A5042270077- Bauxite Residue and Utilization
- Metallurgical Processes and Thermodynamics
- Aluminum Alloys Composites Properties
- Iron and Steelmaking Processes
- Silicon and Solar Cell Technologies
- Metal Extraction and Bioleaching
- Recycling and utilization of industrial and municipal waste in materials production
- Extraction and Separation Processes
- Aluminum Alloy Microstructure Properties
- Advanced ceramic materials synthesis
- Phase Change Materials Research
- Minerals Flotation and Separation Techniques
- Semiconductor materials and interfaces
- Solidification and crystal growth phenomena
- Graphite, nuclear technology, radiation studies
- Chemical Looping and Thermochemical Processes
- Advanced Surface Polishing Techniques
- Adsorption and Cooling Systems
- Silicon Effects in Agriculture
- Solar Thermal and Photovoltaic Systems
- Thermal properties of materials
- Photovoltaic Systems and Sustainability
- Advanced materials and composites
- Mine drainage and remediation techniques
- Advanced Thermoelectric Materials and Devices
Norwegian University of Science and Technology
2012-2025
Materials Science & Engineering
2025
SINTEF
2013-2015
Abstract Metallurgical fundamentals for vacuum refining of molten silicon and the behavior different impurities in this process are studied. A novel mass transfer model removal volatile from induction is developed. The boundary conditions system—the equilibrium partial pressures dissolved elements their actual under vacuum—are determined through thermodynamic kinetic approaches. It indicated that kinetics different, it controlled by one, two, or all three subsequent reaction mechanisms—mass...
Abstract Theories on the evaporation of pure substances are reviewed and applied to study vacuum metals. It is shown that there good agreement between different theories for weak evaporation, whereas differences under intensive conditions. For coefficient in Hertz-Knudsen equation 1.66. Vapor velocity as a function pressure calculated applying several theories. If condensing surface less than one collision length from evaporating surface, applies. case where not close criterion introduced,...
The photovoltaic (PV) industry is in rapid growth and a large supply of PV feedstock materials must be provided to maintain this growth. Since silicon still the dominant material for fabrication solar cells, low-cost solar-grade (SoG-Si) demanded. most cost-effective direct approach producing SoG-Si purify upgrade metallurgical-grade silicon. Many impurities MG-Si can effectively removed through directional solidification molten However, removal boron (B) phosphorus (P) by method difficult...
Decarbonisation is critical for transitioning the steel industry toward sustainable, low-carbon production. As a major greenhouse gas emitter, exploring greener alternatives, such as producing Direct Reduced Iron (DRI) using hydrogen reductant to replace carbon. However, retaining specific carbon content in DRI essential efficient steelmaking. This study investigates carburisation of pellets that were obtained by reduction through hydrogen-methane mixtures with varying CH 4 concentrations...
Starting in January 2017, AMADEUS (www.amadeus-project.eu) is the first project funded by European Commission to research on a new generation of materials and solid state devices for ultra-high temperature energy storage conversion. By exploring temperatures well beyond 1000 °C aims at breaking mark ∼ 600°C rarely exceeded current art thermal (TES) systems. Project, through collaborative between seven partners, develop novel concept latent heat (LHTES) systems with unprecedented high...
Abstract 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 valorization of BR a smelting-reduction process obtain calcium aluminate slags that can be proper feed for recovery via Pedersen process. It investigates thermodynamics and characteristics pig iron from mixtures BR, beneficiation byproduct, lime. In this context, evolution...
This study proposes a sustainable method for utilising bauxite residue by reducing waste and recovering iron alumina. Bauxite residue–calcite pellets were reduced non isothermally at 1000 °C 120 min under 4 NL/min H 2 , converting oxide to metallic alumina leachable calcium aluminate phase. The leached with 60 g/L sodium carbonate (1:10 solid-to-liquid ratio) subjected 800 Gauss magnetic separation recover iron. Analytical techniques employed characterise the phase composition,...
Abstract Vacuum induction refining is a process that can be applied to remove phosphorus from molten silicon for the production of solar grade silicon. Pure was doped by make containing around 17 ppmw phosphorus. The kinetics removal this studied at 0.5 Pa through application vacuum refining. It observed occurs first-order reaction. rate constants evaporation were determined as 2.28
Abstract Boron (B) is the most problematic impurity to be removed in processes applied for production of solar grade silicon. removal from liquid silicon by sodium-silicate slags experimentally studied and it indicated that B can rapidly within short reaction times. The rate higher at temperatures Na 2 O concentrations slag. Based on experimental results thermodynamic calculations, proposed phase takes place through its oxidation slag/Si interfacial area oxidized further gasified slag...
The leaching characteristics and mechanism of synthetic CaO-Al2O3 slags in alkaline solution at atmospheric pressure have been studied. purpose the study is to a better understanding part Pedersen process, as an alternative Bayer process for alumina production. crystalline containing CaAl2O4, Ca3Al2O6, CaAl4O7, Ca12Al14O33 phases, residues (predominantly CaCO3) are characterized by X-ray Diffraction semi-quantitative analysis. Of 120 g/L Na2CO3, slag with highest amount phase most leachable...
Abstract The aluminum recovery from white dross by a mechanical treatment and sizing followed remelting process was investigated. subjected to ball mill, the obtained particles were sized in different ranges. They studied advanced materials characterization techniques. It found that larger contain high metallic portions, most non-metallic components of are fine fraction < 1 mm. Al-rich (> mm) remelted at 900°C recover aluminum. metal structure after is homogeneous consisted dominant...
The hydrogen reduction of bauxite residue lime pellets at elevated temperatures was carried out to recover iron and alumina from the in a new process route. Prior H2 reduction, oxide were initially prepared via mixing an industrial with fine calcite powder followed by calcination high-temperature sintering. chemical, compositional, microstructural properties both reduced studied advanced characterization techniques. It found that is mainly form brownmillerite, calcium-iron-titanate phases,...
This study investigates the properties of H2-reduced calcium-added bauxite residue, self-hardened pellets, and feasibility iron recovery through electrostatic magnetic separation methods. The oxide pellets are prepared via a mixing calcite, quicklime. reduced at 1000 °C with hydrogen gas flow for 120 min. chemical composition, phase identification, microstructural observations executed using X-ray fluorescence (XRF), diffraction (XRD), scanning electron microscopy (SEM), respectively....
For a successful implementation of newly proposed silicon-based latent heat thermal energy storage systems, proper ceramic materials that could withstand contact heating with molten silicon at temperatures much higher than its melting point need to be developed. In this regard, non-wetting behavior and low reactivity are the main criteria determining applicability as potential crucible material for long-term ultrahigh temperature silicon. work, wetting hexagonal boron nitride (h-BN) by was...
This research is devoted to study phosphorus removal from Si-Al alloys by vacuum refining of the ternary system dilute solutions P in Si-20 wt%Al. The experiments were carried out an induction furnace and after process, melt was characterized ICP-MS technique trace concentration change volatile elements. experimental results show that Si-Al-P melts takes place faster compared Si-P Al evaporates during as well. empirical kinetics evaporation discussed apparent activation energy for obtained...
In this paper, the separation of phosphorus from metallurgical-grade silicon was investigated based on an Mg alloying and HCl leaching approach. Experimental results show that P concentration reduced initial 15.1 ppmw to 0.2 with also large extent removal metallic impurities by two times alloying-leaching purification. The mechanism enhanced is clarified owing strong affinity between P, which validated SIMS elemental mapping. A two-parameter analytical model developed predict degree...
A combination of smelting-reduction bauxite and leaching treatment the produced slag for alumina recovery is known as Pedersen process. The process considered to be more sustainable producing metallurgical-grade than Bayer it does not produce residue (red mud), which one most abundant industrial byproducts in world. In this work, leachability a ternary CaO-Al2O3-SiO2 from low-grade has been studied. obtained calcium aluminate-slag consists Ca12Al14O33 CaAl2O4 phases with minor amounts...
The aluminothermic reduction process of manganese oxide from different slags by aluminum was investigated using pure Al and two types industrial dross. Two MnO-containing were used: a synthetic highly CaO-MnO slag an high carbon ferromanganese slag. Mixtures with more than the stoichiometry heated interacted in induction furnace up to 1873 K, yielding molten metal products. characterization produced phases indicated that complete MnO occurs via process. Moreover, as content charge high, it...
Experimental research was carried out to produce pellets from bauxite residue for the further extraction of iron and alumina. Bauxite limestone with three different mixture compositions were pelletized experimentally via agglomeration followed by drying sintering at elevated temperatures. X-Ray diffraction (XRD) scanning electron microscopy (SEM) used phase microstructural analysis, respectively. Tumble, abrasion, breaking load tests applied determine strength pellets. For measurement...
Considering the boom of Si solar cell installation, it is necessary to establish a process for recycling from End-of-life photovoltaics (PVs). Silicon in PVs synthetically doped and coated by various elements hence dedicated methods will be required Si, back SoG-Si. In this research, shredded cells studied means vacuum refining process. research rejected after firing step are treated acid etching techniques remove Al layer Ag finger on front side cells, providing product called de-metallized...
The thermodynamic activities in the silicon binary melts with Al, Ca, Mg, Fe, Ti, Zn, Cu, Ag, Au, Sn, Pb, Bi, Sb, Ga, In, Pt, Ni, Mn and Rh are studied. along liquidus calculated through a quasi-regular solution model using recently determined constants for systems. at its melting point considering regular approximation. of other melt component also graphical integration Gibbs–Duhem equation activity coefficient, which further utilized to determine corresponding liquidus. presented...
Abstract Low-grade bauxite ores are not favorable in the conventional Bayer process for alumina production, as they producing more residue (red mud) and accompanying lower yield than high-grade ores. In current study, thermodynamics characterization of calcium-aluminate slags pig iron produced from smelting reduction high iron- silica-containing bauxites studied. Coke limestone used to reduce oxide adjust basicity slag during smelting. There is evidence that complete separation feasible...