Title of Invention	"AN IMPROVED PROCESS FOR PREPARATION OF HIGH-GRADE MANAGANESE ORE CONCENTRATE FROM FINELY DISSEMINATED LOW-GRADE SILICEOUS MANGANESE ORE"
Abstract	The finely disseminated low-grade siliceous manganese ore was liberated by fine grinding. The aggregates of fine particles were dispersed by ultrasonic treatment and kept in dispersed condition by agitation and high temperature. The dispersion was enhanced by the addition of solution containing sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid. The manganese chloride tetrahydrate was added to create favorable conditions for collector adsorption on manganese minerals. The dilute sodium oleate solution was added to favour monolayer adsorption. The kerosene increased floe formation and floe strength. The floes could be effectively floated in a mechanical flotation cell. It was possible to prepare manganese concentrate of 43.85% Mn grade at 68.24% recovery and concentrate of 48.01% Mn grade at 50.31% recovery.

Title of Invention

"AN IMPROVED PROCESS FOR PREPARATION OF HIGH-GRADE MANAGANESE ORE CONCENTRATE FROM FINELY DISSEMINATED LOW-GRADE SILICEOUS MANGANESE ORE"

Abstract

The finely disseminated low-grade siliceous manganese ore was liberated by fine grinding. The aggregates of fine particles were dispersed by ultrasonic treatment and kept in dispersed condition by agitation and high temperature. The dispersion was enhanced by the addition of solution containing sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid. The manganese chloride tetrahydrate was added to create favorable conditions for collector adsorption on manganese minerals. The dilute sodium oleate solution was added to favour monolayer adsorption. The kerosene increased floe formation and floe strength. The floes could be effectively floated in a mechanical flotation cell. It was possible to prepare manganese concentrate of 43.85% Mn grade at 68.24% recovery and concentrate of 48.01% Mn grade at 50.31% recovery.

