• Alumina feeding and raft formation: Raft collection and process parameters 

      Gylver, Sindre Engzelius; Omdahl, Nina Helene; Prytz, Ann Kristin; Meyer, Astrid Johanne; Lossius, Lorentz Petter; Einarsrud, Kristian Etienne (Journal article; Peer reviewed, 2019)
      Alumina, alongside with electricity and carbon, is the raw material used for production of aluminium in the Hall-Héroult process. An efficient dissolution process is important to acquire stable conditions for the cell, ...
    • An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production 

      Jahrsengene, Gøril; Wells, Hannah C.; Sommerseth, Camilla; Ratvik, Arne Petter; Lossius, Lorentz Petter; Sizeland, Katie H.; Kappen, Peter; Svensson, Ann Mari; Haverkamp, Richard G. (Journal article; Peer reviewed, 2019)
      Lower-quality petroleum coke with higher levels of sulfur and metal impurities will have to be used for the manufacturing of anodes for aluminum production in the future. The sulfur and metallic impurities affect the anode ...
    • Bubble evolution and anode surface properties in aluminium electrolysis 

      Thorne, Rebecca Jayne; Sommerseth, Camilla; Ratvik, Arne Petter; Rørvik, Stein; Sandnes, Espen; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article, 2015)
      One significant contribution to the anodic potential during aluminum electrolysis is the formation of CO2 bubbles that screen the anode surface. This effect creates an additional ohmic resistance as well as an increased ...
    • Comparing Anodic Bubble Behavior of Anodes from Anisotropic and Isotropic Cokes in Laboratory Scale Aluminum Electrolysis Cells 

      Sommerseth, Camilla; Thorne, Rebecca Jayne; Ratvik, Arne Petter; Rørvik, Stein; Linga, Hogne; Lossius, Lorentz Petter; Svensson, Ann Mari (Journal article; Peer reviewed, 2019)
      During production of aluminum in Hall-Héroult cells, carbon anodes electrochemically oxidize to form mainly CO2. The CO2 bubbles block the anode working surface during growth and coalescence, leading to cell voltage loss ...
    • Correlation between coke type, microstructure and anodic reaction overpotential in aluminium electrolysis 

      Thorne, Rebecca Jayne; Sommerseth, Camilla; Ratvik, Arne Petter; Rørvik, Stein; Sandnes, Espen; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article; Peer reviewed, 2015)
      Although the anode process during aluminum electrolysis has a substantial overpotential that increases the energy demand and production cost of aluminum, properties of the coke that can influence the electrochemical ...
    • Effect of Coke Properties on the Bubble Formation at the Anodes During Aluminium Electrolysis in Laboratory Scale 

      Gebarowski, Wojciech; Ratvik, Arne Petter; Rørvik, Stein; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article, 2017)
      The anodic reaction of aluminium electrolysis cells leads to the formation of CO2 bubbles, which partly screen the anode surface and leads to an increase in the cell voltage. An advantage of these bubbles is that the ...
    • Electrochemical Behaviour of Carbon Anodes Produced with Different Mixing Temperatures and Baking Levels—A Laboratory Study 

      Sommerseth, Camilla; Thorne, Rebecca Jayne; Gebarowski, Wojciech; Ratvik, Arne Petter; Rørvik, Stein; Linga, Hogne; Lossius, Lorentz Petter; Svensson, Ann Mari (Chapter, 2019)
      Anodes fabricated from a single source coke were used for investigations of effect of porosity and surface roughness on the electrochemical performance in laboratory scale cells. In order to fabricate anodes differing in ...
    • Electrochemical Reactivity and Wetting Properties of Anodes Made from Anisotropic and Isotropic Cokes 

      Sommerseth, Camilla; Thorne, Rebecca Jayne; Ratvik, Arne Petter; Sandnes, Espen; Rørvik, Stein; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article, 2016)
      High quality anodes require stable raw materials. As the quality of the coke available for production of anodes is changing, future production will rely on cokes that are more isotropic with higher impurity levels than ...
    • Interfacial Boundary between Carbon Anodes and Molten Salt Electrolyte 

      Gebarowski, Wojciech; Sommerseth, Camilla; Ratvik, Arne Petter; Sandnes, Espen; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article, 2016)
      The properties of calcined petroleum cokes (CPC), used in the anodes in the Hall-Héroult process, are important for the electrochemical behaviour of the anodes. CPCs from different sources vary not only in impurity level ...
    • Reactivity of Coke in Relation to Sulfur Level and Microstructure 

      Jahrsengene, Gøril; Rørvik, Stein; Ratvik, Arne Petter; Lossius, Lorentz Petter; Haverkamp, Richard G.; Svensson, Ann Mari (Journal article; Peer reviewed, 2019)
      The quality of coke materials available for anodes for the aluminium industry is changing and industrial cokes with higher impurity levels are now introduced. The cokes in the anodes must meet specifications with respect ...
    • Spatial methods for characterising carbon anodes for aluminium production 

      Sommerseth, Camilla; Thorne, Rebecca Jayne; Rørvik, Stein; Sandnes, Espen; Ratvik, Arne Petter; Lossius, Lorentz Petter; Linga, Hogne; Svensson, Ann Mari (Journal article, 2015)
      Pilot test anodes were designed by Hydro Aluminium for laboratory studies using controlled blends of <2 mm aggregate from two single source cokes. Spa- tial and imaging methods were used to characterise anode surfaces with ...
    • The Effect of Production Parameters on the Performance of Carbon Anodes for Aluminium Production 

      Sommerseth, Camilla (Doctoral thesis at NTNU;2016:108, Doctoral thesis, 2016)
      Carbon anodes are essential when producing aluminium. Oxygen from dissolved aluminium oxide reacts electrochemically on the carbon anode forming CO2. The carbon anode is consumed during the process. The production of ...
    • The Effect of Varying Mixing Temperatures and Baking Level on the Quality of Pilot Scale Anodes - A Factorial Design Analysis 

      Sommerseth, Camilla; Thorne, Rebecca Jayne; Ratvik, Arne Petter; Sandnes, Espen; Linga, Hogne; Lossius, Lorentz Petter; Svensson, Ann Mari (Journal article; Peer reviewed, 2017)
      Identifying optimum anode baking level and mixing temperature are important when producing high quality anodes. The effect of varying mixing temperature and baking level were investigated in terms of the resulting apparent ...
    • Understanding Anode Overpotential 

      Thorne, Rebecca Jayne; Sommerseth, Camilla; Svensson, Ann Mari; Sandnes, Espen; Lossius, Lorentz Petter; Linga, Hogne; Ratvik, Arne Petter (Journal article, 2014)
      In aluminium electrolysis cells the anodic process is associated with a substantial overpotential. Industrial carbon anodes are produced from a blend of coke materials, but the effect of coke type on anodic overpotential ...
    • Vanadium Speciation in Petroleum Cokes for Anodes used in Aluminium Electrolysis 

      Jahrsengene, Gøril; Wells, Hannah C.; Sommerseth, Camilla; Ratvik, Arne Petter; Lossius, Lorentz Petter; Haverkamp, Richard G.; Svensson, Ann Mari (Journal article, 2017)
      The expanding aluminium industry is facing challenges with availability in raw materials. A wider range of petroleum cokes are being taken into use, blurring the border between anode grade and fuel grade coke in anode ...