• A study of anode baking gas composition 

      Aarhaug, Thor Anders; Brandvik, Trond; Kjos, Ole Sigmund; Gaertner, Heiko; Ratvik, Arne Petter (Journal article; Peer reviewed, 2018)
      A method has been developed to measure gas composition inside the pit in open anode baking furnaces. The gas composition can be used to understand attack on and degradation of the refractory lining, baking behavior and ...
    • Cathode Wear in Electrowinning of Aluminum Investigated by a Laboratory Test Cell 

      Wang, Zhaohui; Nobakhtghalati, Saeid; Støre, Anne; Solheim, Asbjørn; Tschöpe, Kati; Ratvik, Arne Petter; Grande, Tor (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2016)
      The lifetime of an aluminum electrolysis cell is mainly determined by the cathode wear, especially for high amperage cells utilizing graphitized carbon cathodes. The cathode wear mechanisms are, however, complex and still ...
    • Direct Method for Producing Scandium Metal and Scandium-Aluminium Intermetallic Compounds from the Oxides 

      Martinez, Ana Maria Cuellar; Osen, Karen Sende; Gudbrandsen, Henrik; Sommerseth, Camilla; Wang, Zhaohui; Darell, Ove (Journal article; Peer reviewed, 2018)
      The electrochemical de-oxidation process, also called FFC-Cambridge process, has been proposed previously to produce reactive metals and their alloys through reduction of their metal oxides. The process works by introducing ...
    • Evaluation of Gas Composition from Laboratory Scale Electrolysis Experiments with Anodes of Different Sulphur Content 

      Aarhaug, Thor Anders; Kjos, Ole Sigmund; Gudbrandsen, Henrik; Ferber, Alain Marc C; Ratvik, Arne Petter (Journal article; Peer reviewed, 2016)
      With the anticipated decrease in available anode raw materials, future anodes are expected to contain higher levels of impurities. Currently the implications of this are being investigated through evaluation of electrochemical ...
    • Formation of aluminium carbide in Hall-Héroult electrolysis cell environments 

      Novák, Bronislav; Ratvik, Arne Petter; Wang, Zhaohui; Grande, Tor (Journal article; Peer reviewed, 2018)
      The formation and dissolution of aluminium carbide under conditions similar to the chemical and electrochemical environments in the Hall-Héroult process were studied in laboratory cells, including cells with reversed ...
    • Impurity Elements in Raw Gas Ultra-Fines from Aluminium Electrolysis Cells 

      Gaertner, Heiko; Ratvik, Arne Petter; Aarhaug, Thor Anders (Peer reviewed; Journal article, 2012)
      The effect of alumina feeding and pot suction rate on the amount and composition of fine particles in raw gases has been investigated. Particle size distribution of ultra-fines (Di < 10 μm) were measured in real time and ...
    • Investigation of Sodium Sulfate Additions into Cryolite-Alumina Melts 

      Meirbekova, Rauan; Haarberg, Geir Martin; Aarhaug, Thor Anders; Sævarsdóttir, Gudrun A. (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2016)
      In the Hall-Héroult process, sulfur impurities may not only emit harmful gases but also reduce current efficiency. To better understand this process, the behaviour of sulfur compounds in a cryolite-alumina melt at 1253 K ...
    • Multi-scale Modelling of Titanium Diboride Degradation Using Crystal Elasticity Model and Density Functional Theory 

      Saai, Afaf; Wang, Zhaohui; Pezzotta, Micol; Friis, Jesper; Ratvik, Arne Petter; Vullum, Per Erik (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2018)
      Titanium diboride (TiB2) is regarded as the most promising material to be used as inert cathodes in the electrochemical reduction of alumina to aluminium metal. TiB2 is well known as a ceramic material with high strength ...
    • Online monitoring of aluminium primary production gas composition by use of Fourier-transform infrared spectroscopy 

      Aarhaug, Thor Anders; Ferber, Alain Marc C; Kjos, Ole Sigmund; Gaertner, Heiko (Journal article; Peer reviewed, 2014)
      Online monitoring of aluminium primary production raw gas is challenging due to the high concentration of HF in the presence of water. Tunable Diode Laser (TDL) analyzers retrofitted with sapphire optical windows allow for ...
    • Particulate emissions from electrolysis cells 

      Gaertner, Heiko; Ratvik, Arne Petter; Aarhaug, Thor Anders (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2011)
      In the dry cleaning of the exhaust gas from the aluminium cells impurities are accumulated in the finer fractions of secondary alumina from the dry scrubbers. The present work describes new methods for the determination ...
    • Perfluorocarbon Formation During Rare Earth Electrolysis 

      Osen, Karen Sende; Martinez, Ana Maria Cuellar; Gudbrandsen, Henrik; Støre, Anne; Sommerseth, Camilla; Kjos, Ole Sigmund; Aarhaug, Thor Anders; Gaertner, Heiko; Chamelot, Pierre; Gibilaro, Mathieu; Massot, Laurent (Journal article; Peer reviewed, 2018)
      A challenge during rare earth (RE) electrolysis is to avoid emissions of perfluorocarbon (PFC) green-house gases. The objective of this work was to study how to operate the RE electrolysis process with neither PFC formation ...
    • PFC evolution characteristics during aluminium and rare earth electrolysis 

      Kjos, Ole Sigmund; Solheim, Asbjørn; Aarhaug, Thor Anders; Osen, Karen Sende; Martinez, Ana Maria Cuellar; Sommerseth, Camilla; Gudbrandsen, Henrik; Støre, Anne; Gaertner, Heiko (Journal article; Peer reviewed, 2018)
    • Validation of Online Monitoring of PFC by QCL with FTIR Spectroscopy 

      Aarhaug, Thor Anders; Ferber, Alain Marc C; Gaertner, Heiko; Kolås, Steinar; Ryman, Sven Olof; Geiser, Peter (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2018)
      Monitoring of perfluorocarbon (PFC) evolution from aluminium smelting is gaining attention, not only because of their high greenhouse gas potentials but also due to process optimization purposes. Conventionally, PFC ...