Full Text	This invention relates an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore. This invention comes under mineral processing and it can be used to prepare high-grade manganese concentrate from finely disseminated low-grade siliceous manganese ore. The basic studies on flotation of pure manganese minerals have been carried out by some authors [ Fuerstenau, M. C. and Rice, D. A., 1968, Trans AIME, V 241, pp 453-457; Natrajan, K. A. and Fuerstenau, D. W., 1983, Int. J. Miner. Process., V 11, pp 139-153; Fuerstenau, D. W. and Shibata, J., 1999, Int. J. Miner. Process., V 57, pp 205-217]. These studies are mainly of academic importance and directly not useful for process development. Manganese ores have been floated by many authors [Mc Carroll, S. J., 1954, J. Min. Eng. Vol 6, No 3 p 289; Kurova, M. D., 1970, Obogashch. Rud., V14, No 2, p 12; Goldberd, Yu. S., Semiotic, V. M. and Uvarov, U. S., 1968, Obogashch. Polez. Iskop., No 3, p 37; Kharlamov, V. S., Kirnosov, E. G. and Makarov, V. N., 1966, Dobycha Obogashch. Pererab, No 2, p 63; Fahrenwald, A. W., 1957, Mining Congress J., Aug., p 72 ]. This knowledge is not useful for preparation of manganese concentrate from the finely disseminated siliceous manganese ore. The floe flotation is considered as an effective means to treat finely disseminated ores and recover valuable minerals from fines [Song, S. and Lopez-Valdivieso, A., 2002, Min. Process. Ext. Metall. Rev, 23: 101-127]. It is realized through selective flocculation of desired mineral fines to increase the size of separation particles, followed by conventional flotation. The hydrophobic floe flotation of sulphide minerals, which are hydrophobic in nature and easily separable are carried out in macro scale [Song, S., Lopez-Valdivieso, A., Reyes-Bahena, J. L. and Lara-Valenzuela, C, 2001, Minerals Engineering, 14(1), pp 87-98] but such type of work for oxide minerals of manganese are not reported. Reference may be made to Mc Carroll, S. J., 1954, J. Min. Eng. Vol 6, No 3 p 289 wherein the -212 micron size manganese ore containing 21.3 % Mn is floated using soap skimmings (byproduct of sulphate paper industry) : 17.80 kg/t, Fuel oil 53.41 kg/t, Oronile S (wetting agent) : 2.67 kg/t, S02 (5%) : 3.78 kg/t and obtained a concentrate with 45.5% grade with 84% recovery. The drawbacks are high reagent consumption and utilization of S02 solution, which is likely to release toxic S02 gas to the atmosphere. In Joda , Orissa huge quantity of finely disseminated low-grade siliceous manganese ore are produced as fines during the mining of manganese ore which is being sold at nominal rate or dumped at the mine site for future use. Such ores require fine grinding for liberation and the available knowledge can not be utilized for the up gradation of ground low grade ore. Flotation is the only alternate method as the other techniques fail to up grade these super fines. It is always wise to use a cheap collector for flotation. Sodium oleate is one of the cheap reagents available for flotation of oxide minerals. Generally a special flotation cell is necessary to float fine (-10 micron) ore particles. In this process attempt is made to float the fine ore in the conventional mechanical flotation cell by flocculating the ore fines prior to flotation by floe flotation technique as super fines could not be floated in conventional cells. The main object of the present invention is to provide an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which obviates the drawbacks of the hitherto known prior art as detailed above. Another object of the present invention is to provide a process for treating finely disseminated low-grade siliceous manganese ore which are available plenty in Joda Area by advanced techniques floe flotation. Yet another object is to select a suitable combination of reagents for effective depression of quartz and flotation of manganese minerals. Yet another object is to provide an effective technique and reaction conditions for dispersion of fine particles and selective flocculation of manganese minerals which facilitate separation by flotation. Still another object of the present invention is to float fine particles in mechanical flotation cell after selective flocculation. The selection of combination of suitable reagents for flotation and the manner in which the reagents are added is a crucial factor. The novelty of the present invention lies in the selective flocculation of manganese mineral for an effective dispersion of particles, which thereafter facilitate the separation by flotation to obtain a high-grade manganese ore concentrate. Accordingly the present invention provides an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which comprises crushing and grinding of finely disseminated low-grade siliceous manganese ore to below 10 micron, adding water to the above said feed material, and optionally subjecting the resultant manganese ore slurry to an ultrasonic treatment at about 250V for a period of about 10 minutes, agitation the above said slurry in a flotation cell at a speed of 1000-1400 rpm, at a temperature in the range of 40-50°C, adding an aqueous solution of a mixture of sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid to the above said slurry followed by conditioning, further successively adding manganese chloride tetrahydrate, solution of dilute (0.2% w/v) sodium oleate and kerosene, respectively, followed by conditioning for a period of 3-5 minutes after every successive addition of the above said material, releasing the air from the flotation cell and carrying out the flotation of floes of manganese minerals, followed by cleaning and re cleaning of the above said float to obtain the desired product. In an embodiment of the present invention the the finally disseminated low grade siliceous manganese ore used contains 20-28% Mn, 4-5% Fe and 40-45% silica. In another embodiment of the present invention the sodium meta silicate used is in the range of 40-60 g/t. In yet another embodiment the concentration of sodium oleate used is in the range of 0.1-0.3% (w/v). In yet another embodiment the ferric nitrate used is in the range of 7-9 g/t. In yet another embodiment the sulphuric acid used is in the range of 24 - 35 g/t. In yet another embodiment the manganese chloride used is in the range of 175-850 g/t. In yet another embodiment the kerosene used is in the range of 1700-1900 g/t. In yet another embodiment the high grade manganese ore obtained has 50-79% Mn with 35-50% recovery. The finely disseminated low-grade siliceous manganese ore was procured from Joda area. The ore was crushed in a Jaw crusher followed by roll crusher to obtain a product of minus 1 mm size. This material was ground in a ball mill for 45 minutes. The product of ball mill was subjected to hydrocyclone to separate minus 10 micron particles. The -10 micron material was stored as feed material. A dry sample of 50 gm was taken and 100 ml of water was added to it. The slurry thus prepared was subjected to ultrasonic treatment at 250V for 10 minutes. The slurry was then transferred into 1L Denver D12 sub-aeration flotation cell. The slurry temperature was increased by adding hot water. While the slurry is in agitation the sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid of predetermined quantity was added and conditioned. The manganese chloride tetrahydrate solution of predetermined quantity was added and conditioned. The sodium oleate solution of predetermined concentration and quantity was added and conditioned. The kerosene oil of predetermined concentration and quantity was added and conditioned The air valve was opened to release the air and flotation was carried out. The finely disseminated manganese minerals were liberated by grinding the ore to minus 10 micron size. These particles form heterogeneous aggregate due to large surface area and high surface energy and difficult to separate from each other due to slime nature. The slurry of the minus 10 micron manganese ore was subjected to ultrasonic treatment to segregate manganese minerals from the other gangue minerals. In the flotation cell agitation and high temperature helped to keep the minerals in dispersed state. To enhance the dispersion further a solution containing sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was added. In conventional flotation generally one dispersant is used. The manganese chloride tetrahydrate was added so that Mn2+ could adsorb on manganese minerals and hydrate which is suitable for adsorption of oleate anion. The sodium oleate was diluted to 0.2% (w/v) to prevent micelle formation, which favored adsorption of mono layer of oleate ion instead of multi layer. Kerosene was added to further improve the hydrophobicity of the oleate ion adsorbed manganese mineral particles and to promote floe formation and to increase floe strength. The high temperature also promoted chemisorption of manganese minerals and oleate ions. The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention. Example 1 50g of minus 10 micron size manganese ore having 27.8% Mn, 4.36% Fe, 43.35% silica was taken in a glass beaker and 100 ml of water was added to it. The slurry thus prepared was subjected to ultrasonic treatment for 10 min at 250V in a Vibronics Ultrasonic Processor, Model P2 of Vibronics Pvt. Ltd., Mumbai. The slurry was transferred to 1L flotation cell and the agitation was set at 1400 rpm. The temperature was adjusted to 46°C by adding hot water. A solution containing sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was added into the slurry and conditioned for 12 min. The quantity of sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was 60.0 g/t, 8.46 g/t and 32.61 g/t, respectively. Manganese chloride tetrahydrate (823.9 g/t) was added in solution form and conditioned for 3 min. Sodium oleate (1922.46 g/t) was added into the slurry as a solution of 0.2% (w/v) concentration and conditioned for 3 min. Kerosene (1800 g/t) was added and conditioned for 3 min. The air was released and flotation was carried out. The froth was collected as concentrate and the rest as tailings. Both the froth and tailing was dried and analysed for manganese. The grade of concentrate was 36.84% at 84.96% Mn recovery. The concentrate was cleaned and recleaned at 1400 rpm without addition of any reagent. The grade of the cleaned product was 43.85% Mn at 68. 24% recovery and the grade of the recleaned product was 48.01% at 50.31% recovery (Table 1). It was possible to prepare a high-grade (48% Mn) manganese ore concentrate at 50.31% recovery from a finely disseminated low-grade siliceous manganese ore, which is otherwise sold at nominal rate or dumped at mine site for future use. In this process the proper combination of reagents and process variables have been designed to disperse the fine particles and form floe of manganese minerals which could be floated in a mechanical flotation cell to obtain a high grade manganese ore concentrate. Table 1 Optmization experiment for recovery of manganese Na2SiO3.9H2O, g/t: 40 Sodium oleate concentration, %( w/v) : 0.2 Kerocene, g/t: 1800 Sodium hydroxide, g/t: 40 Conditioning time for collector, min : 3 Conditioning time for kerosene, min : 3 Conditioning time for sodium hydroxide, min : 3 Conditioning time for MnCI2.4H20, min : 4.5 (Table Removed) Cond. : Conditioning time * In Experiment 7 in addition to the above conditions ultrasonic treatment was given for 10 min at 250V in Vibronics Ultrasonic Processor. The concentrate was cleaned once and recleaned to get 48.01% grade and 50.31% recovery. The details are given in Example 1. The Experiment No. 5 was considered optimum and it is considered as base experiment for the patent. The main advantages of the present invention are 1. Dispersion of fine ore particles by ultrasonic treatment and keeping the particles in dispersed state by agitation and application of high temperature. 2. Enhancement of dispersion by adding a solution of sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid. 3. Addition of manganese chloride tetrahydrate for effective adsorption of collector on manganese minerals. 4. Addition of dilute (0.2% w/v) sodium oleate solution. 5. Addition of kerosene to promote floc formation and increase floe strength. 6. The mechanical flotation cell is suitable for flotation of fine particles. We Claim 1. An improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which comprises crushing and grinding of finely disseminated low-grade siliceous manganese ore to below 10 micron, adding water to the above said feed material, and optionally subjecting the resultant manganese ore slurry to an ultrasonic treatment at about 250V for a period of about 10 minutes, agitation the above said slurry in a flotation cell at a speed of 1000-1400 rpm, at a temperature in the range of 40-50°C, adding an aqueous solution of a mixture of sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid to the above said slurry followed by conditioning, further successively adding manganese chloride tetrahydrate, solution of dilute (0.2% w/v) sodium oleate and kerosene, respectively, followed by conditioning for a period of 3-5 minutes after every successive addition of the above said material, releasing the air from the flotation cell and carrying out the flotation of floes of manganese minerals, followed by cleaning and re cleaning of the above said float to obtain the desired product. 2. An improved process as claimed in claim 1, wherein the finally disseminated low grade siliceous manganese ore used contains 20-28% Mn, 4-5% Fe and 40-45% silica. 3. An improved process as claimed in claims 1&2, wherein the sodium meta silicate used is in the range of 40-60 g/t. 4. An improved process as claimed in claims 1-3, wherein the concentration of sodium oleate used is in the range of 0.1-0.3% (w/v). 5. An improved process as claimed in claims 1-4, wherein the ferric nitrate used is in the range of 7-9 g/t. 6. An improved process as claimed in claims 1-5, wherein the sulphuric acid used is in the range of 24-35 g/t. 7. An improved process as claimed in claims 1-6, wherein the manganese chloride used is in the range of 175-850 g/t. 8. An improved process as claimed in claims 1-7, wherein the kerosene used is in the range of 1700-1900 g/t. 9. An improved process as claimed in claims 1-8, wherein the high grade manganese ore obtained has 50-79% Mn with 35-50% recovery. 10. An improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore, substantially as herein described with reference to the examples.

