Blar i NTNU Open på forfatter "Kolbeinsen, Leiv"

Viser treff 1-20 av 39

    • The beginning and the end of the aluminium value chain 

      Kolbeinsen, Leiv (Peer reviewed; Journal article, 2020)
      Metallic aluminium does not naturally occur in nature, and it was largely unknown, virtually a mystery, until 200 years ago. The modern aluminium production using a hydrometallurgical refining process for making alumina ...

    • Behavior of Slag in Ferromanganese and Silicomanganese Smelting Process 

      Lee, Young E.; Kolbeinsen, Leiv (Peer reviewed; Journal article, 2021)
      A review of studies by Safarian et al. and Kim show that the smelting reaction at equilibrium for ferromanganese and silicomanganese alloys is defined by the coupled reaction in the carbon-saturated condition 2Mn––––+(Si ...

    • 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 ...

    • Characteristics of Calcium-Aluminate Slags and Pig Iron Produced from Smelting-Reduction of Low-Grade Bauxites 

      Azof, Fabian Imanasa; Kolbeinsen, Leiv; Safarian, Jafar (Journal article; Peer reviewed, 2018)
      Low-grade bauxite ores are not favorable in the conventional Bayer process for alumina production, as they are producing more bauxite residue (red mud) and accompanying lower alumina yield than high-grade ores. In the ...

    • 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 ...

    • Dynamic Modelling of Heat and Mass Transfer in the Silicon Arc Furnace 

      Hajdini, Fatbardha (Master thesis, 2019)
      Grunstoffet silisium er av stor betydning for det moderne samfunn. Selv om silisium er det vanligtse grunnstoffet i jordskorpen etter oksygen, så finnes ikke silisium i sin elementære form i naturen. Silisium kan produseres ...

    • Evaluation of Calcium Aluminate Slags and Pig Irons Produced from the Smelting-Reduction of Diasporic Bauxite 

      Lazou, Adamantia; Kolbeinsen, Leiv; Safarian, Jafar (Peer reviewed; Journal article, 2021)
      This work evaluates the characteristics of calcium aluminate slag and pig iron samples obtained from the smelting of calcined and reduced diasporic bauxite ore. The study is conducted in the Pedersen process framework, ...

    • Exergy relations in manganese production: Modelling the submerged arc furnace 

      Schanche, Trygve Lindahl (Master thesis, 2013)
      A model of the ferromanganese submerged arc furnace was purposed to yield valuable information for exergy calculations. A deeper understanding of at what point exergy is lost in the furnace might yield valuable information ...

    • Impurities in Ilmenite - Excess Iron 

      Norhaug, Sondre (Master thesis, 2015)
      During this master s thesis, batches of ilmenite with three different Fe/Ti-ratios were successfully synthesised. After synthesis, the batches underwent pre-oxidation, reduction with ThermoGravimetric Analysis (TGA), before ...

    • Impurities in Ilmenite: Magnesium 

      Kim, Pyung-Hwa (Master thesis, 2015)
      The influence of Mg as main impurity in ilmenite during gaseous reduction with CO and H2 gas was studied in this work. This is of interest for the ilmenite pre-reduction step in the Tyssedal Process as where the impurities ...

    • Iron Separation from Bauxite Through Smelting-Reduction Process 

      Sellæg, Hanne; Kolbeinsen, Leiv; Safarian, Jafar (Chapter, 2017)
      In the alumina production process through the dominant commercial Bayer process red mud, which is not consumable and causes serious environmental challenges is produced. Alternative sustainable process for bauxite treatment ...

    • 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 Analysis of Steam Reforming of Methane on Sponge Iron 

      Ramos Ribeiro, Tiago; Ferreira Neto, João Batista; Rocha Poço, João Guilherme; Takano, Cyro; Kolbeinsen, Leiv; Ringdalen, Eli (Peer reviewed; Journal article, 2022)
      The kinetics of steam reforming of methane catalyzed by sponge iron was studied at temperatures between 875°C and 1050°C. Results shows that sponge iron acts as a catalyst and methane conversion is increased in higher ...

    • Kinetics of the leaching of alumina-containing slag for alumina recovery 

      Azof, Fabian Imanasa; Kolbeinsen, Leiv; Safarian, Jafar (Chapter, 2019)
      The leaching kinetics of an alumina-containing slag produced from the smelting-reduction of low-grade bauxite, which contained a significant amount of iron and low levels of SiO2 and TiO2, is studied. The leaching rates ...

    • Leaching and Precipitation Experiments Related to the Pedersen Process 

      Nedkvitne, Eirik Nøst (Master thesis, 2019)
      Store mengder avfall rødslam generes fra produksjon av metallurgisk aluminiumoksid via den nåværende kommersielle Bayer prosessen. Deponering av avfallet byr på miljøutfordringer. Alternativt kan aluminiumoksid produseres ...

    • Leaching characteristics and mechanism of the synthetic calcium-aluminate slags for alumina recovery 

      Azof, Fabian Imanasa; Yang, Yongxiang; Panias, Dimitrios; Kolbeinsen, Leiv; Safarian, Jafar (Journal article; Peer reviewed, 2019)
      The leaching characteristics and mechanism of synthetic CaO-Al2O3 slags in alkaline solution at atmospheric pressure have been studied. The purpose of the study is to have a better understanding of the leaching part of the ...

    • The (love & hate) role of entropy in process metallurgy 

      Tveit, Halvard; Kolbeinsen, Leiv (Journal article, 2019)
      Abstract. Process metallurgy is the basis for the production, refining and recycling of metals and is based on knowledge of transport phenomena, thermodynamics and reaction kinetics, and of their interaction in high ...

    • Microscopic Study of Carbon Surfaces Interacting with High Carbon Ferromanganese Slag 

      Safarian, Jafar; Kolbeinsen, Leiv (Journal article; Peer reviewed, 2015)
      The interaction of carbon materials with molten slags occurs in many pyro-metallurgical processes. In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic reduction of MnO-containing ...

    • On the Direct Reduction Phenomena of Bauxite Ore Using H2 Gas in a Fixed Bed Reactor 

      Lazou, Adamantia; Eijk, Casper van der; Balomenos, Efthymios; Kolbeinsen, Leiv; Safarian, Jafar (Peer reviewed; Journal article, 2020)
      The Bayer Process is the dominant industrial method to produce alumina from bauxite ore. Due to the generation of large amounts of Bauxite Residue (red mud), an alternative method, called the Pedersen Process, is of our ...

    • Organic binder as a substitute for bentonite in ilmenite pelletization 

      Sunde, Marius (Master thesis, 2012)
      TiZir Titanium & Iron produces high titania slag and high purity pig iron from ilmenite in Tyssedal. The ilmenite is pelletized before smelting. Bentonite is added to the ilmenite concentrate as a binder to give the pellets ...