• Boron Removal from Silicon Melt by gas Blowing Technique 

      Hoseinpur Kermani, Arman; Andersson, Stefan; Müller, Michael; Tang, Kai; Safarian, Jafar (Peer reviewed; Journal article, 2022)
      Due to the detrimental effects of boron (B) on the efficiency of silicon (Si) photovoltaic cells, complete boron removal from Si is necessary to produce solar grade Si (SoG–Si, with a maximum limit of 0.1 ppmw boron). Gas ...
    • Combined silicon refining for boron removal and Si-Kerf recycling using K2O-CaO-SiO2 slags 

      Zhu, Mengyi; Wu, Guixuan; Tang, Kai; Müller, Michael; Safarian, Jafar (Peer reviewed; Journal article, 2024)
      It is crucial for the photovoltaic (PV) industry to establish a circular materials flow for more sustainable solar silicon production. In the present work, a series of K2O-SiO2 and K2O-CaO-SiO2 slags were examined for the ...
    • Combined silicon refining for boron removal and Si-Kerf recycling using K2O-CaO-SiO2 slags 

      Zhu, Mengyi; Wu, Guixuan; Tang, Kai; Müller, Michael; Safarian, Jafar (Peer reviewed; Journal article, 2024)
      It is crucial for the photovoltaic (PV) industry to establish a circular materials flow for more sustainable solar silicon production. In the present work, a series of K2O-SiO2 and K2O-CaO-SiO2 slags were examined for the ...
    • Effects of La2O3 Addition into CaO-SiO2 Slag: Structural Evolution and Impurity Separation from Si-Sn Alloy 

      Zhu, Mengyi; Wu, Guixuan; Azarov, Alexander; Monakhov, Eduard; Tang, Kai; Müller, Michael; Safarian, Jafar (Peer reviewed; Journal article, 2021)
      Boron (B) and phosphorus (P) are the most problematic impurities to be removed in the production of solar-grade silicon by the metallurgical process. In this work, the distribution of B and P between CaO-(La2O3)-SiO2 slags ...
    • Evaluating the Reaction Kinetics on the H2 Reduction of a Manganese Ore at Elevated Temperatures 

      Sarkar, Alok; Schanche, Trygve Lindahl; Wallin, Bogg Maria Elisabeth; Safarian, Jafar (Peer reviewed; Journal article, 2024)
      This study investigates the hydrogen reduction of Nchwaning manganese ore at elevated temperatures to enhance understanding of reaction kinetics and optimize industrial applications. Experimental investigations were conducted ...
    • High temperature interaction between Si–B alloys and Si3N4 

      Jiao, Jian Meng; Tang, Kai; Safarian, Jafar; Grorud, Bettina; Sellevoll, Kathrine; Tangstad, Merete (Peer reviewed; Journal article, 2021)
      Si3N4 is a candidate crucible material for Si–B alloys in high temperature thermal energy storage system. In this regard, the phase formation in the Si–B alloys and the interaction between the alloys and Si3N4 were ...
    • Impurity removal from Si by Si-Ca-Mg ternary alloying-leaching system 

      Zhu, Mengyi; Wan, Di; Tang, Kai; Safarian, Jafar (Peer reviewed; Journal article, 2020)
      In this work, Si-Ca-Mg alloys were made with different compositions and solidification conditions to investigate the impurity segregation and separation performance from Si, especially for the crucial P impurity at several ...
    • 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 ...
    • Magnesiothermic Reduction of Natural Quartz 

      Rasouli, Azam; Herstad, Karl Edvin; Safarian, Jafar; Tranell, Gabriella (Peer reviewed; Journal article, 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 (Journal article; Peer reviewed, 2023)
      undamental 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 ...
    • 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 ...
    • 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 ...
    • Phosphorus separation from metallurgical-grade silicon by magnesium alloying and acid leaching 

      Zhu, Mengyi; Azarov, Alexander; Monakhov, Eduard; Tang, Kai; Safarian, Jafar (Peer reviewed; Journal article, 2020)
      In this paper, the separation of phosphorus from metallurgical-grade silicon was investigated based on an Mg alloying and HCl leaching approach. Experimental results show that P concentration was reduced from initial 15.1 ...
    • Rheological properties of Al2O3–CaO–SiO2 slags 

      Tang, Kai; Eijk, Casper van der; Gouttebroze, Sylvain; Du, Qiang; Safarian, Jafar; Tranell, Gabriella (Peer reviewed; Journal article, 2022)
      The Al2O3–CaO–SiO2 ternary is a basic oxide system relevant for the Pedersen alumina production process and for aluminothermic silicon production with low environmental impact using secondary aluminium and silica raw ...
    • Selective Vacuum Evaporation by the Control of the Chemistry of Gas Phase in Vacuum Refining of Si 

      Hoseinpur Kermani, Arman; Andersson, Stefan; Tang, Kai; Safarian, Jafar (Peer reviewed; Journal article, 2021)
      ( Engelsk ) The evaporation of P from liquid Si under vacuum and reduced pressures of H2, He, and Ar was studied to evaluate the feasibility of effective P removal with insignificant Si loss. It was found that the introduction ...
    • Synthesis and Characterization of 12CaO·7Al2O3 Slags: The Effects of Impurities and Atmospheres on the Phase Relations 

      Azof, Fabian Imanasa; Tang, Kai; You, Jinglin; Safarian, Jafar (Peer reviewed; Journal article, 2020)
      Synthesis of crystalline slags of 12CaO·7Al2O3 phase from the corresponding melt compositions in different atmospheric conditions and different purities is investigated. Observations using a thermogravimetry coupled with ...
    • Toward the recovery of solar silicon from end-of-life PVs by vacuum refining 

      Hoseinpur Kermani, Arman; Tang, Kai; Ulyashin, Alexander; Palitzch, Wolfram; Safarian, Jafar (Peer reviewed; Journal article, 2023)
      Considering the boom of Si solar cell installation, it is necessary to establish a process for recycling of Si from End-of-life photovoltaics (PVs). Silicon in the PVs is synthetically doped and coated by various elements ...