Search for: iron-ores
Article Canadian Metallurgical Quarterly ; Volume 59, Issue 2 , 2020 , Pages 242-250 ; Halali, M ; Hejazi, R ; Saghaeian, M ; Sheikh Zadeh, V ; Sharif University of Technology
Taylor and Francis Ltd 2020
Particle size and shape of iron ore concentrate are effective parameters in the production of quality green pellets. In this research, the effect of particle morphology on green pellet quality was studied. It was concluded that pellet quality improved with increasing specific surface area. Drop number and green compression strength of pellets ground by HPGR were found to be superior over those ground in the ball mill. The chief reasons were related to particle shape and the fraction of fine particles. Smaller particle size results in a higher order of bonding between particles and therefore the formation of a stronger system. Also, the rougher and less circular shape of particles resulted in...
Mathematical modeling of the reaction in an iron ore pellet using a mixture of hydrogen, water vapor, carbon monoxide and carbon dioxide: An isothermal study, Article Advanced Powder Technology ; Volume 17, Issue 3 , 2006 , Pages 277-295 ; 09218831 (ISSN) ; Motamed Hashemi, M. Y ; Saboohi, Y ; Sharif University of Technology
VSP BV 2006
A mathematical time-dependent and isothermal model based on the grain model has been developed to simulate the kinetic and thermal behaviors of a porous iron oxide pellet undergoing chemical reactions with a mixture of hydrogen, carbon monoxide, carbon dioxide and water vapor. Its novelty consists in fact that it can deal with a multi-species reducing gas and oxide pellet. In spite of previous models in which the pure reductant was applied as reducing gas, this model can indicate an actual view of pellet reduction including the effects of reducing gas utility and reducing gas ratio. A finite volume fully implicit technique was applied for solving the governing equations. The model has been...
Kinetics of Incomplete Reduction of Hematite Low Grade Iron Ore to Magnetite Using Mixture of CO and CO2, M.Sc. Thesis Sharif University of Technology ; Halali, Mohammad
In this research the process of incomplete reduction of hematite low iron ore to magnetite in a fluidized bed reactor was investigated. Temperature, composition of reduction air, particle size, and stay time were investigated as effective parameters. In this way, temperatures of 560, 580, 600, 620 and 640 degrees of centigrade, input air with flows of 1.2, 1.3 and 1.4 l/s, particles size of 425-850 µm, 850 µm-1.4 mm, and 1.4-2 mm, stay times of 4, 8, 12, 16, and 20 min were used in this research. The reduced specimens were analyzed by XRD and chemical analysis. The results illustrated that increase of temperature, decrease of input air flow, decrease of particles size, and increase of stay...
Article Special Topics and Reviews in Porous Media ; Volume 4, Issue 4 , 2013 , Pages 299-313 ; 21514798 (ISSN) ; Emami, M. D ; Panjehpour, M ; Sohrabi, S ; Sharif University of Technology
A twodimensional model, based on conservation of mass, momentum and energy equations, is represented in this paper in which the coke combustion process, for iron ore sintering in a packed bed, is simulated numerically. The aforementioned packed bed consists of iron ore, coke, limestone and moisture. The main objective of iron ore sintering is producing resistant agglomerates which can be used in blast furnaces. For this purpose, the sinter mixture is partially melted in high temperature and finally molten is allowed to cool. The molten production and subsequently, the solidification process are totally dependent on composition and components of mixture. Changes in bed porosity, caused by...
Article Computational Materials Science ; Volume 44, Issue 2 , December , 2008 , Pages 296-302 ; 09270256 (ISSN) ; Ferdowsi, A ; Payab, H ; Sharif University of Technology
A mathematical model is developed for induration of the iron-ore pellets in an industrial-scale plant based on the laws of mass, heat and momentum transfer. Physicochemical processes occurring during the induration of pellets such as drying of moisture, calcination of limestone and coke-magnetite reaction are considered to evaluate the gradient of temperature within the pellets. Differential equations describing transport phenomena in a grate bed are simultaneously solved by dividing the space in both x- and z- directions and numerically solving the phenomenological equations. A kinetic model is used for estimation of the change of the strength of the pellets due to firing. The model...
HPGR effect on the particle size and shape of iron ore pellet feed using response surface methodology, Article Transactions of the Institutions of Mining and Metallurgy, Section C: Mineral Processing and Extractive Metallurgy ; 2017 , Pages 1-9 ; 03719553 (ISSN) ; Halali, M ; Hejazi, R ; Saghaeian, M ; Sharif University of Technology
Taylor and Francis Ltd 2017
In this study the effect of HPGR operational parameters on the dimensional properties of pellet feed was examined and optimized using factorial methodology. The operational parameters considered include feed moisture, specific pressure and roll speed. For this study, size and shape of particles with Blaine number in the range 1800–2200 cm2 g−1 was thoroughly investigated. It was deduced that increasing the specific pressure and decreasing the roll speed would result in reduction of D80 but would increase the Blaine number. The circularity, aspect ratio and roughness descriptors of the particles were measured by SEM micrographs and image analysis software. It was observed that particles...
HPGR effect on the particle size and shape of iron ore pellet feed using response surface methodology, Article Mineral Processing and Extractive Metallurgy: Transactions of the Institute of Mining and Metallurgy ; Volume 127, Issue 1 , 2018 , Pages 40-48 ; 25726641 (ISSN) ; Halali, M ; Hejazi, R ; Saghaeian, M ; Sharif University of Technology
Taylor and Francis Ltd 2018
In this study the effect of HPGR operational parameters on the dimensional properties of pellet feed was examined and optimized using factorial methodology. The operational parameters considered include feed moisture, specific pressure and roll speed. For this study, size and shape of particles with Blaine number in the range 1800–2200 cm2g−1 was thoroughly investigated. It was deduced that increasing the specific pressure and decreasing the roll speed would result in reduction of D80 but would increase the Blaine number. The circularity, aspect ratio and roughness descriptors of the particles were measured by SEM micrographs and image analysis software. It was observed that particles tended...
Article Materials ; Volume 14, Issue 24 , 2021 ; 19961944 (ISSN) ; Niknahad, N ; Iljana, M ; Fabritius, T ; Sharif University of Technology
A clean energy revolution is occurring across the world. As iron and steelmaking have a tremendous impact on the amount of CO2 emissions, there is an increasing attraction towards improving the green footprint of iron and steel production. Among reducing agents, hydrogen has shown a great potential to be replaced with fossil fuels and to decarbonize the steelmaking processes. Although hydrogen is in great supply on earth, extracting pure H2 from its compound is costly. Therefore, it is crucial to calculate the partial pressure of H2 with the aid of reduction reaction kinetics to limit the costs. This review summarizes the studies of critical parameters to determine the kinetics of reduction....
Article Environmental Engineering Science ; Volume 28, Issue 5 , 2011 , Pages 333-339 ; 10928758 (ISSN) ; Torkian, A ; Sharif University of Technology
Industrial air pollution from point and nonpoint sources of steel complexes has drawn increasingly more public attention in the past decades. Previous research efforts have been more concentrated on point sources of particulate emissions from these complexes. However, wind-induced particulate emissions from iron ore storage piles not only result in ambient air pollution but also increase economic adverse effects to the industry by loss of process raw materials. Experiments were conducted to assess the impact of wind speed and humidity on particulate emission rates from iron ore storage piles. A wind-generating system and specific iron ore, experimental piles (L:W:H of 30:11.5:5 cm) were...
Ph.D. Dissertation Sharif University of Technology ; Halali, Mohammad
In this study, the effect of iron ore concentrate morphology on green pellet quality was studied. In order to produce concentrate with different morphology using ball mill, ball charge (20-40 %V), grinding time (30-50 min) and ball distribution (15 mm, 23 mm, 15+23 mm) was varied. It was deduced that increasing grinding time and ball charge would result in reduction of D80 but would increase Blaine number. The interaction parameters of ball distribution-grinding time and ball distribution-ball charge had significant effect on Blaine and D80. It was also observed that mixed level of ball distribution would lead to higher Blaine numbers. The equation obtained by CCD was verified by the...
The Feasibility of Decreasing FeO Index in the Final Product of Pellet Factory of Golgohar Mining and Industrial Company, M.Sc. Thesis Sharif University of Technology ; Askari, Masoud ; Yoozbashizadeh, Hossein
As one of the most important agglomeration methods, pelletizing has a very important place in the iron and steel production chain. In the present study, the feasibility of improving FeO index in the final product of Pellet Factory No.1 of GolEGohar Mining and Industrial Company was investigated. The remaining FeO in the iron oxide pellet represents the amount of Magnetite that was not oxidized during the pelletizing process. The remaining FeO in the primary Magnetite is a disturbing structure for the direct reduction process and will cause a decrease in the compressive strength of the pellet (CCS) and as a result it will be crushed. Therefore, the percentage of the remaining FeO in the...
Article ICONN 2010 - Proceedings of the 2010 International Conference on Nanoscience and Nanotechnology, 22 February 2010 through 26 February 2010, Sydney, NSW ; 2010 , Pages 91-93 ; 9781424452620 (ISBN) ; Ghane Motlagh, B ; Ghane Golmohamadi, F ; Ghane Motlagh, R ; Rouhani, S ; Sharif University of Technology
We report the rheological properties of ferro-fluid (FF) containing iron oxide nano-particles. At first, a FF was synthesized by using chemical co-precipitaton. The microstructure study using SEM revealed that the FF contained nano-particles with the mean particle size of 35nm. The XRD study revealed that we have well crystallized structures of magnetite; they appeared to be approximately single crystalline structures. The rheological results proved that the FF has non Newtonian behavior, it is a shear thinning fluid in all magnetic fields, Moreover, the magnetic field increases the viscosity in a definite shear rate due to the nano-particles agglomerations and formation of chain-like...
Process optimization and kinetics for leaching of cerium, lanthanum and neodymium elements from iron ore waste's apatite by nitric acid, Article Transactions of Nonferrous Metals Society of China (English Edition) ; Volume 27, Issue 2 , 2017 , Pages 420-428 ; 10036326 (ISSN) ; Yoozbashizadeh, H ; Sharif University of Technology
Nonferrous Metals Society of China 2017
The leaching of rare earth elements (REEs) including cerium, lanthanum and neodymium from apatite concentrate obtained from iron ore wastes by nitric acid was studied. The effects of nitric acid concentration, solid to liquid ratio and leaching time on the recoveries of Ce, La and Nd were investigated using response surface methodology. The results showed that the acid concentration and solid to liquid ratio have significant effect on the leaching recoveries while the time has a little effect. The maximum REE leaching recoveries of 66.1%, 56.8% and 51.7% for Ce, La and Nd, respectively were achieved at the optimum leaching condition with 18% nitric acid concentration, 0.06 solid to liquid...
A non-isothermal, transient model of a non-catalytic reaction in a packed bed with a multi-component high-temperature gas mixture, Article 3rd M.I.T. Conference on Computational Fluid and Solid Mechanics, Boston, MA, 14 June 2005 through 17 June 2005 ; 2005 , Pages 1023-1025 ; 0080444814 (ISBN); 9780080444819 (ISBN) ; Saboohi, Y ; Sharif University of Technology
A mathematical model has been developed to simulate heterogeneous reactions with a complex set of physicochemical and thermal phenomena in a packed bed. These include the chemical reaction itself, the transport of gaseous species in the pores, the generation or consumption of heat by the reactions, and the transport of heat in the porous domain. Solution of complicated sets of governing equations is based upon the concept of a finite volume fully implicit approach. The model has then been applied to analyze the reduction of a hematite pellet in a moving packed bed reactor. © 2005 Elsevier Ltd
Article Journal of Experimental Nanoscience ; Volume 6, Issue 3 , 2011 , Pages 217-225 ; 17458080 (ISSN) ; Bagherzadeh, M ; Morsali, A ; Sharif University of Technology
In this study, α -Fe2O3 (hematite) nanoparticles were synthesised by a sonochemical method. The influence of different factors such as chemical composition of the precursors, atmosphere of the reactions and type of the sonicator on the chemical formula, crystallinity, morphology and size of the obtained products were investigated. Powder X-ray diffraction, scanning electron microscopy and IR spectroscopy, were used to characterise the nanostructures. The catalytic tests were performed in the reaction of methyl phenyl sulphide oxidation. The results exhibit the good catalytic performance of the as-prepared α -Fe2O3 nanoparticles
Multiphysics flow modeling and in vitro toxicity of iron oxide nanoparticles coated with poly(vinyl alcohol), Article Journal of Physical Chemistry C ; Volume 113, Issue 6 , 2009 , Pages 2322-2331 ; 19327447 (ISSN) ; Shokrgozar, M. A ; Simchi, A ; Imani, M ; Milani, A. S ; Stroeve, P ; Vali, H ; Häfeli, U. O ; Bonakdar, S ; Sharif University of Technology
This study investigated the behavior of ferrofluids containing superparamagnetic iron oxide nanoparticles (SPION) of various compositions for potential applications in drug delivery and imaging. To ensure biocompatibility, the interaction of these SPION with two cell lines (adhesive and suspended) was also investigated using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) assay. The cell lines studied were primary mouse connective tissue cells (adhesive) and human leukemia cells (suspended). SPION were synthesized with a co-precipitation method under different stirring rates and NaOH molarities. The SPION demonstrated a range of magnetic saturations due to their...
Optimal design and characterization of superparamagnetic iron oxide nanoparticles coated with polyvinyl alcohol for targeted delivery and imaging, Article Journal of Physical Chemistry B ; Volume 112, Issue 46 , 2008 , Pages 14470-14481 ; 15206106 (ISSN) ; Simchi, A ; Imani, M ; Milani, A. S ; Stroeve, P ; Sharif University of Technology
American Chemical Society 2008
Superparamagnetic iron oxide nanoparticles (SPION) with narrow size distribution and stabilized by polyvinyl alcohol (PVA) were synthesized. The particles were prepared by a coprecipitation technique using ferric and ferrous salts with a molar Fe3+/Fe2+ ratio of 2. Using a design of experiments (DOE) approach, the effect of different synthesis parameters (stirring rate and base molarity) on the structure, morphology, saturation magnetization, purity, size, and size distribution of the synthesized magnetite nanoparticles was studied by various analysis techniques including X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) with differential scanning calorimetry (DSC)...