As per the National Steel Policy 2017, more than 300 million tons of steel needs to be produced b... more As per the National Steel Policy 2017, more than 300 million tons of steel needs to be produced by 2030, to meet the increased demand due to the tripling of per capita consumption of steel in India. Accordingly, the local steel production from the Ballari steel hub of Sandur schist belt is expected to be raised from present 25 million tons per year to 60 million tons per year by 2030, thus necessitating 150 million tons of high grade hard lumpy/pellets for domestic Ballari steel hub alone excluding long term export commitments. Hence, a strategy for processing lean grade iron ores to augment the demand of high-grade iron ores for metallurgical applications is studied. A composite mixed Banded Hematite Quartzite (BHQ) from different ranges of Sandur schist belt, Ballari district, Karnataka, India was subjected to characterization, mineral processing and palletization studies to produce pellets Fe > 62.5 %, (SiO2+ Al2O3)2, 1.00 % Al2O3and 1.06 % LOI, comprising fine grained (<70...
Mineral Processing and Extractive Metallurgy Review, Apr 27, 2017
High intensity dry magnetic separators are in use for various applications in the mineral as well... more High intensity dry magnetic separators are in use for various applications in the mineral as well as coal processing industries. Evaluation of the performance of these separators treating different minerals has become an active research topic. Several attempts have been made by different researchers and technologists to understand the separation behaviour of particles in each of these separators treating different types of para-magnetic minerals. Despite all these A c c e p t e d M a n u s c r i p t 2 efforts, these separators are yet to find widespread applications to treat different paramagnetic minerals. Therefor the present status of these separators with a brief description of their operating principles, applications, and modeling are reviewed in this article. Also, the research work needs to focus on each separator has been highlighted.
International Journal of Mineral Processing, Mar 1, 2017
Rare earth roll magnetic separators (RERMS) and induced roll magnetic separators (IRMS) are the s... more Rare earth roll magnetic separators (RERMS) and induced roll magnetic separators (IRMS) are the simple and efficient dry high-intensity magnetic separators used for upgrading different paramagnetic minerals. These are the most popularly adopted units for separation of mineral sands, but its application for processing of other minerals is scanty. In the present investigation, an effort has been made to understand the role of different process variables of RERMS and IRMS to separate the hematite fines from a low-grade ore. Before magnetic separation studies, detailed characterisation of the material was carried out regarding physical, chemical, mineralogical and magnetic properties which are discussed critically from the magnetic separation point of view. Based on the findings of the characterisation, magnetic separation was conducted using RERMS and IRMS by varying some of the relevant process variables. Further, the effects of each variable on hematite segregation in these units were discussed, and optimum process conditions were derived for the efficient recovery of hematite fines from the low-grade ore. The separation efficiency of these separators is compared with liberation data obtained from QEMSCAN. Finally, the paper concludes stating that RERMS and IRMS can be utilized as a pre-concentrator/ scavenger unit to discard a maximum amount of gangue in a single stage of dry operation which will save energy regarding the fine grinding of the ore for liberation.
Processing of Ferruginous Chromite Ore by Dry High-Intensity Magnetic Separation
Mineral Processing and Extractive Metallurgy Review, Mar 23, 2016
ABSTRACT Mineral and morphological characteristics of chromite ore strongly affect the separation... more ABSTRACT Mineral and morphological characteristics of chromite ore strongly affect the separation efficiency while upgrading the low-grade deposits. Usually, chromite ore enrichment is carried out by using gravity separation due to high-concentration criterion between chromite and other minerals. However, chromite ore from Sukinda region, India, is a typical ore body with high iron content in the chromite spinel as well as gangue content in the form of oxide and hydroxides of iron-bearing minerals. So, the separation efficiency reduces by gravity method due to the lower value of concentration criterion. To address this, dry magnetic separation is an alternative approach to separate these iron-bearing gangue minerals from the chromite. This work investigated on the application of different dry high-intensity magnetic separators to separate the chromite grains from ferruginous chromite ore deposits of India. Prior to the separation, two different ore deposits of Sukinda region are subjected to detailed mineral, chemical, morphological, as well as magnetic properties characterization to visualize the separation. Tests confirm the effect of magnetic field strength along with other process parameters that influence the process of the separation of iron-bearing gangue minerals. The results on these separators are related to the influence of mineralogy, process parameters, and magnetic property of minerals, based on the experimental and statistical analysis of the process. Also, effect of desliming of the low-grade deposit prior to the dry magnetic separation is highlighted.
In the past coal maceral separation have been carried out based on density difference e.g., sink-... more In the past coal maceral separation have been carried out based on density difference e.g., sink-float analysis, density gradient centrifugation (DGC) techniques etc. These approaches are of limited success. Froth flotation is a physicochemical process separating particles on the basis of difference in surface properties in a vessel consisting of two distinct zones viz., pulp and froth zones. Rate of floatability of individual size range particles varies with their ash percent and the maceral content present. Therefore, the flotation rate constant eventually becomes a function of maceral percentage of a coal particle. In the present paper, an attempt has been made by performing size-wise flotation tests using a sub-bituminous rank coal and flotation kinetics have been established based on maceral percentage reporting to concentrate at different time intervals of flotation. These results have been related to the kinetic behaviour of the process.
Settling tests were conducted on the washery effluent using three types of flocculants namely cat... more Settling tests were conducted on the washery effluent using three types of flocculants namely cationic (Telfloc-3674F), anionic (Magna-1011) and non-ionic (Nalco-83370+). For the study purpose coal washery effluent (having pH of 8.72) was collected from a newly commissioned plant-thickener. Tests were conducted by varying the pH of the pulp at three levels of acidic (4.0), alkaline (11.0) and the natural pH (8.72) of the as collected effluent, besides the flocculent dosages varied at four levels (2, 4, 6 and 8 gpt) for each of the flocculants stated. The results of these tests, estimated in terms of initial settling rate and turbidity indicated that; among the three flocculants tested Telfloc-3674F and Magna-1011 gave best results as compared to Nalco-83370+ flocculent at a washery water pH 8.72. The effect of molecular weight of the flocculants on settling of solids in effluent has been established in terms of the kinetics with a characteristic number for each of the type of floccu...
Carbothermic reduction roasting for processing of ferruginous chromite ore using conventional and microwave heating
Advanced Powder Technology, 2021
Abstract The present study investigates the recovery of chromite from a low-grade ferruginous ore... more Abstract The present study investigates the recovery of chromite from a low-grade ferruginous ore through the carbothermic magnetization route using conventional and microwave heating sources. The carbothermic magnetization of ore is studied in both a horizontal tube furnace and a microwave oven by varying different process variables. The main objective of the study is to enhance the magnetic susceptibility of iron-bearing gangue minerals to enable the separation in a magnetic field. Alteration of crystalline structure and magnetic property of these minerals enables separation of low-grade ore by using magnetic separation. It is found that low-grade ferruginous chromite ore can be upgraded by reduction roasting, and 61.2% Cr2O3 was recovered with a chromium-to-iron ratio of 1.93 from a feed chromium-to-iron ratio of 1.01. The optimum result is achieved at a roasting temperature of 800 °C, with a roasting time of 60 min and a reductant dosage of 7.5%. Similarly, under microwave radiation, the chromium-to-iron ratio was upgraded to 1.81 with a recovery of 22%Cr2O3. The optimum result achieved under microwave radiation is at a microwave power of 900 W and exposure time of 7.5 min, with a reductant dosage of 10%. The findings of these two processing routes are discussed through characterization tools.
Evaluation of floatex density separator performance using silica sand
Abstract The Floatex Density Separator (FDS) is an enhanced hydraulic classifier which utilises b... more Abstract The Floatex Density Separator (FDS) is an enhanced hydraulic classifier which utilises both size and specific gravity for the particle classification. In the present investigation, effect of process variables such as teeter water flow rate, set point, and feed ...
