Dissertations / Theses on the topic 'Phase forward equilibria modelling'
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Mayne, Matthew. "Development of new software tools for phase equilibria modelling of open systems." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSES038/document.
Full textThe investigation of metamorphic processes in the Earth’s crust is integral to understanding the formation and evolution of the Earth. These processes control the preservation potential of the geochronological rock record and give us insight into, amongst others, the pressure and temperature conditions of the Earth’s interior. Further, they control fluid generation and consumption within the crust which influences global geochemical cycles within the lithosphere, hydrosphere and atmosphere. This has important implications on the global climate and the creation of conditions conducive to life. The dominant mechanism of change both within and between these systems are compositional changes invoked by processes of mass transfer. Modern quantitative phase equilibrium modelling allows the calculation of the stable phase assemblage of a rock system at equilibrium given its pressure, temperature and bulk chemical composition. However, current software programs have limited functionalities for the sophisticated handling of a changing bulk composition. A new software tool (Rcrust) has been developed that allows the modelling of points in pressure–temperature–bulk composition space in which bulk compositional changes can be passed between points as the system evolves
Haghighi, Hooman. "Phase equilibria modelling of petroleum reservoir fluids containing water, hydrate inhibitors and electrolyte solutions." Thesis, Heriot-Watt University, 2009. http://hdl.handle.net/10399/2307.
Full textWise, Michael. "Phase equilibria measurement and modelling of petroleum reservoir fluids containing gas hydrate inhibitors and water." Thesis, Heriot-Watt University, 2016. http://hdl.handle.net/10399/3204.
Full textFourie, David Johannes. "The computational thermodynamic modelling of the phase equilibria pertaining to the IiO₂ - Ti₂O₃ - FeO slag system." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50125.
Full textENGLISH ABSTRACT: During the production of pure Ti02 for the pigment industry, ilmenite, containing 35 - 60 % Ti02, is reduced to high titania slag, containing 85 - 95 % Ti02 and pig iron. These ilmenite smelters are operated in very tight operating windows. Over reducing the slag may lead to the formation of TiC and reducing much of the Ti02 to Th03. According to Namakwa Sands furnace operators, this does not only affect the grade of the product, but it can cause slag foaming and furnace eruptions. In under reducing conditions, the liquid slag is fluxed by the FeO and may corrode the furnace lining and consequently lead to run-outs. The reducing conditions in the furnace are not only controlled by carbon addition, but also by temperature. Standard practise in industrial ilmenite smelters is to operate the furnace with a slag freeze lining to protect the refractory lining from chemical and physical attack by the slag. It is therefore clear that it is of great importance to be able to predict the slag liquidus temperature at different compositions. This can help the operator to avoid dangerous operating conditions. Over the past few decades, a number of solution models have been developed to describe non-ideal solutions. With the rapid increase in computer power, these models became more valuable and practical to use in advanced control and decisionsupport. In this study, some of the better-known models are discussed and evaluated for the Ti02 - Th03 - FeO system, based on a critical review of properties and measurements published in literature. Two of these models, the "modified quasi-chemical" model and the "cell" model were chosen to be applied to the high-titania slag system. Both these models are based on statistical thermodynamics with some differences in the initial assumptions. In this study, the model parameters for the cell model were regressed from experimental data. The high-titania slag produced, consists mainly of titanium in different oxidation states and FeO, placing its composition inside the Ti02 - Th03 - FeO ternary system. Reliable experimental data for this system are very limited. All three binary systems contained in the Ti02 - ThO) - FeO system were considered, namely FeO - Ti02, Ti02 - ThO) and FeO - ThO). Only liquidus data for these three binaries were used to regress the model parameters. Accuracy of the models was determined by calculating the root mean square (RMS) error between the experimental data point and the value calculated using the model and the newly determined model parameters. These errors corresponded weil with the reported experimental error of the datasets for both the models and all the binary systems. Due to the fact that this study focussed on the liquidus surface of the system, the results were also plotted in the form of binary phase diagrams and ternary liquidus isotherms. The cell model uses only binary interaction parameters to describe the ternary system. These parameters are not expanded to higher order polynomials, which makes this model more robust, but also less accurate than other models such as the modified quasi-chemical model.
