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Akbar Mehdilo

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Petroleum Research (پژوهش نفت)

Research Institute of Petroleum Industry (RIPI)

Journal Metallurgical and Materials Engineering

Ferdowsi University of Mashhad

Akbarhassan Zadeh

IJAP Iranian Journal of Applied Physics

Journal of Advanced Materials in Engineering

Vahid Haddadi-Asl

Ahmad Reza Bahramian

Tarbiat Modares University

Massoumeh Bagheri

S. Hosseinifard

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Papers by Akbar Mehdilo

Hydrophilicity investigations on PADC surface irradiated by UV ArF laser

Optics and Photonics Society of Iran, 2015

In this study, the surface hydrophilicity changes of PADC due to exposing by ArF laser with 50-50... more In this study, the surface hydrophilicity changes of PADC due to exposing by ArF laser with 50-500 mJ/cm fluences and up to 3000 shots was investigated. It was shown that wettability of the surface is dependent on the total irradiated dose such that, the hydrophilicity initially decreases with increasing of the energy dose up to 50 J/cm and then, increases at higher doses. The value of contact angle variation for 500 mJ/cm fluence is about 2 times greater than that was observed at 50 mJ/cm case. The morphology and chemical results depict that laser-induced surface roughness is the dominant parameter for increasing hydrophilicity on exposed PADC.

Fabrication of self-ruled micro grating on CR-39 using ArF laser-induced rippling

Laser Physics, 2017

Applied Mineralogical Studies on Iranian Titanium Deposits

Acta Mineralogica Sinica, 2013

Qara-aghaj and Skandian as hard rock titanium deposit and Kahnooj one as a placer deposit were in... more Qara-aghaj and Skandian as hard rock titanium deposit and Kahnooj one as a placer deposit were investigated from applied mineralogical point of view. The mineralogical studies were carried out using XRD, XRF, optical microscopy, scanning electron microscopy and microprobe analysis. These studies indicated that ilmenite and magnetite are main valuable minerals in the studied ores. Pyroxene, olivine and plagioclase are the main gangue minerals in Qara-aghaj ore while chlorite and plagioclase are the major gangue minerals in Skandian ore. Plagioclase, clinopyroxene, amphibole, feldspate and some quartz are the important gangue minerals in kahnooj deposit. In all three ores ilmenite is mainly in the form of ilmenite grains but some lamellae of ilmenite with thickness between 0.1 to 20 μm have been occurred as exsolution textures inside magnetite grains, where the magnetite here can be referred to as ilmenomagnetite. In the hard rock ores some fine ilmenites have been disseminated in silicate minerals. The liberation degree of granular ilmenite was determined 150, 140 and 200 μm for Qara-aghaj, Skandian and Kahnooj, respectively. So, only the granular form of ilmenite is recoverable by physical methods. Some sphene and rutile as titanium containing minerals were observed mainly inside ilmenite phase in kahnooj ore. Some fine rutile was also found inside Skandian ilmenite while there were not any other titanium minerals inside Qara-aghaj ilmenite. Apatite is another valuable mineral which was found only in Qara-aghaj ore. Using SEM and microprobe analysis it was found that there are different amounts of exsolved fine lamellae of hematite inside ilmenite in Qara-aghaj and Kahnooj ores while it was not observed in Sckandian one. The average contents of TiO2 in the lattice of Qara-aghaj, Skandian and Kahnooj ilmenite were determined 51.13, 50.9% and 52.02%, respectively. FeO content of ilmenite lattice for all three samples is clearly lower than the theoretical content. This is due to the substitution of Mg and Mn for some Fe2+ ions in the ilmenite lattice. V2O3 content of magnetite lattice is up to 1%. So, magnetite can be a suitable source for production of vanadium as a by-product in all three deposits.

2012, 425−439 Physicochemical Problems of Mineral Processing

Abstract. Leaching with sulfuric and hydrochloric acids for upgrading titanium slag obtained from... more Abstract. Leaching with sulfuric and hydrochloric acids for upgrading titanium slag obtained from the Qara-aghaj ilmenite concentrate to a high grade titanium dioxide (TiO 2 ) was studied. The titanium slag containing 72.7% TiO 2 and 7.8% Fe 2 O 3 was leached at varying solid/liquid (S/L) ratio, particle size, leaching time and acid concentration. The optimum amount of S/L ratio, particle size, acid concentration and leaching time using both acids were determined as 1:4, -100 m, 8% and 2 h. Under optimum conditions, by using sulfuric acid, a titanium dioxide concentrate with 86.8% TiO 2 and 1.87% Fe 2 O 3 was produced, while employing hydrochloric acid resulted in a concentrate containing 91% TiO 2 and 0.61% Fe 2 O 3 . The titanium dioxide concentrate prepared with hydrochloric acid, having acicular texture and by means of elongated separate particles; has less impurities than the one produced by sulfuric acid. The results demonstrate that hydrochloric acid dissolution of titanium ...

Mineralogical Studies of Apatites of Gara-Aghaj Deposit from Mineral Processing Viewpoint

Gara-aghaj deposit located 36km northwest of urumieh is one of the titaniumphosphorous resources ... more Gara-aghaj deposit located 36km northwest of urumieh is one of the titaniumphosphorous resources in Iran. The previous exploration studies indicated that there is 102Mt phosphorous ore deposit with average grading of 2.3% P2O5. In this research, the mineralogical studies of collected representative samples were performed by XRD, XRF, optical microscopy and SEM equipped by EDX. These studies indicated that ilmenite, magnetite and apatite are the main valuable minerals. The gangue minerals consist of the silicate minerals such as pyroxene, olivine, plagioclase and some secondary minerals. Analysis of apatite by EDX showed the presence of fluor-apatite in the ore. From textural viewpoint, apatites is mainly interlocked with ilmenite, magnetite and some gangue minerals with 60 microns liberation degree but there are some inclusions of apatite inside ilmenite and magnetite. The heavy liquid separation tests indicated that the first type of apatites, with density of 3, is mainly concentra...

Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

International Journal of Minerals, Metallurgy and Materials, 2021

The present study initially investigates the kinetics of microwave-assisted grinding and flotatio... more The present study initially investigates the kinetics of microwave-assisted grinding and flotation in a porphyry copper deposit. Kinetic tests were conducted on untreated and microwave-irradiated samples by varying the exposure time from 15 to 150 s. Optical microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy were conducted to determine the mineral liberation and particle surface properties, and to perform mineralogical analyses. Results showed that the ore breakage rate constant monotonically increased by increasing the exposure time, particularly for the coarsest fraction size (400 µm) due to the creation of thermal stress fractures alongside grain boundaries. Excessive irradiation time (>60 s) led to the creation of oxidized and porous surfaces along with a dramatic change in particle morphologies that result in a substantial reduction of chalcopyrite and pyrite flotation rate constants and ultimate recoveries. We concluded that MW-pretreated copper ore was ground faster than the untreated variety, but the two types have slightly similar floatabilities.

Flotation of zinc oxide ores by cationic and mixed collectors

Minerals Engineering, 2012

The flotation of smithsonite from tailing which comes from the cerussite flotation circuit was in... more The flotation of smithsonite from tailing which comes from the cerussite flotation circuit was investigated using Armac C and Armac T as amine collectors. The results indicated that the dosage of sodium sulfide, collector type, and desliming are the main affecting factors on the Zn grade and recovery of smithsonite flotation concentrate. Armac T acts a little more selectively than Armac C, and enhances the Zn grade of the concentrate, while Armac C improves the recovery of Zn. At the mixture ratio of Armac C:Armac T = 1:6, without consumption of any gangue depressants, an optimal concentrate with 94.4% recovery, and 42.3% Zn grade is obtained. In this condition, the collectors’ consumption is decreased significantly. Desliming prior to flotation is essential for successful recovery of smithsonite.

Effect of chemical composition and crystal chemistry on the zeta potential of ilmenite

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013

h i g h l i g h t s • Lattice substitution of Mn, Mg and V influences the zeta potential of ilmen... more

Effects of mineralogical and textural characteristics of ilmenite concentrate on synthetic rutile production