Role of air core in particle separation in cyclones
Mineral Processing and Extractive Metallurgy, 2013
ABSTRACT Detailed studies were carried out to study the effect of air core formation in cyclones ... more ABSTRACT Detailed studies were carried out to study the effect of air core formation in cyclones on separation of particles using statistical techniques. The design and operating variables of a 100 mm perspex hydrocyclone, both flat bottom and conical, were varied and their effect on different types of air core was studied. The results were analysed using analysis of variance. The % underflow split was the most important variable affecting the air core formation. Studies were also carried out with density tracers under different air core conditions. The studies showed that the lighter particles separated better in the absence of the air core. Particle separation tests were then carried out after suppressing the air core with a metal rod. The separation of lighter particles with specific gravity close to the separating fluid was improved when the air core was suppressed. Numerical simulation studies showed that a higher tangential velocity and a lower radial velocity is the reason for better separation efficiency in the absence of the air core.
Investigation and optimization of the recovery of coal fines using oil agglomeration process: Use of waste oils from different sectors
Journal of Dispersion Science and Technology
ABSTRACT The high cost of the bridging liquid subdues the implementation and commercialization of... more ABSTRACT The high cost of the bridging liquid subdues the implementation and commercialization of oil agglomeration process. To overcome this problem, waste oils from different sectors were used in this present study. The performance of the process was assessed based on the responses like ash rejection and organic matter recovery. The aim of the present study was to investigate the usage of waste oils from different sectors and to optimize and analyze the behavioral pattern showcased by different variables (pulp density, oil dosage, agglomeration time and oil type) using response surface methodology (Box-Behnken design). Experimental investigation shows that the optimum pulp density, oil dosage, agglomeration time and oil type condition obtained as 3%, 15%, 15 min and waste engine oil, respectively. At optimum condition, the % ash rejection and % organic matter recovery obtained as 63.94% and 81.8%, respectively. GRAPHICAL ABSTRACT
Experiments conducted on water-only cyclones both at the laboratory (76 mm) and plant scale level... more Experiments conducted on water-only cyclones both at the laboratory (76 mm) and plant scale level (350 ram) treating Coal and Magnetite slurries have revealed that there exists a linear relationship between the flowrates of water in the feed and in the overflow streams. Further, a "Generalised Water Distribution Plot" which is independent of all the design and operating variables has been proposed to predict the water distribution in water-only cyclones. This plot has been represented by an equation of the form:
As per the National Steel Policy 2017, more than 300 million tons of steel needs to be produced b... more As per the National Steel Policy 2017, more than 300 million tons of steel needs to be produced by 2030, to meet the increased demand due to the tripling of per capita consumption of steel in India. Accordingly, the local steel production from the Ballari steel hub of Sandur schist belt is expected to be raised from present 25 million tons per year to 60 million tons per year by 2030, thus necessitating 150 million tons of high grade hard lumpy/pellets for domestic Ballari steel hub alone excluding long term export commitments. Hence, a strategy for processing lean grade iron ores to augment the demand of high-grade iron ores for metallurgical applications is studied. A composite mixed Banded Hematite Quartzite (BHQ) from different ranges of Sandur schist belt, Ballari district, Karnataka, India was subjected to characterization, mineral processing and palletization studies to produce pellets Fe > 62.5 %, (SiO2+ Al2O3)2, 1.00 % Al2O3and 1.06 % LOI, comprising fine grained (<70...
Mineral Processing and Extractive Metallurgy Review, Apr 27, 2017
High intensity dry magnetic separators are in use for various applications in the mineral as well... more High intensity dry magnetic separators are in use for various applications in the mineral as well as coal processing industries. Evaluation of the performance of these separators treating different minerals has become an active research topic. Several attempts have been made by different researchers and technologists to understand the separation behaviour of particles in each of these separators treating different types of para-magnetic minerals. Despite all these A c c e p t e d M a n u s c r i p t 2 efforts, these separators are yet to find widespread applications to treat different paramagnetic minerals. Therefor the present status of these separators with a brief description of their operating principles, applications, and modeling are reviewed in this article. Also, the research work needs to focus on each separator has been highlighted.
International Journal of Mineral Processing, Mar 1, 2017
Rare earth roll magnetic separators (RERMS) and induced roll magnetic separators (IRMS) are the s... more Rare earth roll magnetic separators (RERMS) and induced roll magnetic separators (IRMS) are the simple and efficient dry high-intensity magnetic separators used for upgrading different paramagnetic minerals. These are the most popularly adopted units for separation of mineral sands, but its application for processing of other minerals is scanty. In the present investigation, an effort has been made to understand the role of different process variables of RERMS and IRMS to separate the hematite fines from a low-grade ore. Before magnetic separation studies, detailed characterisation of the material was carried out regarding physical, chemical, mineralogical and magnetic properties which are discussed critically from the magnetic separation point of view. Based on the findings of the characterisation, magnetic separation was conducted using RERMS and IRMS by varying some of the relevant process variables. Further, the effects of each variable on hematite segregation in these units were discussed, and optimum process conditions were derived for the efficient recovery of hematite fines from the low-grade ore. The separation efficiency of these separators is compared with liberation data obtained from QEMSCAN. Finally, the paper concludes stating that RERMS and IRMS can be utilized as a pre-concentrator/ scavenger unit to discard a maximum amount of gangue in a single stage of dry operation which will save energy regarding the fine grinding of the ore for liberation.
Processing of Ferruginous Chromite Ore by Dry High-Intensity Magnetic Separation
Mineral Processing and Extractive Metallurgy Review, Mar 23, 2016
ABSTRACT Mineral and morphological characteristics of chromite ore strongly affect the separation... more ABSTRACT Mineral and morphological characteristics of chromite ore strongly affect the separation efficiency while upgrading the low-grade deposits. Usually, chromite ore enrichment is carried out by using gravity separation due to high-concentration criterion between chromite and other minerals. However, chromite ore from Sukinda region, India, is a typical ore body with high iron content in the chromite spinel as well as gangue content in the form of oxide and hydroxides of iron-bearing minerals. So, the separation efficiency reduces by gravity method due to the lower value of concentration criterion. To address this, dry magnetic separation is an alternative approach to separate these iron-bearing gangue minerals from the chromite. This work investigated on the application of different dry high-intensity magnetic separators to separate the chromite grains from ferruginous chromite ore deposits of India. Prior to the separation, two different ore deposits of Sukinda region are subjected to detailed mineral, chemical, morphological, as well as magnetic properties characterization to visualize the separation. Tests confirm the effect of magnetic field strength along with other process parameters that influence the process of the separation of iron-bearing gangue minerals. The results on these separators are related to the influence of mineralogy, process parameters, and magnetic property of minerals, based on the experimental and statistical analysis of the process. Also, effect of desliming of the low-grade deposit prior to the dry magnetic separation is highlighted.
In the past coal maceral separation have been carried out based on density difference e.g., sink-... more In the past coal maceral separation have been carried out based on density difference e.g., sink-float analysis, density gradient centrifugation (DGC) techniques etc. These approaches are of limited success. Froth flotation is a physicochemical process separating particles on the basis of difference in surface properties in a vessel consisting of two distinct zones viz., pulp and froth zones. Rate of floatability of individual size range particles varies with their ash percent and the maceral content present. Therefore, the flotation rate constant eventually becomes a function of maceral percentage of a coal particle. In the present paper, an attempt has been made by performing size-wise flotation tests using a sub-bituminous rank coal and flotation kinetics have been established based on maceral percentage reporting to concentrate at different time intervals of flotation. These results have been related to the kinetic behaviour of the process.
Settling tests were conducted on the washery effluent using three types of flocculants namely cat... more Settling tests were conducted on the washery effluent using three types of flocculants namely cationic (Telfloc-3674F), anionic (Magna-1011) and non-ionic (Nalco-83370+). For the study purpose coal washery effluent (having pH of 8.72) was collected from a newly commissioned plant-thickener. Tests were conducted by varying the pH of the pulp at three levels of acidic (4.0), alkaline (11.0) and the natural pH (8.72) of the as collected effluent, besides the flocculent dosages varied at four levels (2, 4, 6 and 8 gpt) for each of the flocculants stated. The results of these tests, estimated in terms of initial settling rate and turbidity indicated that; among the three flocculants tested Telfloc-3674F and Magna-1011 gave best results as compared to Nalco-83370+ flocculent at a washery water pH 8.72. The effect of molecular weight of the flocculants on settling of solids in effluent has been established in terms of the kinetics with a characteristic number for each of the type of floccu...
Carbothermic reduction roasting for processing of ferruginous chromite ore using conventional and microwave heating
Advanced Powder Technology, 2021
Abstract The present study investigates the recovery of chromite from a low-grade ferruginous ore... more Abstract The present study investigates the recovery of chromite from a low-grade ferruginous ore through the carbothermic magnetization route using conventional and microwave heating sources. The carbothermic magnetization of ore is studied in both a horizontal tube furnace and a microwave oven by varying different process variables. The main objective of the study is to enhance the magnetic susceptibility of iron-bearing gangue minerals to enable the separation in a magnetic field. Alteration of crystalline structure and magnetic property of these minerals enables separation of low-grade ore by using magnetic separation. It is found that low-grade ferruginous chromite ore can be upgraded by reduction roasting, and 61.2% Cr2O3 was recovered with a chromium-to-iron ratio of 1.93 from a feed chromium-to-iron ratio of 1.01. The optimum result is achieved at a roasting temperature of 800 °C, with a roasting time of 60 min and a reductant dosage of 7.5%. Similarly, under microwave radiation, the chromium-to-iron ratio was upgraded to 1.81 with a recovery of 22%Cr2O3. The optimum result achieved under microwave radiation is at a microwave power of 900 W and exposure time of 7.5 min, with a reductant dosage of 10%. The findings of these two processing routes are discussed through characterization tools.
Evaluation of floatex density separator performance using silica sand
Abstract The Floatex Density Separator (FDS) is an enhanced hydraulic classifier which utilises b... more Abstract The Floatex Density Separator (FDS) is an enhanced hydraulic classifier which utilises both size and specific gravity for the particle classification. In the present investigation, effect of process variables such as teeter water flow rate, set point, and feed ...
Role of air core in particle separation in cyclones
Mineral Processing and Extractive Metallurgy, 2013
ABSTRACT Detailed studies were carried out to study the effect of air core formation in cyclones ... more ABSTRACT Detailed studies were carried out to study the effect of air core formation in cyclones on separation of particles using statistical techniques. The design and operating variables of a 100 mm perspex hydrocyclone, both flat bottom and conical, were varied and their effect on different types of air core was studied. The results were analysed using analysis of variance. The % underflow split was the most important variable affecting the air core formation. Studies were also carried out with density tracers under different air core conditions. The studies showed that the lighter particles separated better in the absence of the air core. Particle separation tests were then carried out after suppressing the air core with a metal rod. The separation of lighter particles with specific gravity close to the separating fluid was improved when the air core was suppressed. Numerical simulation studies showed that a higher tangential velocity and a lower radial velocity is the reason for better separation efficiency in the absence of the air core.
Investigation and optimization of the recovery of coal fines using oil agglomeration process: Use of waste oils from different sectors
Journal of Dispersion Science and Technology
ABSTRACT The high cost of the bridging liquid subdues the implementation and commercialization of... more ABSTRACT The high cost of the bridging liquid subdues the implementation and commercialization of oil agglomeration process. To overcome this problem, waste oils from different sectors were used in this present study. The performance of the process was assessed based on the responses like ash rejection and organic matter recovery. The aim of the present study was to investigate the usage of waste oils from different sectors and to optimize and analyze the behavioral pattern showcased by different variables (pulp density, oil dosage, agglomeration time and oil type) using response surface methodology (Box-Behnken design). Experimental investigation shows that the optimum pulp density, oil dosage, agglomeration time and oil type condition obtained as 3%, 15%, 15 min and waste engine oil, respectively. At optimum condition, the % ash rejection and % organic matter recovery obtained as 63.94% and 81.8%, respectively. GRAPHICAL ABSTRACT
Experiments conducted on water-only cyclones both at the laboratory (76 mm) and plant scale level... more Experiments conducted on water-only cyclones both at the laboratory (76 mm) and plant scale level (350 ram) treating Coal and Magnetite slurries have revealed that there exists a linear relationship between the flowrates of water in the feed and in the overflow streams. Further, a "Generalised Water Distribution Plot" which is independent of all the design and operating variables has been proposed to predict the water distribution in water-only cyclones. This plot has been represented by an equation of the form:
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