Indian journal of science and technology, Sep 25, 2023
Objectives: To ascertain how desliming affects concentration efficiency of low-grade Indian iron ... more Objectives: To ascertain how desliming affects concentration efficiency of low-grade Indian iron ore and how hydrocyclone process parameters affect desliming effectiveness of low-grade iron ores for their optimum utilization. Methods: Low grade Indian iron ores viz high aluminous type slime (sample A) and siliceous type BHQ (sample B) assaying 56.3% Fe, 7.64% SiO 2 , 5.14% Al 2 O 3, 5.34% LOIand 40.5% Fe, 40.6% SiO 2 , 0.7% Al 2 O 3 , 0.5% LOI are used for this study. The samples undergo beneficiation study by employing the techniques like desliming followed by gravity and magnetic separation for the recovery of iron values. Findings: Two ores appear to behave differently depending on the process parameters. Desliming followed by gravity separation of the ores increases the separation efficiency of the concentration process for both sample A and sample B. Improved iron recovery and grade observed in case of desliming-cum-gravity separation than that of direct gravity separation. The particle size and mineral are dominating the separation response in case of iron ore slime sample A, while in BHQ sample B the dominating factor is particle size only. The grade of deslimed product (hydrocyclone underflow) increased in case of sample A. The grade of deslimed product did not increase in sample B but the particle sizes are more segregated. sample A can be processed to produce an iron ore concentrate with a 65% Fe content and weight(%) recovery of 42 by adopting desliming followed by gravity separation techniques. An iron ore concentrates of 64% Fe with 25 weight (%) recovery can also be obtained from sample B by adopting the same. Novelty & Application: Present investigation establishes the response of different low grade ores in terms of separation with and without desliming. Desliming before concentration will be an easier decision resulting in efficient separation.
Froth flotation of weathered coal is a challenging task in a conventional flotation cell using co... more Froth flotation of weathered coal is a challenging task in a conventional flotation cell using commonly used collector and frother. Generally weathered coal shows the erratic flotation behaviour due to the surface oxidation as it makes the coal surface hydrophilic. When the surface gets oxidized, surface modifier is employed to float the clean coal. Frothers play significant role in stabilizing the mineralized bubble. It reduces the bubble size by reducing the interfacial tension at the air water interface. During this investigation, the flotation was carried out with two types of frothers namely; methyl isobutyl carbinol (MIBC), a weak frother and a strong polyglycol type. The Factorial design matrix was used for carrying out the experiments with the different ratio of frother blend, collector and promoter dosage. The high concentration of MIBC is found to be not effective for recovering the significant amount of carbon value as it causes less reduction of the interfacial tension a...
In this investigation the weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and po... more In this investigation the weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG) were used for studying the surface tension of frother blends at various concentrations. The critical micelle concentrations (CMC) were determined using surface tension values at different concentrations. PEG requires very low concentration (100 ppm) to attain the CMC, whereas for MIBC, about ten times more concentration (1000 ppm) is required.The interactions between the different types of frother molecules at different blends were studied through different thermodynamic properties. A more negative value of interaction parameter (â)and heat of adsorption are found at 90:10 ratio of frother blend. Flotation studies of coal fines were studied with above two types of frothers and their blend. It is found that recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother ...
In the present investigation low grade iron ore containing around 54% Fe, 5%SiO 2 and 8% Al 2 O 3... more In the present investigation low grade iron ore containing around 54% Fe, 5%SiO 2 and 8% Al 2 O 3 was taken up. It was observed that in the coarser fraction (-30+10 mm) the Fe content is 60% while the finer fractions in the size range of -10+0.15 mm contain around 54% Fe. The -0.15mm fraction contains less than 35% Fe and was rejected. No significant enrichment was observed for the -30+10 mm fraction using gravity concentration. However, magnetic separation of this fraction in permroll resulted in the generation of a concentrate with 19% yield at 62.75% Fe. In all size fractions ranges between -10 to 0.15 mm gravity concentration techniques were found to be ineffective. Therefore, for further recovery of iron values, the tailings from the magnetic separation of -30+10 mm fraction and the original finer material (-10+0.15 mm) were ground to - 0.15mm and subjected to wet high intensity magnetic separation after desliming to obtain pellet grade concentrate.
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
A major challenge in the processing of PGM-bearing UG2 ore is the fact that it is comprised large... more A major challenge in the processing of PGM-bearing UG2 ore is the fact that it is comprised largely of chromite (60-90% by volume). Chromite is generally not naturally floatable but significant quantities report to the concentrate by entrainment. This is a serious problem for the downstream smelting process, which is generally constrained to a grade of about 3% chromite. Four of the most accessible levers for the control of flotation performance which are available to a plant metallurgist are frother and depressant dosage, air flow rate and froth height. The effects of each of these factors on the flotation performance have been extensively studied, but interactive effects are not well understood. This study presents the results of an investigation into the interactive effects of these parameters using a factorial experimental design approach. The flotation tests were carried out using a 2 m high continuous column flotation cell which facilitated the generation of a deep froth, since this was the phase of most interest. The results were analysed using statistical analysis software that fitted a regression model to the data for each of the outputs. These results highlight the interactive effects of these variables on the flotation performance and illustrate the complexity that is required in process control.
Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is invest... more Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is investigated. Characterization studies indicated that the coal must be processed after reducing the size to 1.18 mm in order to accomplish substantial yield of the clean coal. A gravity based flowsheet for the -1.18+0.5 mm fraction is developed to generate clean coal at 12% ash with 9.2% overall yield. Mechanical cell flotation circuit for the -0.5+0.15 mm size fraction resulted in additional 3.5% yield at the desired ash level. A flotation circuit for the fine fraction (-0.15 mm) is developed using Jameson Cell only that added further 3.0% yield in the overall mass recovery at 12% ash. Thus, a total of 15.7% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Recycling of some of the intermediate product streams is recommended for continuous operation to enhance the overall yield of the clean coal significantly.
Frothers are surface active molecules and facilitate to produce more mechanically stable froth by... more Frothers are surface active molecules and facilitate to produce more mechanically stable froth by reducing the surface tension at air-water interface. It adsorbs at the air-water interface and serves to reduce the loss of water from the lamellae of bubble. In this investigation weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG) were used for studying the surface tension of frother blends at various concentrations. Gibb's surface excess adsorption and surface area were determined from the rate of change of surface tension with logarithm of concentration. The high surface area per molecule of PEG signifies that little amount is enough to significantly reduce the interfacial tension at the air-water interface. The foam volume and its stability were measured for single frothers and their blend. The foam stability (foaminess) of single MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines from eastern part of India were carried out with the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. It was found that coal concentrate contains high ash with single PEG due to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.
In India iron ores processing industries play a vital role in Indian economy. During washing and ... more In India iron ores processing industries play a vital role in Indian economy. During washing and processing of iron ores, slimes less than 0.15 mm are generated and discarded into the tailing pond. These slimes need processing as they cannot be used directly in blast furnaces. In the present investigation, typical iron ore slime sample containing 59.22% Fe, 4.76% SiO2 and
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
Indian iron ores slimes are generally rich in iron content. The presence of high alumina and sili... more Indian iron ores slimes are generally rich in iron content. The presence of high alumina and silica in the iron ores reduces the grade and poses difficulty in processing. Due to fine granulometry and mineralogical complexity, processing of iron ore slimes by conventional physical separation methods such as gravity and magnetic separation, has limited success. Froth flotation is a versatile method used in mineral processing to remove the impurities from the fine ore. The iron ore slime containing 58.7% Fe, 5% SiO2 and 4.88% Al2O3 was used for this investigation. Column flotation was used as it is a better alternative for processing of iron ore slimes. Tests were conducted at alkaline pH using sodium oleate as a collector and MIBC as frother. A factorial design of experimental approach was followed taking three variables namely froth height, superficial air velocity and collector dosage. The interaction effects of variable parameters on recovery and Fe grade of concentrate were studie...