Full Text

This invention relates an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore. This invention comes under mineral processing and it can be used to prepare high-grade manganese concentrate from finely disseminated low-grade siliceous manganese ore. The basic studies on flotation of pure manganese minerals have been carried out by some authors [ Fuerstenau, M. C. and Rice, D. A., 1968, Trans AIME, V 241, pp 453-457; Natrajan, K. A. and Fuerstenau, D. W., 1983, Int. J. Miner. Process., V 11, pp 139-153; Fuerstenau, D. W. and Shibata, J., 1999, Int. J. Miner. Process., V 57, pp 205-217]. These studies are mainly of academic importance and directly not useful for process development. Manganese ores have been floated by many authors [Mc Carroll, S. J., 1954, J. Min. Eng. Vol 6, No 3 p 289; Kurova, M. D., 1970, Obogashch. Rud., V14, No 2, p 12; Goldberd, Yu. S., Semiotic, V. M. and Uvarov, U. S., 1968, Obogashch. Polez. Iskop., No 3, p 37; Kharlamov, V. S., Kirnosov, E. G. and Makarov, V. N., 1966, Dobycha Obogashch. Pererab, No 2, p 63; Fahrenwald, A. W., 1957, Mining Congress J., Aug., p 72 ]. This knowledge is not useful for preparation of manganese concentrate from the finely disseminated siliceous manganese ore. The floe flotation is considered as an effective means to treat finely disseminated ores and recover valuable minerals from fines [Song, S. and Lopez-Valdivieso, A., 2002, Min. Process. Ext. Metall. Rev, 23: 101-127]. It is realized through selective flocculation of desired mineral fines to increase the size of separation particles, followed by conventional flotation. The hydrophobic floe flotation of sulphide minerals, which are hydrophobic in nature and easily separable are carried out in macro scale [Song, S., Lopez-Valdivieso, A., Reyes-Bahena, J. L. and Lara-Valenzuela, C, 2001, Minerals Engineering, 14(1), pp 87-98] but such type of work for oxide minerals of manganese are not reported.
Reference may be made to Mc Carroll, S. J., 1954, J. Min. Eng. Vol 6, No 3 p 289 wherein the -212 micron size manganese ore containing 21.3 % Mn is floated using soap skimmings (byproduct of sulphate paper industry) : 17.80 kg/t, Fuel oil 53.41 kg/t, Oronile S (wetting agent) : 2.67 kg/t, S02 (5%) : 3.78 kg/t and
obtained a concentrate with 45.5% grade with 84% recovery. The drawbacks are high reagent consumption and utilization of S02 solution, which is likely to release toxic S02 gas to the atmosphere.
In Joda , Orissa huge quantity of finely disseminated low-grade siliceous manganese ore are produced as fines during the mining of manganese ore which is being sold at nominal rate or dumped at the mine site for future use. Such ores require fine grinding for liberation and the available knowledge can not be utilized for the up gradation of ground low grade ore. Flotation is the only alternate method as the other techniques fail to up grade these super fines. It is always wise to use a cheap collector for flotation. Sodium oleate is one of the cheap reagents available for flotation of oxide minerals. Generally a special flotation cell is necessary to float fine (-10 micron) ore particles. In this process attempt is made to float the fine ore in the conventional mechanical flotation cell by flocculating the ore fines prior to flotation by floe flotation technique as super fines could not be floated in conventional cells.
The main object of the present invention is to provide an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which obviates the drawbacks of the hitherto known prior art as detailed above.
Another object of the present invention is to provide a process for treating finely disseminated low-grade siliceous manganese ore which are available plenty in Joda Area by advanced techniques floe flotation.
Yet another object is to select a suitable combination of reagents for effective depression of quartz and flotation of manganese minerals.
Yet another object is to provide an effective technique and reaction conditions for dispersion of fine particles and selective flocculation of manganese minerals which facilitate separation by flotation.
Still another object of the present invention is to float fine particles in mechanical flotation cell after selective flocculation.
The selection of combination of suitable reagents for flotation and the manner in which the reagents are added is a crucial factor. The novelty of the present invention lies in the selective flocculation of manganese mineral for an effective dispersion of particles, which thereafter facilitate the separation by flotation to obtain a high-grade manganese ore concentrate.
Accordingly the present invention provides an improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which comprises crushing and grinding of finely disseminated low-grade siliceous manganese ore to below 10 micron, adding water to the above said feed material, and optionally subjecting the resultant manganese ore slurry to an ultrasonic treatment at about 250V for a period of about 10 minutes, agitation the above said slurry in a flotation cell at a speed of 1000-1400 rpm, at a temperature in the range of 40-50°C, adding an aqueous solution of a mixture of sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid to the above said slurry followed by conditioning, further successively adding manganese chloride tetrahydrate, solution of dilute (0.2% w/v) sodium oleate and kerosene, respectively, followed by conditioning for a period of 3-5 minutes after every successive addition of the above said material, releasing the air from the flotation cell and carrying out the flotation of floes of manganese minerals, followed by cleaning and re cleaning of the above said float to obtain the desired product.
In an embodiment of the present invention the the finally disseminated low grade siliceous manganese ore used contains 20-28% Mn, 4-5% Fe and 40-45% silica.
In another embodiment of the present invention the sodium meta silicate used is in the range of 40-60 g/t.
In yet another embodiment the concentration of sodium oleate used is in the range of 0.1-0.3% (w/v).
In yet another embodiment the ferric nitrate used is in the range of 7-9 g/t.
