluidised bed in a second vessel and supplying the hot off-
gas stream containing entrained solids from the first vessel to the fluidised bed in the second
vessel and at least partially reducing the metalliferous feed material in the solid state in the
fluidised bed and discharging a product stream of at least partially reduced metalliferous material
and an off-gas stream containing entrained solids.
2. Process as claimed in claim 1, wherein temperatures are generated in the first vessel that
are higher than the operating temperatures in the second vessel.
3. Process as claimed in claim 1 or 2, wherein the first vessel is operated at temperatures
above 1000°C.
4. Process as claimed in any of the preceding claims, wherein the second vessel is operated at
temperatures below 1000°C.
5. Process as claimed in any of the preceding claims, wherein the oxygen-containing gas is
supplied into the first vessel so that there is a downward flow of the gas in the first vessel.
6. Process as claimed in any of the preceding claims, wherein the introduction of oxygen-
containing gas into the second vessel is performed under such controlled conditions that a
desirable agglomeration of smaller reduced ore particles with other particles of feed material to
form larger reduced ore particles takes place.
7. Process as claimed in any of the preceding claims, wherein an oxygen-containing gas is
supplied into the second vessel, preferably so that there is a downward flow of the gas in the
second vessel.

8. Process as claimed in any of the preceding claims, wherein the oxygen-containing gas is
injected into the first vessel and/or the second vessel via at least one lance having a lance tip with
an outlet positioned in the vessel inwardly of the side wall of the vessel in a central region of the
vessel.
9. Process as claimed in claim 8, wherein the lance tip is directed downwardly, preferably
vertically downwardly.
10. Process as claimed in claim 8 or 9, wherein the position of the lance and, more particularly,
the height of the outlet of the lance tip, are determined by reference to factors, such as the oxygen-
containing gas injection velocity, the vessel pressure, the selection and amounts of the other feed
materials to the vessel, and the fluidised bed density.
11. Process as claimed in any of claims 8 to 10, wherein the lance tip is water-cooled.
12. Process as claimed in any of claims 8 to 11, wherein an outer surface of the lance tip is
water-cooled.
13. Process as claimed in any of claims 8 to 12, wherein the oxygen-containing gas is injected
through a central pipe of the lance.
14. Process as claimed in any of claims 8 to 13, wherein the oxygen-containing gas is injected
with sufficient velocity to form a substantially solids-free zone in the region of the lance tip to
decrease the possibility of accretions forming on the lance tip that could block the injection of the
oxygen-containing gas.
15. Process as claimed in any of the preceding claims, wherein nitrogen and/or steam and/or
other suitable shrouding gas is/are injected for shrouding a lower end of the central pipe.
16. Process as claimed in any of the preceding claims, wherein the metalliferous material and
the hot off-gas stream containing entrained solids are supplied from the first vessel into the
fluidised bed in the second vessel.

17. Process as claimed in any of the preceding claims, wherein the temperature difference
between the bulk temperature in the fluidised bed in the second vessel and the average
temperature of the inwardly facing surface of a side wall of the second vessel is controlled to be no
more than 100°C, preferably no more than 50°C.
18. Process as claimed in any of the preceding claims wherein the metalliferous material is in
the form of iron ore fines, and wherein the bulk temperature in the fluidised bed in the second
vessel is in the range 850°C to 1000°C, preferably at least 900°C, and more preferably at least
950°C.
19. Process as claimed in any of the preceding claims, wherein the temperature variation within
the fluidised bed in the second vessel is controlled to be less than 50°C.
20. Process as claimed in any of the preceding claims, wherein the pressure in at least the
second vessel is controlled to be in the range of 1-10 bar absolute and more preferably 4-8 bar
absolute.
21. Process as claimed in any of the preceding claims wherein the metalliferous material is in
the form of iron ore fines, and wherein the fines are sized to minus 6 mm.
22. Process as claimed in any of the preceding claims, wherein the fines have an average
particle size in the range 0.1-0.8mm.
23. Process as claimed in any of the preceding claims, wherein the solid carbonaceous material
is coal, preferably medium-high volatiles coal crushed to minus 6 mm.
24. Process as claimed in any of the preceding claims, wherein the fluidising gas comprises a
non-oxidising gas.
25. Process as claimed in any of the preceding claims, wherein the fluidising gas in the second
vessel comprises a reducing gas, such as CO and H2.

