Title of Invention	"A PROCESS FOR THE MANUFACTURE OF MANGANOUS MANGANIC OXIDES"
Abstract	The present invention is for a process for the manufacture of Manganous Manganic Oxides. It comprises the reduction of higher oxides of manganese or the oxidation of manganese(II) oxide or manganese (II) hydroxide. The reduced Manganous Oxide is then cooled. Dissolving it and then the impurities are removed. The sludge is seperated and the manganese nitrate solution is concentrated by means of steam evaporator. The concentrated solution is then fed to a reactor which results in decomposition of the manganese nitrate to pure Manganese dioxide crystals and Nitrous Oxide The Manganese dioxide crystals are mixed with fuel oil and after thermal reduction Manganous manganic Oxide(Mn3O4) is obtained.

Title of Invention

"A PROCESS FOR THE MANUFACTURE OF MANGANOUS MANGANIC OXIDES"

Abstract

The present invention is for a process for the manufacture of Manganous Manganic Oxides. It comprises the reduction of higher oxides of manganese or the oxidation of manganese(II) oxide or manganese (II) hydroxide. The reduced Manganous Oxide is then cooled. Dissolving it and then the impurities are removed. The sludge is seperated and the manganese nitrate solution is concentrated by means of steam evaporator. The concentrated solution is then fed to a reactor which results in decomposition of the manganese nitrate to pure Manganese dioxide crystals and Nitrous Oxide The Manganese dioxide crystals are mixed with fuel oil and after thermal reduction Manganous manganic Oxide(Mn3O4) is obtained.