In yet another embodiment the sulphuric acid used is in the range of 24 -
35 g/t.
In yet another embodiment the manganese chloride used is in the range of 175-850 g/t.
In yet another embodiment the kerosene used is in the range of 1700-1900 g/t.
In yet another embodiment the high grade manganese ore obtained has 50-79% Mn with 35-50% recovery.
The finely disseminated low-grade siliceous manganese ore was procured from Joda area. The ore was crushed in a Jaw crusher followed by roll crusher to obtain a product of minus 1 mm size. This material was ground in a ball mill for 45 minutes. The product of ball mill was subjected to hydrocyclone to separate minus 10 micron particles. The -10 micron material was stored as feed material. A dry sample of 50 gm was taken and 100 ml of water was added to it. The slurry thus prepared was subjected to ultrasonic treatment at 250V for 10 minutes. The slurry was then transferred into 1L Denver D12 sub-aeration flotation cell. The slurry temperature was increased by adding hot water. While the slurry is in agitation the sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid of predetermined quantity was added and conditioned. The manganese chloride tetrahydrate solution of predetermined quantity was added and conditioned. The sodium oleate solution of predetermined concentration and quantity was added and conditioned. The kerosene oil of predetermined concentration and quantity was added and conditioned The air valve was opened to release the air and flotation was carried out.
The finely disseminated manganese minerals were liberated by grinding the ore to minus 10 micron size. These particles form heterogeneous aggregate due to large surface area and high surface energy and difficult to separate from each other due to slime nature. The slurry of the minus 10 micron manganese ore was subjected to ultrasonic treatment to segregate manganese minerals from the other gangue minerals. In the flotation cell agitation and high temperature
helped to keep the minerals in dispersed state. To enhance the dispersion further a solution containing sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was added. In conventional flotation generally one dispersant is used. The manganese chloride tetrahydrate was added so that Mn2+ could adsorb on manganese minerals and hydrate which is suitable for adsorption of oleate anion. The sodium oleate was diluted to 0.2% (w/v) to prevent micelle formation, which favored adsorption of mono layer of oleate ion instead of multi layer. Kerosene was added to further improve the hydrophobicity of the oleate ion adsorbed manganese mineral particles and to promote floe formation and to increase floe strength. The high temperature also promoted chemisorption of manganese minerals and oleate ions.
The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention.
Example 1
50g of minus 10 micron size manganese ore having 27.8% Mn, 4.36% Fe, 43.35% silica was taken in a glass beaker and 100 ml of water was added to it. The slurry thus prepared was subjected to ultrasonic treatment for 10 min at 250V in a Vibronics Ultrasonic Processor, Model P2 of Vibronics Pvt. Ltd., Mumbai. The slurry was transferred to 1L flotation cell and the agitation was set at 1400 rpm. The temperature was adjusted to 46°C by adding hot water. A solution containing sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was added into the slurry and conditioned for 12 min. The quantity of sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid was 60.0 g/t, 8.46 g/t and 32.61 g/t, respectively. Manganese chloride tetrahydrate (823.9 g/t) was added in solution form and conditioned for 3 min. Sodium oleate (1922.46 g/t) was added into the slurry as a solution of 0.2% (w/v) concentration and conditioned for 3 min. Kerosene (1800 g/t) was added and conditioned for 3 min.
The air was released and flotation was carried out. The froth was collected as concentrate and the rest as tailings. Both the froth and tailing was dried and analysed for manganese. The grade of concentrate was 36.84% at 84.96% Mn recovery. The concentrate was cleaned and recleaned at 1400 rpm without addition of any reagent. The grade of the cleaned product was 43.85% Mn at 68. 24% recovery and the grade of the recleaned product was 48.01% at 50.31% recovery (Table 1).
It was possible to prepare a high-grade (48% Mn) manganese ore concentrate at 50.31% recovery from a finely disseminated low-grade siliceous manganese ore, which is otherwise sold at nominal rate or dumped at mine site for future use. In this process the proper combination of reagents and process variables have been designed to disperse the fine particles and form floe of manganese minerals which could be floated in a mechanical flotation cell to obtain a high grade manganese ore concentrate.
Table 1 Optmization experiment for recovery of manganese
Na2SiO3.9H2O, g/t: 40
Sodium oleate concentration, %( w/v) : 0.2
Kerocene, g/t: 1800
Sodium hydroxide, g/t: 40
Conditioning time for collector, min : 3
Conditioning time for kerosene, min : 3
Conditioning time for sodium hydroxide, min : 3
Conditioning time for MnCI2.4H20, min : 4.5
(Table Removed)
Cond. : Conditioning time
* In Experiment 7 in addition to the above conditions ultrasonic treatment was given for 10 min at 250V in Vibronics Ultrasonic Processor. The concentrate was cleaned once and recleaned to get 48.01% grade and 50.31% recovery. The details are given in Example 1. The Experiment No. 5 was considered optimum and it is considered as base
experiment for the patent.
The main advantages of the present invention are
1. Dispersion of fine ore particles by ultrasonic treatment and keeping the particles in dispersed state by agitation and application of high temperature.
2. Enhancement of dispersion by adding a solution of sodium meta silicate, ferric nitrate nonahydrate and sulphuric acid.
3. Addition of manganese chloride tetrahydrate for effective adsorption of collector on manganese minerals.
4. Addition of dilute (0.2% w/v) sodium oleate solution.
5. Addition of kerosene to promote floc formation and increase floe strength.
6. The mechanical flotation cell is suitable for flotation of fine particles.

