Title of Invention	AN IMPROVED PROCESS FOR DIRECT LEACHING OF POLYMETALLIC SEA NODULES FOR THE RECOVERY OF METALS
Abstract	The present invention relates to an improved process for direct leaching of polymetallic sea nodules for the recovery of metals like copper, nickel, cobalt and manganese. Polymetallic sea nodules contain various valuable metals. The land based resources of such metals are gradually decreasing. Therefore, it has become necessary to develop such processes. The process of the present invention involves leaching of polymetallic sea nodules with alcohol modified sulfuric acid. The recoveries of metals are greater than 90%. The used alcohol is regenerated by reduction with hydrogen gas.

Title of Invention

AN IMPROVED PROCESS FOR DIRECT LEACHING OF POLYMETALLIC SEA NODULES FOR THE RECOVERY OF METALS

Abstract

The present invention relates to an improved process for direct leaching of polymetallic sea nodules for the recovery of metals like copper, nickel, cobalt and manganese. Polymetallic sea nodules contain various valuable metals. The land based resources of such metals are gradually decreasing. Therefore, it has become necessary to develop such processes. The process of the present invention involves leaching of polymetallic sea nodules with alcohol modified sulfuric acid. The recoveries of metals are greater than 90%. The used alcohol is regenerated by reduction with hydrogen gas.

Full Text	The present invention relates to an improved process for direct leaching of polymetallic sea nodules for the recovery of metals. Polymetallic sea nodules contain valuable metals like copper, nickel, cobalt and manganese. The land-based resources of these metals are gradually depleting. Therefore, it has become necessary to develop suitable metallurgical processing route to recover the metals from the polymetallic sea nodules. Due to complex mineralogy of the polymetallic sea nodules, the extraction process for the recovery of valuable metals particularly nickel and cobalt depends on the breaking up of the manganese dioxide lattice by either pyro-metallurgical or hydro-metallurgical treatment, pyrometallurgical processes include chlorination, segregation and direct smelting and these processes are out of the scope of the present invention. Hydrometallurgical treatment of polymetallic sea nodules includes 1) aqueous acid leaching process, 2) reductive roasting-ammoniacal leaching and 3) reductive aqueous leaching process. Aqueous acid leaching is one of the most attractive ways of leaching for valuable metals. Several investigators have studied the acid leaching behavior of polymetallic sea nodules using the commonly known hydrochloric and sulfuric acid systems. Reference may be made to Kenneth N. Han, Trans. Indian Inst. Met, Vol. 51(1), Feb 97, pp.: 41-54, wherein it is described that simple acid leaching of polymetallic sea nodules takes as much as 100 h and as a result it consumes 50-60% excess of acid than the normal requirement. The major drawback of acid leaching is that it does not render a good recovery of cobalt Reductive roast-ammoniacal leaching technique is important for its selectivity to valuable metals such as copper, nickel and cobalt. The polymetallic sea nodules are heated in a reducing atmosphere approximately at 700 °C and then subjected to leaching in ammoniacal medium. Reference may be made to D. W. Fuestenau and K. N. Han, Metallurgy and processing of marine manganese nodules, Mineral processing and technology review, Vol. 1,1983, pp. 1-83, wherein copper was found more soluble in ammoniacal medium when reduction roasting was conducted at 400° C and when reduced at temperatures higher than 400 °C nickel was found more soluble in ammoniacal medium. The drawback is the low recovery of cobalt, which is to an extent of 50% both at lower and higher temperatures of reduction. In our copending patent application No: 0753/Del/91 attempt has been made to improve the cobalt recovery by adapting a two stage leaching after conducting reduction-roasting of polymetallic sea nodules. The drawbacks are recovery of cobalt obtained 60% and could not be improved any further. In an another two of our copending patent application Nos.: 1031/Del/92 & 1032/Del/92, sea nodules have been roast reduced with different reductants such as charcoal and saw dust prior to ammoniacal leaching. The drawback is the recovery of cobalt did not improve beyond 60%. In reductive aqueous leaching technique polymetallic sea nodules are reduced in the leaching medium itself with a suitable reducing agent so that valuable metals are amenable to leaching. It was found that when reducing reagents are used manganese's are readily dissolved and cobalt exhibits a good recovery. The most commonly used reductant in this connection is sulphur dioxide. Reference may be made to Pahlaman, J. E and Khalafalla, S. E., J. Metals, Aug, 1981, pp. 37-42, wherein sulphur dioxide used in conjunction with acidic medium results in high recoveries of copper, nickel, cobalt, manganese and iron. The drawback is the use of sulphur dioxide is environmentally hazardous and highly noxious. The other reductants used for treating polymetallic sea nodules are manganese metal and alcohols such as methanol, ethanol, butanol and propanol in HC1 medium. In our patent No: 175737 manganese metal in ammoniacal system has been used for reductive leaching of sea nodules. The recoveries of metals obtained in this process are copper = 54%, nickel = 23% and cobalt 18%. Reference may be made to R. K. Jana, D. D. N. Singh and S.K. Roy, Materials Transactions, JIM, Vol. 34 (7), 1993, pp: 593-598, wherein 80% of copper, 30% of nickel, 20% of cobalt, 60% of iron and 17% of manganese were recovered with the use of HC1 concentration of 2.75M. However, in the presence of 18.5 vol% of ethanol in 2.75M HC1, more than 90% of all the metals were recovered. The drawback is that the use of HC1 is technically not feasible due to its corrosiveness. In an another of our copending patent application No: 0697/Del/92, copper, nickel and cobalt have been directly electrowon from the polymetallic sea nodules using a chloride solution as the electrolyte. The drawback of the process is the high corrosiveness of the chloride electrolytes where evolution of chlorine is pertinent. The main object of the present invention is to provide an improved process for direct leaching of polymetallic sea nodules for the recovery of copper, nickel, cobalt and manganese which obviates the drawbacks as detailed above. In the process of present invention manganese dioxide phase in the polymetallic sea nodules, which is enriched with nickel and cobalt is reduced by the alcohol modified sulphuric acid leachant. As such dilute sulphuric acid can not convert appreciable amounts of the higher value manganese (IV) to soluble lower valence manganese (II). The addition of alcohol in sulphuric acid is capable of reducing manganese dioxide. The mechanism involves a redox reaction. The half cells reactions of manganese dioxide to manganous ion is given by: MnO2 + 4H+ + 2e Mn* + 2H2O (1) The half-cell reaction involving the oxidation of ethanol is given by: CH3CH2OH = CH3CHO + 2H+ + 2e (2) combining 1 and 2 gives: MnO2 + CH3CH2OH + 2H+ = Mn2+ + CH3CHO + 2H2O (3) The free energy change (AG°f) of the above reaction has been calculated to be -202,26 kJ/mole, which implies that the reaction is thermodynamically feasible and can take place. Thereby release of valuable metals entrapped in the manganese oxide phase takes place, and dissolution of these metals becomes easier. Accordingly, the present invention provides an improved process for direct leaching of polymetallic sea nodules for the recovery of metals preferably copper, nickel, cobalt and manganese which comprises: [i] crushing and grinding of raw polymetallic sea nodules to ~ lOOmesh (BSS); [ii] leaching the ground polymetallic sea nodules in dilute sulphuric acid medium with addition of alcohol at room temperature under constant stirring; [iii] filtering the leachant slurry obtained in step [ii]; [iv] recovering copper, nickel, cobalt and manganese from the said filtrate by conventional processes. According to the feature of this invention, the polymetallic sea nodules are ground and the ground sea nodules are screened at 100 mesh. The polymetallic sea nodules employed may be selected from ground sea nodules of size -100 mesh (BSS) having composition range: The sulphuric acid used for leaching of polymetallic sea nodules may be of commercial grade and strength of sulphuric acid solution may vary from 5-20 vol% The alcohol used for leaching may be such as methanol, ethanol or propanol of commercial grade and strength in the range of 5-10 vol%, The leaching process may be carried out by stirring ground polymetallic sea nodules in a solution of sulphuric acid and alcohol for a period of 4-6 hours with solid-liquid ratio in the range of 1:20 to 1:30. According to a feature of this invention, the leach-liquor produced on direct leaching process in alcohol modified sulphuric acid media contains copper, nickel, cobalt, manganese and iron, which can be separated and recovered by conventional methods. By the process of present invention metals recovered in the leach solution are Cu = 91%, Ni = 96%, Co = 92%, Mn = 91% and Fe = 65%. The alcohol used may be regenerated by reduction with hydrogen gas. The novelty and innovative step of the improved process is leaching of polymetallic sea nodules with alcohol modified sulphuric acid. The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention. EXAMPLE 1 10 gms of ground sea nodules were leached in a solution containing 10 vol% of H2SO4 and 5 vol% of methanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 79.1% of copper, 74.5% of nickel, 72.6% of cobalt, 65.3% of iron and 53.2% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis. EXAMPLE 2 10 gms of ground sea nodules were leached in a solution containing 1.0 vol% of H2SO4 and 10 vol% of methanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated trom the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 82.5% of copper, 74.8% of nickel, 72.7% of cobalt, 63.4% of iron and 66.5% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis. EXAMPLE 3 10 gms of ground sea nodules were leached in a solution containing 15 vol% of H2SO4 and 10 vol% of ethanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 92.5% of copper, 95.3% of nickel, 88.2% of cobalt, 65.5% of iron and 91.1% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis. EXAMPLE 4 10 gms of ground sea nodules were leached in a solution containing 20 vol% of H2SO4 and 10 vol% of propanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 91.3% of copper, 95.7% of nickel, 91.6% of cobalt, 65.4% of iron and 90.0% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis. The main advantages of the present invention are: i) In the present invention the consumption of energy is less than the conventional processes as it excludes pyrometallurgical pretreatment of the ore body, ii) In the present invention recoveries are greater than 90% of all the valuable metals such as copper, nickel, cobalt and manganese, iii) In the present invention sulphuric acid is used as the leaching media and hence the process is technically feasible due to its less corrosive nature. iv) In the present invention alcohol used can be regenerated by reduction with hydrogen gas. v) As the process is not involved with the evolution of any hazardous gas, it is an eco-friendly process vi) In the present invention the capital investment cost of the process is less than the existing processes_ We Claim: 1. An improved process for direct leaching of polymetallic sea nodules for the recovery of metals preferably copper, nickel, cobalt and manganese which comprises: [i] crushing and grinding of raw polymetallic sea nodules to lOOmesh (BSS); [ii] leaching the ground polymetallic sea nodules in dilute sulphuric acid medium with addition of alcohol at room temperature under constant stirring; [iii] filtering the leachant slurry obtained in step [ii]; [iv] recovering copper, nickel, cobalt and manganese from the said filtrate by conventional processes. 2. A process as claimed in claim 1, wherein the polymetallic sea nodules employed are selected from ground polymetallic sea nodules having composition range: 3. A process as claimed in claim 1, wherein the sulfuric acid used for leaching of polymetallic sea nodules is of commercial grade. 4. A process as claimed in claim 1, wherein the strength of sulfuric acid solution used is in the range of 5 to 20 vol%. 5. A process as claimed in claim 1, wherein the alcohol used is selected from methanol, ethanol or propanol of commercial grade and strength in the range of 5 to 10 vol%. 6 A process as claimed in claim 1, wherein the leaching process is carried out for a period of 4 to 6 hours. 7. A process as claimed in claim 1, wherein the ratio of polymetallic sea nodules to the mixture of sulfuric acid and alcohol is in the range of 1:20 to 1:30. 8 A process as claimed in claim 1, wherein the alcohol is regenerated by reduction with hydrogen gas. 9. An improved process for direct leaching of polymetallic sea nodules for the recovery of metals substantially as herein described with reference to the foregoing examples.

Full Text

The present invention relates to an improved process for direct leaching of polymetallic sea nodules for the recovery of metals.
Polymetallic sea nodules contain valuable metals like copper, nickel, cobalt and manganese. The land-based resources of these metals are gradually depleting. Therefore, it has become necessary to develop suitable metallurgical processing route to recover the metals from the polymetallic sea nodules.
Due to complex mineralogy of the polymetallic sea nodules, the extraction process for the recovery of valuable metals particularly nickel and cobalt depends on the breaking up of the manganese dioxide lattice by either pyro-metallurgical or hydro-metallurgical treatment, pyrometallurgical processes include chlorination, segregation and direct smelting and these processes are out of the scope of the present invention. Hydrometallurgical treatment of polymetallic sea nodules includes 1) aqueous acid leaching process, 2) reductive roasting-ammoniacal leaching and 3) reductive aqueous leaching process.
Aqueous acid leaching is one of the most attractive ways of leaching for valuable metals. Several investigators have studied the acid leaching behavior of polymetallic sea nodules using the commonly known hydrochloric and sulfuric acid systems. Reference may be made to Kenneth N. Han, Trans. Indian Inst. Met, Vol. 51(1), Feb 97, pp.: 41-54, wherein it is described that simple acid leaching of polymetallic sea nodules takes as much as 100 h and as a result it consumes 50-60% excess of acid than the normal requirement. The major drawback of acid leaching is that it does not render a good recovery of cobalt
Reductive roast-ammoniacal leaching technique is important for its selectivity to valuable metals such as copper, nickel and cobalt. The polymetallic sea nodules are heated in a reducing atmosphere approximately at 700 °C and then subjected to leaching in ammoniacal medium. Reference may be made to D. W. Fuestenau and K. N. Han, Metallurgy and processing of marine manganese nodules, Mineral processing and technology review, Vol. 1,1983, pp. 1-83, wherein copper was found more soluble in ammoniacal medium when reduction roasting was conducted at 400° C and when reduced at temperatures higher than 400 °C nickel was found more soluble in ammoniacal medium. The drawback is the low recovery of cobalt, which is to an extent of 50% both at lower and higher temperatures of reduction. In our copending patent application No: 0753/Del/91 attempt has been made to improve the cobalt recovery by adapting a two stage leaching after conducting reduction-roasting of polymetallic sea nodules. The drawbacks are recovery of cobalt obtained 60% and could
not be improved any further. In an another two of our copending patent application Nos.: 1031/Del/92 & 1032/Del/92, sea nodules have been roast reduced with different reductants such as charcoal and saw dust prior to ammoniacal leaching. The drawback is the recovery of cobalt did not improve beyond 60%.
In reductive aqueous leaching technique polymetallic sea nodules are reduced in the leaching medium itself with a suitable reducing agent so that valuable metals are amenable to leaching. It was found that when reducing reagents are used manganese's are readily dissolved and cobalt exhibits a good recovery. The most commonly used reductant in this connection is sulphur dioxide. Reference may be made to Pahlaman, J. E and Khalafalla, S. E., J. Metals, Aug, 1981, pp. 37-42, wherein sulphur dioxide used in conjunction with acidic medium results in high recoveries of copper, nickel, cobalt, manganese and iron. The drawback is the use of sulphur dioxide is environmentally hazardous and highly noxious. The other reductants used for treating polymetallic sea nodules are manganese metal and alcohols such as methanol, ethanol, butanol and propanol in HC1 medium. In our patent No: 175737 manganese metal in ammoniacal system has been used for reductive leaching of sea nodules. The recoveries of metals obtained in this process are copper = 54%, nickel = 23% and cobalt 18%. Reference may be made to R. K. Jana, D. D. N. Singh and S.K. Roy, Materials Transactions, JIM, Vol. 34 (7), 1993, pp: 593-598, wherein 80% of copper, 30% of nickel, 20% of cobalt, 60% of iron and 17% of manganese were recovered with the use of HC1 concentration of 2.75M. However, in the presence of 18.5 vol% of ethanol in 2.75M HC1, more than 90% of all the metals were recovered. The drawback is that the use of HC1 is technically not feasible due to its corrosiveness. In an another of our copending patent application No: 0697/Del/92, copper, nickel and cobalt have been directly electrowon from the polymetallic sea nodules using a chloride solution as the electrolyte. The drawback of the process is the high corrosiveness of the chloride electrolytes where evolution of chlorine is pertinent. The main object of the present invention is to provide an improved process for direct leaching of polymetallic sea nodules for the recovery of copper, nickel, cobalt and manganese which obviates the drawbacks as detailed above.
In the process of present invention manganese dioxide phase in the polymetallic sea nodules, which is enriched with nickel and cobalt is reduced by the alcohol modified sulphuric acid leachant. As such dilute sulphuric acid can not convert appreciable amounts of the higher value manganese (IV) to soluble lower valence manganese (II). The addition of alcohol in sulphuric acid is capable of
reducing manganese dioxide. The mechanism involves a redox reaction. The half cells reactions of manganese dioxide to manganous ion is given by:
MnO2 + 4H+ + 2e Mn* + 2H2O (1)
The half-cell reaction involving the oxidation of ethanol is given by:
CH3CH2OH = CH3CHO + 2H+ + 2e (2)
combining 1 and 2 gives:
MnO2 + CH3CH2OH + 2H+ = Mn2+ + CH3CHO + 2H2O (3)
The free energy change (AG°f) of the above reaction has been calculated to be -202,26 kJ/mole, which implies that the reaction is thermodynamically feasible and can take place. Thereby release of valuable metals entrapped in the manganese oxide phase takes place, and dissolution of these
metals becomes easier.
Accordingly, the present invention provides an improved process for direct leaching of
polymetallic sea nodules for the recovery of metals preferably copper, nickel, cobalt and manganese which comprises:
[i] crushing and grinding of raw polymetallic sea nodules to ~ lOOmesh (BSS);
[ii] leaching the ground polymetallic sea nodules in dilute sulphuric acid medium with addition of alcohol at room temperature under constant stirring;
[iii] filtering the leachant slurry obtained in step [ii];
[iv] recovering copper, nickel, cobalt and manganese from the said filtrate by conventional
processes. According to the feature of this invention, the polymetallic sea nodules are ground and the ground
sea nodules are screened at 100 mesh. The polymetallic sea nodules employed may be selected from ground sea nodules of size -100 mesh (BSS) having composition range:
The sulphuric acid used for leaching of polymetallic sea nodules may be of commercial grade and strength of sulphuric acid solution may vary from 5-20 vol%
The alcohol used for leaching may be such as methanol, ethanol or propanol of commercial grade and strength in the range of 5-10 vol%,
The leaching process may be carried out by stirring ground polymetallic sea nodules in a solution of sulphuric acid and alcohol for a period of 4-6 hours with solid-liquid ratio in the range of 1:20 to 1:30.
According to a feature of this invention, the leach-liquor produced on direct leaching process in alcohol modified sulphuric acid media contains copper, nickel, cobalt, manganese and iron, which can be separated and recovered by conventional methods. By the process of present invention metals recovered in the leach solution are Cu = 91%, Ni = 96%, Co = 92%, Mn = 91% and Fe = 65%.
The alcohol used may be regenerated by reduction with hydrogen gas.
The novelty and innovative step of the improved process is leaching of polymetallic sea nodules with alcohol modified sulphuric acid.
The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention.
EXAMPLE 1
10 gms of ground sea nodules were leached in a solution containing 10 vol% of H2SO4 and 5 vol% of methanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 79.1% of copper, 74.5% of nickel, 72.6% of cobalt, 65.3% of iron and 53.2% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis.
EXAMPLE 2
10 gms of ground sea nodules were leached in a solution containing 1.0 vol% of H2SO4 and 10 vol% of methanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were
separated trom the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 82.5% of copper, 74.8% of nickel, 72.7% of cobalt, 63.4% of iron and 66.5% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis.
EXAMPLE 3
10 gms of ground sea nodules were leached in a solution containing 15 vol% of H2SO4 and 10 vol% of ethanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 92.5% of copper, 95.3% of nickel, 88.2% of cobalt, 65.5% of iron and 91.1% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis.
EXAMPLE 4
10 gms of ground sea nodules were leached in a solution containing 20 vol% of H2SO4 and 10 vol% of propanol at 1:20 solid to liquid ratio and stirred moderately for 4 h. Then the solids were separated from the solution by filtration and the solution was analyzed for metals. The recoveries obtained from the solution analysis were found to be 91.3% of copper, 95.7% of nickel, 91.6% of cobalt, 65.4% of iron and 90.0% of manganese. The residue was also analyzed for metal content and the results were found to be in good agreement with the values obtained by solution analysis. The main advantages of the present invention are: i) In the present invention the consumption of energy is less than the conventional processes as it
excludes pyrometallurgical pretreatment of the ore body, ii) In the present invention recoveries are greater than 90% of all the valuable metals such as copper,
nickel, cobalt and manganese, iii) In the present invention sulphuric acid is used as the leaching media and hence the process is
technically feasible due to its less corrosive nature.
iv) In the present invention alcohol used can be regenerated by reduction with hydrogen gas. v) As the process is not involved with the evolution of any hazardous gas, it is an eco-friendly process vi) In the present invention the capital investment cost of the process is less than the existing
processes_

We Claim:
1. An improved process for direct leaching of polymetallic sea nodules for the recovery of
metals preferably copper, nickel, cobalt and manganese which comprises:
[i] crushing and grinding of raw polymetallic sea nodules to lOOmesh (BSS);
[ii] leaching the ground polymetallic sea nodules in dilute sulphuric acid medium with addition of alcohol at room temperature under constant stirring;
[iii] filtering the leachant slurry obtained in step [ii];
[iv] recovering copper, nickel, cobalt and manganese from the said filtrate by conventional processes.
2. A process as claimed in claim 1, wherein the polymetallic sea nodules employed are
selected from ground polymetallic sea nodules having composition range:
3. A process as claimed in claim 1, wherein the sulfuric acid used for leaching of polymetallic
sea nodules is of commercial grade.
4. A process as claimed in claim 1, wherein the strength of sulfuric acid solution used is in the
range of 5 to 20 vol%.
5. A process as claimed in claim 1, wherein the alcohol used is selected from methanol,
ethanol or propanol of commercial grade and strength in the range of 5 to 10 vol%.
6 A process as claimed in claim 1, wherein the leaching process is carried out for a period of 4 to 6 hours.
7. A process as claimed in claim 1, wherein the ratio of polymetallic sea nodules to the mixture of sulfuric acid and alcohol is in the range of 1:20 to 1:30.
8 A process as claimed in claim 1, wherein the alcohol is regenerated by reduction with hydrogen gas.
9. An improved process for direct leaching of polymetallic sea nodules for the recovery of metals substantially as herein described with reference to the foregoing examples.

Documents:

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566-del-2000-correspondence-others.pdf

566-del-2000-correspondence-po.pdf

566-del-2000-description (complete).pdf

566-del-2000-form-1.pdf

566-del-2000-form-19.pdf

566-del-2000-form-2.pdf

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Patent Number

212646

Indian Patent Application Number

566/DEL/2000

PG Journal Number

50/2007

Publication Date

14-Dec-2007

Grant Date

10-Dec-2007

Date of Filing

09-Jun-2000

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG NEW DELHI-110001 INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	RANJIT KUMAR JANA	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR-831007, BIHAR INDIA
2	PUVVADA GEORGE VIJAY KUMAR	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR-831007, BIHAR, INDIA

PCT International Classification Number

C12B 15/08

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA