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. |
---|
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
967-KOL-2007-AMANDED CLAIMS.pdf
967-kol-2007-correspondence.pdf
967-KOL-2007-DESCRIPTION (COMPLETE).pdf
967-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf
967-kol-2007-examination report.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-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:
|
|||||||||||||
PCT International Classification Number | G01N 21/73 | ||||||||||||
PCT International Application Number | N/A | ||||||||||||
PCT International Filing date | |||||||||||||
PCT Conventions:
|