We Claim
1. An improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore which comprises crushing and grinding of finely disseminated low-grade siliceous manganese ore to below 10 micron, adding water to the above said feed material, and optionally subjecting the resultant manganese ore slurry to an ultrasonic treatment at about 250V for a period of about 10 minutes, agitation the above said slurry in a flotation cell at a speed of 1000-1400 rpm, at a temperature in the range of 40-50°C, adding an aqueous solution of a mixture of sodium meta silicate, ferric nitrate nonahydrate, and sulphuric acid to the above said slurry followed by conditioning, further successively adding manganese chloride tetrahydrate, solution of dilute (0.2% w/v) sodium oleate and kerosene, respectively, followed by conditioning for a period of 3-5 minutes after every successive addition of the above said material, releasing the air from the flotation cell and carrying out the flotation of floes of manganese minerals, followed by cleaning and re cleaning of the above said float to obtain the desired product.
2. An improved process as claimed in claim 1, wherein the finally disseminated low grade siliceous manganese ore used contains 20-28% Mn, 4-5% Fe and 40-45% silica.
3. An improved process as claimed in claims 1&2, wherein the sodium meta silicate used is in the range of 40-60 g/t.
4. An improved process as claimed in claims 1-3, wherein the concentration of sodium oleate used is in the range of 0.1-0.3% (w/v).
5. An improved process as claimed in claims 1-4, wherein the ferric nitrate used is in the range of 7-9 g/t.
6. An improved process as claimed in claims 1-5, wherein the sulphuric acid used is in the range of 24-35 g/t.
7. An improved process as claimed in claims 1-6, wherein the manganese chloride used is in the range of 175-850 g/t.
8. An improved process as claimed in claims 1-7, wherein the kerosene used is in the range of 1700-1900 g/t.
9. An improved process as claimed in claims 1-8, wherein the high grade manganese ore obtained has 50-79% Mn with 35-50% recovery.
10. An improved process for the preparation of high-grade manganese ore concentrate from finely disseminated low-grade siliceous manganese ore, substantially as herein described with reference to the examples.

Documents:

1978-del-2005-Abstract-(12-12-2012).pdf

1978-del-2005-abstract.pdf

1978-del-2005-Claims-(12-12-2012).pdf

1978-del-2005-claims.pdf

1978-DEL-2005-Correspondence Others-(07-03-2012).pdf

1978-del-2005-Correspondence Others-(12-12-2012).pdf

1978-del-2005-correspondence-others.pdf

1978-del-2005-description (complete).pdf

1978-del-2005-form-1.pdf

1978-del-2005-form-18.pdf

1978-del-2005-form-2.pdf

1978-DEL-2005-Form-3-(07-03-2012).pdf

1978-del-2005-form-3.pdf

1978-del-2005-form-5.pdf

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Patent Number

255528

Indian Patent Application Number

1978/DEL/2005

PG Journal Number

09/2013

Publication Date

01-Mar-2013

Grant Date

28-Feb-2013

Date of Filing

26-Jul-2005

Name of Patentee

COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH

Applicant Address

ANUSANDHAN BHAWAN, RAFI MARG, NEW DELHI - 110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	PRADYUMNA KUMAR NAIK,2.PALLI SITA RAMA REDDY,3.VIBHUTI NARAIN MISRA	REGIONAL RESEARCH LABORATORY (CSIR), BHUBANESWAR-751013 ORISSA, INDIA.

PCT International Classification Number

C22B 3/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA