• Investigation of slag and condensate from the charge top in a FeSi75 furnace 

      Folstad, Marit Buhaug; Jusnes, Karin Fjeldstad; Tangstad, Merete (Chapter, 2023)
      Metallurgical silicon/ferrosilicon is produced industrially in submerged arc furnaces by carbothermic reduction of quartz. In addition to raw materials, oxide impurities are present in the furnace. Accumulated slag is ...
    • Parameters Affecting Softening and Melting of Quartz 

      Jusnes, Karin Fjeldstad (Master thesis, 2016)
      The aim of this work was to develop and improve a new method for investigating how different parameters affect the softening and melting of quartz. The method should give quantitative results. Quartz is the stable phase ...
    • Phase transformation in quartz at elevated temperatures 

      He, Jiali; Jusnes, Karin Fjeldstad; Tangstad, Merete (Peer reviewed; Journal article, 2021)
      Natural quartz is a raw material in Si production. During heating, it will go through a series of phase transformations before melting in the furnace, from quartz to an intermediate amorphous phase and further to cristobalite. ...
    • Phase transformations and thermal degradation in industrial quartz 

      Jusnes, Karin Fjeldstad (Doctoral theses at NTNU;2020:205, Doctoral thesis, 2020)
      Quartz is used as the silicon source for silicon and ferrosilicon production. Together with various carbon materials, the quartz is added to a submerged arc furnace. Energy is supplied through three carbon electrodes, which ...
    • Phase Transformations from Quartz to Cristobalite 

      Jusnes, Karin Fjeldstad; Tangstad, Merete; Ringdalen, Eli (The Minerals, Metals & Materials Series;, Chapter, 2018)
      Two quartz types used in the silicon and ferrosilicon industry were heated to temperatures of 1600 and 1700 °C. The parameters varied were the temperature and the holding time at maximum temperature. The amount of quartz, ...
    • Phase transformations in quartz used in silicon and ferrosilicon 

      Jusnes, Karin Fjeldstad; Tangstad, Merete; Ringdalen, Eli (Peer reviewed; Journal article, 2021)
      Different quartz types are used as raw material for silicon and ferrosilicon production. Upon heating, the quartz will experience phase transformations to other silica polymorphs. In this study the phase transformation ...
    • Shock Heating Test of Quartz for Si and FeSi Production 

      Jusnes, Karin Fjeldstad; Tangstad, Merete; Ringdalen, Eli (Research report, 2017)
      Six different quartz types used as raw material for Si and FeSi production, were shock heated to 1500 °C in an induction furnace. The amounts of fines produced were measured and compared. The method has been used before ...