• A multiscale numerical approach of the dripping slag in the coke bed zone of a pilot scale Si-Mn furnace 

      Letout, Sebastien Romain; Ratvik, Arne Petter; Tangstad, Merete; Johansen, Stein Tore; Olsen, Jan Erik (Chapter, 2017)
      The Si-Mn alloy process production in submerged arc furnaces (SAF) is investigated. The aim of the studies currently in progress is an enhancement of the knowledge about the key reactions and the mass transport phenomenon ...
    • AMADEUS: Next generation materials and solid state devices for ultra high temperature energy storage and conversion 

      Datas, Alejandro; Cristobal, Ana Belen; del Cañizo, Carlos; Antolin, Elisa; Beaughon, Michel; Nikolopoulos, Nikolaos; Nikolopoulos, Aristeidis; Zeneli, Myrto; Sobczak, Natalia; Polkowski, Wojciech; Tangstad, Merete; Safarian, Jafar; Trucchi, Daniele M; Bellucci, Alessandro; Girolami, Marco; Marx, Roman; Bestenlehner, Dominik; Lang, Stephan; Vitulano, Aniello; Sabbatella, Gianfranco; Marti, Antonio (Journal article; Peer reviewed, 2018)
      Starting in January 2017, AMADEUS (www.amadeus-project.eu) is the first project funded by the European Commission to research on a new generation of materials and solid state devices for ultra-high temperature energy storage ...
    • As-tapped Liquid Silicon Temperature Measurements in an Industrial Furnace 

      Werner, Tobias (Master thesis, 2019)
      Denne oppgaven tar for seg temperaturmålinger av smeltet silisium i rennen fra en industriell ovn. For at silisiumindustrien skal kunne oppfylle egne og myndigheters mål om forbedret energieffektivitet og lavere ...
    • Boron Removal from Silicon Melts by H2O/H2 Gas Blowing: Mass Transfer in Gas and Melt 

      Sortland, Øyvind Sunde; Tangstad, Merete (Journal article; Peer reviewed, 2014)
      Metallurgical routes for solar grade silicon production are being developed as alternatives to chemical processes for their potential to achieve cost reductions, increased production volume, and reduced environmental and ...
    • CFD Modeling of boron removal from liquid silicon with cold gases and plasma 

      Vadon, Mathieu; Sortland, Øyvind Sunde; Nuta, Ioana; Chatillon, Christian; Tangstad, Merete; Chichignoud, Guy; Delannoy, Yves (Journal article; Peer reviewed, 2018)
      The present study focuses on a specific step of the metallurgical path of purification to provide solar-grade silicon: the removal of boron through the injection of H2O(g)-H2(g)-Ar(g) (cold gas process) or of Ar-H2-O2 ...
    • 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 ...
    • Charcoal as an Alternative Reductant in Ferroalloy Production: A Review 

      Surup, Gerrit Ralf; Trubetskaya, Anna; Tangstad, Merete (Peer reviewed; Journal article, 2020)
      This paper provides a fundamental and critical review of biomass application as renewable reductant in integrated ferroalloy reduction process. The basis for the review is based on the current process and product quality ...
    • Comparative study of AC and DC solvers based on current and power distributions in a submerged arc furnace 

      Tesfahunegn, Yonatan; Magnusson, Tordur; Tangstad, Merete; Sævarsdottir, Gudrun A. (Peer reviewed; Journal article, 2020)
      This work discusses 3D models of current distribution in a three-phase submerged arc furnace that contains several components, such as electrodes, central arcs, craters, crater walls, and side arcs that connect electrodes ...
    • Compatibility Study of Carbon-Based Refractory Materials utilized in Silicomanganese Production Furnaces 

      Mølnås, Håvard (Master thesis, 2011)
      Tap hole refractories constitute critical parts of the refractory lining in submerged arc furnaces. For several hours every day, molten slag and metal flow through the tap hole calling for thorough selection of refractory ...
    • 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 ...
    • 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 ...
    • Densification of Biocarbon and Its Effect on CO2 Reactivity 

      Kaffash, Hamideh; Tangstad, Merete; Surup, Gerrit Ralf (Peer reviewed; Journal article, 2021)
      Charcoal is an interesting reducing agent because it is produced from biomass which is renewable and does not contribute to global warming, provided that there is a balance between the felling of timber and growth of trees. ...
    • Dissolution kinetics of carbon materials in FeMn 

      Kaffash, Hamideh (Doctoral theses at NTNU;2019:226, Doctoral thesis, 2019)
      Submerged electric arc furnace (SAF) is the main process for industrial production of ferroalloys, in which metal oxides are reduced by carbon. To decrease the production cost and reduce the CO2 emissions, a variety of ...
    • Dynamic Current and Power Distributions in a Submerged Arc Furnace 

      Tesfahunegn, Yonatan; Magnusson, Thordur; Tangstad, Merete; Saevarsdottir, Gudrun (Journal article; Peer reviewed, 2019)
      Most submerged arc furnaces used for the production of ferroalloys run on three-phase alternating current. This affects the electrical operation of the furnace and thus it is of interest to study alternating current ...
    • Dynamic Current Distribution in the Electrodes of Submerged Arc Furnace Using Scalar and Vector Potentials 

      Tesfahunegn, Yonatan; Magnusson, Thordur; Tangstad, Merete; Saevarsdottir, Gudrun (Journal article; Peer reviewed, 2018)
      This work presents computations of electric current distributions inside an industrial submerged arc furnace. A 3D model has been developed in ANSYS Fluent that solves Maxwell’s equations based on scalar and vector potentials ...
    • Effect of Charge Basicity of Two Compositions on MnO Reduction During Smelting Ferromanganese 

      Mwana Bute Ngoy, D; Kalenga wa Kalenga, M; Tangstad, Merete (Journal article; Peer reviewed, 2018)
      The effect of basicity of two different basic charges for reduction of MnO by solid carbon during smelting ferromanganese is considered. The effect of different charge compositions on MnO reduction in the temperature range ...
    • Electrical Resistivity of Carbonaceous Bed Material at High Temperature 

      Surup, Gerrit Ralf; Pedersen, Tommy Andre; Chaldien, Annah; Beukes, Johan Paul; Tangstad, Merete (Peer reviewed; Journal article, 2020)
      This study reports the effect of high-temperature treatment on the electrical properties of charcoal, coal, and coke. The electrical resistivity of industrial charcoal samples used as a reducing agent in electric arc ...
    • Electrode paste behaviour in Søderberg electrodes in ferroalloys production 

      Skjeldestad, Aslak (Doctoral thesis, 2019)
      The main goal of this work has been to study the melting behavior of electrode paste used in Søderberg electrodes in ferroalloy production. It has been done by first measuring temperatures in an industrial electrode and ...