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1
Gao, Zimin. "Phase Relationships in the System CaO-MgO-Al2O3-SiO2 in Plagioclase Lherzolite Field." FIU Digital Commons, 1991. http://digitalcommons.fiu.edu/etd/3615.
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Unreversed phase equilibrium studies were carried out in a model mantle composition CaO-MgO-Al2O3-SiO2 (CMAS) system at 5-9 kb and 12 7 0-13 3 CPC. The experiments provide a set of data which narrowly constraints the position of the solidus in the system CMAS in the plagioclase lherzolite field. All runs were conducted in a 2.54 cm core-diameter piston-cylinder apparatus with salt-cell pressure medium. The equilibrium compositions of the mineral phases and glass were analyzed with an electron microprobe. The A12O3 contents in orthopyroxene and clinopyroxene coexisting with olivine and plagioclase increase with pressure. The deduced alumina isopleths in orthopyroxene and clinopyroxene have higher slope in P-T space than those of theoretical calculations. An empirical pyroxene geobarometer has been developed and applied to the plagioclase lherzolite xenoliths in Hawaiian basalt.
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Ponton, Clive Brian. "The mechanical properties of glass-ceramics in the system CaO-MgO-Al2O3-SiO2." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/47692.
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Hota, Belma [Verfasser], and Joachim [Akademischer Betreuer] Deubener. "Einfluss der Gefügeentwicklung auf die Kratzempfindlichkeit von Glaskeramiken im System MgO-Al2O3-SiO2 und Li2O-SiO2 / Belma Hota ; Betreuer: Joachim Deubener." Clausthal-Zellerfeld : Technische Universität Clausthal, 2018. http://d-nb.info/1231363819/34.
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Ma, Haoyuan. "Study on preparation of high performance CaO-MgO-Al2O3-SiO2 system glass-ceramic with industrial by-products." Scholarly Commons, 2014. https://scholarlycommons.pacific.edu/uop_etds/221.
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Blast furnace slag (BFS), iron ore tailings (IOT), and coal fly ash (CFA) are common industrial by-products with huge annual yield and low reuse rate (< 30%). This research was intended to prepare high performance glass-ceramics from these three industrial by-products. What's more, two energy saving methods were put forward. One was application of single-stage heat treatment, another was mixing cold solid raw material (IOT, CFA) with melted BFS discharged at 1500 in iron making process instead of mixing all the raw material in room temperature and then heating them to melt. Different binary basicity (MCaO /MSiO2 ) and content of Al2O3 had been studied to determine the best formula for high performance glass-ceramic in terms of mechanical properties. Sample 04 (MCaO /MSiO2 =0.4, Al2O3 wt. %=9%) and Sample 05Al-2 (MCaO /MSiO2 =0.5, Al2O3 wt. %=12%) were found with the highest bending strength, 94 MPa and 89 MPa respectively. In addition, with augite and diopside as primary crystalline phase, they also had a Vickers micro-hardness of 6.2 GPa and 6.3 GPa. When applied single-stage heat treatment, sample H4 obtained a bending strength of 77.89MPa and Vickers micro-hardness of 6.5 GPa, very close to H0. Meanwhile, when applied hot liquid-cold solid mixing method, M3 obtained a bending strength of 80.51 MPa, also very close to M0. Which indicates that these two energy saving method are all feasible to be applied to prepare high performance glass-ceramic.
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Welch, Mark David. "Experimental studies of selected amphiboles in the system Na2O-CaO-MgO-Al2O3-SiO2-H2O-F2 and its subsystems." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/11947.
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Dittmer, Marc [Verfasser], Christian [Akademischer Betreuer] Rüssel, and Dörte [Akademischer Betreuer] Stachel. "Gläser und Glaskeramiken im System MgO-Al2O3-SiO2 mit ZrO2 als Keimbildner / Marc Dittmer. Gutachter: Christian Rüssel ; Dörte Stachel." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2012. http://d-nb.info/1018652973/34.
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Shin, Jin-Wook. "The experimantal and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=975613715.
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Shin, Jin-Wook. "The experimental and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 /." Aachen : Shaker, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013110727&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Veit, Ulrike [Verfasser], Christian [Gutachter] Rüssel, and Dörte [Gutachter] Stachel. "Entwicklung hochfester Gläser aus dem CaO-(MgO-)Al2O3-SiO2-System für die Verstärkung von Kompositmaterialien / Ulrike Veit ; Gutachter: Christian Rüssel, Dörte Stachel." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/117039678X/34.
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Shin, Jin-Wook [Verfasser]. "The experimental and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 / Jin-Wook Shin." Aachen : Shaker, 2004. http://d-nb.info/1181602912/34.
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Song, Minho. "A Study on the Correlation between Ladle Glaze and Non-Metallic Inclusions in the Ladle Treatment." Doctoral thesis, KTH, Mikro-modellering, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-27640.
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In the present thesis, the correlation between ladle glaze and non-metallic inclusions in the ladle treatment was studied. A number of industrial trials with full scale ladle and laboratory works were performed to investigate the inclusions in the ladle treatment. BaO was used as tracer in the ladle slag to investigate the effect of slag on inclusion composition and the formation of non-metallic inclusions by ladle glaze. BaO was detected in the inclusions of all followed heats. This observation showed strong evidence for the generation of non-metallic inclusions by the ladle glaze. The increase of the fractions of BaO containing inclusions and their average content of BaO in the first heat with tracer suggested that the effect of slag on the composition of inclusions was a very slow process. The detachment of ladle glaze and the chemical transformations of oxide solution in the MgO matrix were investigated. The experimental results evidently showed that the ladle glaze could be the source of inclusions continually during the ladle treatment. Samples of liquid oxide solution to simulate the liquid oxide inclusions carried over from EAF were equilibrated with molten steel under controlled atmosphere. The results along with thermodynamic calculation suggested that the SiO2 content of inclusions from EAF could be considerably reduced by dissolved aluminium in the steel. This would explain the vanishing of inclusions containing high SiO2 content after deoxidation. Due to the lack of experimental data, the viscosities of slags in the Al2O3-CaO-MgO-SiO2 system were measured using the rotating cylinder method in the temperature range of 1720 to 1910 K. Eight different slag compositions related to the secondary steel making operations were selected. Viscosities in this system and its sub-systems were expressed as a function of temperature and composition based on the viscosity model developed earlier at KTH. The activities of oxide components in the Al2O3-CaO-MgO-SiO2 systems at 1873 K were measured by equilibrating liquid slag and metal. Either silicon or copper was used as the metal phase and the oxygen partial pressure was controlled with different mixing rates of Ar and CO gas flow in equilibrium with graphite. Iso-activity lines were drawn from the measured activity values in the isothermal section of the slag systems. Nine series of industrial trials were carried out using the same ladle in each series to examine the effect of ladle slag on the number of non-metallic inclusions in the next heat. It was found that the number of inclusions increased with SiO2 content of the ladle slag in the previous heat. No clear trends were found for the effects of viscosity and MgO activity of the previous slag on the number of inclusions. Theoretical analysis based on the experimental results suggested that the formation of 2CaO∙SiO2 followed but the dusting of the compound made the refractory more porous, which was reasonable for the number of non-metallic inclusions.
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Purwin, Horst [Verfasser], Hans-Joachim [Akademischer Betreuer] Kleebe, and Gerhard P. [Akademischer Betreuer] Brey. "Eine experimentelle Studie des Oxidationszustandes von Eisen in Granat und Klinopyroxen als Funktion der Temperatur im System CaO-FeO-Fe2O3-MgO-Al2O3-SiO2: Implikationen für die Granat-Klinopyroxen-Geothermometrie / Horst Purwin. Betreuer: Hans-Joachim Kleebe ; Gerhard P. Brey." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2012. http://d-nb.info/1106453387/34.
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Jakobsson, Lars Klemet. "Distribution of boron between silicon and CaO-SiO2, MgO-SiO2,CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags at 1600°C." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24010.
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New energy sources are needed for a sustainable future. Solar cells have a huge potential as a sustainable energy source but further development of this technology is needed for solar cells to become cost-competitive with other energy sources. Silicon produced by metallurgical refining methods has the potential of reducing the cost of crystalline silicon solar cells significantly but boron has proven to be hard to remove from silicon by these methods. Slag refining is however a promising refining method for removal of boron from silicon. The aim of this thesis was to determine accurate data for the distribution of boron between silicon and selected slags. All published values of the distribution coefficient of boron have been critically reviewed in this work. The thermodynamic properties and distribution of other major components of the system have also been reviewed. Several experiments with silicon and CaO-SiO2, MgO-SiO2, CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags have been conducted at 1600 °C under argon atmosphere. A series of experiments with ferrosilicon and CaO-SiO2 slags have also been carried out. Accurate data for the distribution of boron