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  • 1.
    Alexis, Jonas
    et al.
    Swerea-Mefos.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Heat and fluid-flow models for stirring conditionsin ladle furnaces and their practical implications in secondary refiningoperations1997Inngår i: Clean Steel 5, Vol 1,  2-4 June 1997, Balatonszeplak,Hungary, Balatonszeplak, 1997, s. 49-58Konferansepaper (Fagfellevurdert)
  • 2.
    Alexis, Jonas
    et al.
    Swerea-Mefos.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    A model of an induction-stirred ladle accounting for slag and surface deformation1999Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 39, nr 8, s. 772-778Artikkel i tidsskrift (Fagfellevurdert)
  • 3.
    Andersson, Margareta
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Hallberg, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Slag/metal reactionsduring ladle treatment with focus on desulphurisation2000Inngår i: 6thInternational Conference on Molten Slags, Fluxes and Salts, 2000Konferansepaper (Fagfellevurdert)
  • 4.
    Arvanitidis, Ioannis
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Intrinsic kinetics of some high temperature gas-solid reactions1998Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Many materials processes are based on gas-solid reactions.An understanding of the mechanisms underlying these reactionsis essential for optimization of the process parameters andinvention of new process routes. Modelling of gas-solidreactions is made difficult in view of the complexitiesinvolved, like the chemical reaction including adsorption anddesorption, determination of the diffusion constants and masstransfer coeffrcients as well as the heat conductivity and heattransfer coeffrcients. The present doctoral thesis deals withthe experimental studies of a few selected reactions, which areof both theoretical as well as practical interest, with a viewto develop reaction models from the measured kineticparameters.

    The reactions studied in the present work are:SrcO3(s) = Sro(s) + CO2(g)BaCO3(s) = BaO(s) + CO2(g)FeCr2O4(s) + H2(g) = Fe(s) + Cr2O2(s) + H2O(g)FeTiO3+ H2(g) = Fe(s) + Tio2(s) + H2O(g)CoTiO,(s) + H,(g) = Co(s) + Tio,(s) + H,O(g)NiTiO3+ H2(g) = Ni(s) + Tio2(s) + H2O(g)

    The main experimental technique used in the present work isthe thennogravimetric analysis (TGA) coupled with differentialthermal analysis (DTA). The chemical reactions were highlightedin some of the experiments by conducting the reactions inshallow powder beds of fine particles, while the mass and heattransfer aspects were focused on in experiments with densecompacts. The TGA-DTA experiments were complemented by SEM-EDSand X-ray analysis and in some cases with BET measurements ofthe stiace area. In the case of decomposition of SrCO3the laser flash technique was used in order todevelop a model for the calculation of the effective thermalconductivity of porous SrC03and SrO.

    Decomposition of alkaline-earth carbonates: From the resultsof the measurements on the decomposition of fine synthetic SrC03powder, the activation energy for the reaction wasevaluated as 2 10 kJ*mol-1. The reaction rate was found to be unaffected bythe phase transformation occurring in the carbonate. Thedecomposition of porous pellets of SrC03was studied. The overall reaction rate wascalculated for a decomposing compact of SrC03based on the heat and mass transports and thechemical reaction. The kinetics of decomposition of BaCO, wasfound to be complicated as an eutectic melt was fornred at theinterfac; between BaC03and the BaO product. The activation energy forBaC03decomposition was found to be 305 kJ.mol-1.

    Reduction of Transition metal oxycompounds: In the case ofthe reduction of transition metal oxycompounds, FeCr2O4was found to be first reduced to iron and chromiumoxide before the latter was further reduced to chromium below1373 K. At higher temperatures, the reduction of Cr2O3appeared to occur before the fi.rll recovery ofiron.The reduction of FeCr,O, was found to proceed in two stepsbelow 1373 K, viz.

    FeCr2O4(s) + H2(g) = Fe(s) + Cr203(s) + H2O(g) Cr2O3(s) + 3H2(g) = 2Cr(s) + 3H2O(g)

    The activation energy for the reduction of FeCr2O4to Fe and Cr203was calculated to be 13 1 kJ.mol-1.