AFRIKAANSE OPSOMMING: Tydens die produksie van suiwer Ti02 vir die pigmentbedryf, word ilmeniet, wat 35 tot 60 % Ti02 bevat, gereduseer tot 'n hoë titaan slak, met 'n Ti02 inhoud van 85 tot 95 % Ti02, en potyster. Hierdie ilmeniet smeltoonde word binne baie nou bedryfskondisies beheer. Oor-redusering van die slak kan lei tot the formasie van TiC en die redusering van Ti02 tot Th03. Dit affekteer nie net die produk se kwaliteit nie, maar kan volgens Namakwa Sands oond operateurs ook slak skuiming en ontploffings tot gevolg hê. Gedurende onder-reduserende omstandighede in die oond, word die vloeibaarheid van die slak verhoog deur die hoër FeO inhoud in die slak. Dit maak die slak meer korrosief en kan lei tot faling van die vuurvaste stene. Die mate van redusering in die oond word nie net bepaal deur die toevoeging van koolstof nie, maar ook deur die temperatuur van die slak. Dit is 'n standaard praktyk van die industrie om die oond te bedryf met 'n gevriesde slak laag om sodoende die vuurvaste stene te beskerm teen chemiese en fisiese aanval van die slak. Dit is dus duidelik dat dit baie belangrik is om die slak se smeltpunt by verskillende samestellings te kan voorspel. Dit kan die operateur help om die oond binne veilige bedryfskondisies te hou. 'n Hele aantaloplossingsmodelle is oor die afgelope paar dekades ontwikkel vir die beskrywing van nie-ideale oplossings. Hierdie modelle het oor die afgelope paar jaar baie toegeneem in praktiese waarde as gevolg van die snelle toename in rekenaarkapasiteit en -spoed. Dit het veral groot waarde in gevorderde beheerstelsels en besluitneming steun. Sommige van die meer bekende modelle word in hierdie studie bespreek en ge-evalueer vir die Ti02 - Th03 - FeO stelsel, gebaseer op 'n kritiese evaluasie van eienskappe en eksperimentele data gepubliseer in die literatuur. Twee van hierdie modelle, die "gemodifiseerde kwasi-chemiese" model en die "sel" model, is gebruik om die hoë titaan slak stelsel te beskryf. Beide hierdie modelle is gebaseer op statistiese termodinamika en het klein verskille m.b.t. die aanvanklike aannames. Die model veranderlikes vir die sel model is in hierdie studie afgelei vanaf die eksperimentele data. Die hoë titaan slak wat tydens hierdie proses geproduseer word, bestaan hoofsaaklik uit FeO en titaan in sy verskillende oksidasie toestande. Dit plaas die samestelling van die slak reg binne die Ti02 - Th03 - FeO temêre stelsel. Betroubare eksperimentele data vir hierdie stelsel is baie beperk. In hierdie studie word daar gekyk al drie binêre stelsels binne die Ti02 - Th03 - FeO temêre stelsel, naamlik: FeO - Ti02, Ti02 - Th03 en FeO - Th03. Slegs die smeltpunt temperatuur data vir hierdie twee binêre is gebruik in die afskatting van die model veranderlikes. Die akkuraatheid van die modelle is bepaal deur die wortel van die gemiddelde kwadraat van die fout tussen die eksperimentele waardes en die berekende waardes te bepaal. Albei die modelle het 'n relatiewe klein fout in vergelyking met die geraporteerde eksprimentele fout gehad vir al die binêre stelsels. Hierdie studie het gefokus op die smeltpunt temperatuur van die slak en die resultate is daarom ook in die vorm van binêre fasediagramme en isoterme projeksies op die temêre fasediagramme gestip. Die "sel" model gebruik slegs binêre interaksie parameters om die temêre stelsel te beskryf Hierdie parameters word vir die "sel" model nie uitgebrei tot hoër order polinome en dit maak die "sel" model meer robuust, maar minder akkuraat as ander modelle soos byvoorbeeld die "kwasi-chemiese" model.
Bratberg, Johan. "Phase equilibria and thermodynamic properties of high-alloy tool steels : theoretical and experimental approach." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-453.
Full textKjellqvist, Lina. "Studies of Steel/Slag Equilibria using Computational Thermodynamics." Licentiate thesis, Stockholm Stockholm : Materialvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3914.
Full textEriksen, Daniel. "Molecular-based approaches to modelling carbonate-reservoir fluids : electrolyte phase equilibria, and the description of the fluid-fluid interface." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/49242.
Full textKlyukin, Yury Igorevich. "Modelling and analytical studies of magmatic-hydrothermal processes." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/84442.
Full textPh. D.
Philipp, Frauke. "Prinzipien der Syntheseplanung in der anorganischen Festkörperchemie: Analyse der Phasenbildung in Systemen M/P/Te, M = Ti,Ce,Si." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1234301400524-98886.
Full textPhilipp, Frauke. "Prinzipien der Syntheseplanung in der anorganischen Festkörperchemie: Analyse der Phasenbildung in Systemen M/P/Te, M = Ti,Ce,Si." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A23662.
Full textTeyssier, Angélique. "Caractérisation des phases solides colmatantes observées lors du traitement acide de minerais uranifères : contribution à l’étude des équilibres liquides-solides dans le système complexe Al – Fe – K – P – S – H2O (± Ca et Mg)." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10132.
Full textDuring the uranium extraction by acid leaching, AREVA observed the precipitation of not well crystallized solid phases, leading to the clogging of various equipment. The analyses of these precipitates highlighted the formation of a minor yellow precipitate and a major white precipitate containing calcium sulphate and aluminium hydroxisulphate. To understand the phenomena leading to the precipitation and to predict, prevent or at least limit their formation, this thesis work consisted of the solid-liquid equilibria experimental study of the Al–Fe–K–P–S–H2O (± Ca and Mg) system in an acidic environment at 25°C, with the identification of solid phases which may appear in natural ore as the major goal. The results could complete the thermodynamic database used to model global behaviour of the environment during acid mining. Based on the observed precipitates, two quaternary systems were defined, such as the H2O-Al3+, Ca2+ // O2-, SO42- system. After the development of appropriate analytical techniques, the work focused on the delimitation of the liquid-solid equilibria of the system based on the white precipitate and particularly on the analysis of the ternaries involving aluminium hydroxisulphates. As clogging occurs during acidification, the hydroxisulphate precipitation depending on the pH was studied in the presence of minority cations (Na+, K+, Mg2+, Ca2+), in order to characterise the solid phases which were formed, and to define their solubility constants. For the solubility constant determination, a calculation model of the ion activity coefficients in solution was used. A dynamic survey on a column containing natural ore was done and compared to static results
Collins, L. J. "Low-temperature mica schists of Anglesey, UK: cold subduction on the margin of Avalonia." Thesis, 2017. http://hdl.handle.net/2440/126658.
Full textAnglesey in North Wales is considered to contain the oldest exposures of lawsonite-glaucophane blueschist in the world, marking the first appearance of lawsonite in the geological record, and heralding the emergence of truly modern subduction thermal regimes. The blueschists formed in the late Neoproterozoic during subduction beneath Avalonia. Interlayered within the blueschist unit are rare lenses of garnet-bearing metapelite that form part of a lithological association with more voluminous garnet-free metapelites. Detrital U-Pb zircon geochronology of the metapelites indicates that deposition of the protolith occurred ~630-590 Ma ago. The dominant detrital zircon ages correspond to the age of arc magmatism along the inferred margin of Avalonia, suggesting that the bulk of the detritus was derived from erosion of the arc. The presence of less abundant older zircons that range in age up to 2Ga, suggest that the arc was built on an ancient continental margin. This suggestion is supported by Nd isotopic compositions of the metapelites, which indicate derivation from an evolved source. The rare garnet metapelites contain the metamorphic assemblage garnet-muscovite-chlorite-albite-quartz-titanite-rutile-pyrite in which coronas of rutile surround titanite. Phase equilibria forward modelling of the metapelites indicates a prograde burial path that culminated with conditions around 400-450°C, at pressures of 10-12kbar. These conditions give an average thermal gradient of around 40°C/kbar, which is comparatively warm for lawsonite-bearing rocks. This suggests the Anglesey lawsonite-bearing blueschists record the onset of global subduction thermal regimes in the late Neoproterozoic that can stabilise lawsonite, rather than simply being a fortuitous preservation of widely developed refrigerated metamorphic rock systems.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2017
Greenslade, M. M. "Ultrahigh temperature metamorphism: testing models for collision vs extension." Thesis, 2015. http://hdl.handle.net/2440/118029.
Full textThe Warumpi Province has been interpreted to be exotic and accreted to the Northern Australian Craton (NAC) during the Liebig Orogeny at c.1640Ma. However, phase equilibria modelling of melt-deficient, Mg-Al rich granulite facies rocks at Hill 830, in the Mount Liebig area show contradictory evidence of a decompressional pressure-temperature path and a high metamorphic gradient of 90°Ckbar. This interpretation in conjunction with abundant c.1780- 1740Ma and c.1640Ma magmatism in the southern Aileron and Warumpi Provinces, indicate that the tectonic regime at c.1640Ma may instead be a south-migrating, extensional scenario, compared to the previously accepted collisonal regime; speculating that the Warumpi Province is not ‘exotic’ to the NAC.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2015
Walsh, A. K. "Duration of the Petermann Orogeny from coupled diffusion and phase equilibria modelling." Thesis, 2010. http://hdl.handle.net/2440/106280.
Full textThe Ediacaran to Cambrian (600-500 Ma) intraplate Petermann Orogeny significantly affected the crustal architecture of Central Australia, resulting in the exhumation of the Musgrave Province from beneath the Centralian Superbasin. In the western Musgrave Province response to intensive deformation is variable, with pervasive mylonitic reworking and localised migmitisation in the western Mann Ranges, and discrete mylonitisation in the eastern Mann Ranges. The duration of this period of intraplate orogenesis is a currently debated topic. Ti-in-zircon thermometry coupled with SHRIMP U-Pb zircon geochronology indicate that peak temperatures of 733±23°C in the western Mann Ranges occurred at circa 540 Ma. Combined diffusion-cooling modelling, U-Pb rutile and titanite isotopic data and calculated phase equilibria of recrystallised metagranites from the Cockburn Shear Zone and kyanite-bearing mylonites from the Mt. Charles Thrust indicate exhumation driven cooling from peak P-T conditions of 12-14 kbars and 700-750°C to 6-7 kbars and 550-600°C at c. 500 Ma occurred at a rate of 3.75-5.6°C/ My. These results indicate a slow-cooling and long-lived thermal regime and additionally suggests that final exhumation of the Musgrave Province had not occurred by c. 500 Ma, much younger than previously estimated. These findings suggest that granulite-facies metamorphism in the Musgrave Province was regional and that other factors such as fluid, control the variations in style of structural reworking. This study lends support to the notion that the intraplate Petermann Orogeny was long-lived and does not advocate short-lived orogenesis or the theory that shear heating is the driving force for metamorphism.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010
Macfarlane, J. E. "Anisotropic forward modelling of fluid injection and phase angles exceeding 90o in magnetotellurics." Thesis, 2012. http://hdl.handle.net/2440/95175.
Full textElectrical anisotropy, defined as the directional dependence of electrical conductivity within a medium, causes changes in the electromagnetic signal measured by magnetotellurics (MT) and as such is an important property to consider when interpreting MT data. This study concentrates on replicating the MT response measured at two distinctively different geological settings using a series of 2 dimensional anisotropic forward models. Results presented in this study show that 2-dimensional anisotropic forward modelling is able to account for subtle differences in subsurface anisotropic resistivity structures. Specifically, 2-dimensional anisotropic forward modelling is able to reproduce the measured difference in MT response between pre- and post fluid injection conditions at the Paralana Geothermal System using an anisotropic fluid volume. A second application in constraining the source of the anomalous phase angles exceeding 90o observed in MT measurements of the Capricorn Orogen, shows that 2-dimensional anisotropic MT models are not able to produce phase angles exceeding 90o in the MT data which has its electric field orientated perpendicular to the geoelectric strike. These findings provide a case supporting the use of 2-dimensional anisotropic forward modelling as a means of modelling changes caused by the flow of a fluid through the crust. In addition, they also highlight issues associated with its application to complicated structures perpendicular to the strike of the profile.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 2012
Alessio, Kiara Louise. "The effects of high temperature metamorphic and melting processes on granulite-facies rocks." Thesis, 2019. http://hdl.handle.net/2440/122416.
Full textThesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2019