Browsing NTNU Open by Author "Kolbeinsen, Leiv"
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Phase Transitions and Microstructural Changes During Oxidation and Reduction of a Weathered Ilmenite Concentrate
Salehi, Hossein; Seim, Stian; Kolbeinsen, Leiv; Safarian, Jafar (Peer reviewed; Journal article, 2021)The present work aims to investigate the link between the oxidation and reduction of a weathered ilmenite concentrate in terms of phase transitions, microstructural changes, and element distribution. An ilmenite concentrate ... -
Pyrometallurgical and Hydrometallurgical Treatment of Calcium Aluminate-containing Slags for Alumina Recovery
Azof, Fabian Imanasa (Doctoral theses at NTNU;2020:82, Doctoral thesis, 2020)The pyrometallurgical and hydrometallurgical part of the Pedersen process has been studied. The process can be seen as one of the most potent alternative processes to recover alumina from bauxite more sustainably than the ... -
Recycling of Aluminium from Mixed Household Waste
Eggen, Sigvart; Sandaunet, Kurt; Kolbeinsen, Leiv; Kvithyld, Anne (Chapter, 2020)Aluminium is used in packaging due to its density, strength and preservative capabilities. This paper outlines a methodology to evaluate the recyclability of aluminium waste, where parameters of scrap type, pre-treatment ... -
Recycling of Aluminium from Mixed Household Waste
Eggen, Sigvart; Sandaunet, Kurt; Kolbeinsen, Leiv; Kvithyld, Anne (Chapter, 2020)Aluminium is used in packaging due to its density, strength and preservative capabilities. This paper outlines a methodology to evaluate the recyclability of aluminium waste, where parameters of scrap type, pre-treatment ... -
Reduction Mechanisms in Manganese Ore and Deposition of Carbon from Natural Gas
Svoen, Stine (Master thesis, 2017)This report investigates the deposition of carbon from natural gas onto manganese ore and the effect of reduction of the higher manganese oxides. Manganese ore has been heated in an argon atmosphere, before methane was ... -
Reduction of bauxite and Alcontaining waste to produce calcium aluminate slags and iron
Lazou, Adamantia (Doctoral theses at NTNU;2021:192, Doctoral thesis, 2021)The production of metallurgical grade Al2O3 from bauxite ores is mainly done through the Bayer process. This process is well established and efficient, but it has environmental challenges, and the main being the formation ... -
Reduction of Norwegian and Indian ilmenite with carbon monoxide and hydrogen gas blends
Lobo, Stephen Ceasar; Kolbeinsen, Leiv; Seim, Stian (Journal article, 2016)Synthesis gas, produced from natural gas, can be used to minimise coal consumption and carbon dioxide emissions during the processing of ilmenite. Two different ilmenite ores have been reduced with carbon monoxide and ... -
Reduction of Pelletized Tyssedal Ilmenite and the Effect of Changing Gas Composition and Flow, Pellet Size and Pre Oxidation Condition
Jørstad, Steinar (Master thesis, 2011)This master thesis is based on reduction experiments of pelletized Tyssedal ilmenite. The focus is set on the effect of changing parameters such as gas composition, gas flow, pellet size and pre-oxidation condition. The ... -
Road-map for gas in the Norwegian metallurgical industry: greater value creation and reduced emissions
Dalaker, Halvor; Ringdalen, Eli; Kolbeinsen, Leiv; Mårdalen, Jostein (Research report, 2017)In order to increase the use of gas in metal production, we will need to develop new – and to further develop existing – gas-based technologies, which will need to be adopted on an industrial scale. In order to provide a ... -
Slag Refining of Iron with Respect to Phosphorus
Saadieh, Raghed (Master thesis, 2014)TiZir Titanium and Iron produces high purity pig iron and titania slag from ilmenite. However, new ilmenite ores from Grande Côte Mineral Sands Project mine contain high level of phosphorus, which will contaminate the ... -
Smelting-reduction of bauxite for sustainable alumina production
Safarian, Jafar; Kolbeinsen, Leiv (Chapter, 2016)Bauxite ore is the main raw material for aluminum production, it is converted into alumina (Al2O3) to obtain a proper charge material for aluminum production in Hall-Heroult process. Bayer process is the main commercial ... -
Solidification of Titanium Slags and Influence on Post Processing
Stana, Rune Hagberg (Master thesis, 2016)Ilmenite is a titanium-rich ore, and accounts for almost all the world's consumption of titanium bearing minerals. One of the main uses of titanium is as powdered TiO2, used extensively as whitening pigment. The first step ... -
State of Reactions in Silicomanganese Smelting Process
Lee, Young E.; Kolbeinsen, Leiv (Peer reviewed; Journal article, 2022)Recent studies by Safarian et al. and Kim show that carbothermic smelting processes for SiMn alloys proceed by multiple reactions consisting of oxidation of carbon, simultaneous reduction of MnO and SiO2 species, and ... -
Steam Reforming of Methane on Sponge Iron: Influence of GasComposition on Reaction Rate
Ramos Ribeiro, Tiago; Neto, João Batista Ferreira; Poco, Joao G R; Takano, Cyro; Kolbeinsen, Leiv; Ringdalen, Eli (Peer reviewed; Journal article, 2020)Direct Reduction processes use gases (CO and H2) for iron reduction and production of sponge iron or direct reduced iron (DRI). The generation of this gas occurs through methane reforming, which can be done in a reformer ... -
Sustainability in alumina production from bauxite
Safarian, Jafar; Kolbeinsen, Leiv (Chapter, 2016)Alumina (Al2O3) is the main material used for the aluminum production, which is originated from bauxite ore through hydrothermal processes. Although bauxite conversion to alumina can be done through a few competitive ... -
Synthesis and Reduction-Carburization of (Fe,Mg)(Cr,Al)2O4 Composite Spinel Solid Solution With CH4
Canaguier, Vincent (Doctoral theses at NTNU;2018:193, Doctoral thesis, 2018) -
Synthesis of ilmenite
Canaguier, Vincent Yves (Master thesis, 2014)Ilmenite ores are currently processed at TiZir Titanium & Iron AS in Tyssedal. To be prepared for a change in the raw material composition, the effect of the impurities in the ilmenite ores has to be investigated. It is ... -
The Leachability of Calcium Aluminate Phases in Slags for the Extraction of Alumina
Azof, Fabian Imanasa; Safarian, Jafar; Kolbeinsen, Leiv (Journal article, 2017)Alumina is used primarily as feedstock for aluminum production. It occurs naturally in bauxite and clay and other minerals, and can be concentrated in industrial by-products such as coal gangue, fly ash, blast furnace slag, ... -
The Utilization of Bauxite Residue with a Calcite-Rich Bauxite Ore in the Pedersen Process for Iron and Alumina Extraction
Lazou, Adamantia; Eijk, Casper van der; Tang, Kai; Balomenos, Efthymios; Kolbeinsen, Leiv; Safarian, Jafar (Peer reviewed; Journal article, 2021)Metallurgical grade alumina is produced worldwide through the well-known Bayer process, which unavoidably generates bauxite residue (BR, also known as red mud) in almost equal amounts to alumina. This study aims the ...