26. Process as claimed in claim 25, wherein the amount of H2 in the fluidising gas in the second
vessel is selected to be at least 10% by volume of the total volume of CO and H2 in the gas.
27. Process as claimed in any of the preceding claims, wherein at least partially reduced
metalliferous feed material and at least a portion of other solids are separated from the product
stream from the second vessel.
28. Process as claimed in claim 27, wherein at least a part of the other solids separated from
the product stream are returned to the first vessel and/or the second vessel.
29. Process as claimed in any of the preceding claims, wherein at least a portion of the solids is
separated from the off-gas stream from the second vessel.
30. Process as claimed in claim 29, wherein the solids separated from the output off-gas stream
are supplied to the first vessel.
31. Process as claimed in any of the preceding claims, wherein metalliferous feed material is
preheated with the off-gas from the second vessel.
32. Process as claimed in claim 31, wherein the off-gas is treated after the preheating step and
at least a part of the treated off-gas is returned to the first vessel and/or the second vessel as
fluidising gas.
33. Process as claimed in claim 32, wherein the off-gas treatment comprises one or more of (a)
solids removal, (b) cooling, (c) H2O removal; (d) CO2 removal, (e) compression, and (f) reheating.
34. Process as claimed in claim 32 or 33, wherein the off-gas treatment comprises returning at
least a portion of the separated solids to the first vessel and/or the second vessel.
35. Process as claimed in any of the preceding claims, wherein the oxygen-containing gas
comprises at least 90% by volume oxygen.

36. Process as claimed in any of the preceding claims, wherein an additional smelting process
is carried out for melting and further reducing the partially reduced metalliferous material to molten
metal.
37. A direct reduction apparatus for a metalliferous material comprising:

(a) a first vessel for generating a hot off-gas stream containing entrained solids, the first vessel
comprising an inlet means for supplying a solid carbonaceous material, a fluidising gas, and an
oxygen-containing gas into the first vessel and maintaining a fluidised bed in the vessel and
producing the hot off-gas stream containing entrained solids, and an outlet means for discharging
the hot off-gas stream containing entrained solids from the vessel; and
(b) a second vessel for at least partially reducing metalliferous material in a solid state in a
fluidised bed in the second vessel, the second vessel comprising an inlet means for supplying the
metalliferous material, the hot off-gas stream containing entrained solids from the first vessel, and a
fluidising gas into the second vessel and maintaining the fluidised bed in the vessel, an outlet
means for discharging a predominantly solids stream of at least partially reduced metalliferous feed
material from the second vessel, and an outlet means for discharging a stream of an off-gas and
entrained solids from the second vessel.

38. Apparatus as claimed in claim 37, wherein the first vessel comprises separate inlet means
for supplying each of the solid carbonaceous material, the fluidising gas, and the oxygen-containing
gas into the first vessel.
39. Apparatus as claimed in claim 38, wherein the inlet means for supplying oxygen-containing
gas into the first vessel comprises a lance having a lance tip with an outlet positioned in the vessel
inwardly of the side wall of the vessel in a central region of the vessel.
40. Apparatus as claimed in claim 39, wherein the lance tip is directed downwardly in a central
region of the vessel for injecting the oxygen-containing gas in a downward flow.
41. Apparatus as claimed in any of claims 37 to 40, wherein the second vessel comprises
separate inlet means for supplying each of the metalliferous feed material, the hot off-gas stream
containing entrained solids from the first vessel, and the fluidising gas into the second vessel.

42. Apparatus as claimed in any of claims 37 to 41, wherein the second vessel comprises an
inlet means for supplying oxygen-containing gas into the second vessel.
43. Apparatus as claimed in claim 42, wherein the inlet means for supplying oxygen-containing
gas into the second vessel comprises a lance having a lance tip with an outlet positioned in the
vessel inwardly of the side wall of the vessel in a central region of the vessel.
44. Apparatus as claimed in claim 43, wherein the lance tip is directed downwardly in a central
region of the second vessel for injecting the oxygen-containing gas in a downward flow.
45. Apparatus as claimed in any of claims 37 to 44, which is provided with a means for
separating entrained solids from the off-gas stream from the second vessel.
46. Apparatus as claimed in claim 45, wherein the first vessel has an inlet means for supplying
separated solids from the off-gas separation means into the first vessel.
47. Apparatus as claimed in claim 45 or 46, which is provided with a means for processing the
off-gas stream from the second vessel and producing at least part of the fluidising gas for the first
vessel and/or the second vessel.