A low volatile medium coking coal from Jharia coal field, India was used for this investigation. ... more A low volatile medium coking coal from Jharia coal field, India was used for this investigation. The proximate analysis of the sample shows that it contains about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The sizewise ash analysis of -0.5 mm coal indicates that -0.5+0.15 mm fraction contains lower ash (21.9%) than -0.15 mm fraction (29.7%). The flotation characteristics of the -0.5 mm coal were determined by release analysis. The study reveals that recovery of combustible at 15% ash is about 27% and 43% at 17% ash level. The low recovery is due to the presence of high ash in finer fraction. In order to improve the recovery, the -0.5 mm feed was classified into -0.5+0.15 mm and -0.15 mm fractions, and subjected to flotation separately. The recoverable combustible obtained from the release analysis of -0.5+0.15 mm at 15% ash level is 46%. The effect of collector dosage, frother dosage and aeration rate on flotation was studied. The responses of these variables in collecto...
ABSTRACT Iron ores slimes of India contain high alumina and silica that reduces the grade and pos... more ABSTRACT Iron ores slimes of India contain high alumina and silica that reduces the grade and poses difficulty in processing. This investigation addresses the interactive effect of process parameters on the processing of Indian iron ore slimes by using column flotation. The iron ore slime containing 58.7% Fe, 5.2% SiO2 and 4.9% Al2O3 was used for this investigation. The subsequent size analysis, chemical characterisation, desliming and column flotation tests were performed targeting the effect of process parameters on the flotation behaviour of the slimes. A factorial design of experimental approach was followed using three variables at two levels namely froth height, superficial air velocity, collector dosage. The dosages of frother and depressant were held constant. Froth height plays a significant role on recovery and Fe-grade in the concentrate. The interaction effects of the variable factors on recovery and Fe grade of concentrate were studied. The relationship between the residence time of air in froth zone and recovery was also established. Increased residence time demands more collector dosage for high recovery of the concentrate. Recovery of the concentrate could be improved to 63% (54.6% overall recovery) with a grade of 64.3% Fe, 1.9% silica and 2.2% alumina.
Journal of Minerals and Materials Characterization and Engineering, 2014
ABSTRACT A large volume of overburden and mine wastes is generated during the extraction and bene... more ABSTRACT A large volume of overburden and mine wastes is generated during the extraction and beneficia-tion of the low grade ores. The waste low grade manganiferous iron ore fine from southern part of India was studied for recovery of iron values. The chemical assay of the sample is 52.36% Fe, 4.75% Mn, 8.5% SiO 2 and 2.82% Al 2 O 3 . The characterization study of the sample indicates the presence of microplaty hematite, goethite, pyrolusite, cryptomelane with minor amount of quartz and kaolinite. The beneficiation study of the sample does not respond to the conventional route of desliming the ground feed followed by gravity separation and magnetic separation. Therefore, an alternative technique of reduction roasting using a producer gas was attempted at different condi-tions. The characterization of roasted product reveals the phase transformation to magnetite and microplaty magnetite. The low intensity magnetic separation conducted with the roasted products generated at optimal condition shows that 70% concentrate having 64.5% Fe and 1.87% Mn could be produced. The high manganese in the concentrate works as an additive for making pellet with enhancement in pellet strength and drop in reducibility. Utilization of mines waste has significant impact on mineral resources and environmental hazard.
ABSTRACT The low rank or oxidized coals show unpleasant flotation behaviour. The non-coking coal ... more ABSTRACT The low rank or oxidized coals show unpleasant flotation behaviour. The non-coking coal from Talcher, containing 26.8% ash, 4.9% moisture, 35.7% volatile matter and 1% oxygen was used for the investigation. The flotation performance of the weathered coal in a mechanical and column flotation cell was compared at low ash level of about 12%.
Frothers are surface active molecules and facilitate to produce more mechanically stable froth by... more Frothers are surface active molecules and facilitate to produce more mechanically stable froth by reducing the surface tension at air–water interface. It adsorbs at the air–water interface and serves to reduce the loss of water fromthe lamellae of bubble. In this investigation weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG)were used for studying the surface tension of frother blends at various concentrations. Gibb's surface excess adsorption and surface area were determined from the rate of change of surface tension with logarithm of concentration. The high surface area per molecule of PEG signifies that little amount is enough to significantly reduce the interfacial tension at the air–water interface. The foam volume and its stability were measured for single frothers and their blend. The foam stability (foaminess) of single MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines fromeastern part of Indiawere carried outwith the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. Itwas found that coal concentrate contains high ashwith single PEGdue to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.
… Journal of Coal Preparation and Utilization, 2012
Beneficiation of a high-ash (35%) medium coking coal to obtain a low-ash (12%) clean coal product... more Beneficiation of a high-ash (35%) medium coking coal to obtain a low-ash (12%) clean coal product is investigated. Characterization studies indicated that this coal can be processed after reducing the size to 1.18 mm in order to achieve reasonable yield of the clean coal at such a low target-ash level. The desired ash reduction is possible only after treating different size fractions of the −1.18 mm crushed coal separately. A gravity-based processing scheme comprising of a spiral-floatex circuit along with multigravity separator for the −1.18 + 0.5 mm fraction is developed to generate clean coal at 12% ash with 10.3% overall yield. Mechanical cell flotation circuit for the −0.5 + 0.15 mm size fraction resulted in additional 5.2% yield at 12% target ash level for the clean coal. A flotation circuit for the ultrafine fraction (−0.15 mm) is also developed using Jameson cell flotation that added further 4.4% yield in the overall mass recovery of the combustibles at the desired ash level. Thus, a total of 20% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Application of the clean coal is recommended for metallurgical purpose. Out of the remaining 80% material, 35% is recovered at a 27% ash level that is recommended for use in sponge iron sector. The balance 45% with an ash level of 50% is marked for use in fluidized bed combustion for power generation. A complex flowsheet such as the one described in the present article is likely to be the future requirement for processing high-ash medium coking coals to a high-value low-ash product to enhance its utilization potential for metallurgical purpose.
Indian journal of science and technology, Sep 25, 2023
Objectives: To ascertain how desliming affects concentration efficiency of low-grade Indian iron ... more Objectives: To ascertain how desliming affects concentration efficiency of low-grade Indian iron ore and how hydrocyclone process parameters affect desliming effectiveness of low-grade iron ores for their optimum utilization. Methods: Low grade Indian iron ores viz high aluminous type slime (sample A) and siliceous type BHQ (sample B) assaying 56.3% Fe, 7.64% SiO 2 , 5.14% Al 2 O 3, 5.34% LOIand 40.5% Fe, 40.6% SiO 2 , 0.7% Al 2 O 3 , 0.5% LOI are used for this study. The samples undergo beneficiation study by employing the techniques like desliming followed by gravity and magnetic separation for the recovery of iron values. Findings: Two ores appear to behave differently depending on the process parameters. Desliming followed by gravity separation of the ores increases the separation efficiency of the concentration process for both sample A and sample B. Improved iron recovery and grade observed in case of desliming-cum-gravity separation than that of direct gravity separation. The particle size and mineral are dominating the separation response in case of iron ore slime sample A, while in BHQ sample B the dominating factor is particle size only. The grade of deslimed product (hydrocyclone underflow) increased in case of sample A. The grade of deslimed product did not increase in sample B but the particle sizes are more segregated. sample A can be processed to produce an iron ore concentrate with a 65% Fe content and weight(%) recovery of 42 by adopting desliming followed by gravity separation techniques. An iron ore concentrates of 64% Fe with 25 weight (%) recovery can also be obtained from sample B by adopting the same. Novelty & Application: Present investigation establishes the response of different low grade ores in terms of separation with and without desliming. Desliming before concentration will be an easier decision resulting in efficient separation.