Arabian Journal of Geosciences, 2012

The effect of mineralogy and texture of Qara-aghaj ilmenite concentrate on titanium dioxide prepa... more The effect of mineralogy and texture of Qara-aghaj ilmenite concentrate on titanium dioxide prepared via reduction-slagging acid leaching process as a raw material in chloride route was investigated. The concentrate contains 44.5 % TiO 2 and its content in ilmenite lattice varies from 41.6-48 %. Hematite exsolved lamellae inside ilmenite which affect the reduction process positively are host of the most of the Cr and V as pigment colorizer metals. Apatite fine inclusions inside ilmenite as the source of Ca and P could have negative effects on synthetic rutile. Spinel ultrafine particles inside ilmenite containing Al and Si could also affect the synthetic rutile negatively. The other important elements which have been substituted in ilmenite lattice are Mg and Mn. The prepared titanium dioxide concentrate containing 91 % TiO 2 and 0.6 % Fe 2 O 3 is mainly formed by rutile and small amount of anatase and Ti 2 O 3 phases. The solid solution of rutile inside Ti 2 O 3 was also observed. The content of Cr, V, Mn, and Al are decreased to permissible amount during slagging and leaching process while the quantity of other impurities such as Mg, Si, and Ca are relatively high in the product, and they cause some difficulties in pigment production via chloride route. The Mg and Ca sourced from ilmenite lattice and apatite inclusions, respectively, can affect the precipitation process. So, it is predicted that Qara-aghaj ilmenite concentrate will be suitable for sulfate route, but it is necessary to investigate comprehensively.

Applied mineralogical characterization of ilmenite from Kahnuj placer deposit , Southern Iran

Kahnuj placer deposit contains ilmenite and magnetite as the main valuable minerals. Microscopic ... more Kahnuj placer deposit contains ilmenite and magnetite as the main valuable minerals. Microscopic and microprobe analyses show that ilmenite occurs in two forms as individual grains and exsolved lamellae within magnetite. Exsolved lamellae of hematite, sphene of different shape and rare rutile and zircon are found as inclusions in ilmenite. According to microprobe analysis data the TiO2 content of ilmenite (52.1 wt%) with small amounts of Mg and Mn and is very close to the theoretical one (52.6 wt%). Based on the XRF analysis, the maximum content of TiO2 in the purified ilmenite concentrate without any gangue minerals is obtained at 44 wt%. The low grade of TiO2 in the purified ilmenite is attributed to the presence of sphene and hematite inside ilmenite. The presence of sphene as a source of Ca and Si can negatively affect the quality of ilmenite concentrate and the further product titanium dioxide manufactured via chloride and sulphate routes. It is found that the magnetite from th...

Evaluation of pyrolusite flotation behavior using a cationic collector

Floatability of pyrolusite from an Iranian low grade manganese ore (13.6% MnO) containing calcite... more Floatability of pyrolusite from an Iranian low grade manganese ore (13.6% MnO) containing calcite as the main gangue mineral was investigated with Armac C as a cationic collector. In the single mineral flotation experiments, the maximum recovery of pyrolusite is obtained at 82.2%, using 2000 g/t Armac C at a pH of 9, while at these conditions the flotation recovery of calcite is almost 78%. Quebracho and sodium hexa methaphosphate (SH) depress both minerals strongly at a wide range of dosages while low dosages of sodium silicate and zinc oxide depress the calcite mineral more than pyrolusite. Ca2+ ions affect the flotation recovery of pyrolusite negatively. The effective depression of calcite occurs using 1000–2000 g/t sodium silicate. However, in the ore flotation experiments, the favorable selective flotation of pyrolusite does not occur but the optimal concentrate containing 21.5% MnO with 51% recovery is obtained using 2000 g/t collector and 1000 g/t sodium silicate. A concentra...

Chemical and mineralogical composition of ilmenite: Effects on physical and surface properties

Some physical and chemical properties of three ilmenite samples: IL-F (purchased from the mineral... more Some physical and chemical properties of three ilmenite samples: IL-F (purchased from the mineral dealership of A and F Krantz), IL-Q (Qara-aghaj deposit, Iran) and IL-K (Kahnuj deposit, Iran) were studied. The substitution of different amounts of Mg, Mn and V in the crystal structure of ilmenite was identified by microprobe analysis. Different amounts of hemoilmenite exsolution were observed inside all three ilmenite samples using SEM, electron microprobe and X-ray diffraction analysis. Using these analytical techniques, titanite phase was found inside the IL-K ilmenite. The XPS analysis indicated that the contents of Fe3+ are 5.66, 5.33 and 3.72% for IL-F, IL-Q and IL-K, respectively which are in good agreement with the amounts of hemoilmenite exsolution. Mg and V contents in the ilmenite crystal structure have a good negative correlation with lattice constants (LC), unit cell volume, crystallinity index, specific gravity and IEP, while the Mn content correlates positively with th...

Characterization and beneficiation of iranian low-grade manganese ore

The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusi... more The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3-4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 microns. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with -500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained ...

Angular dependence of ArF laser induced self-aligning microstructures on CR39

High quality regular surface rippling is observed for certain UV exposure conditions. Self-aligni... more High quality regular surface rippling is observed for certain UV exposure conditions. Self-aligning microstructures are created on poly allyl diglycol carbonate samples using UV laser at 193 nm for a range of incidence angles. The treated area is notably enlarged at higher incidence angles while the fluence threshold and corresponding UV dose required to achieve those periodic structures is significantly reduced. Despite the spatial period remains nearly invariant versus dose and fluence at a certain incident angle; however the self-aligning orientation always aligns along the P-polarization component of the incident beam.

IMPACTS OF SURFACE MODİFİCATİON ON ISOTHERM AND KİNETİCS OF COLLECTOR ADSORPTİON Omid

Surface dissolution is one of the surface modification methods which has been used prior to the f... more Surface dissolution is one of the surface modification methods which has been used prior to the flotation process to improve minerals flotability. In this study, the effect of surface dissolution has been investigated on isotherm and adsorption kinetics of sodium oleate as a collector on the surface of ilmenite, olivine-pyroxene and quartz. Conditioning time, pH, temperature, activation energy, specific area and contact angle were the parameters which were studied before and after surface dissolution. The results of adsorption isotherms of Langmuir, Freundlich and Temkin, and kinetic models of elovich, lagergerin and pseudo second-order showed that the collector adsorption on the minerals surfaces can be well described by Langmuir isotherm and pseudo second-order kinetic model. The collector adsorption on the minerals surfaces is occurred mainly based on adsorption capacity from solution and single layer. Results indicated that the surface dissolution increases of the collector adso...

Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite

In the cationic flotation of pyrolusite using dodecyl ammine (DDA), the depressive effect of sodi... more In the cationic flotation of pyrolusite using dodecyl ammine (DDA), the depressive effect of sodium carbonate and calcium chloride on the calcite mineral was investigated systematically through flotation experiments, FTIR analysis, contact angle measurements and zeta potential tests. The microflotation experiments showed that both depressant agents decrease the flotation recovery of calcite significantly. In addition, sodium carbonate acts as activator agent for pyrolusite, and increases its floatability. The flotation experiments and contact angle measurements indicated that the selective depression effect of sodium carbonate on the calcite mineral is more than that of calcium chloride. As evidenced by zeta potential and FT-IR analysis, sodium carbonate decreases the negative charges on the surface of calcite mineral and subsequently reduces the adsorption of DDA collector through electrostatic forces. At a pH of 7.5, using 2000 g/t DDA and 1500 g/t sodium carbonate, a pyrolusite c...

Applied mineralogical characterization of ilmenite in Iranian placer deposit

Kahnouj titanium ore located in the south of iran is a placer deposit with ilmenite and magnetite... more Kahnouj titanium ore located in the south of iran is a placer deposit with ilmenite and magnetite as the main valuable minerals. There isn’t any ilmenite alteration in Kahnouj deposit; and it exhibits Ferrian to hydrated ilmenite. Microscopic and microprobe analysis show that ilmenite occurs in two forms including ilmenite grains and exsolved lamellae of ilmenite inside magnetite forming ilmenomagnetite texture. It was found that there are some exsolved lamellae of hematite and sphene with thickness finer than 10 mm inside ilmenite. The other heavy minerals which were mainly found inside ilmenite are the negligible amount of rutile and zircone. The microprobe analysis indicate that FeO content of ilmenite crystal lattice is lower than its theoretical amount because of Mg 2+ and Mn 2+ substitution for Fe 2+ while TiO 2 content (52.06%) is very close to the theoretical content (52.6%). The maximum content of TiO 2 in the purified ilmenite without any gangue minerals is obtained 44%. T...

Surface modification of ilmenite and its accompanied gangue minerals by thermal pretreatment: Application in flotation process

Transactions of Nonferrous Metals Society of China

Effect of surface dissolution on kinetic parameters in flotation of ilmenite from different gangue minerals

Transactions of Nonferrous Metals Society of China

The effect of microwave’s location in a comminution circuit on improving grindability of a porphyry copper deposit

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Hydrophilicity investigations on PADC surface irradiated by UV ArF laser

Optics and Photonics Society of Iran, 2015

In this study, the surface hydrophilicity changes of PADC due to exposing by ArF laser with 50-50... more In this study, the surface hydrophilicity changes of PADC due to exposing by ArF laser with 50-500 mJ/cm fluences and up to 3000 shots was investigated. It was shown that wettability of the surface is dependent on the total irradiated dose such that, the hydrophilicity initially decreases with increasing of the energy dose up to 50 J/cm and then, increases at higher doses. The value of contact angle variation for 500 mJ/cm fluence is about 2 times greater than that was observed at 50 mJ/cm case. The morphology and chemical results depict that laser-induced surface roughness is the dominant parameter for increasing hydrophilicity on exposed PADC.

Fabrication of self-ruled micro grating on CR-39 using ArF laser-induced rippling

Laser Physics, 2017

Applied Mineralogical Studies on Iranian Titanium Deposits

Acta Mineralogica Sinica, 2013

Qara-aghaj and Skandian as hard rock titanium deposit and Kahnooj one as a placer deposit were in... more Qara-aghaj and Skandian as hard rock titanium deposit and Kahnooj one as a placer deposit were investigated from applied mineralogical point of view. The mineralogical studies were carried out using XRD, XRF, optical microscopy, scanning electron microscopy and microprobe analysis. These studies indicated that ilmenite and magnetite are main valuable minerals in the studied ores. Pyroxene, olivine and plagioclase are the main gangue minerals in Qara-aghaj ore while chlorite and plagioclase are the major gangue minerals in Skandian ore. Plagioclase, clinopyroxene, amphibole, feldspate and some quartz are the important gangue minerals in kahnooj deposit. In all three ores ilmenite is mainly in the form of ilmenite grains but some lamellae of ilmenite with thickness between 0.1 to 20 μm have been occurred as exsolution textures inside magnetite grains, where the magnetite here can be referred to as ilmenomagnetite. In the hard rock ores some fine ilmenites have been disseminated in silicate minerals. The liberation degree of granular ilmenite was determined 150, 140 and 200 μm for Qara-aghaj, Skandian and Kahnooj, respectively. So, only the granular form of ilmenite is recoverable by physical methods. Some sphene and rutile as titanium containing minerals were observed mainly inside ilmenite phase in kahnooj ore. Some fine rutile was also found inside Skandian ilmenite while there were not any other titanium minerals inside Qara-aghaj ilmenite. Apatite is another valuable mineral which was found only in Qara-aghaj ore. Using SEM and microprobe analysis it was found that there are different amounts of exsolved fine lamellae of hematite inside ilmenite in Qara-aghaj and Kahnooj ores while it was not observed in Sckandian one. The average contents of TiO2 in the lattice of Qara-aghaj, Skandian and Kahnooj ilmenite were determined 51.13, 50.9% and 52.02%, respectively. FeO content of ilmenite lattice for all three samples is clearly lower than the theoretical content. This is due to the substitution of Mg and Mn for some Fe2+ ions in the ilmenite lattice. V2O3 content of magnetite lattice is up to 1%. So, magnetite can be a suitable source for production of vanadium as a by-product in all three deposits.

2012, 425−439 Physicochemical Problems of Mineral Processing

Abstract. Leaching with sulfuric and hydrochloric acids for upgrading titanium slag obtained from... more Abstract. Leaching with sulfuric and hydrochloric acids for upgrading titanium slag obtained from the Qara-aghaj ilmenite concentrate to a high grade titanium dioxide (TiO 2 ) was studied. The titanium slag containing 72.7% TiO 2 and 7.8% Fe 2 O 3 was leached at varying solid/liquid (S/L) ratio, particle size, leaching time and acid concentration. The optimum amount of S/L ratio, particle size, acid concentration and leaching time using both acids were determined as 1:4, -100 m, 8% and 2 h. Under optimum conditions, by using sulfuric acid, a titanium dioxide concentrate with 86.8% TiO 2 and 1.87% Fe 2 O 3 was produced, while employing hydrochloric acid resulted in a concentrate containing 91% TiO 2 and 0.61% Fe 2 O 3 . The titanium dioxide concentrate prepared with hydrochloric acid, having acicular texture and by means of elongated separate particles; has less impurities than the one produced by sulfuric acid. The results demonstrate that hydrochloric acid dissolution of titanium ...