There is disclosed a direct reduction process for a metalliferous material comprises:
supplying a solid carbonaceous material (43) and an oxygen-containing gas (45) into a fluidised
bed in a first vessel (3) and generating heat by reactions between the oxygen-containing gas and
the solid carbonaceous material and any other oxidisable solids and gases in the fluidised bed and
discharging a hot off-gas stream containing entrained solids (7); and supplying the metalliferous
material to a fluidised bed in a second vessel (5) and supplying the hot off-gas stream containing
entrained solids (7) from the first vessel (3) to the fluidised bed in the second vessel (5) and at
least partially reducing the metalliferous feed material in the solid state in the fluidized bed and
discharging a product stream of at least partially reduced metalliferous material and an off-gas
stream containing entrained solids (61).

Documents:

03175-kolnp-2006 abstract.pdf

03175-kolnp-2006 claims.pdf

03175-kolnp-2006 correspondence others.pdf

03175-kolnp-2006 description(complete).pdf

03175-kolnp-2006 drawings.pdf

03175-kolnp-2006 form-1.pdf

03175-kolnp-2006 form-3.pdf

03175-kolnp-2006 form-5.pdf

03175-kolnp-2006 international publication.pdf

03175-kolnp-2006 pct others.pdf

03175-kolnp-2006-assignment.pdf

03175-kolnp-2006-correspondence others-1.1.pdf

03175-kolnp-2006-pct form.pdf

03175-kolnp-2006-priority document.pdf

3175-KOLNP-2006-ABSTRACT.pdf

3175-KOLNP-2006-AMANDED CLAIMS.pdf

3175-KOLNP-2006-ASSIGNMENT.pdf

3175-KOLNP-2006-CORRESPONDENCE.pdf

3175-KOLNP-2006-DESCRIPTION (COMPLETE).pdf

3175-KOLNP-2006-DRAWINGS.pdf

3175-KOLNP-2006-EXAMINATION REPORT REPLY RECIEVED.pdf

3175-KOLNP-2006-EXAMINATION REPORT.pdf

3175-KOLNP-2006-FORM 1.pdf

3175-KOLNP-2006-FORM 18.1.pdf

3175-kolnp-2006-form 18.pdf

3175-KOLNP-2006-FORM 2.pdf

3175-KOLNP-2006-FORM 3.1.pdf

3175-KOLNP-2006-FORM 3.pdf

3175-KOLNP-2006-FORM 5.pdf

3175-KOLNP-2006-FORM-27-1.1.pdf

3175-KOLNP-2006-FORM-27.pdf

3175-KOLNP-2006-GPA.pdf

3175-KOLNP-2006-GRANTED-ABSTRACT.pdf

3175-KOLNP-2006-GRANTED-CLAIMS.pdf

3175-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

3175-KOLNP-2006-GRANTED-DRAWINGS.pdf

3175-KOLNP-2006-GRANTED-FORM 1.pdf

3175-KOLNP-2006-GRANTED-FORM 2.pdf

3175-KOLNP-2006-GRANTED-SPECIFICATION.pdf

3175-KOLNP-2006-OTHERS.pdf

3175-KOLNP-2006-OTHERS1.1.pdf

3175-KOLNP-2006-PA.pdf

3175-KOLNP-2006-PETITION UNDER RULE 137-1.1.pdf

3175-KOLNP-2006-PETITION UNDER RULE 137.pdf

3175-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

3175-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-03175-kolnp-2006.jpg


Patent Number 249756
Indian Patent Application Number 3175/KOLNP/2006
PG Journal Number 45/2011
Publication Date 11-Nov-2011
Grant Date 08-Nov-2011
Date of Filing 31-Oct-2006
Name of Patentee OUTOKUMPU TECHNOLOGY OYJ
Applicant Address RIIHITONTUNTIE 7 , FI-02200 ESPOO, FINLAND
Inventors:
# Inventor's Name Inventor's Address
1 ORTH ANDREAS OBERE ROMERHOFSTRASSE 132, 61381 FRIEDRICHSDORF, GERMANY
2 PHILP DONALD KEITH (DECEASED) 1 SHERBROOK GARDENS,BIBRA LAKE, W.A.6163, AUSTRALIA
3 DRY ROD 326 THE BOULEVARD, CITY BEACH,W.A. AUSTRALIA
4 EICHBERGER HEINZ AM HAAG 12J, 65812 BAD SODEN, GERMANY
PCT International Classification Number C21B13/00; C21B13/14
PCT International Application Number PCT/EP2005/005464
PCT International Filing date 2005-05-20
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2004902899 2004-05-31 Australia