Froth flotation of weathered coal is a challenging task in a conventional flotation cell using co... more Froth flotation of weathered coal is a challenging task in a conventional flotation cell using commonly used collector and frother. Generally weathered coal shows the erratic flotation behaviour due to the surface oxidation as it makes the coal surface hydrophilic. When the surface gets oxidized, surface modifier is employed to float the clean coal. Frothers play significant role in stabilizing the mineralized bubble. It reduces the bubble size by reducing the interfacial tension at the air water interface. During this investigation, the flotation was carried out with two types of frothers namely; methyl isobutyl carbinol (MIBC), a weak frother and a strong polyglycol type. The Factorial design matrix was used for carrying out the experiments with the different ratio of frother blend, collector and promoter dosage. The high concentration of MIBC is found to be not effective for recovering the significant amount of carbon value as it causes less reduction of the interfacial tension a...
In this investigation the weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and po... more In this investigation the weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG) were used for studying the surface tension of frother blends at various concentrations. The critical micelle concentrations (CMC) were determined using surface tension values at different concentrations. PEG requires very low concentration (100 ppm) to attain the CMC, whereas for MIBC, about ten times more concentration (1000 ppm) is required.The interactions between the different types of frother molecules at different blends were studied through different thermodynamic properties. A more negative value of interaction parameter (â)and heat of adsorption are found at 90:10 ratio of frother blend. Flotation studies of coal fines were studied with above two types of frothers and their blend. It is found that recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother ...
In the present investigation low grade iron ore containing around 54% Fe, 5%SiO 2 and 8% Al 2 O 3... more In the present investigation low grade iron ore containing around 54% Fe, 5%SiO 2 and 8% Al 2 O 3 was taken up. It was observed that in the coarser fraction (-30+10 mm) the Fe content is 60% while the finer fractions in the size range of -10+0.15 mm contain around 54% Fe. The -0.15mm fraction contains less than 35% Fe and was rejected. No significant enrichment was observed for the -30+10 mm fraction using gravity concentration. However, magnetic separation of this fraction in permroll resulted in the generation of a concentrate with 19% yield at 62.75% Fe. In all size fractions ranges between -10 to 0.15 mm gravity concentration techniques were found to be ineffective. Therefore, for further recovery of iron values, the tailings from the magnetic separation of -30+10 mm fraction and the original finer material (-10+0.15 mm) were ground to - 0.15mm and subjected to wet high intensity magnetic separation after desliming to obtain pellet grade concentrate.
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
A major challenge in the processing of PGM-bearing UG2 ore is the fact that it is comprised large... more A major challenge in the processing of PGM-bearing UG2 ore is the fact that it is comprised largely of chromite (60-90% by volume). Chromite is generally not naturally floatable but significant quantities report to the concentrate by entrainment. This is a serious problem for the downstream smelting process, which is generally constrained to a grade of about 3% chromite. Four of the most accessible levers for the control of flotation performance which are available to a plant metallurgist are frother and depressant dosage, air flow rate and froth height. The effects of each of these factors on the flotation performance have been extensively studied, but interactive effects are not well understood. This study presents the results of an investigation into the interactive effects of these parameters using a factorial experimental design approach. The flotation tests were carried out using a 2 m high continuous column flotation cell which facilitated the generation of a deep froth, since this was the phase of most interest. The results were analysed using statistical analysis software that fitted a regression model to the data for each of the outputs. These results highlight the interactive effects of these variables on the flotation performance and illustrate the complexity that is required in process control.
Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is invest... more Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is investigated. Characterization studies indicated that the coal must be processed after reducing the size to 1.18 mm in order to accomplish substantial yield of the clean coal. A gravity based flowsheet for the -1.18+0.5 mm fraction is developed to generate clean coal at 12% ash with 9.2% overall yield. Mechanical cell flotation circuit for the -0.5+0.15 mm size fraction resulted in additional 3.5% yield at the desired ash level. A flotation circuit for the fine fraction (-0.15 mm) is developed using Jameson Cell only that added further 3.0% yield in the overall mass recovery at 12% ash. Thus, a total of 15.7% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Recycling of some of the intermediate product streams is recommended for continuous operation to enhance the overall yield of the clean coal significantly.
Frothers are surface active molecules and facilitate to produce more mechanically stable froth by... more Frothers are surface active molecules and facilitate to produce more mechanically stable froth by reducing the surface tension at air-water interface. It adsorbs at the air-water interface and serves to reduce the loss of water from the lamellae of bubble. In this investigation weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG) were used for studying the surface tension of frother blends at various concentrations. Gibb's surface excess adsorption and surface area were determined from the rate of change of surface tension with logarithm of concentration. The high surface area per molecule of PEG signifies that little amount is enough to significantly reduce the interfacial tension at the air-water interface. The foam volume and its stability were measured for single frothers and their blend. The foam stability (foaminess) of single MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines from eastern part of India were carried out with the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. It was found that coal concentrate contains high ash with single PEG due to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.
In India iron ores processing industries play a vital role in Indian economy. During washing and ... more In India iron ores processing industries play a vital role in Indian economy. During washing and processing of iron ores, slimes less than 0.15 mm are generated and discarded into the tailing pond. These slimes need processing as they cannot be used directly in blast furnaces. In the present investigation, typical iron ore slime sample containing 59.22% Fe, 4.76% SiO2 and
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean gr... more Background/Objectives: Due to soaring demand and rapid depletion of high-grade iron ores, lean grade iron ores of India like BHJ and BHQ needs to be utilized through suitable beneficiation techniques. Methods: Banded Hematite Jasper (BHJ) sample of Bonai-Keonjhar belt (BK belt), Odisha, India assayed 35.3 % Fe, 47.1% SiO 2 and 0.96% Al 2 O 3 was investigated in respect of mineralogy, liberation characteristics and chemistry to finding out its optimum beneficiation potential. In the present investigation, efforts have been made to characterize the BHJ sample with reference to its beneficiation response. The sample was subjected to various beneficiation operations like Jigging followed by hydrocyclone, two-stage tabling and magnetic Separation. Findings: Mineralogical studies indicate that quartz and hematite are the major mineral phases, whereas goethite, martitized magnetite and clay (kaolinite) are present in very minor amounts. The liberation characteristic indicates that the average band thickness of Iron bearing mineral is of 1680 microns and 80% of the iron bearing minerals are liberated at-105 microns size. The two stage tabling of jig concentrate with desliming gives better outcome as compared with direct tabling of jig concentrate. An iron ore concentrate assayed 64.5% Fe, 5.6% SiO 2 and 0.80% Al 2 O 3 with wt% recovery of 23.2% can be obtained from two stage tabling. Another concentrate from magnetic separation of table middling and hydrocyclone assayed 63.2% Fe, 7.2% SiO 2 and 0.7% Al 2 O 3 with wt% recovery of 12.4% can be obtained. Novelty/ Application: Here a conventional beneficiation flow sheet is developed with a finding that, in order to beneficiate ore like banded hematite jasper (BHJ), an integral characterization approach is very much essential. Both of the concentrates obtained through the flow sheet assayed 64% Fe, 6.2% SiO 2 and 0.7% Al 2 O 3 with a wt% recovery of 35.6% can be utilized as a feed stock for pellet making in iron ore industries.
Indian iron ores slimes are generally rich in iron content. The presence of high alumina and sili... more Indian iron ores slimes are generally rich in iron content. The presence of high alumina and silica in the iron ores reduces the grade and poses difficulty in processing. Due to fine granulometry and mineralogical complexity, processing of iron ore slimes by conventional physical separation methods such as gravity and magnetic separation, has limited success. Froth flotation is a versatile method used in mineral processing to remove the impurities from the fine ore. The iron ore slime containing 58.7% Fe, 5% SiO2 and 4.88% Al2O3 was used for this investigation. Column flotation was used as it is a better alternative for processing of iron ore slimes. Tests were conducted at alkaline pH using sodium oleate as a collector and MIBC as frother. A factorial design of experimental approach was followed taking three variables namely froth height, superficial air velocity and collector dosage. The interaction effects of variable parameters on recovery and Fe grade of concentrate were studie...
A low volatile medium coking coal from Jharia coal field, India was used for this investigation. ... more A low volatile medium coking coal from Jharia coal field, India was used for this investigation. The proximate analysis of the sample shows that it contains about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The sizewise ash analysis of -0.5 mm coal indicates that -0.5+0.15 mm fraction contains lower ash (21.9%) than -0.15 mm fraction (29.7%). The flotation characteristics of the -0.5 mm coal were determined by release analysis. The study reveals that recovery of combustible at 15% ash is about 27% and 43% at 17% ash level. The low recovery is due to the presence of high ash in finer fraction. In order to improve the recovery, the -0.5 mm feed was classified into -0.5+0.15 mm and -0.15 mm fractions, and subjected to flotation separately. The recoverable combustible obtained from the release analysis of -0.5+0.15 mm at 15% ash level is 46%. The effect of collector dosage, frother dosage and aeration rate on flotation was studied. The responses of these variables in collecto...
ABSTRACT Iron ores slimes of India contain high alumina and silica that reduces the grade and pos... more ABSTRACT Iron ores slimes of India contain high alumina and silica that reduces the grade and poses difficulty in processing. This investigation addresses the interactive effect of process parameters on the processing of Indian iron ore slimes by using column flotation. The iron ore slime containing 58.7% Fe, 5.2% SiO2 and 4.9% Al2O3 was used for this investigation. The subsequent size analysis, chemical characterisation, desliming and column flotation tests were performed targeting the effect of process parameters on the flotation behaviour of the slimes. A factorial design of experimental approach was followed using three variables at two levels namely froth height, superficial air velocity, collector dosage. The dosages of frother and depressant were held constant. Froth height plays a significant role on recovery and Fe-grade in the concentrate. The interaction effects of the variable factors on recovery and Fe grade of concentrate were studied. The relationship between the residence time of air in froth zone and recovery was also established. Increased residence time demands more collector dosage for high recovery of the concentrate. Recovery of the concentrate could be improved to 63% (54.6% overall recovery) with a grade of 64.3% Fe, 1.9% silica and 2.2% alumina.
Journal of Minerals and Materials Characterization and Engineering, 2014
ABSTRACT A large volume of overburden and mine wastes is generated during the extraction and bene... more ABSTRACT A large volume of overburden and mine wastes is generated during the extraction and beneficia-tion of the low grade ores. The waste low grade manganiferous iron ore fine from southern part of India was studied for recovery of iron values. The chemical assay of the sample is 52.36% Fe, 4.75% Mn, 8.5% SiO 2 and 2.82% Al 2 O 3 . The characterization study of the sample indicates the presence of microplaty hematite, goethite, pyrolusite, cryptomelane with minor amount of quartz and kaolinite. The beneficiation study of the sample does not respond to the conventional route of desliming the ground feed followed by gravity separation and magnetic separation. Therefore, an alternative technique of reduction roasting using a producer gas was attempted at different condi-tions. The characterization of roasted product reveals the phase transformation to magnetite and microplaty magnetite. The low intensity magnetic separation conducted with the roasted products generated at optimal condition shows that 70% concentrate having 64.5% Fe and 1.87% Mn could be produced. The high manganese in the concentrate works as an additive for making pellet with enhancement in pellet strength and drop in reducibility. Utilization of mines waste has significant impact on mineral resources and environmental hazard.
ABSTRACT The low rank or oxidized coals show unpleasant flotation behaviour. The non-coking coal ... more ABSTRACT The low rank or oxidized coals show unpleasant flotation behaviour. The non-coking coal from Talcher, containing 26.8% ash, 4.9% moisture, 35.7% volatile matter and 1% oxygen was used for the investigation. The flotation performance of the weathered coal in a mechanical and column flotation cell was compared at low ash level of about 12%.
Frothers are surface active molecules and facilitate to produce more mechanically stable froth by... more Frothers are surface active molecules and facilitate to produce more mechanically stable froth by reducing the surface tension at air–water interface. It adsorbs at the air–water interface and serves to reduce the loss of water fromthe lamellae of bubble. In this investigation weak and powerful frothers, like methyl isobutyl carbinol (MIBC) and polyethylene glycol-600 (PEG)were used for studying the surface tension of frother blends at various concentrations. Gibb's surface excess adsorption and surface area were determined from the rate of change of surface tension with logarithm of concentration. The high surface area per molecule of PEG signifies that little amount is enough to significantly reduce the interfacial tension at the air–water interface. The foam volume and its stability were measured for single frothers and their blend. The foam stability (foaminess) of single MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines fromeastern part of Indiawere carried outwith the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. Itwas found that coal concentrate contains high ashwith single PEGdue to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.
… Journal of Coal Preparation and Utilization, 2012
Beneficiation of a high-ash (35%) medium coking coal to obtain a low-ash (12%) clean coal product... more Beneficiation of a high-ash (35%) medium coking coal to obtain a low-ash (12%) clean coal product is investigated. Characterization studies indicated that this coal can be processed after reducing the size to 1.18 mm in order to achieve reasonable yield of the clean coal at such a low target-ash level. The desired ash reduction is possible only after treating different size fractions of the −1.18 mm crushed coal separately. A gravity-based processing scheme comprising of a spiral-floatex circuit along with multigravity separator for the −1.18 + 0.5 mm fraction is developed to generate clean coal at 12% ash with 10.3% overall yield. Mechanical cell flotation circuit for the −0.5 + 0.15 mm size fraction resulted in additional 5.2% yield at 12% target ash level for the clean coal. A flotation circuit for the ultrafine fraction (−0.15 mm) is also developed using Jameson cell flotation that added further 4.4% yield in the overall mass recovery of the combustibles at the desired ash level. Thus, a total of 20% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Application of the clean coal is recommended for metallurgical purpose. Out of the remaining 80% material, 35% is recovered at a 27% ash level that is recommended for use in sponge iron sector. The balance 45% with an ash level of 50% is marked for use in fluidized bed combustion for power generation. A complex flowsheet such as the one described in the present article is likely to be the future requirement for processing high-ash medium coking coals to a high-value low-ash product to enhance its utilization potential for metallurgical purpose.
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Papers by Santosh Pani
MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines fromeastern part of Indiawere carried outwith the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. Itwas found that coal concentrate contains high ashwith single PEGdue to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was
observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.
MIBC is very less however; it could be improved significantly using a small amount of strong frother (PEG). Flotation studies of coal fines fromeastern part of Indiawere carried outwith the above two types of frothers and their blend. The performances were compared with reference to recovery of combustibles for clean coal and rejects. Itwas found that coal concentrate contains high ashwith single PEGdue to high froth stability that results the entrainment of the gangues, while single MIBC produces high grade concentrate with low recovery. It was
observed that the recovery of carbon value increases significantly when a 10% (w/w) of powerful frother was added with MIBC. The recovery of carbon at 90:10 ratio of frother blend is 77.6% at 17% ash. The recovery could be increased to 86% when ash in clean coal increases to 19.7% and loss of combustibles in the tailing could also be reduced to 14%.