Blar i NTNU Open på forfatter "Safarian, Jafar"
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Isothermal Hydrogen Reduction of a Lime-Added Bauxite Residue Agglomerate at Elevated Temperatures for Iron and Alumina Recovery
Olivia Bogen, Skibelid; Ose Velle, Sander; vollan, Frida; Eijk, Casper van der; Hoseinpur Kermani, Arman; Safarian, Jafar (Peer reviewed; Journal article, 2022)The hydrogen reduction of bauxite residue lime pellets at elevated temperatures was carried out to recover iron and alumina from the bauxite residue in a new process route. Prior to the H2 reduction, oxide pellets were ... -
Kinetic study of vacuum evaporation of elements from ternary melts; case of dilute solution of P in Si-Al melts
Hoseinpur Kermani, Arman; Tang, Kai; Safarian, Jafar (Journal article; Peer reviewed, 2019)This research is devoted to study phosphorus removal from Si-Al alloys by vacuum refining of the ternary system of dilute solutions of P in Si-20 wt%Al. The experiments were carried out in an induction furnace and after ... -
Kinetics of Magnesiothermic Reduction of Natural Quartz
Rasouli, Azam; Tsoutsouva, Maria; Safarian, Jafar; Tranell, Gabriella (Peer reviewed; Journal article, 2022)In this work, the kinetics of natural quartz reduction by Mg to produce either Si or Mg2Si was studied through quantitative phase analysis. Reduction reaction experiments were performed at various temperatures, reaction ... -
Kinetics of the leaching of alumina-containing slag for alumina recovery
Azof, Fabian Imanasa; Kolbeinsen, Leiv; Safarian, Jafar (Chapter, 2019)The leaching kinetics of an alumina-containing slag produced from the smelting-reduction of low-grade bauxite, which contained a significant amount of iron and low levels of SiO2 and TiO2, is studied. The leaching rates ... -
Kinetics Study on the Hydrogen Reduction of Bauxite Residue-Calcite Sintered Pellets at Elevated Temperature
Kar, Manish Kumar; Eijk, Casper van der; Safarian, Jafar (Peer reviewed; Journal article, 2023)In this study, the isothermal reduction of bauxite residue-calcite sintered pellets by hydrogen at elevated temperatures and different gas flow rates was investigated. A thermogravimetric technique was applied to study the ... -
Leaching and Precipitation Experiments Related to the Pedersen Process
Nedkvitne, Eirik Nøst (Master thesis, 2019)Store mengder avfall rødslam generes fra produksjon av metallurgisk aluminiumoksid via den nåværende kommersielle Bayer prosessen. Deponering av avfallet byr på miljøutfordringer. Alternativt kan aluminiumoksid produseres ... -
Leaching characteristics and mechanism of the synthetic calcium-aluminate slags for alumina recovery
Azof, Fabian Imanasa; Yang, Yongxiang; Panias, Dimitrios; Kolbeinsen, Leiv; Safarian, Jafar (Journal article; Peer reviewed, 2019)The leaching characteristics and mechanism of synthetic CaO-Al2O3 slags in alkaline solution at atmospheric pressure have been studied. The purpose of the study is to have a better understanding of the leaching part of the ... -
Leaching kinetics and mechanism of slag produced from smelting-reduction of bauxite for alumina recovery
Azof, Fabian Imanasa; Safarian, Jafar (Peer reviewed; Journal article, 2020)In the present study, we investigate the kinetics and mechanism of the leaching of calcium aluminate slag in Na2CO3 solution for alumina recovery. The slag consists of leachable phases, e.g., 12CaO·7Al2O3, CaO·Al2O3, ... -
Leaching of Hydrogen Pre-Reduced Mn ore to Produce MnO2
Shakya, Utsav; Knive, Haldor Andersen (Bachelor thesis, 2023)HAlMan project team har som mål å utvikle en bærekraftig metode for produksjon av mangandioksid (MnO2). De jobber også med produksjon av manganholdige legeringer for stål og aluminium i tillegg til å utforske ekstraksjon ... -
Magnesiothermic Reduction of Natural Quartz
Rasouli, Azam; Herstad, Karl Edvin; Safarian, Jafar; Tranell, Gabriella (Journal article; Peer reviewed, 2022)In the current work, the metallothermic reduction of natural quartz by magnesium has been studied at 1373 K under different reaction conditions, i.e. quartz type, quartz particle size, Mg:SiO2 mole ratio and reaction time. ... -
Magnesiothermic Reduction of Silica: A Machine Learning Study
Tang, Kai; Rasouli, Azam; Safarian, Jafar; Ma, Xiang; Tranell, Maria Gabriella (Peer reviewed; Journal article, 2023)Fundamental studies have been carried out experimentally and theoretically on the magnesiothermic reduction of silica with different Mg/SiO2 molar ratios (1–4) in the temperature range of 1073 to 1373 K with different ... -
Manganese and Aluminium Recovery from Ferromanganese Slag and Al White Dross by a High Temperature Smelting-Reduction Process
Kudyba, Artur; Safarian, Jafar (Peer reviewed; Journal article, 2022)The recovery of Mn and Al from two industrial waste of ferromanganese and aluminum production processes was investigated via implementing a high temperature smelting—aluminothermic reduction process. The experiments were ... -
Mechanisms and Kinetics of Boron Removal from Silicon by Humidified Hydrogen
Safarian, Jafar; Tang, Kai; Olsen, Jan Erik; Andersson, Stefan; Tranell, Gabriella; Hildal, Kjetil (Journal article; Peer reviewed, 2016)The removal of boron from silicon by top blowing of humidified hydrogen has been studied in the present work through experimental work, thermodynamic calculations, computational fluid dynamic modeling, and quantum chemistry ... -
Mechanisms of graphite crucible degradation in contact with Si–Al melts at high temperatures and vacuum conditions
Hoseinpur Kermani, Arman; Safarian, Jafar (Journal article; Peer reviewed, 2019)Graphite is a common refractory material for processing high purity silicon; however, it cannot be applied for holding Si–Al melts at high temperatures due to significant melt infiltration into the crucible. This research ... -
Microscopic Study of Carbon Surfaces Interacting with High Carbon Ferromanganese Slag
Safarian, Jafar; Kolbeinsen, Leiv (Journal article; Peer reviewed, 2015)The interaction of carbon materials with molten slags occurs in many pyro-metallurgical processes. In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic reduction of MnO-containing ... -
Modeling Viscosity of High Titania Slag
Hu, Kai; Tang, Kai; Lv, Xuewei; Safarian, Jafar; Yan, Zhiming; Song, Bing (Peer reviewed; Journal article, 2020)TiO2-FeO-Ti2O3 slag system is the dominant system for industrial high-titania slag production. In the present work, viscosities of TiO2-FeO and TiO2-FeO-Ti2O3 systems were experimentally determined using the concentric ... -
New Insights into Silicon Purification by AlloyingLeaching Refining: A Comparative Study of MgSi, CaSi, and CaMgSi Systems
Zhu, Mengyi; Shengying, Yue; Tang, Kai; Safarian, Jafar (Peer reviewed; Journal article, 2020)In the present work, a comparative study of the silicon alloying–leaching purification process was carried out on the recently developed Mg–Si system, the Ca–Si system, and the novel ternary Ca–Mg–Si system. Insights were ... -
On the Direct Reduction Phenomena of Bauxite Ore Using H2 Gas in a Fixed Bed Reactor
Lazou, Adamantia; Eijk, Casper van der; Balomenos, Efthymios; Kolbeinsen, Leiv; Safarian, Jafar (Peer reviewed; Journal article, 2020)The Bayer Process is the dominant industrial method to produce alumina from bauxite ore. Due to the generation of large amounts of Bauxite Residue (red mud), an alternative method, called the Pedersen Process, is of our ... -
On the phosphorus evaporation from liquid silicon by Knudsen effusion mass spectrometry
Hoseinpur Kermani, Arman; Sergeev, Dmitry; Müller, Michael; Safarian, Jafar (Peer reviewed; Journal article, 2022)Silicon refining for solar applications is intensively on demand, and removal of phosphorus from Si is one of the most challenging steps. Evaporation of P from liquid Si in a vacuum refining process is the most efficient ... -
P removal from Si by Si-Ca-Al alloying-leaching refining: Effect of Al and the CaAl2Si2 phase
Zhu, Mengyi; Yue, Shengying; Wu, Guixuan; Tang, Kai; Xu, Yijiang; Safarian, Jafar (Peer reviewed; Journal article, 2021)Phosphorus (P) is a critical impurity in metallurgical-grade Si that needed to be removed for solar-grade Si production. The Si-Ca-Al-P system is one of the most crucial alloy systems for Si refining, where P can be separated ...