Mineralogical Studies of Apatites of Gara-Aghaj Deposit from Mineral Processing Viewpoint

Gara-aghaj deposit located 36km northwest of urumieh is one of the titaniumphosphorous resources ... more Gara-aghaj deposit located 36km northwest of urumieh is one of the titaniumphosphorous resources in Iran. The previous exploration studies indicated that there is 102Mt phosphorous ore deposit with average grading of 2.3% P2O5. In this research, the mineralogical studies of collected representative samples were performed by XRD, XRF, optical microscopy and SEM equipped by EDX. These studies indicated that ilmenite, magnetite and apatite are the main valuable minerals. The gangue minerals consist of the silicate minerals such as pyroxene, olivine, plagioclase and some secondary minerals. Analysis of apatite by EDX showed the presence of fluor-apatite in the ore. From textural viewpoint, apatites is mainly interlocked with ilmenite, magnetite and some gangue minerals with 60 microns liberation degree but there are some inclusions of apatite inside ilmenite and magnetite. The heavy liquid separation tests indicated that the first type of apatites, with density of 3, is mainly concentra...

Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

International Journal of Minerals, Metallurgy and Materials, 2021

The present study initially investigates the kinetics of microwave-assisted grinding and flotatio... more The present study initially investigates the kinetics of microwave-assisted grinding and flotation in a porphyry copper deposit. Kinetic tests were conducted on untreated and microwave-irradiated samples by varying the exposure time from 15 to 150 s. Optical microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy were conducted to determine the mineral liberation and particle surface properties, and to perform mineralogical analyses. Results showed that the ore breakage rate constant monotonically increased by increasing the exposure time, particularly for the coarsest fraction size (400 µm) due to the creation of thermal stress fractures alongside grain boundaries. Excessive irradiation time (>60 s) led to the creation of oxidized and porous surfaces along with a dramatic change in particle morphologies that result in a substantial reduction of chalcopyrite and pyrite flotation rate constants and ultimate recoveries. We concluded that MW-pretreated copper ore was ground faster than the untreated variety, but the two types have slightly similar floatabilities.

Flotation of zinc oxide ores by cationic and mixed collectors

Minerals Engineering, 2012

The flotation of smithsonite from tailing which comes from the cerussite flotation circuit was in... more The flotation of smithsonite from tailing which comes from the cerussite flotation circuit was investigated using Armac C and Armac T as amine collectors. The results indicated that the dosage of sodium sulfide, collector type, and desliming are the main affecting factors on the Zn grade and recovery of smithsonite flotation concentrate. Armac T acts a little more selectively than Armac C, and enhances the Zn grade of the concentrate, while Armac C improves the recovery of Zn. At the mixture ratio of Armac C:Armac T = 1:6, without consumption of any gangue depressants, an optimal concentrate with 94.4% recovery, and 42.3% Zn grade is obtained. In this condition, the collectors’ consumption is decreased significantly. Desliming prior to flotation is essential for successful recovery of smithsonite.

Effect of chemical composition and crystal chemistry on the zeta potential of ilmenite

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013

h i g h l i g h t s • Lattice substitution of Mn, Mg and V influences the zeta potential of ilmen... more

Effects of mineralogical and textural characteristics of ilmenite concentrate on synthetic rutile production

Arabian Journal of Geosciences, 2012

The effect of mineralogy and texture of Qara-aghaj ilmenite concentrate on titanium dioxide prepa... more The effect of mineralogy and texture of Qara-aghaj ilmenite concentrate on titanium dioxide prepared via reduction-slagging acid leaching process as a raw material in chloride route was investigated. The concentrate contains 44.5 % TiO 2 and its content in ilmenite lattice varies from 41.6-48 %. Hematite exsolved lamellae inside ilmenite which affect the reduction process positively are host of the most of the Cr and V as pigment colorizer metals. Apatite fine inclusions inside ilmenite as the source of Ca and P could have negative effects on synthetic rutile. Spinel ultrafine particles inside ilmenite containing Al and Si could also affect the synthetic rutile negatively. The other important elements which have been substituted in ilmenite lattice are Mg and Mn. The prepared titanium dioxide concentrate containing 91 % TiO 2 and 0.6 % Fe 2 O 3 is mainly formed by rutile and small amount of anatase and Ti 2 O 3 phases. The solid solution of rutile inside Ti 2 O 3 was also observed. The content of Cr, V, Mn, and Al are decreased to permissible amount during slagging and leaching process while the quantity of other impurities such as Mg, Si, and Ca are relatively high in the product, and they cause some difficulties in pigment production via chloride route. The Mg and Ca sourced from ilmenite lattice and apatite inclusions, respectively, can affect the precipitation process. So, it is predicted that Qara-aghaj ilmenite concentrate will be suitable for sulfate route, but it is necessary to investigate comprehensively.

Applied mineralogical characterization of ilmenite from Kahnuj placer deposit , Southern Iran

Kahnuj placer deposit contains ilmenite and magnetite as the main valuable minerals. Microscopic ... more Kahnuj placer deposit contains ilmenite and magnetite as the main valuable minerals. Microscopic and microprobe analyses show that ilmenite occurs in two forms as individual grains and exsolved lamellae within magnetite. Exsolved lamellae of hematite, sphene of different shape and rare rutile and zircon are found as inclusions in ilmenite. According to microprobe analysis data the TiO2 content of ilmenite (52.1 wt%) with small amounts of Mg and Mn and is very close to the theoretical one (52.6 wt%). Based on the XRF analysis, the maximum content of TiO2 in the purified ilmenite concentrate without any gangue minerals is obtained at 44 wt%. The low grade of TiO2 in the purified ilmenite is attributed to the presence of sphene and hematite inside ilmenite. The presence of sphene as a source of Ca and Si can negatively affect the quality of ilmenite concentrate and the further product titanium dioxide manufactured via chloride and sulphate routes. It is found that the magnetite from th...

Evaluation of pyrolusite flotation behavior using a cationic collector

Floatability of pyrolusite from an Iranian low grade manganese ore (13.6% MnO) containing calcite... more Floatability of pyrolusite from an Iranian low grade manganese ore (13.6% MnO) containing calcite as the main gangue mineral was investigated with Armac C as a cationic collector. In the single mineral flotation experiments, the maximum recovery of pyrolusite is obtained at 82.2%, using 2000 g/t Armac C at a pH of 9, while at these conditions the flotation recovery of calcite is almost 78%. Quebracho and sodium hexa methaphosphate (SH) depress both minerals strongly at a wide range of dosages while low dosages of sodium silicate and zinc oxide depress the calcite mineral more than pyrolusite. Ca2+ ions affect the flotation recovery of pyrolusite negatively. The effective depression of calcite occurs using 1000–2000 g/t sodium silicate. However, in the ore flotation experiments, the favorable selective flotation of pyrolusite does not occur but the optimal concentrate containing 21.5% MnO with 51% recovery is obtained using 2000 g/t collector and 1000 g/t sodium silicate. A concentra...

Chemical and mineralogical composition of ilmenite: Effects on physical and surface properties

Some physical and chemical properties of three ilmenite samples: IL-F (purchased from the mineral... more Some physical and chemical properties of three ilmenite samples: IL-F (purchased from the mineral dealership of A and F Krantz), IL-Q (Qara-aghaj deposit, Iran) and IL-K (Kahnuj deposit, Iran) were studied. The substitution of different amounts of Mg, Mn and V in the crystal structure of ilmenite was identified by microprobe analysis. Different amounts of hemoilmenite exsolution were observed inside all three ilmenite samples using SEM, electron microprobe and X-ray diffraction analysis. Using these analytical techniques, titanite phase was found inside the IL-K ilmenite. The XPS analysis indicated that the contents of Fe3+ are 5.66, 5.33 and 3.72% for IL-F, IL-Q and IL-K, respectively which are in good agreement with the amounts of hemoilmenite exsolution. Mg and V contents in the ilmenite crystal structure have a good negative correlation with lattice constants (LC), unit cell volume, crystallinity index, specific gravity and IEP, while the Mn content correlates positively with th...

Characterization and beneficiation of iranian low-grade manganese ore

The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusi... more The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3-4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 microns. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with -500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained ...

Angular dependence of ArF laser induced self-aligning microstructures on CR39

High quality regular surface rippling is observed for certain UV exposure conditions. Self-aligni... more High quality regular surface rippling is observed for certain UV exposure conditions. Self-aligning microstructures are created on poly allyl diglycol carbonate samples using UV laser at 193 nm for a range of incidence angles. The treated area is notably enlarged at higher incidence angles while the fluence threshold and corresponding UV dose required to achieve those periodic structures is significantly reduced. Despite the spatial period remains nearly invariant versus dose and fluence at a certain incident angle; however the self-aligning orientation always aligns along the P-polarization component of the incident beam.

IMPACTS OF SURFACE MODİFİCATİON ON ISOTHERM AND KİNETİCS OF COLLECTOR ADSORPTİON Omid

Surface dissolution is one of the surface modification methods which has been used prior to the f... more Surface dissolution is one of the surface modification methods which has been used prior to the flotation process to improve minerals flotability. In this study, the effect of surface dissolution has been investigated on isotherm and adsorption kinetics of sodium oleate as a collector on the surface of ilmenite, olivine-pyroxene and quartz. Conditioning time, pH, temperature, activation energy, specific area and contact angle were the parameters which were studied before and after surface dissolution. The results of adsorption isotherms of Langmuir, Freundlich and Temkin, and kinetic models of elovich, lagergerin and pseudo second-order showed that the collector adsorption on the minerals surfaces can be well described by Langmuir isotherm and pseudo second-order kinetic model. The collector adsorption on the minerals surfaces is occurred mainly based on adsorption capacity from solution and single layer. Results indicated that the surface dissolution increases of the collector adso...

Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite

In the cationic flotation of pyrolusite using dodecyl ammine (DDA), the depressive effect of sodi... more In the cationic flotation of pyrolusite using dodecyl ammine (DDA), the depressive effect of sodium carbonate and calcium chloride on the calcite mineral was investigated systematically through flotation experiments, FTIR analysis, contact angle measurements and zeta potential tests. The microflotation experiments showed that both depressant agents decrease the flotation recovery of calcite significantly. In addition, sodium carbonate acts as activator agent for pyrolusite, and increases its floatability. The flotation experiments and contact angle measurements indicated that the selective depression effect of sodium carbonate on the calcite mineral is more than that of calcium chloride. As evidenced by zeta potential and FT-IR analysis, sodium carbonate decreases the negative charges on the surface of calcite mineral and subsequently reduces the adsorption of DDA collector through electrostatic forces. At a pH of 7.5, using 2000 g/t DDA and 1500 g/t sodium carbonate, a pyrolusite c...

Applied mineralogical characterization of ilmenite in Iranian placer deposit

Kahnouj titanium ore located in the south of iran is a placer deposit with ilmenite and magnetite... more Kahnouj titanium ore located in the south of iran is a placer deposit with ilmenite and magnetite as the main valuable minerals. There isn’t any ilmenite alteration in Kahnouj deposit; and it exhibits Ferrian to hydrated ilmenite. Microscopic and microprobe analysis show that ilmenite occurs in two forms including ilmenite grains and exsolved lamellae of ilmenite inside magnetite forming ilmenomagnetite texture. It was found that there are some exsolved lamellae of hematite and sphene with thickness finer than 10 mm inside ilmenite. The other heavy minerals which were mainly found inside ilmenite are the negligible amount of rutile and zircone. The microprobe analysis indicate that FeO content of ilmenite crystal lattice is lower than its theoretical amount because of Mg 2+ and Mn 2+ substitution for Fe 2+ while TiO 2 content (52.06%) is very close to the theoretical content (52.6%). The maximum content of TiO 2 in the purified ilmenite without any gangue minerals is obtained 44%. T...

Surface modification of ilmenite and its accompanied gangue minerals by thermal pretreatment: Application in flotation process

Transactions of Nonferrous Metals Society of China

Effect of surface dissolution on kinetic parameters in flotation of ilmenite from different gangue minerals

Transactions of Nonferrous Metals Society of China

The effect of microwave’s location in a comminution circuit on improving grindability of a porphyry copper deposit

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects