FIELD OF THE INVENTION
The present invention relates to an equipment for the production of titanium
oxide from Ilmenite. More particularly, the present invention relates to a system
for producing high purity titanium oxide from Ilmenite ore at low cost.
BACKGROUND OF THE INVENTION
The conventional processes for the production of titanium oxide for example,
Benilite process, Sorel process, Reptile technology, Beechar process, allinvolves
either chemical reaction between the ore and a suitable medium or leaching of
the ore after partial reduction. In the sulphate process, the ore is leached with
sulphuric acid followed by removal of iron values through precipitation. The
hydroxide of titanium is precipitated subsequently followed by calcination to
produce the oxide. In the chlorination process, the ore is chlorinated in chlorine
gas and iron chloride is separated subsequently. In the Beechar process, iron in
the ore is reduced to the metallic state followed by its removal through aeration
in aqueous medium. The residual titanium oxide is recovered for further
processing. Partial reduction of iron in the Ilmenite to the ferrous state is carried
out at 900°C in a kiln using heavy oil. The reduced iron is leached with
hydrochloric acid at high pressures and suitable temperatures, and synthetic
Rutile is recovered from the slurry. In the Sorell process, the ore is reduced 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.

The processes discussed above all suffer from a number of draw-backs. For
example, the processes involve high capital and operation cost and generates a
large quantity of effluents offensive to the environment. Treatment of the
effluents is a major challenge. Also, the iron values in the ore are lost as a part
of the effluent and the metal, which would be a valuable by-product, is not
recovered. Smelting of Ilmenite 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 to the known prior art processes as discussed hereinabove, have
also been disclosed by several inventors. For example, Auger et. al. discusses in
US-4097574, 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 the
leaching. U.S. patent US 3816099 describes a process where iron present in the
Ilmenite ore is reduced to a 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 the separation of metallic iron from
the titanium oxide, further requires several stages of purification to get the
desired level of purity. US Patent US 541179 teaches a process for producing
acid soluble titania by adding a compound of manganese or magnesium or both
to Ilmenite mineral which is subsequently subjected to a carbonaceous reducing
agent to produce metallic iron. The iron is then leached through aqueous
chemical treatment. This process suffers from the drawbacks that it adds

external elements such as manganese and magnesium which are undesirable in
the final product and that the metallic iron is lost through leaching. A process
consisting of the pre-reduction of Ilmenite ore followed by smelting in plasma
has been disclosed in US Patent US 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 this process is that the
particle size of metallic iron formed is very fine and inseparable completely from
the titanium oxide, which interalia requires an additional melting step, thereby
increasing the energy consumption of the process. Therefore, the major
problem to be addressed is proposing a technology to produce iron particles
which are larger in size and completely separable from the titanium oxide, in an
inexpensive means. Patent Application US 20070068344 describes a process in
which the ferric oxide in Ilmenite ore is reduced to ferrous oxide by carbon
injection at 1600 °C. The ferrous oxide forms a slag which is separable 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 get separated from the titanium oxide. After cooling at 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 a high operational temperatures and is applicable to only those ores
which can easily form a ferrous oxide phase, can be 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 is. therefore
required to reduce the cost of production and make the process applicable to all
Ilmenite ores.

OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose a system for
producing high purity titanium oxide from Ilmenite ore at low cost, which
obviates the drawbacks of prior art.
Another object of the present invention is to propose a system for producing
high purity titanium oxide from Ilmenite ore at low cost, which reduces the
number of unit operations in production of titanium oxide.
A still another object of the present invention is to propose a system for
producing high purity titanium oxide from Ilmenite ore at low cost, which
reduces the quantum use of the ore in the process by adapting natural gas or
liquefied petroleum gas.
A further object of the present invention is to propose a process implemented in
a system reduction of use-quantum of Ilmenite ore, by adapting a gaseous
reducing agent.
SUMMARY OF THE INVENTION
Accordingly, there is provided a system for production of titanium oxide from
Ilmenite ore which comprises a combustion chamber, a main reaction chamber,
a wind box , a cyclone separator, a chimney , an air compressor, a plurality of
control valves with gauges and a gas station with instrument panel, wherein
the combustion chamber having a square cross-section in a range of 250X250 to
400X400 mm2 and a height in a range of 500 to 600 mm, fitted with the gas

station Including the control panel and placed to the main reaction chamber in
such a way that the furnace chamber can be lifted and placed on a vertical
platform to enable charging of materials and removing them from the main
reaction,sealing the interface between the two chamber to ensure that gas
from the two chambers does not escape into the surrounding atmosphere
chamber.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Figure 1- Schematically shows a system for producing high purity titanium oxide
from ilmenite ore at low cost.
DETAIL DESCRIPTION OF THE INVENTION
As shown in fig. 1, the present invention provides a system essentially
comprising a furnace chamber [1], a main reaction chamber [2], a wind box [3],
a cyclone separator [4], a chimney [5] , an air compressor [6], a plurality of
control valves with gauges [7], a gas station [8], and an instrument panel [8].
The furnace chamber [1] has a square cross-section with dimensions exactly
matching that of the main reaction chamber (2) which has a matching square
cross-section measuring. A gas burner with a control panel is fitted to a roof of
the furnace chamber (1), which has a height double the cross section. When the
furnace chamber (1) is fitted to the main reaction chamber (2), there is tight fit
at the interface between the two chambers (1,2). Side plates, which can be
fastened with bolts and nuts to the furnace chamber (1), seal the interface. Glass
wool is fixed to the side plates to ensure that the sealing is strong and gas from
the two chambers (1,2) does not escape into the surrounding atmosphere. At

least four side plates are used for sealing the interface along the four walls of the
chambers (1,2). The furnace chamber (1) can be lifted and placed on a vertical
platform to enable charging of materials and removing them from the main
reaction chamber(2);
The main reaction chamber [2] of the system has a height of 580 mm. The
chamber (2) is made of mild steel shell lined with high alumina refractory with
hangers for holding the refractory material in position. A metallic grate made of
Inconel alloy is placed at the bottom of the chamber (2). The furnace chamber
(1) where combustion occurs is placed on top of the main reaction chamber [2].
There are at least four ports on one of the walls of the main reaction chamber
(2). These are used for measuring the pressure inside the chamber (2) and for
measuring the temperature of the charge bed. The outer walls of the main
chamber (2) reach a maximum temperature of 10 °C, above the ambient during
operations. The total volume of the free space available in the main chamber (2)
is around 0.063162 m3. This can hold about 100 kg. of pellets. However, in order
to protect the grate at the bottom of the chamber (2) from direct heating by the
burner flame and to maintain a low temperature at the grate, it is necessary to
pack the chamber (2) with alumina grog upto a bed height of about 250 mm.
The volume available for placing the (ore+coke) pellets under the exemplary
structure of the system, is sufficient to hold more than 50 kg of pellets.
The Wind Box [3] is a hollow chamber placed below the main reaction chamber
(2). The Inconel grate separates the Wind Box [3] from the main reaction
chamber (2). It serves to collect fine particles passing through the grate and for
cooling the exhaust gas. Thermo well provided.projecting into the Wind.Box [3]
allows monitoring of the temperature of the exhaust gas.

Gas is drawn from said gas station [8] through the Wind Box [3] into the exhaust
line, leading to the chimney [5]. A cyclone (4) separate or fitted in the exhaust
line, between the Wind Box (3) and the chimney (5) serves to collect fine
particles of dust carried away by the exhaust gas. An ID fan serves to draw the
exhaust gas into the chimney (5). Thermo wells at suitable locations monitor the
temperature of the exhaust gas at the "inlet" and "outlet" of said I.D. fan.
An air compressor [6] feeds the air required for burning the LPG in the furnace.
A valve (7) in the compressor (6) regulates the flow rate of air. The flow rate is
monitored using a mass flow meter. This reads the flow rate in the range 0-700
m3/hr.
Data on the flow rate of LPG and that of compressed air are transmitted to the
instrument panel [8] which displays the flow rates in a digital form. This panel
(8) displays the temperature of the furnace chamber (1) and that of the main
reaction chamber (2). The temperature of the exhaust gas at the Wind Box (3)
and at the "inlet" and "outlet" of the ID fan are also displayed.
The pressure inside the main reaction chamber [2] is measured using a
manometer containing water. The pressure inside the chamber (2) can be
controlled in one of the following manners, (i) by controlling the flow rates of air
and LPG, (ii) by controlling a throttle valve at the bottom of the chimney (3) by
controlling the opening of the discharge port of the cyclone separator and (iii) by
controlling additional valves at the bottom of the main reaction chamber (2)
through which air can be allowed into the system.

The system can be operated in a sequence for example,(i) checking the gas line
for leakages, (ii) rectifying the leakages, if any, (iii) connecting required number
of LPG cylinders to the gas pipe line, keeping all the cylinders closed , (iv)
removing the furnace chamber (1) and placing it on a platform, (v) filling the
main reaction chamber (2) with alumina grog up to half of its depth, (v) charging
the (ore+carbon) pellets into the remaining volume of the main chamber (2), to
a desired depth (or the desired mass of pellets is charged), (vi) replacing the
furnace chamber (1) on the main reaction chamber (2), (vii) sealing the interface
between the two chambers (1,2) (furnace chamber and main reaction chamber)
with the side plates and fastening them, (viii) introducing a thermo well with a
thermocouple through the thermocouple port, (ix) connecting the monometer
port to the monometer using a polythene tube, (x) opening the gas valves and
pressurizing the gag line to a desired pressure level. The pressure in the main
Bourdon gauge (Ml) should read 3 kg/cm2 at this stage, (xi) activating a main
switch of the instrument panel (8), (xii) activating a personal computer and a
data logging system, (xiii) activating the ID fan, (xiv) activating the compressor
(6), (xv) activating a solenoid switch on the instrumentation panel (8), (xvi)
activating the "burner" switch on the instrumentation panel (8) (xvii) opening the
valve (7) leading to the mass flow meter of the LPG line. The flow rate of LPG
can be maintained between 1 and 3 m3/hr, (xviii) opening the valve (7) of the air
compressor (6) to the desired degree. The flow rate of compressed air can be
adjusted to be about 100 m3/hr and (xix) opening the valve (7) above the mass
flow meter so that the pressure gauge (7) reads 200-300 mbar. On completion
of the steps described above, the burner in the furnace chamber (1) is activated.
All the process data are displayed on the instrumentation panel (8) and are also
logged simultaneously.

The combustion chamber [1] having a square cross-section for example, in the
range of 250X250 to 400X400 mm2 and height for. example, in the range of 500
to 600 mm, fitted with the gas station [8] and a control panel [8] and placed to
the main reaction chamber [2] in such a way that the furnace chamber (1) can
be lifted and placed on a vertical platform to enable of charging of materials and
removing them from the main reaction, sealing the interface between the two
chamber [1,2] to ensure that gas from the two chambers (1,2) does not escape
into the surrounding atmosphere chamber.
The pressure inside the main reaction chamber [2] may be maintained above
100 mm height of water column.
The pressure of LPG may be maintained in the range of 0.2 to 6 kg/cm2
The temperature of the exhaust gas in the Wind Box and ID fan may be
maintained below 200 °C.
The novelty of the process lies in the design of a system for reduction of Ilmenite
ore with natural gas and the like at low temperatures, around 1300 °C, and the
process of reduction to produce titanium oxide of high purity.
The following examples are given by way of illustration of the working of the
invention in actual practice and therefore should not be construed to limit the
scope of the present invention.
Graphite used in the experiments contained 99.9% carbon. The chemical
analysis of the Ilmenite ore used is given in Table 1. XRD analysis showed that
FeTiO3 was the predominant phase present in the ore. In the following examples,


Example 1
1.006 kg of the (ore+graphite) pellets of average diameter of 15 mm, were
taken in the reduction chamber and heated at an average temperature of 1276
°C, for a period of 60 minutes. The pressure inside the reduction chamber was
about 252 mm, water column, on average. Liquefied petroleum gas was passed
at a rate of 5 m3/hr and compressed air was passed at 85 m3/hr. The pellets
were allowed to cool in the reduction chamber to room temperature after
reduction was complete. The reduced pellets were subjected to magnetic
separation. The non-magnetic fraction analysed 87.80%TiO2.
Example 2
500 g of the (ore+graphite) pellets of average diameter of 10 mm, were taken in
the reduction chamber and heated at an average temperature of 1412 °C, for a
period of 100 minutes. The pressure inside the reduction chamber was 280 mm,
water column, on average. Liquefied petroleum gas was passed at a rate of
6m3/hr and compressed air was passed at a rate of 98 m3/hr. the pellets were
allowed to cool in the reduction chamber to room temperature, at the end of the
reduction period. The pellets were subjected to magnetic separation after
cooling. The non-magnetic fraction analysed 81.03-88.32% TiO2.

Example 3
0.956 kg of pellets, of average diameter in the range 15-20 mm, were taken in
the reduction chamber and heated at an average.temperature of 1409 °C for a
period of 180 minutes. The pressure inside the reduction chamber was 288-348
mm, on average. Liquefied petroleum gas was passed at a rate of 6m3/hr and
compressed air was passed at a rate of 100 m3/hr. The pellets were allowed to
cool in the reduction chamber to room temperature at the end of reduction. The
pellets were subjected to magnetic separation after cooling. The non-magnetic
fraction analysed 85.04-89.08% TiO2.
Example 4
30.05 kg of pellets, of average diameter in the range 15-20 mm, were taken in
the reduction chamber and heated at an average temperature of 1345 °C for a
period of 180 minutes. The pressure in the reduction chamber was 356 mm, on
average. Liquefied petroleum gas was passed at a rate of 6m3/hr and
compressed air was passed at a rate of 92 m3/hr. The pellets were allowed to
cool to room temperature in the reduction chamber at the end of reduction. The
reduced pellets analysed 83.53% TiO2, on average.
Example 5
3 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1402 °C, for a period of 150
minutes. The pressure inside the reduction chamber was 296 mm, water column,
on average. Liquefied petroleum gas was passed at a rate of 3 m3/hr and
compressed air was passed at a rate of 100 m3/hr. the pellets were allowed to
cool in the reduction chamber to room temperature, at the end of reduction. The
reduced pellets analysed 94.95% TiO2, on average.

Example 6
2 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1398 °C for a period of 240
minutes. The pressure inside the chamber was 340 mm, water column, on
average. Liquefied petroleum gas passed at a rate of 4m3/hr and compressed air
was passed at a rate of 102 m3/hr. The pellets were allowed to cool in the
reduction chamber to room temperature, at the end of reduction. The reduced
pellets analysed 98.19-98,32% TiO2, on average.
Example 7
3 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1358 °C for a period of 180
minutes. The pressure inside the chamber was 120-360 mm, water column.
Liquefied petroleum gas passed at a rate of 5 m3/hr and compressed air was
passed at a rate of 10-245 m3/hr. the pellets were allowed to cool in the
reduction chamber to room temperature, at the end of reduction. The reduced
pellets analysed 89.33-99.29% TiO2, on average.
Example 8
3.004 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1369 °C for a period of 360
minutes. The pressure inside the chamber was i20-220 mm, water column.
Liquefied petroleum gas was passed at a rate of 4 m3/hr and compressed air was
passed at a rate of 120-250 m3/hr. The pellets were allowed to cool in the
reduction chamber to room temperature , at the end of reduction. The reduced
pellets analysed 90-93.63% TiO2, on average.

Example 8
5.010 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1369 °C for a period of 150
minutes. The pressure inside the reduction chamber was 120-220 mm, water
column. Liquefied petroleum gas was passed at a rate of 7m3/hr and compressed
air was passed at a rate of 200 m3/hr. the pellets were allowed to cool in the
reduction chamber to room temperature, after reduction. The reduced pellets
analysed 90.10-90.78% TiO2, on average.
Example 9
6.604 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1344 °C for a period 240
minutes.The pressure in the reduction chamber was 140-536 mm , water
column. Liquefied petroleum gas was passed at a rate 4 m3/hr and compressed
air was passed at a rate of 140 m3/hr. the pellets were allowed to cool in the
reduction chamber to room temperature, at the end of reduction. The reduced
pellets analysed 90.10-96.29% TiO2, on average.
Example 10
5.472 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature 1369 °C for 180 minutes. The
pressure in the chamber was 150 mm , water column, on average. Liquefied
petroleum gas was passed at a rate of 4 m3/hr and compressed air was passed
at a rate of 142 m3/hr. The pellets were allowed to cool in the reduction chamber
to room temperature, after reduction. The reduced pellets analysed 90.54-
99.03% TiO2, on average.

Example 11
5.20 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1110 °C for a period of 240
minutes. The pressure inside the reduction chamber was 250 mm, water column.
Liquefied petroleum gas passed at a rate of 5 m3/hr and compressed air was
passed at a rate of 92 m3/hr. the pellets were allowed to cool in the reduction
chamber to room temperature, at the end of reduction. The reduced pellets
analysed 90.54-99.03% TiO2, on average.
Example 12
9.0 kg of pellets, of average diameter 15-20 mm, were taken in the reduction
chamber and heated at an average temperature of 1131 °C for a period of 120
minute. The pressure inside the reduction chamber was 460 mm, water column.
Liquefied petroleum gas passed at a rate of 2 m3/hr and compressed air was
passed at a rate of 224-310 m3/hr. the pellets were allowed to cool in the
reduction chambertcrroom temperature, at the end of reduction. The reduced
pellets analysed 83.93-99.16% TiO2, on average.
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 be carried out at temperatures significantly lower than that
employed in conventional processes.
3. It uses natural gas directly for reduction
4. It produces high purity titanium oxide in one step without any need of
additional steps for removing iron
5. It can reduce the energy consumption in the production of the titanium
oxide and is free of any adverse impact on the environment.

We claims
1. A system for production of titanium oxide from Ilmenite ore which
comprises a combustion chamber [1], a main reaction chamber [2], a
wind box [3], a cyclone separator [4], a chimney [5] , an air compressor
[6], a plurality of control valves with gauges [7] and a gas station [8]
with instrument panel [8], wherein the combustion chamber [1] having a
square cross-section in a range of 250X250 to 400X400 mm2 and a height
in a range of 500 to 600 mm, fitted with the gas station [8] including the
control panel [8] and placed to the main reaction chamber [2] in such a
way that the furnace chamber (1) can be lifted and placed on a vertical
platform to enable charging of materials and removing them from the
main reaction, sealing the interface between the two chamber [1,2] to
ensure that gas from the two chambers (1,2) does not escape into the
surrounding atmosphere chamber.
2. The system as claimed in claims 1 or 2, wherein the main reaction
chamber [2] is made of mild steel shell lined with high alumina refractory
with plurality of hangers to hold the refractory material in position,
wherein the free space inside the chamber [2] is selected in a range of
0.04 to 0.08 m3 to hold 100 to 150 kg of pallets, fitted with metallic grate
made of Inconel alloy and placed at the bottom of the chamber [2],
having four ports to measure the pressure inside the chamber [2] and for
measuring the temperature of the charge bed though the instrumental
panel [9], packing the chamber [2] with alumina grog to a bed height of
200-250 mm to protect the grate at the bottom of the chamber[2] from
direct heating by the flame and to maintain a low temperature at the
grate.

3. The system as claimed in claims 1 or 2, wherein the Wind Box [3] is a
hollow chamber which is used to draw gas from the gas station [8]
disposed below the main reaction chamber [2] in such a way that the
Inconel grate separates the Wind Box [3] from the main reaction chamber
[2] to collect fine particles passing through the grate and for cooling the
exhaust gas.
4. The system as claimed in any of claims 1 to 3, wherein the cyclone
separator [4] is fitted an exhaust line between the Wind Box [3] and the
chimney [5] to collect fine particles of dust carried away by the exhaust
gas using an ID fan and placing a plurality of thermo wells to monitor the
temperature of the exhaust gas.
5. The system as claimed in one of claims 1 to 4 wherein the air compressor
[6] connected with combustion chamber [1] feeds the air for burning the
LPG by regulating a flow rate in a range 0-700 m3/hr through the
instrument panel [8].
6. The system as claimed in any of claims 1 to 5, wherein pressure inside
the main reaction chamber [2] is measured by a manometer containing
water and the pressure inside the chamber [2] is controlled by controlling
the flow rates of air and LPG, including controlling a throttle valve
installed at the bottom of the chimney [5] which the opening of the
discharge port of the cyclone separator [4] is controlled, and wherein the
controlling valves (7) installed at the bottom of the main reaction chamber
[2] is controlled to allow input of air into the system.

7. The system as claimed in any of claims 1 to 6, wherein the pressure inside
the main reaction chamber [2] is maintained above 100 mm height of
water column.
8. The system as claimed in any of claims 1 to 7, wherein the pressure of
LPG is maintained in a range of 0.2 to 6 kg/cm2
9. The system as claimed in any of claims 1 to 8, wherein the temperature of
the exhaust gas in the Wind Box and the ID fan is maintained below 200
°C.
10. A system for production of titanium oxide from Ilmenite ore substantially
as herein described with respect to the examples and drawing
accompanied with this specification.

ABSTRACT

The invention relates to a system for production of titanium oxide from Ilmenite
ore which comprises a combustion chamber [1], a main reaction chamber [2], a
wind box [3], a cyclone separator [4], a chimney [5] , an air compressor [6], a
plurality of control valves with gauges [7] and a gas station [8] with instrument
panel [8], wherein the combustion chamber [1] having a square cross-section in
a range of 250X250 to 400X400 mm2 and a height in a range of 500 to 600 mm,
fitted with the gas station [8] including the control panel [8] and placed to the
main reaction chamber [2] in such a way that the furnace chamber (1) can be
lifted and placed on a vertical platform to enable charging of materials and
removing them from the main reaction, sealing the interface between the two
chamber [1,2] to ensure that gas from the two chambers (1,2) does not escape
into the surrounding atmosphere chamber.