Title of Invention	A METHOD OF CONTINUOUS MANUFACTURE OF SPONGE IRON AND A PORTED ROTARY KILN THEREFOR.
Abstract	A METHOD OF CONTINUOUS MANUFACTURE OF SPONGE IORN IN A PORTED ROTARY KILN WHEREIN A CHARGE COMPRISING SIZED IRON ORE, ORE FINES, COAL AS FUEL AND REDUCTANT AND LIMESTONE/DOLOMITE ISFED CONTINUOUSLY INTO THE KILN FROM THE FEED END THEREOF, HAVING THE STEP OF REDUCTION OF ACCRETION AND FOULING OF AIR PIPE LINES AND PORTS OF SAID PORTED ROTARY KILN IN WHICH AIR PORTS IN THE PREHEAT ZONES OF THE KILN ARE SUBSTITUTED BY AXIL PORTY TUBES, CHARACTERIZED IN THAT AIR OR OXYGEN OR AIR-OXYGEN MIXTURE IS SUPPLIED AT A PRESSURE BETWEEN 200 AND 600 MMWC BY SAID TUBES FOR SIMULTANEOUS COMBUSTION AND GENERATION OF REDUCING GAS SO THAT THE RELEASED VOLATILE MATTERS COMING IN CONTACT WITH AIR OR OXYGEN GET CONVERTD INTO GASES THEREBY DISPENSING WITH AND AVOIDING ACCRETION AND FOULING OF AIR PIPELINES AND PORTS OF SAID ROTARY KILN.

Title of Invention

A METHOD OF CONTINUOUS MANUFACTURE OF SPONGE IRON AND A PORTED ROTARY KILN THEREFOR.

Abstract

A METHOD OF CONTINUOUS MANUFACTURE OF SPONGE IORN IN A PORTED ROTARY KILN WHEREIN A CHARGE COMPRISING SIZED IRON ORE, ORE FINES, COAL AS FUEL AND REDUCTANT AND LIMESTONE/DOLOMITE ISFED CONTINUOUSLY INTO THE KILN FROM THE FEED END THEREOF, HAVING THE STEP OF REDUCTION OF ACCRETION AND FOULING OF AIR PIPE LINES AND PORTS OF SAID PORTED ROTARY KILN IN WHICH AIR PORTS IN THE PREHEAT ZONES OF THE KILN ARE SUBSTITUTED BY AXIL PORTY TUBES, CHARACTERIZED IN THAT AIR OR OXYGEN OR AIR-OXYGEN MIXTURE IS SUPPLIED AT A PRESSURE BETWEEN 200 AND 600 MMWC BY SAID TUBES FOR SIMULTANEOUS COMBUSTION AND GENERATION OF REDUCING GAS SO THAT THE RELEASED VOLATILE MATTERS COMING IN CONTACT WITH AIR OR OXYGEN GET CONVERTD INTO GASES THEREBY DISPENSING WITH AND AVOIDING ACCRETION AND FOULING OF AIR PIPELINES AND PORTS OF SAID ROTARY KILN.

Full Text	The present invention pertains to a method of continuous manufacture of sponge iron and a ported rotary kiln therefor. The production of sponge iron is effected by removing oxygen from heated iron oxide by using non-coking coal as the reductant. The reduction is achieved in the solid state without resorting to melting of the iron oxide. The improvement particularly lies in the reduction of accretion and fouling of air pipelines and ports in a ported rotary kiln used for sponge iron manufacture and the improved kiln for carrying out the method. The prior art developments in the rotary ported kiln was directed at control of accretion in view of (a) progressive depletion of reductant carbon in the kiln, and (b) management of hot spots in the areas surrounding air admission points i.e. ports. While the problem management was optimised and hardware designed on the basis of a particular non-coking coal quality, the gradual deterioration in the available coal quality over the years has put the old hardware configuration out of date. The main factors which are now affecting the operation are low fixed carbon, higher volatile matter, higher ash content, and increase in the high boiling fraction of volatile matter, which are causing fouling of air pipelines by putting a coating of bitumen binded fines on the grids of ports. The volatile matters formed in the preheating zone passes into the air pipelines getting deposited inside the throats together with ore fines resulting in choking. This problem is mostly concentrated in the preheating zone of the kiln where maximum volatile matters including high boiling volatile matter, such as tar, are released from the non-coking coal in the temperature range 600°C-800°C, whereas the temperature at which reduction of iron takes place is in the range of 1000°C-1050°C. The choking of air pipelines and grids of the air ports result in supply of inadequate air into the kiln which slows down the rise of temperature, even resulting in inadequate reduction. It also upsets the distribution pattern of air over the length of the kiln. All these affect the plant capacity, product quality, control over accretion and campaign life. The aim of the present invention is to overcome the disadvantages of accretion and fouling of air pipelines and air ports as stated above. In order to prevent choking of air pipelines, according to the invention, axial air tubes have been provided to substitute air ports in the preheat zone of the kiln where release of volatile matters takes place under lower temperature conditions. One or more axial tubes are put in the first 1/3 rd. length of the kiln, depending on the capacity and size of the kiln. Besides high volatile coal, the modification, according to the present invention, will be able to handle higher percentage of fines in raw material from the feed end of the kiln. The impurities and ingredients of coal used in bringing about the reduction of iron ore or ore fines may vary widely, as shown below : FC .......... 35%-42% VM .......... 26%-36% Ash .......... 23%-28% Ash softening point - 1200°C - 1400°C (IDT ) Reactivity 1.6-2.0 The raw materials used as feedstock may have the following dimensions : Feed end iron ore 5.20 mm .......... 6 mm Discharge end iron ore (Upto 11% of total feed) 3.6 mm .......... 3 mm Feed end coal 3.25 mm .......... 3 mm .......... 5mm Discharge end coal 3.6 mm .......... 3 mm (In two/three fractions) 6.15 mm 15.25 mm The ultimate motto is the maintenance of uniform and adequate temperature environment in the reduction zone of the kiln. Since ports are replaced by axial air tubes only in the preheat zone it will not affect uniformity of temperature in the reduction, thus there is no adverse effect on reaction in the reduction zone. The requirement of slinger coal in the preheat zone is not necessary as the feed end coal provides fresh carbon requirement in this zone and, therefore, obstruction provided by axial air tubes in the reactor is for least consequence. The invention is discussed and described hereinbelow with reference to the accompanying drawings wherein : Figure-1 shows the partly sectional schematic view of the prior art ported rotary kiln ; Figure-2 shows a sectional sketch of prior art ported configuration indication zones of high volatile release in the preheat zones of the kiln ; Figure-3 shows in schematic view of the replacement of air ports in the preheat zones by axial air tubes according to the invention. Referring to Figure-1, where a ported rotary kiln of prior art is shown with a large number of ports 2 distributed over the length and periphery of the kiln covering most of its reactive length. Sized iron ore, fines and coal as reductant are fed into the kiln continuously from the the feed end. In the figure, 2 indicates the ports, 3 indicates after burner 4 indicates stack, 5 indicates the reactive zone of the kiln, 6 indicates preheating zone, 7 indicates feed end and 8 indicates the discharge end of the kiln. Referring Figure-2, and as shown in the Figure the reactor is divided into 12 zones, namely Zone 1 to Zone 12 with Zone 1 starting from the discharge end and Zone 12 ending at the feed end. Ports 2 provide air to the radial air ports in each Zone from Zone 1 to Zone 10. Thus air supplied to the reactor provides necessary oxygen for combustion and generation of reducing gas. Release of volatile matters is maximum in the zones 8 and 9 while in the other it is less. The high boiling fraction of the volatile matters such as tar released in the temperature range of 600°C-800°C in the liquid state from the non-coking coal gets inside the air pipelines and ports and chokes them. The effect of choking results in supply of inadequate into the kiln which slows down the rise of temperature in the reduction zone and even results in inadequate reducing/ operating temperature which is normally in the range of 1000°C-1050°C. Referring to and as shown in Figure-3, according to the invention, axial air tubes 13 substitute air ports in the preheat zone of the kiln where release of volatile matters take place under lower temperature condition. One or more axial tubes are put in the first 1/3 rd. length of the kiln depending on capacity and size of the kiln. Since ports are replaced by the axial air tubes only in the prheat zones, it will not affect in the uniformity of temperature in the reduction zones when maintenance of uniform temperature in the said zones is the ultimate motto of a ported rotary kiln. This modified kiln will reduce accretion and fouling of air pipelines and ports to a great extent. Besides high volatile coal, this modified fila is capable of handling higher percentage of ore fines in the raw material charge fed from the feed end. In this modified kiln the requirement of slinger coal in the preheat zones is not necessary as the feed end coal provides fresh carbon requirement in this area, therefore, obstruction provided by axial air tubes in the reactor is least consequence. A method of continuous manufacture of sponge iron in a ported rotary kiln according to this invention, wherein a charge comprising sized iron ore, ore fines, coal as fuel and reductant and limestone/dolomite is fed continuously into the kiln from the feed end thereof, having the step of reduction of accretion and fouling of air pipe lines and ports of said ported rotary kiln in which air ports in the preheat zones of the kiln are substituted by axial port tubes, characterized in that air or oxygen, air-oxygen mixture is supplied at a hressure between 200 and 600 wc by said tubes for simultaneous combustion and generation of reducing gas so that the released volatile matters coming in contact with air or oxygen get converted into gases thereby dispensing with and avoiding accretion and fouling of air pipelines and ports of said rotary kiln. The present invention also relates to a ported rotary kiln for carrying out the method as defined above, comprising (i) air ports along the length and periphery of the reduction zones of the kiln ; (ii) feed end through which a charge of raw material such as sized iron ores, fines, coal as fuel and reductant and limestone/dolomite is fed to the preheat zones of the kiln, and (iii) a discharge end, characterised in that beside discharged sponge iron, coal, ore fines and limestone/dolomite are slung back into the reduction zone of the kiln wherein axial air tubes are provided only in the preheat zones of the said kiln. We claim : 1. A method of continuous manufacture of sponge iron in a ported rotary kiln wherein a charge comprising sized iron ore, ore fines, coal as fuel and reductant and limestone/ dolomite is fed continuously into the kiln from the feed end thereof having the step of reduction of accretion and fouling of air pipe lines and ports of said ported rotary kiln in which air ports in the preheat zones of the kiln are substituted by axial port tubes, characterized in that air or oxygen or air-oxygen mixture is supplied at a harsser between 200 and 600 wc by said tubes for simultaneous combustion and generation of reducing gas so that the released volatile matters coming in contact with air or oxygen get converted into gases thereby dispensing with and avoiding accretion and fouling of air pipelines and ports of said rotary kiln. 2. A method as claimed in Claim 1, wherein said coal is high volatile coal. 3. A method as claimed in Claim 1, wherein said charge may contain inter alia higher percentage of fines in raw material fed from the feed end. 4. A method as claimed in Claims 1 and 2, wherein use of slinger coal in the preheat zone of the kiln is avoided as volatile coal introduced at the feed end of the said kiln satisfies requirement of fresh carbon in this area. 5. A method as claimed in Claims 1 to 4, wherein axial air tubes are provided in the first 1/3 rd. length of the kiln, their numbers depending on the capacity and size of the kiln. 6. A method as claimed in Claims 1 to 4, wherein the ingredients/impurities of said coal may vary widely as below: FC .......... 35% - 42% VM .......... 26% - 36% Ash .......... 23% - 28% Ash softening point - 1200°C - 1400°C (IDT) Reactivity 1.6 - 2.0 7. A method as claimed in Claim 6, wherein the raw material sizes are as below: Feed end iron ore 5.20 mm .......... 6 mm Discharge end iron ore (Upto 11% of total feed) 3.6 mm .......... 3 mm Feed end coal 3.25 mm .......... 3 mm .......... 5mm Discharge end coal 3.6 mm .......... 3 mm (In two/three fraction) 6.15 mm 15.25 mm 8. A method as claimed in any of the preceding claims, wherein any suitable equipment may be used for slinging ore, coal, limestone/dolomite freely and accurately into reduction zones of the kiln from the discharge end so that the axial air tubes are not affected. 9. A method of reduction as claimed in any of the preceding claims wherein gas or oil may be injected through the air ports in addition to the air. 10. A ported rotary kiln for carrying out the method as claimed in any one of Claims 1-9, comprising- (i) air ports along the length and periphery of the reduction zones of the kiln ; (ii) feed end through which a charge of raw material such as sized iron ores, fines, coal as fuel and reductant and limestone/dolomite is fed to the preheat zones of the kiln, and (iii) a discharge end, characterised in that beside discharged sponge iron, coal, ore fines and limestone/dolomite are slung back into the reduction zone of the kiln wherein axial air tubes are provided only in the preheat zones of the said kiln. 11. A ported rotary kiln as claimed in Claim 10, wherein one or more axial air tubes are provided in the first 1/3 rd. length from the feed end of the kiln depending on the capacity and size of the kiln. 12. A method of continuous manufacture of sponge iron, substantially as hereinbefore described with reference to the accompanying drawings. 13. A ported rotary kiln substantially as hereinbefore described with reference to the accompanying drawings. 1. A method of continuous manufacture of sponge iron in a ported rotary kiln wherein a charge comprising sized iron ore, ore fines, coal as fuel and reductant and limestone dolomite is fed continuously into the kiln from the feed end thereof having the step of reduction of accretion and fouling of air pipe lines and ports of said ported rotary kiln in which air ports in the preheat zones of the kiln are substituted by axial port tubes, characterized in that air or oxygen or air-oxygen mixture is supplied at a pressure between 200 and 600 mm Wc by said tubes for simultaneous combustion and generation of reducing gas so that the released volatile matters coming in contact with air or oxygen get converted into gases thereby dispensing with and avoiding accretion and fouling of air pipelines and ports of said rotary kiln.

Full Text

The present invention pertains to a method of continuous manufacture of
sponge iron and a ported rotary kiln therefor. The production of sponge iron is
effected by removing oxygen from heated iron oxide by using non-coking coal as
the reductant. The reduction is achieved in the solid state without resorting to
melting of the iron oxide. The improvement particularly lies in the reduction of
accretion and fouling of air pipelines and ports in a ported rotary kiln used for
sponge iron manufacture and the improved kiln for carrying out the method.
The prior art developments in the rotary ported kiln was directed at control
of accretion in view of (a) progressive depletion of reductant carbon in the kiln,
and (b) management of hot spots in the areas surrounding air admission points
i.e. ports.
While the problem management was optimised and hardware designed
on the basis of a particular non-coking coal quality, the gradual deterioration in
the available coal quality over the years has put the old hardware configuration
out of date. The main factors which are now affecting the operation are low fixed
carbon, higher volatile matter, higher ash content, and increase in the high
boiling fraction of volatile matter, which are causing fouling of air pipelines by
putting a coating of bitumen binded fines on the grids of ports. The volatile
matters formed in the preheating zone passes into the air pipelines getting
deposited inside the throats together with ore fines resulting in choking. This
problem is mostly concentrated in the preheating zone of the kiln where
maximum volatile matters including high boiling volatile matter, such as tar, are
released from the non-coking coal in the temperature range 600°C-800°C,
whereas the temperature at which reduction of iron takes place is in the range
of 1000°C-1050°C.
The choking of air pipelines and grids of the air ports result in supply of
inadequate air into the kiln which slows down the rise of temperature, even
resulting in inadequate reduction. It also upsets the distribution pattern of air
over the length of the kiln. All these affect the plant capacity, product quality,
control over accretion and campaign life.
The aim of the present invention is to overcome the disadvantages of
accretion and fouling of air pipelines and air ports as stated above.
In order to prevent choking of air pipelines, according to the invention,
axial air tubes have been provided to substitute air ports in the preheat zone of
the kiln where release of volatile matters takes place under lower temperature
conditions. One or more axial tubes are put in the first 1/3 rd. length of the
kiln, depending on the capacity and size of the kiln.
Besides high volatile coal, the modification, according to the present
invention, will be able to handle higher percentage of fines in raw material from
the feed end of the kiln.
The impurities and ingredients of coal used in bringing about the
reduction of iron ore or ore fines may vary widely, as shown below :
FC .......... 35%-42%
VM .......... 26%-36%
Ash .......... 23%-28%
Ash softening point - 1200°C - 1400°C (IDT )
Reactivity 1.6-2.0
The raw materials used as feedstock may have the following dimensions :
Feed end iron ore 5.20 mm .......... 6 mm Discharge end iron ore
(Upto 11% of total feed) 3.6 mm .......... 3 mm Feed end coal 3.25 mm .......... 3 mm .......... 5mm Discharge end coal 3.6 mm .......... 3 mm (In two/three fractions) 6.15 mm
15.25 mm
The ultimate motto is the maintenance of uniform and adequate
temperature environment in the reduction zone of the kiln. Since ports are
replaced by axial air tubes only in the preheat zone it will not affect uniformity
of temperature in the reduction, thus there is no adverse effect on reaction in
the reduction zone.
The requirement of slinger coal in the preheat zone is not necessary as
the feed end coal provides fresh carbon requirement in this zone and, therefore,
obstruction provided by axial air tubes in the reactor is for least consequence.
The invention is discussed and described hereinbelow with reference to
the accompanying drawings wherein :
Figure-1 shows the partly sectional schematic view of the prior art ported
rotary kiln ;
Figure-2 shows a sectional sketch of prior art ported configuration indication
zones of high volatile release in the preheat zones of the kiln ;
Figure-3 shows in schematic view of the replacement of air ports in the preheat
zones by axial air tubes according to the invention.
Referring to Figure-1, where a ported rotary kiln of prior art is shown with
a large number of ports 2 distributed over the length and periphery of the kiln
covering most of its reactive length. Sized iron ore, fines and coal as reductant
are fed into the kiln continuously from the the feed end. In the figure, 2 indicates
the ports, 3 indicates after burner 4 indicates stack, 5 indicates the reactive
zone of the kiln, 6 indicates preheating zone, 7 indicates feed end and 8 indicates
the discharge end of the kiln.
Referring Figure-2, and as shown in the Figure the reactor is divided into
12 zones, namely Zone 1 to Zone 12 with Zone 1 starting from the discharge end
and Zone 12 ending at the feed end. Ports 2 provide air to the radial air ports in
each Zone from Zone 1 to Zone 10. Thus air supplied to the reactor provides
necessary oxygen for combustion and generation of reducing gas. Release of
volatile matters is maximum in the zones 8 and 9 while in the other it is less.
The high boiling fraction of the volatile matters such as tar released in the
temperature range of 600°C-800°C in the liquid state from the non-coking coal
gets inside the air pipelines and ports and chokes them. The effect of choking
results in supply of inadequate into the kiln which slows down the rise of
temperature in the reduction zone and even results in inadequate reducing/
operating temperature which is normally in the range of 1000°C-1050°C.
Referring to and as shown in Figure-3, according to the invention, axial
air tubes 13 substitute air ports in the preheat zone of the kiln where release of
volatile matters take place under lower temperature condition. One or more
axial tubes are put in the first 1/3 rd. length of the kiln depending on capacity
and size of the kiln. Since ports are replaced by the axial air tubes only in the
prheat zones, it will not affect in the uniformity of temperature in the reduction
zones when maintenance of uniform temperature in the said zones is the ultimate
motto of a ported rotary kiln.
This modified kiln will reduce accretion and fouling of air pipelines and ports to
a great extent.
Besides high volatile coal, this modified fila is capable of handling higher
percentage of ore fines in the raw material charge fed from the feed end.
In this modified kiln the requirement of slinger coal in the preheat zones
is not necessary as the feed end coal provides fresh carbon requirement in this
area, therefore, obstruction provided by axial air tubes in the reactor is least
consequence.
A method of continuous manufacture of sponge iron in a ported rotary
kiln according to this invention, wherein a charge comprising sized iron ore, ore
fines, coal as fuel and reductant and limestone/dolomite is fed continuously
into the kiln from the feed end thereof, having the step of reduction of accretion and
fouling of air pipe lines and ports of said ported rotary kiln in which air ports in
the preheat zones of the kiln are substituted by axial port tubes, characterized
in that air or oxygen, air-oxygen mixture is supplied at a hressure between 200 and 600 wc by said tubes for
simultaneous combustion and generation of reducing gas so that the released
volatile matters coming in contact with air or oxygen get converted into gases
thereby dispensing with and avoiding accretion and fouling of air pipelines and
ports of said rotary kiln.
The present invention also relates to a ported rotary kiln for carrying out
the method as defined above, comprising
(i) air ports along the length and periphery of the reduction zones of
the kiln ;
(ii) feed end through which a charge of raw material such as sized iron
ores, fines, coal as fuel and reductant and limestone/dolomite is
fed to the preheat zones of the kiln, and
(iii) a discharge end,
characterised in that beside discharged sponge iron, coal, ore fines and
limestone/dolomite are slung back into the reduction zone of the kiln wherein
axial air tubes are provided only in the preheat zones of the said kiln.
We claim :
1. A method of continuous manufacture of sponge iron in a ported rotary kiln wherein
a charge comprising sized iron ore, ore fines, coal as fuel and reductant and limestone/
dolomite is fed continuously into the kiln from the feed end thereof having the step of reduction of
accretion and fouling of air pipe lines and ports of said ported rotary kiln in which air ports in
the preheat zones of the kiln are substituted by axial port tubes, characterized in that air or
oxygen or air-oxygen mixture is supplied at a harsser between 200 and 600 wc by said tubes for simultaneous combustion and
generation of reducing gas so that the released volatile matters coming in contact with air or
oxygen get converted into gases thereby dispensing with and avoiding accretion and fouling
of air pipelines and ports of said rotary kiln.
2. A method as claimed in Claim 1, wherein said coal is high volatile coal.
3. A method as claimed in Claim 1, wherein said charge may contain inter alia higher
percentage of fines in raw material fed from the feed end.
4. A method as claimed in Claims 1 and 2, wherein use of slinger coal in the preheat zone
of the kiln is avoided as volatile coal introduced at the feed end of the said kiln satisfies
requirement of fresh carbon in this area.
5. A method as claimed in Claims 1 to 4, wherein axial air tubes are provided in the
first 1/3 rd. length of the kiln, their numbers depending on the capacity and size of the kiln.
6. A method as claimed in Claims 1 to 4, wherein the ingredients/impurities of said coal
may vary widely as below:
FC .......... 35% - 42%
VM .......... 26% - 36%
Ash .......... 23% - 28%
Ash softening point - 1200°C - 1400°C (IDT)
Reactivity 1.6 - 2.0
7. A method as claimed in Claim 6, wherein the raw material sizes are as below:
Feed end iron ore 5.20 mm .......... 6 mm Discharge end iron ore
(Upto 11% of total feed) 3.6 mm .......... 3 mm Feed end coal 3.25 mm .......... 3 mm .......... 5mm Discharge end coal 3.6 mm .......... 3 mm (In two/three fraction) 6.15 mm
15.25 mm
8. A method as claimed in any of the preceding claims, wherein any suitable equipment
may be used for slinging ore, coal, limestone/dolomite freely and accurately into reduction
zones of the kiln from the discharge end so that the axial air tubes are not affected.
9. A method of reduction as claimed in any of the preceding claims wherein gas or oil may
be injected through the air ports in addition to the air.
10. A ported rotary kiln for carrying out the method as claimed in any one of Claims 1-9,
comprising-
(i) air ports along the length and periphery of the reduction zones of the kiln ;
(ii) feed end through which a charge of raw material such as sized iron ores, fines,
coal as fuel and reductant and limestone/dolomite is fed to the preheat zones
of the kiln, and
(iii) a discharge end,
characterised in that beside discharged sponge iron, coal, ore fines and limestone/dolomite
are slung back into the reduction zone of the kiln wherein axial air tubes are provided only in
the preheat zones of the said kiln.
11. A ported rotary kiln as claimed in Claim 10, wherein one or more axial air tubes are
provided in the first 1/3 rd. length from the feed end of the kiln depending on the capacity and
size of the kiln.
12. A method of continuous manufacture of sponge iron, substantially as hereinbefore
described with reference to the accompanying drawings.
13. A ported rotary kiln substantially as hereinbefore described with reference to the
accompanying drawings.
1. A method of continuous manufacture of sponge iron in a ported rotary kiln wherein
a charge comprising sized iron ore, ore fines, coal as fuel and reductant and limestone dolomite is fed continuously into the kiln from the feed end thereof having the step of reduction of accretion and fouling of air pipe lines and ports of said ported rotary kiln in which air ports in the preheat zones of the kiln are substituted by axial port tubes, characterized in that air or oxygen or air-oxygen mixture is supplied at a pressure between 200 and 600 mm Wc by said tubes for simultaneous combustion and generation of reducing gas so that the released volatile matters coming in contact with air or oxygen get converted into gases thereby dispensing with and avoiding accretion and fouling of air pipelines and ports of said rotary kiln.

Documents:

00426-cal-2000-abstract.pdf

00426-cal-2000-assignment.pdf

00426-cal-2000-claims.pdf

00426-cal-2000-correspondence.pdf

00426-cal-2000-description (complete).pdf

00426-cal-2000-drawings.pdf

00426-cal-2000-form 1.pdf

00426-cal-2000-form 18.pdf

00426-cal-2000-form 2.pdf

00426-cal-2000-form 3.pdf

00426-cal-2000-form 5.pdf

00426-cal-2000-letter patent.pdf

00426-cal-2000-pa.pdf

00426-cal-2000-reply f.e.r.pdf

426-CAL-2000-(08-02-2012)-FORM 27.pdf

426-CAL-2000-CORRESPONDENCE 1.1.pdf

426-CAL-2000-FORM 27.pdf

« Previous Patent

Next Patent »

Patent Number

211275

Indian Patent Application Number

426/CAL/2000

PG Journal Number

43/2007

Publication Date

26-Oct-2007

Grant Date

24-Oct-2007

Date of Filing

27-Jul-2000

Name of Patentee

ORISSA SPONGE IRON LIMITED

Applicant Address

CHATTERJEE INTERNATIONAL CENTRE, 11TH FLOOR, 33A J.L. NEHRU ROAD, CALCUTTA 700 071.

Inventors:

#	Inventor's Name	Inventor's Address
1	MR. PRASANTA KUMAR MOHANTY	C/O. ORISSA SPONGE IRON LIMITED, CHATTERJEE INTERNATIONAL CENTRE, 11TH FLOOR, 33A J.L. NEHRU ROAD, CALCUTTA 700 071.

PCT International Classification Number

C21B 13/08

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA