FIELD OF THE INVENTION
The present invention relates to a process for production of titanium oxide and
metallic iron from llmenite. More particularly, the present invention relates to a
process for simultaneous producing of high purity titanium oxide and metallic iron
from llmenite ore.
BACKGROUND OF THE INVENTION
Most of the conventional processes for production of titanium oxide such as the
Beechar process, the Benilite process, Reptile technology, Sorel process, involve
one of the following process steps: (a) leaching the llmenite ore with sulphuric
acid followed by removal of iron values through precipitation, in the sulphate
process; the hydroxide of titanium is precipitated subsequently followed by
calcination to produce the oxide; (b) chlorination of llmenite in chlorine gas and
separation of iron chloride; (c) reduction of iron in the ore to a metallic state
followed by its removal through aeration in aqueous medium; the residual
titanium oxide is recovered for further processing; (d) partial reduction of iron in
llmenite to the ferrous state at 900°C in a kiln using heavy oil in another process;
the reduced iron is leached with hydrochloric acid at high pressures and suitable
temperatures; synthetic Rutile is recovered from the slurry; (e) reduction of the
ore in a submerged arc furnace using solid carbonaceous reducing agent; liquid
pig iron and a slag rich in titanium oxide are produced; the slag is further treated
to produce high purity oxide of titanium.
All of the processes discussed herein above, suffer from a number of draw-
backs. They involve high capital and operational cost and generate a large
quantity of effluents offensive to the environment. Treatment of the effluents is a
major challenge. Also, the iron values in the ore is lost as a part of the effluent
and the metal, which would be a valuable by-product, is not recovered. Smelting

of llmenite to the produce titania-rich slags is high energy- intensive and is costly,
particularly in locations where the cost of power is high. Also, these processes
involve a number of unit operations leading to unwanted complexity of operation
and loss of efficiency.
Alternatives processes to the known processes as discussed hereinabove, are
also disclosed by several inventors. Reference may be made to Auger et. al.
who, in their patent (US-4097574), discuss a process where the ilmenite is pre-
oxidised followed by reduction in hydrogen atmosphere to reduce the iron to a
metallic state; the reduced iron is leached out using aeration leaching. The main
drawbacks of this process are that a costly reducing agent is used and iron is lost
as an oxide during leaching. Reference may be made to another U.S. patent,
(No. 3816099), where Stewart et. al. describe a process where the iron in the
llmenite ore is reduced to the metallic state in the presence of a catalyst. Iron is
separated from titanium oxide by a suitable means such as magnetic separation.
The major drawback of this process is that a complete. separation of metallic iron
from titanium oxide can not be achieved, unless the process is continued to
several additional stages of purification to get the desired level of purity. Hollitt et.
al. have described a process (US Patent 541179) for producing acid soluble
titania by adding a compound of manganese or magnesium or both to llmenite
mineral which is subsequently reduced with a carbonaceous reducing agent to
produce metallic iron. The iron is then leached through aqueous chemical
treatment. The process suffers from the drawbacks that it adds external elements
such as manganese and magnesium which are undesirable in the final product
and also that the metallic iron is lost through leaching. A process consisting of
the pre-reduction of llmenite ore followed by smelting in plasma has been
described in US Patent 6306195 B1. The process involves reduction of the ore
using non-metallurgical coke and separation of the metallic part using magnetic
separation. The magnetic part is then melted in plasma to produce a slag rich in
titania and liquid iron. The major drawback of process is that the particle size of

the metallic iron formed is very fine and not separable from the titanium oxide
completely, necessitating an additional melting step, thereby increasing the total
energy consumption of the process. Therefore, the major problem to be
addressed, is to develop a technology to produce iron particles which are larger
in size and completely detachable from the titanium oxide, in order to easily
separate' them from the lattices through inexpensive means. USPTO Patent
Application 20070068344 describes a process in which the ferric oxide in the
llmenite ore is reduced to ferrous oxide by carbon at 1600 °C. The ferrous oxide
forms a slag which separates from the residual titanium oxide. The ferrous oxide
slag is reduced with a solid carbon at 1700 °C, in a second stage of operation
and iron droplets are formed. These droplets solidify and separate from the
titanium oxide. After cooling to room temperature, the solidified iron is separated
from the titanium oxide through a physical means. This process however, suffers
from the drawbacks that it requires very high operational temperature and is
applicable to only those ores which can easily form a ferrous oxide phase,
melted, and separated from the titanium oxide. A process that can be operated at
lower temperatures and is not limited by the need to form ferrous oxide phase in
the first step and does not involve a second step of reduction and smelting of
slag is required reduce the cost of production and make it applicable to all
llmenite ores.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose an improved process
for production of titanium oxide from llmenite ore, which obviates the
drawbacks of prior art.

Another object of the present invention is to propose an improved process for
production of titanium oxide from Ilmenite ore, which is enabled to
simultaneously produce metallic iron of high purity.
A still another object of the present invention is to propose an improved process
for production of titanium oxide from Ilmenite ore, which reduces the number
of unit operations in the production process of titanium oxide.
Yet another object of the present invention is to propose an improved process for
production of titanium oxide from Ilmenite ore, which can produce molten iron
including segregation of the solidified iron particles from the residual titanium
oxide through sieving.
A further object of the present invention is to propose an improved process for
production of titanium oxide from Ilmenite ore , which separates the finer
particles of iron from the reduced Ilmenite ore through magnetic separation.
DETAIL DESCRIPTION OF THE INVENTION
Accordingly, the present invention provides an improved process for production
of titanium oxide from Ilmenite ore, which comprises:
(i) mixing of Ilmenite ore and a reducing agent in a ratio ranging
between 10 to 12% of carbon with respect to Ilmenite ore,
(ii) converting the above mixture into pellets using a binder selected
from molasses and like,
(iii) drying the pellets in air at 100-200 °C for a period of 10 to 24 hours,

(iv) heating the dried pellets to temperature ranging between 1600 to
1650 °C in a furnace for a period of 0.5 to 3 hours,
(v) retrieving the pellets from the furnace after cooling to room
temperature,
(vi) breaking the residual mass into smaller blocks
(vii) retrieving the large granules of iron from the broken mass, through
simple sieving
(viii) crushing the residual mass to a particle size ranging between 100
to 300 microns,
(ix) retrieving a non-magnetic part rich in titanium oxide and a magnetic
part rich in metallic iron by known method.
In an embodiment of the present invention, the used llmenite ore has following
composition:
Ti: 45 to 65%
Fe: 25 to 35%
In another embodiment of the present invention, the reducing agent may be
selected from graphite, coke and like.
In still another embodiment of the present invention, a reducing agent may be
mixed in a mass ratio ranging between 10:1 to 10:1.2
In still another embodiment of the present invention, the binder used for
pelletising may be selected from, starch, resin, molasses and like.

in yet another embodiment of the present invention, the pellets may be heated in
the temperature ranging between 1600-1650 °C for a period of 30 to 180 minutes
Solid carbonaceous reducing agents such as coke, which are more economical
compared to gaseous reductants such as hydrogen, natural gas etc., can be
used for reducing the oxidized iron in llmenite to the metal. The metal is usually
leached out, in the conventional processes, to recover titanium oxide. This leads
to an unnecessary loss of iron values and contributes to the high cost of the
process. On the other hand, recovery of the metal using an arc furnace or
plasma process leads to high power consumption and operations at very high
temperatures around 1700-1800°C in the molten phases. However, it is possible
iron which subsequently would segregate from the residual solid slag and
solidify. Therefore, reduction and melting can be carried out in one step. This can
effect a total separation of the phases. The solidified iron can be separated from
the oxide through simple sieving. The finer particles of iron can be further
separated by magnetic separation.
The essence of the inventive process lies in a single step the reduction of iron in
llmenite ore, as well as melting of the iron-reduced ilmenite ore at low
temperatures, around 1600 °C, followed by a step of sieving and magnetic
separation of the solidified iron-carbon alloy.
The following examples are given by way of illustration of working of the
invention in practice and therefore should not be construed to limit the scope of
the present invention.

Graphite used in the experiments contained 99.9% carbon. In some experiments
coke was used. The coke analysed 87.43% fixed carbon, 8.82% ash, 2.813%
volatile matter and 0.926% moisture. The chemical analysis of the llmenite ore
used is given in table 1. XRD analysis showed that FeTiO3 was the predominant
phase present in the ore. In each of the following examples, graphite of 100 μm
size and as-received llmenite ore, about 300 μm size were used. A layer of a fine
powder of the reductant was placed at the bottom of a crucible or a shallow box,
made of graphite. The (ore+reductant) pellets were placed on this layer. This was
further covered with a layer of the reductant powder. The crucible/box containing
the pellets as described above was introduced into the heating chamber of the
furnace and heated to the desired temperature. The pellets were held in the
chamber at the desired temperature for a pre-determined period of time. At the
end of this period the crucible/box was withdrawn from the furnace chamber and
cooled to room temperature. The residual mass in the crucible/box contained
large granules of metallic iron. These were separated from the rest of the matrix
through after initially breaking the fused mass into smaller pieces. The residual
material, after the removal of iron granules were subjected to magnetic
separation after grinding. The magnetic and non-magnetic fractions were
separated.


Example 1
183.6 g.of pellets were held at 1650 °C for a period of 20 minutes in the furnace.
At the end of this period, the pellets were withdrawn, cooled to room
temperature The metallic granules were segregated as described above. The
residue was subjected to magnetic separation after grinding to a fine size. The
non-magnetic fraction contained 79.18% titanium oxide.
Example 2
100 g of pellets were heated at 1650 °C for a period of 40 minutes in the furnace.
The pellets were cooled to room temperature at the end of this period. The
metallic granules were recovered as described above. The residue was
subjected to magnetic separation after grinding to a finer size. The non-magnetic
part contained 83.91% titanium oxide.
Example 3
177.8 g of pellets.were heated at 1650 °C for a period of 60 minutes in the
furnace. The pellets were allowed to cool to room temperature at the end of this
period. After the cooling period, granules of metallic iron were segregated from
the residue as described above. The residue was subjected to magnetic
separation after grinding. The non-magnetic part contained 85.13% titanium
oxide.
Example 4
185.4 g of pellets were heated at 160 °C for a period of 60 minutes in the
furnace. The pellets were allowed to cool to room temperature at the end of this
period. Granules of metallic iron were recovered from the residue after .cooling to
room temperature, as described above. The residual material was subjected to
magnetic separation after grinding to finer size. The non-magnetic part contained
86.29% titanium oxide.

Example 5
189.4 g of pellets were heated at 1650 °C for a period of 40 minutes in the
furnace. The pellets were allowed to cool to room temperature at the end of this
period. After cooling to room temperature, granules of metallic iron were
segregated from the residue as described above. The residual material was
subjected to magnetic separation after grinding to finer size. The non-magnetic
part contained 85.44% titanium oxide.
Example 6
182.2 g of pellets were heated at 1650 °C for. a period of 40 minutes in the
furnace. The pellets were allowed to cool to room temperature at the end of the
heating period. After cooling to room temperature, granules of metallic iron were
segregated from the residue as described above. The residual material was
subjected to magnetic separation after grinding to finer size. The non-magnetic
part contained 80.57% titanium oxide.
Example 7
182 g of pellets were heated at 1650 °C for a period of 60 minutes in the furnace.
The pellets were allowed to cool to room temperature at the end of this period.
Granules of metallic iron were segregated from the residue after the pellets were
cooled to room temperature, as already describe d above. The residual material
was subjected to magnetic separation after grinding to a finer size. The non-
magnetic part contained 84.54% titanium oxide.
Example 8
159.2 g of pellets were heated at 1650 c for a period of 40 minutes in the
furnace. The pellets were cooled to room temperature at the end of the heating
period. Granules of metallic iron were segregated from the residue, as already
described, after the pellets were cooled to room temperature. The residual
material was subjected to magnetic separation after grinding to a finer size. The
non-magnetic part contained 78.04% titaniuim oxide.

Example 9
169.2 g of pellets were heated at 1650 °C for a period of 60 minutes in the
furnace. The pellets were allowed to cool to room temperature at the end of the
heating period. Granules of metallic iron were, segregated from the reside as
described above, after the pellets were cooled to room temperature. The residual
material was subjected to magnetic separation after grinding to finer size. The
non-magnetic part contained 82.44% titanium oxide.
Example 10
98 g of pellets were heated at 1650 °C for a period of 60 minutes in the furnace.
The pellets were allowed to cool to room temperature at the end of this period.
Granules of metallic iron were segregated from the residue, as described above,
after the pellets cooled to room temperature. The residual material was subjected
to magnetic separation after grinding to finer size. The non-magnetic part
contained 84.98% titanium oxide.
Example 11
110 g of pellets were heated at 1650 °C for a period of 60 minutes in the furnace.
The pellets were allowed to cool to room temperature at the end of this period.
Granules of metallic iron were segregated fro the residue, as already described,
after the pellets cooled to room temperature. The residual material was subjected
to magnetic separation after grinding to finer size. The non-magnetic part
contained 80.68% titanium oxide.
Example 12
106 g of pellets were heated at 1650 °C for a period of 60 minutes in the furnace.
The pellets were allowed to cool to room temperature at the end of this period.
Granules of metallic iron were segregated from the residue, as already
described, after the pellets cooled to room temperature. The residual material
was subjected to magnetic separation after grinding to a finer size. The non-
magnetic part contained 72.48% titanium oxide.

The examples above illustrate that iron in ilmenite can be reduced at low
temperatures around 1200-1400 °C forming large particles of liquid which can be
effectively separated from the residual titanium oxide after solidification through
magnetic separation; the non-magnetic parts essentially consists of titanium
oxide and the magnetic part is rich in metallic iron.
The main advantages of the present invention are:
1. It reduces the number of process steps required to produce titanium oxide
from Ilmenite ore.
2. It can produce metallic iron as a valuable by-product.
3. It is simple in operation
4. It is free of any adverse impact on the environment.

We claim:
1. An improved process for production of titanium oxide from Ilmenite ore,
comprising the steps of:
(a) mixing an Ilmenite ore and a reducing agent in a ratio ranging
between 10 to 12% of carbon with respect to Ilmenite ore;
(b) converting the above mixture into pellets using a binder selected from
molasses and like;
(c) drying the pellets in air at 100-200 °C for a period of 10 to 24 hours;
(d) heating the dried pellets to a temperature ranging between 1600 to
1650°C in a furnace for a period of 0.5 to 3 hours;
(e) retrieving the pellets from the furnace after cooling to room
Temperature;
(f)' recovering granules of metallic iron after gentle crushing of the pellets;
(g) crushing the residual pellets to a particle size ranging between 100 to
300 microns; and
(h) retrieving a non-magnetic portion rich in titanium oxide and a magnetic
portion rich-in-metallic-iron by a known method.
2. A process as claimed in claim 1 wherein the used Ilmenite ore have the
following composition:
Ti: 45 to 65%
Fe: 25 to 35%

3. A process as claimed in claims in claim 2-3 wherein the reducing agent is
selected from graphite, coke and like.
4. A process as ciaimed in claims in claim 2-4 wherein the reducing agent is
mixed in a mass ratio ranging between 10:1 to 10:1.2
5. A process as claimed in claims in claim 2-5 wherein the binder used for
pelletising is selected from starch, resin, molasses and like.
6. A process as claimed in claims in claim 2-6 wherein the pellets are heated
in the temperature ranging between 1600-1650 °C for a period of 30 to
180 minutes.
7. A process for the production of titanium oxide and metallic iron from
llmenite substantially as herein described with respect to the examples
accompanying this specification.

ABSTRACT

The invention describes a process for the production of titanium oxide and
metallic iron from llmenite is described. This process consists of heating a
pelletised mixture of llmenite ore and a carbonaceous reducing agent in an
appropriate ratio at a high temperature, around 1650 °C. Iron in the ore is
reduced to the metal during this process. Excess carbon in the mixture dissolves
in the metallic iron forming an alloy. The iron-carbon alloy melts at relatively low
temperatures, around 1200 °C. The.melting temperature depends on the amount
of carbon dissolved in the metal. The particles of molten iron coalesce and
segregate from the residual titanium oxide effectively. The segregated iron
particles are easily removed from the oxide of titanium. Thus highly pure titanium
oxide and metallic iron are produced in this process. Both can be used as raw
materials for industrial applications.