Full Text	The present invention relates to the process for the preparation of Manganous-Manganic oxide. BACKGROUND OF THE INVENTION: Manganese oxide occurs in nature as the green mineral manganosite. It can be prepared by heating Manganese carbonate in the absence of air or by passing hydrogen or carbon as a starting material for the manufacture of manganese salts, where manganese dioxide is the most important manganese compound and is the principal source of manganese and all its compounds. It is known that Manganous Manganic Oxide (Mn3O4) can readily be prepared by either reduction of a higher oxide of manganese such as manganese(III) oxide, a manganese (IV) oxides and MnOOH, or by oxidation of lower Oxide or hydroxide of manganese such as manganese (II) oxide and manganese (II) hydroxide. The known art provides us the process for the preparation of Manganous Manganic Oxide (Mn3O4) which comprises the reductive roasting of a higher oxide of manganese in the presence of a reducing gas, specifically methane. In this process the higher oxides of manganese such as MnO2, Mn2O3 or MnOOH, and the like, is heated in a kiln , in the presence of an excess current of methane gas. Operating temperatures are limited to levels between 250° C and 550°C to prevent further reduction of Mn3O4 product formed to manganese (II) oxide. The advantages of this process are asserted to be that it is simpler to carry out than alternate wet processes involving the precipitation of manganese (II) hydroxide and the subsequent oxidation of this hydroxide to the desired manganous-manganic oxide product. The process also is asserted to offer significant advantages over other dry reduction processes employing temperatures higher than 550°C. For example , high temperatures dry reduction processes resulting in the production of manganese(II) oxide which then must be reoxidized to the desired manganous-manganic oxide product. Also, the resulting manganous-manganic oxide product has a lower surface area and activity due to sintering. A wet process for the preparation of manganous-manganic oxide comprises oxidation of an aqueous suspension of manganese (II) hydroxides at elevated temperatures and at super-atmospheric pressures. In general, the operating temperatures and pressures employed in this process range from 100°C to 140°C and from 40psi to 70psi, respectively. The advantageous of this process over other wet oxidation processes are asserted to be that reaction times are shorter, the manganous manganic oxide product is more readily filtered and the product is less contaminated. Mainly, these advantages are attributable to the use of superatmospheric pressures during the oxidation reation. The present invention provides an improved process for the preparation of manganous manganic oxide (Mn3O4) and particularly to the production of a purer Mn3O4 than obtained by the conventional processes. Unlike the prior known processes which generally comprise the reduction of higher oxides of manganese or the oxidation of manganese (II) oxide or manganese (II) hydroxide. The main embodiment of the present invention resides in the reduction of MnO2 The present invention has been proved to be more economical for the preparation of Manganous manganic oxide (Mn3O4) The Manganous manganic oxide (Mn3O4) thus produced is readily filterable and possesses little or no contamination when compared to Manganous manganic oxide (Mn3O4) prepared from known processes. The other embodiment of the present invention lies in the 100% utilisation of MnO2, without any wastage. Another embodiment of the present invention is that it is not only highly economical and cost-effective, but also environmental friendly as it reduces the waste disposal problem. The present invention relates to the process for the preparation of pure Mn3O4 comprising the steps of: Reduction of Mntu : First step in the preparation of pure Mn3O4 , is the reduction of MnO2 in Rotary kiln using fuel oil and saw dust to convert MnO2 into MnO and other carbonaceous materials by removal of O2. The saw dust and MnO2 are mixed in the ratio of approximately 9-15: 85-91% at the temperature of 650-675° C by using fuel oil for approximately 35-45 minutes. Cooling of MnO: After the reduction of MnO2 to MnO, the available MnO is cooled in water cool spiral conveyor at temperature between 125°-150°C. The cooled MnO is then transferred into container (mild steel) at ambient temperature .and atmosphere. Dissolution of MnO with Nitric acid : The available MnO is then dissolved in 50% commercial Nitric acid with equal quantity of water. The MnO is added to the said mixture of water and concentrated HNO3 very slowly by vibratory feeder, till the time it gets free from Nitric acid, maintaing the pH level at more than 3 at a temperature of about 85-100°C. This results in the production of impure manganese nitrate solution with all the soluble nitrates Purification of Mangenese Nitrate: Mangnese hydroxide is added in the solution to raise the pH to 5-5.5 as this eliminates most of the impurities by precipitation as hydroxides. Poly-electrolytes used as coagulating agent are added to increase the consistency resulting in the formation of sludge in compact form. Filtration: The Manganese Nitrate solution containing Manganese Hydroxide and polyelectrolytes are filtered and solid sludge is separated from the Magnese Nitrate solution resulting in the formation of pure Manganese Nitrate with minor impurities.. Evaporation: 82-84% Mangenese Nitric solution is concenterated to 55% solution by evaporation done in short tube steam evaporator at temperature . between 100-150° C. resulting in the production of Cone. Mangnese Nitrate solution. Thermal decomposition: Said Manganese Nitrate solution is fed to reactor by centrifugal pump at a temp. 135-146 degress centigrade with a steam pressure of 100-120 psi, resulting in the thermal decomposition of manganese nitrate to pure manganese dioxide (Mno2) and NO2 Separation of MnO^from NO2 : Sugary crystals of MnO2 are taken into a tank, where they are centrifuged, separated and washed with de-mineralised water and dried in a dryer. Since the decomposition is not 100%. whatever quantity is taken after decomposition, is again fed to reactor. Recycling of MnO^ in the circulating tank: The leftover MnO2 along with NO2 are then passed to a circulating tank containing Mn(NO3)2 solution and water. Thermal reduction of MnCK: The washed sugary crystals of MnO2 are mixed with fuel oil for the thermal reduction, at the temperature of 650-700° C on a continuous basis. The following non-limiting examples are presented as being illustrative of the practice of the present invention and are not intended to limit, in any manner, the spirit and scope of the invention. EXAMPLE-I A series of experiments were carried out using the process of the present invention. In an experiment, for the process of thermal reduction about 2500 kg. of MnO2 ores is used by reducing the carbon and cooling it resulting in the production of about 2000 Kg of MnO. . In the cooled MnO of about 2000 Kg , about 2200 Kg. of 55% Nitric Acid and about 2200 Kg of water is added to make the Manganese Nitrate solution in a dilute form. The purification of said solution is done by the process of filteration at about 90-100 ° C by adding manganese hydroxide and poly-electrolytes resulting in about 9500 litre solution of Manganese Nitrate purified solution. The steam evaporization of the about 83-87% of Manganese Nitrate purified solution is done to make it in concenterated form of about 55% solution by reducing it to 3000 litre solution, said mixture is further decomposed at about 140-150°C resulting in the formation of Manganese Dioxide in crystal form and Mangenese Nitrate solution. The crystals of manganese dioxide are separated by the process of filtration resulting in about 1000 kg of the said crystals. These crystals are then dried before the step of thermal reduction at the temperature of about 625-650 °C in the presence of fuel air (LPG) resulting in about 880 Kg of Mn3O4. The leftover MnO2 along with NO2 after the separation of crystal of MnO2 is again fed to the reactor with Mn ore at about 50° C, passes through the absorption zone resulting in Manganese Nitrate solution, which is reused in the process. EXAMPLE-II A series of experiments were carried out using the process of the present invention. In an experiment, for the process of thermal reduction about 2800 kg. of MnO2 ores is used by reducing the carbon and cooling it resulting in the production of about 2300 Kg of MnO. . In the cooled MnO of about 2300 Kg , about 2500 Kg. of 55% Nitric Acid and about 2500 Kg of water is added to make the Manganese Nitrate solution in a dilute form. The purification of said solution is done by the process of filtration at about 92-102°C by adding Mangenese hydroxide and poly-electrolytes resulting in about 9800 litre solution of Manganese Nitrate purified solution. The steam evaporization of about 85-89% of Manganese Nitrate purified solution is done to make it in concenterated form of about 55% solution by reducing it to 3300 litre solution, said mixture is further decomposed at about 142-153°C resulting in the formation of Manganese Dioxide in crystal form and Mangenese Nitrate solution. The crystals of manganese dioxide are separated by the process of filtration resulting in about 1300 kg of the said crystals. These crystals are then dried before the step of thermal reduction at the temperature of about 628-655 °C in the presence of fuel air (coke) resulting in about 1080 Kg of Mn3O4. The leftover MnO2 along with NO2 after the separation of crystal of Mn02 is again fed to the reactor with Mn ore at about 52° C, passes through the absorption zone resulting in Manganese Nitrate solution, which is reused in the process. We Claim: 1) A process for the preparation of Manganous Manganic Oxide (Mn3O4) comprising: reduction of Manganese dioxide (MnO2) to Manganous Oxide (MnO) in reducing atmosphere in a kiln at an elevated temperature of 625-675° C in the presence of reducing agents; cooling the reduced Manganous Oxide (MnO) to a temperature of 125-150°C; dissolving the said reduced and cooled MnO in a diluted commercial acid slowly by means of a feeder; maintaining the pH at the desired level; removing the impurities by precipitation by adding Manganese hydroxide and coagulating agents and raising the pH to 5-5.5, resulting in the formation of sludge of hydroxides in the compact form; separating the solid sludge leaving the pure manganese nitrate solution with minor impurities; concentrating the said solution by means of steam evaporator; feeding the said concentrated solution to a reactor by pumping means at a steam pressure resulting in the thermal decomposition of the manganese nitrate to pure manganese dioxide crystals and Nitrous Oxide and mixing the said manganese dioxide crystals with fuel oil and subjecting to thermal reduction of Manganese dioxide to obtain Manganous manganic oxide (Mn304). 2. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said reducing agents present are carbon, saw dust, coal, coke fines, any of the reducing gases or a combination of them. 3. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said cooling of the reduced Manganous oxide (MnO) is preferably done in water cool spiral conveyor. 4. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the reduced and cooled Manganous Oxide (MnO) is dissolved in dilute commercial nitric acid while maintaining the pH at around 3 and the temperature at 85°-100°C. 5. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said coagulating agents are preferably polyelectrolytes. 6. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said seperation of manganese nitrate from sludge occurs by filtration of the solution formed. 7. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said concentration of the solution occurs in a steam evaporator at temperatures of 100-150° C. 8. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said thermal reduction of manganese dioxide occurs at an elevated temperature of 650 -700 C. 9. A process for the preparation of Manganous manganic oxide (Mn3O4) as claimed in claim 1, wherein the said feeder is a vibratory feeder. 10. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 1, comprising a rotary kiln having means for supplying reducing agents at a reduced atmospheric pressure; means for cooling the said reduced Manganous Oxide (MnO); means for properly dissolving the reduced Manganous oxide (MnO) in the dilute acid; means for filtering the manganese nitrate from the sludge formed in the reaction mixture; means for concentrating the manganese nitrate solution at elevated temperatures; means for thermally decomposing the manganese nitrate solution at an elevated temperatures and pressures; means for centrifuging, separating and washing the crystals of Manganese dioxide (MnO2) formed; means for thermal reduction of Mangnese dioxide at an elevated temperature of650°-700°C. 10. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for cooling the said reduced Manganous Oxide (MnO) are water cool spiral conveyor. 11. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for for properly dissolving the reduced Manganous Oxide (MnO) in the dilute acid is a vibratory feeder. 12. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for concentrating the manganese nitrate solution at elevated temperatures are steam evaporators. 13. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for filtering the manganese nitrate from the sludge are filters of the mesh size of about 3-9microns. 14. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for thermally decomposing the manganese nitrate solution at an elevated temperature is agitated jacketed vessel. 15. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in claim 9, wherein the said means for centrigugating the crystals of Mmanganese dioxide are centrifugating machines. 16. A process for the preparation of Manganous manganic oxide (Mn3O4) as hereinbefore described with reference to the foregoing examples. 17. An apparatus for preparing Manganous manganic oxide (Mn3O4) as hereinbefore described with reference to the foregoing examples.

Full Text

The present invention relates to the process for the preparation of Manganous-Manganic oxide.
BACKGROUND OF THE INVENTION:
Manganese oxide occurs in nature as the green mineral manganosite. It can be prepared by heating Manganese carbonate in the absence of air or by passing hydrogen or carbon as a starting material for the manufacture of manganese salts, where manganese dioxide is the most important manganese compound and is the principal source of manganese and all its compounds.
It is known that Manganous Manganic Oxide (Mn3O4) can readily be prepared by either reduction of a higher oxide of manganese such as manganese(III) oxide, a manganese (IV) oxides and MnOOH, or by oxidation of lower Oxide or hydroxide of manganese such as manganese (II) oxide and manganese (II) hydroxide. The known art provides us the process for the preparation of Manganous Manganic Oxide (Mn3O4) which comprises the reductive roasting of a higher oxide of manganese in the presence of a reducing gas, specifically methane. In this process the higher oxides of manganese such as MnO2, Mn2O3 or MnOOH, and the like, is heated in a kiln , in the presence of an excess current of methane gas. Operating temperatures are limited to levels between 250° C and 550°C to prevent further reduction of Mn3O4 product formed to manganese (II) oxide. The advantages of this process are asserted to be that it is simpler to carry out than alternate wet processes involving the precipitation of manganese (II) hydroxide and the subsequent oxidation of this hydroxide to the desired manganous-manganic oxide product. The process also is asserted to offer significant advantages over other dry reduction processes employing temperatures higher than 550°C. For example , high temperatures dry reduction processes resulting in the production of manganese(II) oxide which then must be reoxidized to
the desired manganous-manganic oxide product. Also, the resulting manganous-manganic oxide product has a lower surface area and activity due to sintering.
A wet process for the preparation of manganous-manganic oxide comprises oxidation of an aqueous suspension of manganese (II) hydroxides at elevated temperatures and at super-atmospheric pressures. In general, the operating temperatures and pressures employed in this process range from 100°C to 140°C and from 40psi to 70psi, respectively. The advantageous of this process over other wet oxidation processes are asserted to be that reaction times are shorter, the manganous manganic oxide product is more readily filtered and the product is less contaminated. Mainly, these advantages are attributable to the use of superatmospheric pressures during the oxidation reation.
The present invention provides an improved process for the preparation of manganous manganic oxide (Mn3O4) and particularly to the production of a purer Mn3O4 than obtained by the conventional processes. Unlike the prior known processes which generally comprise the reduction of higher oxides of manganese or the oxidation of manganese (II) oxide or manganese (II) hydroxide. The main embodiment of the present invention resides in the reduction of MnO2
The present invention has been proved to be more economical for the preparation of Manganous manganic oxide (Mn3O4) The Manganous manganic oxide (Mn3O4) thus produced is readily filterable and possesses little or no contamination when compared to Manganous manganic oxide (Mn3O4) prepared from known processes.
The other embodiment of the present invention lies in the 100% utilisation of MnO2, without any wastage.
Another embodiment of the present invention is that it is not only highly economical and cost-effective, but also environmental friendly as it reduces the waste disposal problem.
The present invention relates to the process for the preparation of pure Mn3O4 comprising the steps of:
Reduction of Mntu : First step in the preparation of pure Mn3O4 , is the reduction of MnO2 in Rotary kiln using fuel oil and saw dust to convert MnO2 into MnO and other carbonaceous materials by removal of O2. The saw dust and MnO2 are mixed in the ratio of approximately 9-15: 85-91% at the temperature of 650-675° C by using fuel oil for approximately 35-45 minutes.
Cooling of MnO: After the reduction of MnO2 to MnO, the available MnO is cooled in water cool spiral conveyor at temperature between 125°-150°C. The cooled MnO is then transferred into container (mild steel) at ambient temperature .and atmosphere.
Dissolution of MnO with Nitric acid : The available MnO is then dissolved in 50% commercial Nitric acid with equal quantity of water. The MnO is added to the said mixture of water and concentrated HNO3 very slowly by vibratory feeder, till the time it gets free from Nitric acid, maintaing the pH level at more than 3 at a temperature of about 85-100°C. This results in the production of impure manganese nitrate solution with all the soluble nitrates
Purification of Mangenese Nitrate: Mangnese hydroxide is added in the solution to raise the pH to 5-5.5 as this eliminates most of the impurities by precipitation as hydroxides. Poly-electrolytes used as coagulating agent are added to increase the consistency resulting in the formation of sludge in compact form.
Filtration: The Manganese Nitrate solution containing Manganese Hydroxide and polyelectrolytes are filtered and solid sludge is separated from the Magnese Nitrate solution resulting in the formation of pure Manganese Nitrate with minor impurities..
Evaporation: 82-84% Mangenese Nitric solution is concenterated to 55% solution by evaporation done in short tube steam evaporator at temperature . between 100-150° C. resulting in the production of Cone. Mangnese Nitrate solution.
Thermal decomposition: Said Manganese Nitrate solution is fed to reactor by centrifugal pump at a temp. 135-146 degress centigrade with a steam pressure of 100-120 psi, resulting in the thermal decomposition of manganese nitrate to pure manganese dioxide (Mno2) and NO2
Separation of MnO^from NO2 : Sugary crystals of MnO2 are taken into a tank, where they are centrifuged, separated and washed with de-mineralised water and dried in a dryer. Since the decomposition is not 100%. whatever quantity is taken after decomposition, is again fed to reactor.
Recycling of MnO^ in the circulating tank: The leftover MnO2 along with NO2 are then passed to a circulating tank containing Mn(NO3)2 solution and water.
Thermal reduction of MnCK: The washed sugary crystals of MnO2 are mixed with fuel oil for the thermal reduction, at the temperature of 650-700° C on a continuous basis.
The following non-limiting examples are presented as being illustrative of the practice of the present invention and are not intended to limit, in any manner, the spirit and scope of the invention.
EXAMPLE-I
A series of experiments were carried out using the process of the present invention. In an experiment, for the process of thermal reduction about 2500 kg. of MnO2 ores is used by reducing the carbon and cooling it resulting in the production of about 2000 Kg of MnO. . In the cooled MnO of about 2000 Kg , about 2200 Kg. of 55% Nitric
Acid and about 2200 Kg of water is added to make the Manganese Nitrate solution in a dilute form. The purification of said solution is done by the process of filteration at about 90-100 ° C by adding manganese hydroxide and poly-electrolytes resulting in about 9500 litre solution of Manganese Nitrate purified solution. The steam evaporization of the about 83-87% of Manganese Nitrate purified solution is done to make it in concenterated form of about 55% solution by reducing it to 3000 litre solution, said mixture is further decomposed at about 140-150°C resulting in the formation of Manganese Dioxide in crystal form and Mangenese Nitrate solution. The crystals of manganese dioxide are separated by the process of filtration resulting in about 1000 kg of the said crystals. These crystals are then dried before the step of thermal reduction at the temperature of about 625-650 °C in the presence of fuel air (LPG) resulting in about 880 Kg of Mn3O4. The leftover MnO2 along with NO2 after the separation of crystal of MnO2 is again fed to the reactor with Mn ore at about 50° C, passes through the absorption zone resulting in Manganese Nitrate solution, which is reused in the process.
EXAMPLE-II
A series of experiments were carried out using the process of the present invention. In an experiment, for the process of thermal reduction about 2800 kg. of MnO2 ores is used by reducing the carbon and cooling it resulting in the production of about 2300 Kg of MnO. . In the cooled MnO of about 2300 Kg , about 2500 Kg. of 55% Nitric Acid and about 2500 Kg of water is added to make the Manganese Nitrate solution in a dilute form. The purification of said solution is done by the process of filtration at about 92-102°C by adding Mangenese hydroxide and poly-electrolytes resulting in about 9800 litre solution of Manganese Nitrate purified solution. The steam evaporization of about 85-89% of Manganese Nitrate purified solution is done to make it in concenterated form of about 55% solution by reducing it to 3300 litre solution, said mixture is further decomposed at about 142-153°C resulting in the formation of Manganese Dioxide in crystal form and Mangenese Nitrate solution. The crystals of manganese dioxide are separated by the process of filtration resulting in about 1300 kg of the said crystals. These crystals are then dried before the step of
thermal reduction at the temperature of about 628-655 °C in the presence of fuel air (coke) resulting in about 1080 Kg of Mn3O4. The leftover MnO2 along with NO2 after the separation of crystal of Mn02 is again fed to the reactor with Mn ore at about 52° C, passes through the absorption zone resulting in Manganese Nitrate solution, which is reused in the process.

We Claim:
1) A process for the preparation of Manganous Manganic Oxide (Mn3O4) comprising:
reduction of Manganese dioxide (MnO2) to Manganous Oxide (MnO) in reducing atmosphere in a kiln at an elevated temperature of 625-675° C in the presence of reducing agents;
cooling the reduced Manganous Oxide (MnO) to a temperature of 125-150°C;
dissolving the said reduced and cooled MnO in a diluted commercial acid slowly by means of a feeder; maintaining the pH at the desired level;
removing the impurities by precipitation by adding Manganese hydroxide and coagulating agents and raising the pH to 5-5.5, resulting in the formation of sludge of hydroxides in the compact form;
separating the solid sludge leaving the pure manganese nitrate solution with minor impurities;
concentrating the said solution by means of steam evaporator;
feeding the said concentrated solution to a reactor by pumping means at a steam pressure resulting in the thermal decomposition of the manganese nitrate to pure manganese dioxide crystals and Nitrous Oxide and
mixing the said manganese dioxide crystals with fuel oil and subjecting to thermal reduction of Manganese dioxide to obtain Manganous manganic oxide (Mn304).
2. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said reducing agents present are carbon, saw dust,
coal, coke fines, any of the reducing gases or a combination of them.
3. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said cooling of the reduced Manganous oxide (MnO)
is preferably done in water cool spiral conveyor.
4. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the reduced and cooled Manganous Oxide (MnO) is

dissolved in dilute commercial nitric acid while maintaining the pH at around 3 and the temperature at 85°-100°C.
5. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said coagulating agents are preferably
polyelectrolytes.
6. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said seperation of manganese nitrate from sludge
occurs by filtration of the solution formed.
7. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said concentration of the solution occurs in a steam
evaporator at temperatures of 100-150° C.
8. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said thermal reduction of manganese dioxide occurs at
an elevated temperature of 650 -700 C.
9. A process for the preparation of Manganous manganic oxide (Mn3O4) as
claimed in claim 1, wherein the said feeder is a vibratory feeder.
10. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 1, comprising a rotary kiln having means for supplying reducing agents at a
reduced atmospheric pressure;
means for cooling the said reduced Manganous Oxide (MnO);
means for properly dissolving the reduced Manganous oxide (MnO) in the dilute acid;
means for filtering the manganese nitrate from the sludge formed in the reaction mixture;
means for concentrating the manganese nitrate solution at elevated temperatures;

means for thermally decomposing the manganese nitrate solution at an elevated temperatures and pressures;
means for centrifuging, separating and washing the crystals of Manganese dioxide (MnO2) formed;
means for thermal reduction of Mangnese dioxide at an elevated temperature of650°-700°C.
10. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for cooling the said reduced Manganous Oxide
(MnO) are water cool spiral conveyor.
11. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for for properly dissolving the reduced Manganous
Oxide (MnO) in the dilute acid is a vibratory feeder.
12. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for concentrating the manganese nitrate solution at
elevated temperatures are steam evaporators.
13. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for filtering the manganese nitrate from the sludge are
filters of the mesh size of about 3-9microns.
14. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for thermally decomposing the manganese nitrate
solution at an elevated temperature is agitated jacketed vessel.
15. An apparatus for preparing Manganous manganic oxide (Mn3O4) as claimed in
claim 9, wherein the said means for centrigugating the crystals of Mmanganese
dioxide are centrifugating machines.

16. A process for the preparation of Manganous manganic oxide (Mn3O4) as
hereinbefore described with reference to the foregoing examples.
17. An apparatus for preparing Manganous manganic oxide (Mn3O4) as
hereinbefore described with reference to the foregoing examples.

Documents:

2960-del-1997-abstract.pdf

2960-del-1997-claims.pdf

2960-del-1997-correspondence-others.pdf

2960-del-1997-correspondence-po.pdf

2960-del-1997-description (complete).pdf

2960-del-1997-form-1.pdf

2960-del-1997-form-19.pdf

2960-del-1997-form-2.pdf

2960-del-1997-form-4.pdf

2960-del-1997-gpa.pdf

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Patent Number

219969

Indian Patent Application Number

2960/DEL/1997

PG Journal Number

28/2008

Publication Date

11-Jul-2008

Grant Date

15-May-2008

Date of Filing

14-Oct-1997

Name of Patentee

STERLING OXIDE LIMITED

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	SHAMIM AHMED

PCT International Classification Number

C01G 45/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA