Title of Invention

A METHOD OF ESTIMATION OF NA2O AND K2O CONTENT IN ORES, FLUXES, SLAGS AND COAL ASH BY INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROSCOPY

Abstract The present invention relates to a method of estimation of Na2O and K2O in ores, fluxes, coal and coke ash by inductively coupled plasma - atomic emission spectroscopy (ICP-AES) comprising the steps of optimizing torch height, plasma power and nebuliser flow of the spectrometer on aspirating standard solutions of Na and K into argon plasma for particular intensity lines of Na and K, count rate and wave length scans of Na and K respectively; preparing a number of calibration solutions of manganese ores containing Na2O and K2O along with a standard blank solution, calibrating and standardizing the said standard solutions on powering the spectrometer, drawing calibration curves for both the constituents Na2O and K2O through mathematical regression and comparing the values obtained from the regression curves with actual ones; preparing solutions of unknown temples of ores, fluxes, coal and coke ash as produced and used in integrated steel plants, aspirating the solutions into plasma, comparing the values obtained for Na2O and K2O along with the certified values of Na2O and K2O and correcting the result for the respective dilution done; ensuring the performance of the method for accurate determination of Na and K contents by evaluating standard deviations for standard samples.
Full Text The present invention relates to a method of correct estimation of a Na2O and
K2O contents slags, in ores, fluxes, coal and coke ash as used / produced in an
integrated steel plant by inductively coupled plasma-atomic emission
spectroscopy (ICP-AES), More specifically the present invention relates to
determination of Na2O and K2O contents of various materials used / produced fn
an integrated steel plant by ICP-AES on optimizing different operating
parameters of a ICP-AE spectrometer, preparing standardized values from
standard sample solutions of the said materials on aspiration of those into
plasma in the spectrometer, obtaining accurate values of Na2O and K2O contents
of unknown samples on aspiration of those into plasma along with certified
values of Na2O and K2O contents of those samples and correcting the result
obtained for those respective samples.
BACKGROUND OF THE INVENTION
Performance of blast furnaces plays a key role in the successful operation of
integrated steel plants. Present day practice is to increase the sinter content of
the blast furnace burden to as high as 80 %, to achieve higher productivity and
lower cost. One of the major concerns of the blast furnace operators is alkali
balancing, especially Na2O and K2O contents, as accumulation of alkali in the
blast furnaces leads to adverse conditions that affect production. These are
present in various raw materials that are used in sinter / iron making. However,
the extent of Na2O and K2O present in coal, coke, iron ore, fluxes like limestone,
dolomite, pyroxinite etc., depends upon the material type and source. During
the process of iron making, they accumulate in the blast furnace in the form of
carbonates, intercalation compounds of carbon and as complex silicates.
These compounds decompose in the lower part of blast furnace to give metallic
alkali, which consume high heat and release the same in a colder region during
condensation. Overall effect is cooling of the hearth and heating of the top
zone. Alkalies in the stack lead to formation of accerations and descend
intermittently, which can result in serious instability. As such alkali balancing is
essential. This requires estimation of alkali content of the inputs as and when
their source of procurement or operational practices change. In addition, as
some amount of alkali goes out through slag, hence knowledge on the alkali
content of slag is also essential.
Several methods such as flame emission spectrometry, Atomic Absorption
Spectrometry (AAS) inductively coupled plasma-atomic emission spectrometry, X-
ray fluorescence spectrometry and wet chemical methods, are in use for the
estimation of alkalis.
Flame emission spectrometry is extensively used for determination of alkali and
alkaline earth metals, which have low excitation energy, especially for biological
and agriculture samples. But intensity of the emitted radiation is highly sensitive
and changes with flame temperature. In addition, it suffers for spectral
interferences and self-absorption. Scope for optimization of operational
parameters for achieving high level of accuracy is limited in case of flame
photometers. Quite often one faces the problem with flow of solutions,
especially when large numbers of samples are to be analyzed, leading to poor
repeatability.
Sample preparation techniques used for Atomic Absorption Spectrometry (AAS)
are similar to those followed for flame emission. Decomposition, of different
ores, siliceous rock materials and refractory materials involves the use of hot
mineral acids like sulfuric acid, perchloric acid, nitric acid and hydrofluoric acids.
The advantages and disadvantages of the two widely used flame methods are
explained later on. Both the methods suffer from similar chemical interferences,
but atomic absorption is subjected to less spectral interferences.
Chemical interference and matrix effects are significantly lower with plasma
sources than with atomizers.
Reports on the use of ICP-AES for the estimation of alkali in limestone are
available in literature. (ASTM). Published methods of estimation of K2O and
Na2O have been searched from the following standard text material.
1. A.I. Vogel, Test book of quantitative Analysis Chapter XXII.
2. J.A. Dean and T.C. Rains, Flame Emission and Atomic Spectroscopy, Vol.
1, 2, 3, Eds., Marcel Decker: New York: 1969-75.
3. American Standards for Testing Materials E863, Vol. 03.06.
4. ASTM E1479 and Annual books of ASTM STD vol. 03.06.
5. Standard test method for major and trace elements in limestone and lime
by ICP-AES and AAS by ASTM Proc. C1301-95.
6. N. Howell Furman, Standard of Chemical Analysis. Chapter 1, Vol.1 and
reference their in.
7. Douglas A Skoog, Prinicipal of Instrumental analysis (3rd Edition),
Saunders college Publications Chapter 9,
8. F.W. Fifield and D. Kealey, Principals and Practice of Analytical Chemistry,
(3rd Edition), Chapter 8, page 293.
9. E.E. Pickett and S.R. Koirtyohann., Anal. Chem. 1969 41(14) 28A.
However, no standard method Is available for the determination of Na2O and K2O
in materials like iron ore, manganese ore, pyroxinite, dunite, dolomite and coal
or coke ash. Present Invention is aimed to remove the prior difficulties of prior
art (standard test procedure) with the development of a method, for the
estimation of Na2O and K2O in these materials, using ICP-AES. The proposed
invention includes preparation Of solution, optimization of the instrumental
parameters and establishing Its validity by verification with Certified Reference
Materials, and repeatability of the proposed method.
DESCRIPTION OF THE INVENTION
One object of the invention is to develop a modified method of analysis of Na2O
and K2O in ores, fluxes, slags, coal and coke ash as used / produced in
integrated steel plant by carrying out study on spectro circus, inductively coupled
plasma spectrometer.
Another object of the Invention is to optimize torch height of the plasma-atomic
emission spectrometer on aspirating particular solutions of Na and K into Argon
plasma for particular intensities of Na and K lines being monitored by varying the
torch height and finding optimized horizontal and vertical positions for Na and K,
Yet another object of the invention is to optimize plasma power of the
spectrometer on aspirating a standard solution of K and Na into the plasma by
varying count rate with respect to power being monitored to optimize the plasma
power on finding out maximum power count for K and Na.
A still another object of the invention is to optimize the nebuliser flow of the
plasma on intensity fines selection of Na and Ka, by aspirating standard solutions
covering maximum and minimum concentrations of Na and K into plasma one by
one under the optimized conditions of torch position and power and scanning the
intensity lines of Na and K to find out optimized wave lengths for Na and K.
A further object of the invention is to prepare a number of calibration solutions
of manganese ore containing Na2O and K2O along with a standard blank solution,
calibrating and standardizing the said standard solutions on powering in the
spectrometer and drawing calibration curves for both the constituents of Na2O
and K2O through mathematical regression and comparing the values obtained for
the regression curves with the actual ones.
A still further object of the invention is to prepare solutions for unknown
samples, aspirating the sample solutions into plasma, the values obtained for
Na2O and K2O are compared along with the certified values of Na2O and K2O and
correcting the result for respective dilutions done.
The modified method of analysis of Na2O and K2O in ores, fluxes, coal and coke
ash is carried on by inductively coupled plasma-atomic emission spectroscopy
(ICP) on first optimization of torch height, plasma power and nebuliser flow of
the spectrometer through standard solutions of Na and K and detecting
optimized Na and K intensity lines, plasma power and wave length scans.
Operational parameters used for such intensity line selection by wave
length scans are:
1. Plasma Power: 1200 watt.
2. Nebulizer flow: 8 - 8.5 Its / min, (Cross Flow)
3. Torch position: 3.8 mm (Vertical) and 4.8 mm (Horizontal)
4. Wave lengths used: Sodium: 589.592 nm and Potassium: 766.490 nm
5. Integration time: 45 seconds
6. Number of measurements: 2
7. Stabilization of plasma: 30 minutes and
8. Back ground correction.
Quality of Reagents used are:
1. Chemicals: All reagents used in this work were AR / GR grades.
2. Water: Double distilled water confirming to Type II of ASTM.
Standard calibration solutions are prepared through the optimized spectrometer
and they are calibrated and standardized to obtain multiple calibration standards,
on comparison with the actual ones.
Unknown solutloris containing K2O and Na2O are then prepared, aspirated into
plasma and the resulted values are compared along with selected certified values
corresponding different certified reference materials and confirm accurate
determination of sodium and Potassium in various materials used / produced in
integrated steel plants.
The proposed invention will be better understood from the following description
with reference to the accompanying drawings in which
Figure l shows plots of count rate (CPS) of intensity lines of Potassium and
Sodium Vs torch height representing optimization of torch height for
K and Na at concentration of 0.43 PPM and 0.032 PPM respectively.
Figure 2 shows plots of count rate of intensity fines Vs plasma power in
watt for K representing optimization of plasma power for K.
Figure 3 shows count rate of intensity lines of Na Vs power of plasma
in watt representing optimization of plasma power for Na.
Figure 4 represents wave length scans for sodium on monitoring Intensity
lines 330.237 and 330.298 nm on aspiration of plasma for four
standard Na solutions including a blank standard solution Alk-Blank 1
Figure 5 represents wave length scans for sodium on monitoring
intensity lines 589.592 nm and for four standard solutions
of sodium including a blank standard solution.
Figure 6 represents wave length scans for sodium on monitoring
intensity lines 588.995 nm for four standard solutions of Na.
Figure 7 represents wave length scans for Potassium on monitoring
intensity lines 404.721 nm for four standard solutions of K.
Rgure 8 represents wave length scans for potassium on monitoring
intensity line 766.490 nm for four standard solutions of K.
Rgure 9 represents calibration curve for Na on regression of Na
intensity lines at 589.592 nm, on plot of count
rate Vs concentration for seven standard Sodium solutions.
Figure 10 represents calibration curve of K on regression of K intensity
lines at 779.490 nm for seven standard solutions of Potassium.
Optimization of torch height:
Solution containing 0.03 PPM of Na and 0.44 PPM of K was aspirated into Argon
plasma and the intensities of 589.592 nm of sodium and 766.490 nm of
potassium lines were monitored by varying the torch height from one extreme to
the other in steps of 0.5 mm. The plots of count rate versus torch height are as
shown in Figure 1. As per these findings horizontal and vertical positions is fixed
at 4.2 mm and 3.85 mm respectively.
Optimization of plasma power:
Standard solution containing 0.16 PPM of Na and 2.16 PPM of K was aspirated
into the plasma and the variation of count rate with respect to power is
monitored to optimize the plasma power. It is observed from Figure 2 and 3,
that maximum count rate is obtained at 1200 Watts.
Line selection;
For this purpose, four standard solutions covering the minimum and maximum
concentrations were used. These solutions were aspirated into plasma one by
one under the optimized conditions of torch position and power. In case of
sodium four lines, viz 330.237, 330.298, 589.592 and 588.995 nm were
monitored and the respective scans are shown in Figures 4,5 and 6.
Wave length scans for Na (588.995 nm)
It is observed that the first two lines have problems of overlap, while third and
fourth are free from overlaps. In addition, background signal in case of first two
lines is significant and in fact it dominates the signal leading to erratic results
with solution of low concentration. Hence, these were found to be unsuitable for
quantitative analysis. Background in case in third and fourth lines was
insignificant, almost zero even in case of the solution with low concentration.
In case of potassium, two lines viz., 404.721 and 766.490 nm were monitored
and scans are given in Figures 7 and 8. It is observed that signal to background
ratio is low in case of the first line (404.721 nm), while it is quite high in case of
second line (766.490 nm).
Hence the lines 589.592 nm and 766.490 nm were selected for sodium and
potassium respectively in the present study.
Preparation of Calibration solutions:
0.01 gm, 0.02 gm, 0.05 gm, 0.1 gm, 0.2 gm and 0.4 gm of certified reference
material, Manganese ore-BS No: 176/1, were weighed into six different 100 ml
beakers provided with covers. 25 ml of cone, hydrochloric acid was added to
each one of these beakers and allowed to digest under low heat over a hot plate
until the reaction ceased. After complete digestion these were allowed to cool
and filtered to separate the insoluble silica. The solutions were then transferred
to six 250 ml volumetric flasks and volumes were made up to the mark with
double distilled water and were marked as a STD-2 to STD-7 respectively.
A standard Wank was prepared by taking 25 ml of cone, hydrochloric acid into a
250 ml volumetric flask and volume made up with double distilled water and
marked as a STD-1. Na2O and K2O contents in the standard solutions are given
in Table-1.
Table-1: Concentration of standard solutions used for calibration of
the spectrometer.
Calibration and standardization:
Power to the spectrometer was put on and left for half an hour for the electronic
parts to stabilize. Calibration standard-1, blank, was aspirated for 10 minutes to
achieve stability of emission with the solution of interest. Then the seven
calibration solutions were aspirated one after the other. Each measurement was
taken in triplicate and the average intensity ratios were recorded. Calibration
curves for both the constituents were obtained by performing mathematical
regression. The curves obtained are shown in Figures 9 and 10.
The values of the seven calibration standards obtained from the calibrations
curves are compared with the actual values in Table-2.
Table 2: Comparison of values obtained from the regression curves
with the actual ones.
Preparation of solutions of unknown samples:
Method-1: Representative samples collected by coning and quartering were
finely powdered and dried at 100° - 110° C for 2 hours. 100 mgs of the sample
was taken in a 100 ml beaker and moistened with few drops of water. 25 ml of
Cone, hydrochloric acid was added to it. The sample was dissolved by heating
the beaker with its contents on a hot plate at low heat for 30 minutes. The
solution was cooled and filtered through Whatmann filter paper (No. 40) in a 250
ml. volumetric flask and the residue was washed thoroughly with double distilled
water. The volume was made up to the mark.
However, to estimate sodium content in samples of limestone, Pyroxinite, dunite,
and iron ore the preparation method used was different from the above and is as
given below:
Method-II:
100 mg of the sample was taken in a 100 ml beaker and moistened with few
drops of water. 25 ml of Cone, hydrochloric acid, followed by 10 ml. of perchloric
were added to it. The sample was dissolved at low heat over a hot plate. It was
then cooled and 50 ml of double distilled water was added. The solution was
then filtered through Whattmann filter paper (No. 40) in a 250 ml. volumetric
flask. The residue was washed with double distilled water. Volume was made
up to the mark.
Whenever sodium or potassium readings are beyond the range, the test should
be repeated by taking more or less weight of the sample and the results
obtained is corrected for the weight.
Analysis of Unknown samples:
1. Standardize the program by Low point (Blank, STD) and high point (STD-
7),
2. Verify the response by checking the results of a certified standard sample,
3. Prepare the sample solutions,
4. Aspirate the sample solutions into plasma,
5. Note the readings and correct the result for dilutions done.
Conclusion
Ten different certified reference materials were selected in the present study.
The standards were dried 100-110° C for 2 hours to remove the moisture. These
were analyzed as unknown samples and the values obtained for Na2O and K2O
are compared along with the certified values in Table-3.
Table-3: Comparison of the values obtained by the present method
with the actual ones. Figures in bold indicate larger variation of
obtained values with standard values.
Observation of Table-3 reveals that K2O results obtained by adopting method-1
for sample preparation are close to the true values in case of all types of
samples, but in case of Na2O, the results are close to the true values only in case
of Blast Furnace slag, iron ore sinter and Manganese ore only. For the rest of
the material types, the obtained values are not matching with true values.
However, in these cases the results obtained following solution preparation
method-2 are in agreement with the true values. This may be due to the fact
the alkali metals come into solution by addition of perchloric acid, as a result of
the rupture of the mineralogical structure. However, among the alkali metals
only potassium suffers the problem of insolubility.
It may be noted that Manganese ore is an exception in that both the solution
preparation methods give the result that are close to the true value.
To assess the capability of the method with respect to repeatability, ten standard
samples were tested eight times each and the standard deviations in case of all
the standards were estimated and are shown in Tables 4 and 5.
The present method of analysis of Na2O and K2O thus clearly reveals the
potentiality of ICP-AES method for accurate determination of sodium and
Potassium contents in various materials used / produced in integrated steel
plants.
The invention as narrated herein with exemplary embodiments should not be
read and construed in a restrictive manner as various modifications in analytical
procedure, alterations in parameters involved in the method and adaptations are
possible within the scope and ambit of the invention as defined In the appended
claims.
WE CLAIM

1. A method of estimation of Na2O and K2O in ores, fluxes, coal and coke ash by
inductively coupled plasma - atomic emission spectroscopy (ICP-AES) comprising
the steps of optimizing torch height, plasma power and nebuliser flow of the
spectrometer on aspirating standard solutions of Na and K into argon plasma for
particular intensity lines of Na and K, count rate and wave length scans of Na
and K respectively; preparing a number of calibration solutions of manganese
ores containing Na2O and K2O along with a standard blank solution, calibrating
and standardizing the said standard solutions on powering the spectrometer,
drawing calibration curves for both the constituents Na2O and K2O through
mathematical regression and comparing the values obtained from the regression
curves with actual ones; preparing solutions of unknown temples of ores, fluxes,
coal and coke ash as produced and used in integrated steel plants, aspirating the
solutions into plasma, comparing the values obtained for Na2O and K2O along
with the certified values of Na2O and K2O and correcting the result for the
respective dilution done; ensuring the performance of the method for accurate
determination of Na and K contents by evaluating standard deviations for
standard samples.

2. A method of estimation of Na2O and K2O as claimed in claim 1, wherein torch
height of the spectrometer is optimized on aspirating solutions containing 0.03
PPM of Na and 0.44 PPM of K into argon plasma and the intensities of 589.592
nm of sodium and 766.490 nm of potassium lines are monitored by varying the
torch height from one extreme to the other in steps of 0.5 mm, plotting count
rate versus torch height to find out horizontal and vertical positions of Na and K
to be fixed at 4.2 mm and 3.85 mm respectively.
3. A method of estimation of Na and K as claimed in claim 1, wherein standard
solution containing 0.16 PPM of Na and 2.16 PPM of K are aspirated into the
plasma and the variation of count rate with respect to power is monitored to
optimize the plasma power to be obtained as 1200 watt for maximum count rate.
4. A method of estimation of Na and K as claimed in claim 1, wherein nebuliser flow
of the plasma is optimized on selecting intensity lines for four standard solutions
covering the minimum and maximum concentration when aspirated into plasma
one by one under the optimized conditions of torch position and power and when
for sodium and potassium four lines are monitored and scanned of their wave
length on regressing curve of count rate versus wave length and intensity lines
are selected optimizingly.


5. A method of estimation of Na2O and K2O as claimed in claim 4, wherein in case
of sodium four lines 330.237, 330.298, 589.592 and 588.995 nm and for
potassium two lines 404.721 and 766.490 nm are selected for optimization of
nebular flow of plasma.
6. A method of estimation of Na2O and K2O as claimed in claims 4 and 5, wherein
operational parameters used for such intensity line selection by wave length
scans are:
- Plasma Power: 1200 watt
- Nebulizer flow: 8-8.5 Its/min. (Cross Flow)
- Torch position: 3.8 mm (Vertical) and 4.8 mm (Horizontal)
- Wave lengths used: Sodium: 589.592 nm and Potassium: 766.490 nm
- Integration time: 45 seconds
- Number of measurements: 2
- Stabilization of plasma: 30 minutes and
- Background correction
and reagents used for samples preparation are of AR/GR grades and water used are
double distilled water confirming to type II of ASTM.
7. A method of estimation of Na2O and K2O as claimed in claim 1, wherein
calibration solutions are prepared from 0.01 gm, 0.02 gm, 0.05 gm, 0.1 gm and
0.4 gm of certified reference material, manganese ore-BS No. 176/1, being
weighed into six different 100 ml beakers provided with covers, adding 25 ml of
cone, hydrochloric acid to each one of the said beakers and allowed to digest
under low heat over a hot plate until reaction ceased, cooling the digested
solution and filtering to separate insoluble silica, the resultant solutions then
transferred to six 250 ml volumetric flasks and volumes are made to the mark
with double distilled water and marked as a STD-2 to STD-7 respectively along
with a standard blank prepared by taking 25 ml of concentrated hydrochloric acid
into a 250 ml volumetric flask and volume made up with double distilled water
and marked as a STD-1 and in which N20 and K2O contents in the standard
solutions are shown in Table-1.
8. A method of estimation of Na2O and K2O as claimed in claims 1 and 7, wherein
calibration and standardization of the standard solutions are made on powering
the spectrometer and left for half an hour for stabilization of electronic parts of
the spectrometer, calibrating standard 1, blank on aspirating for 10 minutes to
achieve stability of emission with the solution of interest, then aspirating the
seven calibration solutions one after the other on taking measurement in


triplicate and recording average intensity ratios, obtaining calibration curves for
both the constituents by performing mathematical regression and comparing the
values of the seven calibration standards obtained from the calibration curves with
the actual values according to Table 2.
9. A method of estimation of Na2O and K2O as claimed in claim 1, wherein
representative solutions of unknown samples of ores, fluxes, coal and coke ash
are prepared on collection by coning and quartering collected samples being
finely powdered and dried at 100-110°C for two hours, 100 msgs of the sample
taken to 100 ml beaker and moistened with few drops of water, adding 25 ml of
concentrated hydrochloric acid to it, dissolving the sample by heating the beaker
with its contents on a hot plate at low heat for 30 minutes, cooling the resultant
solution and filtering through Whatmann filter paper No- 40 in a 250 ml
volumetric flask, washing the residue thoroughly with double distilled water and
making up the volume upto the mark.
10. A method of estimation of Na2O and K2O as claimed in claims 1 and 9, wherein in
case of estimation of sodium content in samples of lime stone, pyroxinite, dunite
and iron ore the step of addition of 25 ml concentrated hydrochloric acid is
followed by addition of 10 ml of perchloric acid, other steps remaining the same.
11. A method of estimation of Na2O and K2O as claimed in preceding claims, wherein
the unknown samples are evaluated by the following sequential steps of
standardizing the programme by low point (Blank, STD) and high point (STD-7),
verifying the response by checking the results of a certified standard sample,
preparing the unknown sample solutions, aspirating the unknown sample
solutions into plasma and noting the reading and correcting the final result for
dilutions done.
12.A method of estimation of Na2O and K2O as claimed in claims 1 and 11, wherein
ten different reference materials of ores, flux, coal and coke ash are selected and
dried at 100°C to 110°C for two hours to remove moisture of those, the standard
solution prepared of those are analyzed as unknown samples and the resultant
values obtained for Na2O and K2O are compared along with the certified values
as enumerated in Table 3.
13. A method of estimation of Na2O and K2O as claimed in claims 1 and 12, wherein
the performance of the method in repeatability is ensured by testing ten
standard samples eight time each and the standard deviations in case of all the
said standards are estimated in Tables 4 and 5.


The present invention relates to a method of estimation of Na2O and K2O in ores,
fluxes, coal and coke ash by inductively coupled plasma - atomic emission spectroscopy
(ICP-AES) comprising the steps of optimizing torch height, plasma power and nebuliser
flow of the spectrometer on aspirating standard solutions of Na and K into argon
plasma for particular intensity lines of Na and K, count rate and wave length scans of
Na and K respectively; preparing a number of calibration solutions of manganese ores
containing Na2O and K2O along with a standard blank solution, calibrating and
standardizing the said standard solutions on powering the spectrometer, drawing
calibration curves for both the constituents Na2O and K2O through mathematical
regression and comparing the values obtained from the regression curves with actual
ones; preparing solutions of unknown temples of ores, fluxes, coal and coke ash as
produced and used in integrated steel plants, aspirating the solutions into plasma,
comparing the values obtained for Na2O and K2O along with the certified values of Na2O
and K2O and correcting the result for the respective dilution done; ensuring the
performance of the method for accurate determination of Na and K contents by
evaluating standard deviations for standard samples.

Documents:

00967-kol-2007-abstract.pdf

00967-kol-2007-claims.pdf

00967-kol-2007-correspondence others 1.1.pdf

00967-kol-2007-correspondence others 1.2.pdf

00967-kol-2007-correspondence others.pdf

00967-kol-2007-description complete.pdf

00967-kol-2007-drawings.pdf

00967-kol-2007-form 1 1.2.pdf

00967-kol-2007-form 1.pdf

00967-kol-2007-form 18.pdf

00967-kol-2007-form 2.pdf

00967-kol-2007-form 3.pdf

00967-kol-2007-gpa.pdf

967-KOL-2007-ABSTRACT.pdf

967-KOL-2007-AMANDED CLAIMS.pdf

967-kol-2007-correspondence.pdf

967-KOL-2007-DESCRIPTION (COMPLETE).pdf

967-KOL-2007-DRAWINGS.pdf

967-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

967-kol-2007-examination report.pdf

967-KOL-2007-FORM 1.pdf

967-kol-2007-form 18.pdf

967-KOL-2007-FORM 2.pdf

967-kol-2007-form 3.pdf

967-kol-2007-form 5.1.pdf

967-KOL-2007-FORM 5.pdf

967-kol-2007-gpa.pdf

967-kol-2007-granted-abstract.pdf

967-kol-2007-granted-claims.pdf

967-kol-2007-granted-description (complete).pdf

967-kol-2007-granted-drawings.pdf

967-kol-2007-granted-form 1.pdf

967-kol-2007-granted-form 2.pdf

967-kol-2007-granted-specification.pdf

967-KOL-2007-OTHERS.pdf

967-kol-2007-reply to examination report.pdf


Patent Number 248247
Indian Patent Application Number 967/KOL/2007
PG Journal Number 26/2011
Publication Date 01-Jul-2011
Grant Date 29-Jun-2011
Date of Filing 06-Jul-2007
Name of Patentee TATA STEEL LIMITED
Applicant Address JAMSHEDPUR
Inventors:
# Inventor's Name Inventor's Address
1 SARKAR, S. TATA STEEL LIMITED JAMSHEDPUR 831 001
2 CHAKRABORTI, INDRANIL TATA STEEL LIMITED JAMSHEDPUR 831 001
3 SUBRAHMANYAM, V.V.V. TATA STEEL LIMITED JAMSHEDPUR 831 001
PCT International Classification Number G01N 21/73
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA