• Briquetting of Manganese Oxide Fines with Organic Binders - How well suited are organic binders for agglomeration of Mn-oxide fines? 

      By, Thomas (Master thesis, 2017)
      Dust and fines are created throughout the ferromanganese metal production. These fines are collected from ventilation filters, screening operations and off-gas cleaning facilities. As the fines contain a substantial amount ...
    • Characterisation of a Real-World Søderberg Electrode 

      Glastonbury, Ralph; Beukes, Paul; van Zyl, Pieter Gideon; Tangstad, Merete; Ringdalen, Eli; Dall, Douglas; Steenkamp, Joalet Dalene; Mushwana, Masana (Peer reviewed; Journal article, 2021)
      Very little research on Søderberg electrodes has been published in the journal peer reviewed public domain. The main aim of this work is to characterise a Søderberg electrode that was cut off approximately 0.5 m below the ...
    • Characterization of a Si-SiO2 mixture generated from SiO and CO 

      Broggi, Andrea; Tangstad, Merete; Ringdalen, Eli (Journal article; Peer reviewed, 2019)
      The reaction between SiO(g) and CO(g) is a relevant intermediate reaction in the silicon production process. One of the products generated from this gas mixture is called by its color, brown condensate. In this paper, ...
    • Characterization, thermodynamics and mechanism of formation of SiC-SiOx core–shell nanowires 

      Broggi, Andrea; Ringdalen, Eli; Tangstad, Merete (Peer reviewed; Journal article, 2020)
      Silicon carbide nanowires are valuable for electronic and optical applications, due to their high mechanical and electrical properties. Previous studies demonstrated that nanowires can be produced easily, by mixing a ...
    • Condensation of SiO and CO in silicon and ferrosilicon production 

      Broggi, Andrea (Doctoral theses at NTNU;2021:93, Doctoral thesis, 2021)
      Kondensasjon av SiO(g) er kombinasjon av to reaksjoner i silisiumprosessen. Den første er interaksjonen mellom SiO(g) og CO(g). Den andre er reaksjonen mellom to SiO(g) molekyler. Disse to reaksjonene foregår i lavtemperatursonen ...
    • C–O–H2 ternary diagram for evaluation of carbon activity in CH4-containing gas mixtures 

      Ribeiro, T.R.; Ferreira Neto, Neto; Takano, C.; Poço, J.G.R.; Kolbeinsen, Leiv; Ringdalen, Eli (Peer reviewed; Journal article, 2021)
      The C–O–H2 ternary diagram is presented to characterize the carbon activity in equilibrium with gas mixtures containing CH4, CO, CO2, H2O, and H2 at different temperatures and pressures. The three reactions for carbon ...
    • Damring formation during rotary kiln chromite pre-reduction: Effects of pulverized carbonaceous fuel selection and partial pellet melting 

      van Staden, Yolindi; Beukes, Johan Paul; van Zyl, Pieter Gideon; Ringdalen, Eli; Tangstad, Merete; Kleynhans, Ernst L.J.; Bunt, John Reginald (Journal article; Peer reviewed, 2018)
      Electricity consumption is the largest cost contributing factor in the production of ferrochrome. Currently the pelletized chromite pre-reduction process (solid-state reduction of chromite) is the process option with the ...
    • Effect of Different Polymorphs of SiO2 on the Reaction between SiO2 and SiC in Si Production 

      Folstad, Marit Buhaug (Master thesis, 2017)
      The aim of this work have been to investigate the phase transformations in silica (SiO2) during heating to target temperature, and the effect of SiO2 polymorphs on the reduction reaction between SiO2 and silicon carbide ...
    • Effect of different SiO2 polymorphs on the reaction between SiO2 and SiC in Si production 

      Folstad, Marit Buhaug; Ringdalen, Eli; Tveit, Halvard; Tangstad, Merete (Peer reviewed; Journal article, 2021)
      This work investigates the phase transformations in silica (SiO2) during heating to a target temperature between 1700 °C and 1900 °C and the effect of SiO2 polymorphs on the reduction reaction 2SiO2 + SiC = 3SiO + CO in ...
    • Evolution of SiOx shell layers on SiC-SiOx core-shell nanowires 

      Broggi, Andrea; Ringdalen, Eli; Tangstad, Merete (Peer reviewed; Journal article, 2020)
      Composite core-shell SiC-SiOx nanowires can be produced by heating quartz and SiC powders, with addition of Ar(g) or He(g). The two powders are mixed to create pellets, which will react to SiO(g) and CO(g) at elevated ...
    • Extent of Ore Prereduction in Pilot-scale Production of High Carbon Ferromanganese 

      Mukono, Tichaona; Gjøvik, Jonas Einan; Gaertner, Heiko; Wallin, Maria; Ringdalen, Eli; Tangstad, Merete (Peer reviewed; Journal article, 2021)
      Three pilot-scale experiments have been conducted at SINTEF/NTNU in a 440 kVA AC electric furnace to demonstrate the process operation, energy requirements and CO2 emissions in the production of high carbon ferromanganese ...
    • Formation and characterization of β-and α-Silicon Carbide produced during Silicon/Ferrosilicon process 

      Jayakumari, Sethulakshmy (Doctoral theses at NTNU;2020:252, Doctoral thesis, 2020)
      Silicon carbide (SiC) is one of the main intermediate compounds generated during primary silicon (Si) production in submerged arc furnaces. Carbon materials, either biomass-based (charcoal and wood chips) or based on fossil ...
    • Karbiddannelse i Manganovner 

      Øvrelid, Sigurd Johannes Slåtsve (Master thesis, 2019)
      Når karbon løses opp i silikomangan(SiMn)-prosessen kan det dannes titankarbid (TiC), silisiumkarbid (SiC) eller grafitt i ovnen. Silisiuminnholdet i legeringen avgjør om silisiumkarbid eller grafitt vil være den stabile ...
    • Kinetic Study of SiO2 + SiC Reaction in Silicon Production 

      Adisty, Dian (Master thesis, 2013)
      A number of researches related to kinetics of SiO2 + SiC reaction in the silicon production are limited and there is a gap between the real kinetics and mechanism of SiO2 + SiC reaction and people?s knowledge of that ...
    • Kinetics and Mechanism of Phase Transformations from Quartz to Cristobalite 

      Kjelstadli, Marthe Erdal (Master thesis, 2016)
      The largely debated silica polymorphism has in this thesis been investigated for the transformation from β-quartz to β-cristobalite. It is done as a step in understanding and improve the furnace operations of the silicon ...
    • Ore melting and reduction in silicomanganese production 

      Ringdalen, Eli; Gaal, S.; Tangstad, Merete; Ostrovski, Oleg (Journal article; Peer reviewed, 2010)
      The charge for silicomangansese production consists of manganese ore (often mixed with ferromanganese slag) dolomite or calcite, quartz, and in some cases, other additions. These materials have different melting properties, ...
    • 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 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; Conference object, 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 ...