    The reduction studies of FeTiO3showed that, below 1186 K, the solid reductionproducts are Fe and TiO2. The activation energy for this reaction was foundto be 108 kJ.mol-1.At higher temperatums, TiO2was found to be reduced to TiO2Ti2O3.

    The activation energy for the reduction of CoTiO3by hydrogen to Co and TiO2was evaluated to be 15 1 kJ.mol-1and the activation energy for the reduction ofNiTiO by hydrogen to Ni and Tio, was evaluated to be 153 kJ.mol-1.

    A better fit of the experimental reaction rate data wasachieved by multiplication of AG0by 1/T which was plotted as the x-axis of theArrhenius plot.

    Key words:Chemical kinetics, decomposition, reduction,mass transfer, heat transfer, gas-solid reactions, SrC03, BaCO3FeTiO3,CoTiO3, NiTiO3, FeCr2O4, thermogravimetry, thermal diffusivity, Arrhenittsequation.

  • 5.
    Bitima, Gemechu
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Biomass combustion mathematical modelling - drying and pyrolysis1998Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 6.
    Bitima, Gemechu
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Mathematical modelling of biomass thermal degradation in a fixed bed reactor1999Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    A mathematical model of biomass thermal degradation in afixed bed has been developed. Theoretical analysis of drying,pyrolysis and char combustion has been carried out. The basicequations ofbiomass degradation kinetics, heat and masstransfer differential equations are formulated and detailedanalysis of the relevant parameters and biomass characteristicsare done and the equations of transport phenomena in a fixedbed are solved both analytically and numerically.

    Pyrolysis and drying kinetics (paper I), theoreticalanalysis and mathematical modeling of char combustion problemsin a fixed bed of biomass reactor (paper II), mathematicalmodelling of heat and mass transfer during drying (paper III),pyrolysis (paper IV) and char combustion (paper V) have beendone.

    This final work analyzes the above mentioned papers and adetailed theoretical analysis is given. The study focuses onheat and mass transfer mathematical modelling, especiallyemphasis being given to the thermal non-equilibrium conditiondeveloped due to the difference in temperature of solid fueland gas phase which lead to the formulation of differentequations for solid and gas phase separately. The mathematicalmodel results are compared with some experimental results.

    Keywords:Pyrolysis, fixed bed, gasification, drying,combustion, biomass, kinetic.

    ©Gemechu Bitima, 1999

  • 7.
    Björkvall, Johan
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Thermodynamic study of multicomponent slags2000Doktoravhandling, med artikler (Annet vitenskapelig)
  • 8.
    Björkvall, Johan
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Thermodynamic study of silicate and aluminate melts: a model approach1998Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 9.
    Boström, Anna
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    A model for multicomponent reactions between metal/slag using thermo-calc: applied for removal of sulphur during ladle treatment1997Licentiatavhandling, monografi (Annet vitenskapelig)
  • 10.
    Bustnes, John Are
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Kinetic studies of the reduction of some transition metal oxycompounds by hydrogen1999Doktoravhandling, med artikler (Annet vitenskapelig)
  • 11.
    Dong, Wei
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Three-dimensional computer simulation for grate combustion and NO emission with a new air supply ecotube system1998Licentiatavhandling, monografi (Annet vitenskapelig)
  • 12.
    Drakaliysky, Evgeni
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Sulphide capacities of CaO-AlO slags containing SiO, MgO and CrO1997Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 13. Eriksson, Robert
    et al.
    Tilliander, Anders
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Materialvetenskap.
    An experimental study of the velocity field during filling of an ingot mould2003Inngår i: Steel research, ISSN 0177-4832, Vol. 74, nr 7, s. 423-430Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present study the velocity field in a 1:3 scale water model of a 4.2-tonne ingot mould was determined using Laser Doppler Anemometry (LDA). The velocity was measured in the horizontal and vertical directions at several different locations along the centre plane of the model. The effect of different volumetric flow rates and water temperatures was also investigated. The reproducibility of the measurements was found to be satisfactory, since the mean velocity at any measurement location had an average difference of around 10% between two fillings. The effect of different volumetric flow rates showed that while decreasing the flow rate, the mean velocity at the bottom turned from an upward direction to a downward direction. At the top of the model the difference between the mean velocities for the different flow rates was less pronounced. An influence of the temperature on the mean velocity could be observed. However, further studies are required to verify this result.

  • 14.
    Fredriksson, Patrik
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Thermodynamic studies of some iron oxide-containing slag systems2000Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In the present investigation experimental measurements ofthe thermodynamic activities of iron oxide in the systems:Al2O3-“FeO”, CaO-“FeO”,“FeO”-SiO2 and, CaO-“FeO”-SiO2 wereperformed by using gas equilibration technique. Theexperimental measurements were performed in the temperaturerange 1823-1923 K for the binary systems and, at 1873 K for theternary system respectively. The molten slag, kept in aPt-crucible was brought to equilibrium with a Ar-CO-CO2 gasmixture. A part of the Fe from the”FeO”was reducedand the metal formed dissolved in the Pt phase. The sampleswere quenched after the required equilibration time and theslag phase as well as the platinum crucible were subjected tochemical analysis. The activities of”FeO”in theslag were calculated from the experimental data usingthermodynamic information on the Fe-Pt binary metallic system.The thermodynamic activities of iron in iron-platinum solidalloys were measured by the solid electrolyte galvanic cellmethod in the temperature range 1073–1273 K. Sixdifferent Fe-Pt alloys covering the entire composition rangewere studied. The results were fitted into a regular solutiondescription in order to extrapolate the activities of thedissolved iron to the experimental temperatures for the slagmeasurements. The experimental results are discussed on thebasis of the earlier work.

    Keywords:Thermodynamics, activities, slags,iron-platinum alloys, solid electrolytes, galvanic cell, gasequilibration technique.

  • 15.
    Grip, Carl-Erik
    et al.
    Luleå Tekniska Universitet.
    Jonsson, Kjell Olov
    Eriksson, Sven
    Jonsson, Lage
    MEFOS, Luleå, Sweden.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Pan, Yuhua
    Theoretical and practical study of thermal stratification and drainage in ladles of different geometry2000Inngår i: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 29, nr 1, s. 30-38Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    SSAB Lulea, SSAB Oxelosund, MEFOS and Lulea University of Technology have cooperated in developing theoretical models for prediction of thermal stratification and drainage in steel ladles. Predicted results have been verified by measurements done in production ladles with heat weighs of 105 and 200 tonne as well as in a 7-tonne pilot plant ladle. The thermal stratification was measured by thermocouples at different depths. The drainage flow was studied by means of tracer experiments. Numerical simulation models of the steel flow were developed for 7, 105 and 200 tonne steel ladles. The agreement between predictions and measurements was found to be good. The conclusion is that CFD simulation gives a good prediction of stratification and drainage flows in production ladles.

  • 16.
    Grip, Carl-Erik
    et al.
    Luleå Tekniska Universitet.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Physical behavior of slag in a 107 tonne ladle. Production scale experiments and theoretical simulation2000Inngår i: ISBN91-7170-606-2, 2000Konferansepaper (Fagfellevurdert)
  • 17.
    Grip, Carl-Erik
    et al.
    Luleå Tekniska Universitet.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Prediction of emptying flows in ladles and verification with data fromtrace element plant trials1997Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 37, nr 11, s. 1081-1090Artikkel i tidsskrift (Fagfellevurdert)
  • 18.
    Grip, Carl-Erik
    et al.
    Luleå Tekniska Universitet.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Kjell Olov
    Numerical predication and experimental verification of thermalstratification in pilot plant and production ladles1999Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 39, nr 7, s. 715-721Artikkel i tidsskrift (Fagfellevurdert)
  • 19.
    Gyllenram, Rutger
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Expert systems or systems for export2001Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 20.
    Görnerup, Mårten
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Studies of slag metallurgy in stainless steelmaking1997Doktoravhandling, med artikler (Annet vitenskapelig)
  • 21.
    Hallberg, Malin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Alexis, Jonas
    Swerea-Mefos.
    Modelling of hydrogen and sulphur refining during vacuum degassing in a ladle furnace1999Inngår i: SCANMET I, 1999, s. 119-169Konferansepaper (Fagfellevurdert)
  • 22.
    Hallberg, Malin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    The Use of FundamentalModels in Developing Practical Process Control Models for Sulphur and HydrogenRefining2003Konferansepaper (Fagfellevurdert)
  • 23. Jauhiainen, Anu
    et al.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Modelling of alloy mixing into steel - The influence of porous plugplacement in the ladle bottom on the mixing of alloys into steel in agas-stirred ladle – A comparison made by numerical simulation2001Inngår i: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 30, s. 242-253Artikkel i tidsskrift (Fagfellevurdert)
  • 24.
    Ji, Fuzhong
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Experimental studies of viscosities of some multicomponent slags1997Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 25.
    Ji, Fuzhong
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Studies on viscosites of some multicomponent slags1998Doktoravhandling, med artikler (Annet vitenskapelig)
  • 26.
    Jonsson, Lage
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Seetharaman, Seshadri
    KTH, Tidigare Institutioner, Metallurgi.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Process Models for Ladle Refining - A FundamentalApproach2000Inngår i: 6th Japan-Nordic Countries Joint Symposium, Nagoya, 2000, s. 77-84Konferansepaper (Fagfellevurdert)
  • 27.
    Jönsson, Pär
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Viscosities of LF slag’s and their impact on ladle refining1997Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 37, nr 11, s. 484-491Artikkel i tidsskrift (Fagfellevurdert)
  • 28.
    Jönsson, Pär
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage T. I.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    The use of fundamental process models in studying ladle refining operations2001Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 41, nr 11, s. 1289-1302Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Existing fundamental models of ladle refining operations have been reviewed. No fundamental model that takes all the individual parts of ladle refining into account has been found in the open literature. Nor does a model exist which considers all refining in only one part of a refining step such as vacuum treatment. However, separate fundamental models for prediction regarding alloying, temperature, hydrogen, sulfur, reoxidation, and inclusion growth and removal do exist. In one case, a reoxidation model has also been combined with a sulfur-refining model. Predicted values from the separate models for alloying, temperature, sulfur and hydrogen have been found to agree well with corresponding measured data. The verification of the models for reoxidation and the growth and removal of inclusions is currently lacking and separate models for refining operations such as nitrogen or carbon removal need to be developed. Also, more complex models of parts of ladle refining such as vacuum treatment need to be developed, incorporating the sulfur, hydrogen, reoxidation and inclusion growth and removal models. The ultimate goal is, of course, one overall model that can predict desired parameter values for all steps of ladle refining. Even though such a model does not exist today, the usefulness of existing fundamental models is exemplified. This is to illustrate the potential of more complex and more realistic ladle models in process optimization.

  • 29.
    Jönsson, Pär
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Tilliander, Anders
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Eriksson, Robert
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Hallberg, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Mathematical Modeling of Metallurgical Processes2003Konferansepaper (Fagfellevurdert)
  • 30.
    Lille, Simon
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Experimental study of single fuel jet in conditions of highly preheated air combustion1999Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 31.
    Lucas, Carlos
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Modelling of the fixed bed biomass fired furnace1999Licentiatavhandling, monografi (Annet vitenskapelig)
  • 32.
    Nzotta, Mselly M.
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Experimental and modelling studies of sulphide capacities of some silicate and aluminate melts1997Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 33.
    Nzotta, Mselly M.
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Sulphide capacities of mulicomponent slags1999Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    In the present thesis, experimental measurements have beencarried out to determine the sulphide capacities of the binaryslags Al2O3-MnO, "FeO"-SiO2, "FeO"-CaO, "FeO"-MnO, ternary slags Al2O3-MgO-SiO2, Al2O3-MnO-SiO2, Al2O3-CaO-MgO, MgO-MnO-SiO2, Al2O3-MgO-MnO,"FeO"-Al2O3-SiO2, "FeO"-CaO-SiO2, "FeO"-MgO-SiO2, "FeO"-MnO-SiO2,quatenary slags Al2O3-CaO-MgO-MnO, Al2O3- CaO-MgO-SiO2,Al2O3-CaO-MnO-SiO2, CaO-MgO-MnO-SiO2, quinary slag Al2O3-CaO-MgO-MnO-SiO2, and the six component slag "FeO"-Al2O3-CaO-MgO-MnO-SiO2.

    The technique used was to bring the melt to equilibrium witha gas mixturecontaining Ar-CO-CO2-SO2. Extreme precautions were taken in theexperimental measurements to ensure the accuracy of the resultsobtained.The results have been incorporated into the sulphidecapacity modeldeveloped earlier in the Department ofMetallurgy, Royal Institute ofTechnology. The model parametersup to ternary interactions, which wereobtained based on theexperimental data for corresponding binary andternary systemsare provided. These model parameters were used to predictthesulphide capacities of four-, five- and six component systemsand themodel predictions were compared with experimentalresults for chosen slagscompositions. Good agreement betweenexperimental data and the results ofmodel prediction wasobtained for all the systems investigated.

    The industrial experiments were carried out at ScanaBjörneborg AB. Theaim was to see if the model, based onlaboratory experiments cansuccessfully be applied to the plantpractice. Comparison with the plantdata enabled a criticalsurvey of the industrial practice and eventualdeviations fromequilibrium conditions.

    KEY WORDS:Sulphide capacity, Slags, Desulphurization,Model, Sulphur,Multicomponent

  • 34.
    Sandberg, Fredrik
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Improvements in calculation of roll force during temper rolling1998Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 35.
    Seetharaman, Seshadri
    et al.
    KTH, Tidigare Institutioner, Metallurgi.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Modelling of Metallurgical Reactions Towards Process Simulations2000Konferansepaper (Fagfellevurdert)
  • 36.
    Shahbazian, Fatemeh
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Viscosities of some CaF-containing slags1998Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 37.
    Shahbazian, Fatemeh
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Viscosities of some Slag systems containing Calcium Fluoride2001Doktoravhandling, med artikler (Annet vitenskapelig)
  • 38.
    Sheng, D.Y.
    et al.
    Westinghouse Electric Sweden.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Application of CFD Technology in Steel Refining2000Inngår i: International Conference on Applied ComputationalFluid Dynamics, ACFD 2000, 2000, s. 162-169Konferansepaper (Fagfellevurdert)
  • 39.
    Sheng, D.Y.
    et al.
    Westinghouse Electric Sweden.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Investigation of transient fluid flow and heat transfer in a continuouscasting tundish by numerical analysis verified with non-isothermal water modelexperiments1999Inngår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 30B, nr 5, s. 979-985Artikkel i tidsskrift (Fagfellevurdert)
  • 40.
    Sheng, D.Y.
    et al.
    Westinghouse Electric Sweden.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Two-fluid Simulation on the Mixed Convection Flow Pattern in aNon-isothermal Water Model of Continuous Casting Tundish2000Inngår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 31B, nr 4, s. 867-873Artikkel i tidsskrift (Fagfellevurdert)
  • 41.
    Sheng, D.Y.
    et al.
    Westinghouse Electric Sweden.
    Söder, Mats
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Recent Efforts in Sweden to Study InclusionCharacteristics During Ladle Refining2000Inngår i: ISBN91-7170-606-2, Trita Met 85 June 2000, Stockholm- Helsinki, 2000Konferansepaper (Fagfellevurdert)
  • 42.
    Sjöqvist, Thobias
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Effect of ferromanganese and calcium carbide additions on inclusion characteristics in steel1999Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 43. Solhed, Henrik
    et al.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    An investigation of slag floatation and entrapment in acontinuous casting tundish using fluid flow simulations, sampling and physicalmetallurgy2000Inngår i: ISBN 91-7170-606-2, 2000Konferansepaper (Fagfellevurdert)
  • 44. Solhed, Henrik
    et al.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    An investigation of slag floatation and entrapment in acontinuous-casting tundish using fluid-flow simulations, sampling and physicalmetallurgy2003Inngår i: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 32, s. 15-32Artikkel i tidsskrift (Fagfellevurdert)
  • 45. Solhed, Henrik
    et al.
    Jonsson, Lage
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    A theoretical and experimental study ofcontinuous-casting tundishes focusing on slag-steel interaction2002Inngår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 32B, s. 173-185Artikkel i tidsskrift (Fagfellevurdert)
  • 46.
    Sterneland, Jerker
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Some aspects on the behaviour of olivine iron ore pellets under simulated blast furnace conditions1997Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 47.
    Sterneland, Thérèse
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Thermodynamic Investigation of Co-Cr Alloys2001Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In a collaborative effort between the Divison of Metallurgyand the Divison of Computational Thermodynamics, RoyalInstitute of Technology (KTH), Stockholm, Sweden, experimentalinvestigations have been carried out in the binary Co-Crsystem. The experimental strategy has been to measure thethermodynamic activities of Cr by the solid oxide electrolytegalvanic cell technique, as well as to measure the molar heatcapacities of the alloys, as function of temperature, by theDSC technique.

    The thermodynamic properties of four Co-Cr alloys, in thecompositional range 25 to 85 wt. % Cr, have been determined inthe temperature interval 1026 - 1297 K by the solid oxideelectrolyte galvanic cell technique. Equations for the measuredelectromotive force (EMF), E (V) = A + B*T (K), were derived inthe temperature intervals of interest. The Cr activities aswell as the relative partial molar Gibbs energies and entropieswere calculated. The break points in the EMF-temperature linesare compared with the phase diagram data available inliterature for the Co-Cr binary system.

    The molar heat capacities of several Co-Cr alloys have beendetermined in the temperature interval 318 - 1660 K by the useof the Differential Scanning Calorimetric (DSC) technique. Thecompositional range of the alloys investigated extended from 10to 90 wt. % Cr. Heat capacity equations, Cp (J/mol*K) = A + B*T(K), were derived in the temperature interval of interest tofit the experimental data. The phase transformations observedare compared with the phase diagram data available inliterature for the Co-Cr binary system.

    Key words:Cobalt, chromium, experimentalthermodynamics, solid state galvanic cell technique,Differential Scanning Calorimetric (DSC) technique,CALPHAD-technique, Thermo-Calc, phase diagram, experimentaldata.

  • 48.
    Sundström, Johan
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Dehydration and electrolysis of rare earth chlorides for the preparation of rare earth-iron alloys1997Doktoravhandling, med artikler (Annet vitenskapelig)
  • 49.
    Tilliander, Anders
    et al.
    KTH, Tidigare Institutioner                               , Tillämpad processmetallurgi.
    Jonsson, Lage T. I.
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Jonsson, P. G.
    A mathematical model of the heat transfer and fluid flow in AOD nozzles and its use to study the conditions at the gas/steel interface2001Inngår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 41, nr 10, s. 1156-1164Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Knowledge of process gas parameters in the area where the gas leaves the nozzle and then enters the molten steel in AOD converters is necessary in order to determine the boundary conditions needed to model the converter process. Using a newly developed mathematical model for an AOD nozzle verified by comparison against laser Doppler anemometer measurements, the objective of this study was to predict characteristics of non-isothermal heat transfer and fluid flow at the nozzle for pure oxygen gas injected into an AOD converter. The inlet boundary conditions for the nozzle simulation were taken from plant data. The investigation showed that the thermodynamic and physical phenomena in the region where the gas enters the steel melt cannot be determined if the transformation of kinetic energy of gas into heat is not considered because this would amount to oversight of the influences of bubble frequency, temperature, etc. on the process. The possible ranges of bubble frequency and temperature for the nozzle conditions in the study were also determined.

  • 50.
    Tilliander, Anders
    et al.
    KTH, Tidigare Institutioner, Tillämpad processmetallurgi.
    Jonsson, P. G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Effect of Ar/O-2 gas mixtures on heat-transfer and fluid-flow characteristics in AOD nozzles2000Inngår i: Steel research, ISSN 0177-4832, Vol. 71, nr 11, s. 429-434Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A model of fluid flow and heat transfer in a nozzle used for injection of argon and oxygen in AOD converters was developed earlier. In this study the model was used to determine the effect of changes in the ratio of argon to oxygen in argon-oxygen gas mixtures injected through the nozzle on fluid flow and heat transfer. It was found, for the studied conditions, that the temperature and laminar kinematic viscosity at the nozzle outlet were not dependent on the gas composition. However, the velocity, density, turbulent kinetic energy and dissipation of kinetic energy varied with a change in the fraction of oxygen injected. It is therefore concluded that for use as boundary-condition input data for an AOD converter model (under development), it is important to be able to calculate reliable velocity and turbulence parameter data for gas mixtures of different argon/oxygen ratios.

12 1 - 50 of 52
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