between silicon and CaO-SiO2, MgO-SiO2, CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags at 1600 °C has been determined. The distribution of other major slag components between slag and silicon has also been found in these slag systems. The distribution of calcium and boron between ferrosilicon and CaO-SiO2 slags at 1600 °C has been determined. Activities of slag forming components have been determined in the CaO-SiO2, MgO-SiO2 and CaO-MgO-SiO2 systems. The activity coefficient of BO1.5 at infinite dilution in these slags has also been determined. Activity coefficients of calcium, magnesium and aluminium at infinite dilution in silicon and the activity coefficient of calcium and boron at infinite dilution in ferrosilicon have been determined. An alternative equation for mass transfer has been derived and the mass transfer coefficient of boron in a 37.9%CaO-62.1%SiO2 slag has been estimated to be ks = 5.2 · 10-7m/s. The refining efficiency of CaO-MgO-SiO2 slags has been found to be approximately the same independently of slag composition with a distribution coefficient of boron between 2 and 2.5. This also includes the binary CaO-SiO2 and MgO-SiO2 systems. The activity coefficient of BO1.5 at infinite dilution in CaO-MgO-SiO2 slags, including the binary CaO-SiO2 and MgO-SiO2 systems, has been found to follow the activity coefficient of SiO2 where . A linear decrease of the distribution coefficient was found with increasing Al2O3 content in a ternary CaO-Al2O3-SiO2 slag. This has been found to be caused by an increasing activity coefficient of BO1.5 at infinite dilution in slag relative to the activity coefficient of SiO2 where<img src="https://innsida.ntnu.no/user/fonn/ansatt/hvaskjer/-/messageservice/channel?p_p_auth=GBC0v8FP&p_p_lifecycle=2&p_p_resource_id=fileSyndView&p_p_cacheability=cacheLevelPage&_readadvancedportlet_WAR_messageserviceportlets_csrfToken=94fa41c2-3215-4437-9f5d-8a6050bffa43&_readadvancedportlet_WAR_messageserviceportlets_messageId=urn%3Auuid%3Abc6ab711-a6b7-3a80-9394-9fbf3c1f5d8f&file=2e0405bc-d564-3f6e-ad46-de0a45593b60" />. The distribution coefficient of boron between ferrosilicon and CaO-SiO2 slags was found to be unchanged with iron content in silicon
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Lira, Claudia. "Obtenção de esmaltes vitrocerâmicos de elevado desempenho nos sistemas MgO-Al2O3-SiO2 e CaO-Al2O3-SiO2." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/84173.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência e Engenharia de Materiais.<br>Made available in DSpace on 2012-10-20T06:57:41Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-26T02:20:11Z : No. of bitstreams: 1
190170.pdf: 33566657 bytes, checksum: c675bd5bf55bac6ed81d265a5a165e9b (MD5)<br>Este trabalho estudou a viabilidade tecnológica de obtenção de esmaltes vitrocerâmicos de elevado desempenho, caracterizando uma alta resistência à abrasão, resistência ao manchamento e ao ataque químico. Inicialmente, procedeu-se à seleção de composições adequadas para a obtenção de fritas. Esta seleção foi realizada a partir de sistemas com cristalização de fases de alta dureza e baixo coeficiente de dilatação térmica, além da facilidade de obtenção e utilização industrial das matérias-primas. Foram investigadas diversas composições nos sistemas MgO-Al2O3-SiO2 e CaO-Al2O3-SiO2, com relação ao seu comportamento térmico de sinterização e cristalização, caracterização microestrutural e dilatométrica. Foram selecionadas duas composições com características mais adequadas à obtenção de esmaltes, segundo os critérios: formação das fases cristalinas cordierita e anortita, baixa porosidade e coeficiente de dilatação térmica adequado aos suportes cerâmicos comerciais. As composições selecionadas para a obtenção de fritas foram: Mg-C2 7% Na2O (composição aproximada: 20%MgO, 24%Al2O3, 49%SiO2, 7%Na2O, % em massa), do sistema MgO-Al2O3-SiO2 e Ca-Z1 do sistema CaO-Al2O3-SiO2 (composição aproximada: 31%CaO, 13%Al2O3, 52%SiO2, 4%ZnO, % em massa). As fritas obtidas a partir das composições selecionadas foram utilizadas na formulação de esmaltes e aplicadas sobre suportes cerâmicos de grês-porcelanato para monoqueima. Para a definição dos parâmetros mais adequados de formulação do esmalte e condições de tratamento térmico foram realizados diversos testes de aplicação, segundo um delineamento experimental pelo método Taguchi. Os esmaltes testados foram avaliados com relação às características visuais, porosidade, medidas de dureza ao risco, dureza Vickers e dureza Mohs. O esmalte obtido a partir da frita Mg-C2 7% Na2O, utilizando queima à temperatura máxima de 1200°C obteve o melhor desempenho na avaliação. Este esmalte apresentou características de elevada dureza ao risco (» 15 GPa), baixa porosidade (» 2%), elevada resistência à abrasão (PEI 5), ao manchamento (classe 5) e ao ataque químico (classe GA e GLA). Estas características se mostraram compatíveis e, em muitos casos, superiores a outros materiais como vitrocerâmicos sinterizados, granito, grês-porcelanato e revestimento para piso classe PEI 5, utilizados como referência. Desta forma, o esmalte vitrocerâmico desenvolvido demonstrou características adequadas a um revestimento cerâmico de alto desempenho, com viabilidade de obtenção segundo os processos convencionais de produção em monoqueima de revestimentos cerâmicos esmaltados.
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Mao, Huahai. "Thermodynamic modelling and assessment of some alumino-silicate systems." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-251.
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Dong, Pengli. "Measurements of the thermodynamic activities of chromium and vanadium oxides in CaO-MgO-Al2O3-SiO2 slags." Licentiate thesis, KTH, Materials Science and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9940.
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<p>In the present work, the thermodynamic activities of chromium and vanadium oxide in CaO-SiO2-MgO-Al2O3 slags were measured using gas-slag equilibration technique. The slag was equilibrated with a gas mixture of CO, CO2 and Ar gases enabling well-defined oxygen partial pressures in the gas mixture (PO2=10-3,10-4,10-5 Pa) at temperatures 1803, 1823K, 1873, 1923 K. The slags were kept in Pt crucibles during the equilibration and the duration of which was 20 h. From a knowledge of the thermodynamic activity of chromium and vanadium in Cr or V in Pt alloy, obtained from literature, and the oxygen partial pressure in the gas stream calculated by Thermo Calc software, the thermodynamic activity of chromium, vanadium oxide in the slags could be observed.An assessment of the experimental studies in earlier works reveal that, the activities of chromium at low chromium contents and vanadium in their respective alloys in platinum exhibits a strong negative deviation from ideality, the logarithms of activity coefficient of these elements were found to increase with increasing mole fractions of these metals in the Pt-alloys.Regarding the slag phase, all the chromium in the slags was assumed to be present in the divalent state in view of the low Cr contents and the low oxygen potentials employed in the present studies. Analogously, vanadium in the slag was assumed to be in the trivalent state in view of the low vanadium contents in the slag and the low oxygen partial pressure in the gas phase. Activity of chromium oxide, CrO decreases with increasing temperature and decreasing content of chromium oxide in slag and oxygen partial pressure in the gas phase. Activity of vanadium oxide, VO1.5 in slag phase shows a negative deviation from ideality. Activity coefficient of vanadium oxide shows a decrease with basicity of slag and the “break point” occurs at about slag basicity of 1 under the oxygen partial pressure of 10-3 Pa and temperature of 1873 K.A relationship for estimating the actual content of chromium, vanadium in slag as a function of activities of chromium or vanadium, temperature, oxygen partial pressure and slag basicity were developed from the present results, the agreement between the estimated and experimental values is satisfactory, especially at lower oxygen partial pressure.</p>
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Akins, Joseph A. Asimow Paul David. "Dynamic compression of minerals in the MgO-FeO-SiO2 system /." Diss., Pasadena, Calif. : California Institute of Technology, 2003. http://resolver.caltech.edu/CaltechETD:etd-05302003-142219.
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Polli, Elise. "Incorporação da areia descartada de fundição (ADF) na fabricação de vitrocerâmicos do sistema SiO2 CaO MgO Al2O3." Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/1654.
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Previous issue date: 2014-02-07<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The foundry is the fastest way to obtain metals pieces through the casting of liquid metal in green sand moulds. The main components of foundry sands are natural sand, bentonite and carbonaceous additive. During the foundry process, the components lose their mixture characteristics, in addition to the decrease in volume, becoming necessary the discard part of the foundry sand, generating the wasted foundry sand (WFS). In Brazil are discarded approximately 2.76 millions of tons annually and this number has become an environmental concern due to the difficulty of dispose of the residue. In this context,
several lines of research aimed at waste recycling has been studied, among than the use of WSF in glass and glassceramic. This work studies the incorporation of calcined WFS replacing the pure silica in percentages 25, 50, 75 e 100% in manufacturing of glass and glassceramic belonging to the quaternary system SiO2 CaO MgO Al2O3. The samples were melted in alumina crucibles at 1400 °C for one hour. After obtaining, the vitreous samples were underwent annealing at 750 °C for half hour and after, were submitted to spectroscopy ultraviolet visible and heat treatment to 900, 950 and 1000 °C to 90 minutes. After heat treatment, the samples were sent for X ray diffraction analysis, optical microscopy, and only the samples 50 and 100% were sent to scanning electron microscopy, in order to analyze the recrystallization of the samples. For the heat treatment to 900 ° C, the crystalline phases were found akermanita and diopside. As the temperature increased to 950 ° C, the first crystals gehlenita and melilite began to appear and crystallization increased with higher heat treatment temperature. The images obtained by both microscopies relate to the formation of a dendritic structure for the samples 25, 50 and 75% for the three heat treatments. For the heat treatment at 900 ° C crystallization is related to the diopside, and for treatment at 950 to 1000 ° C is related to melilita. For the sample was 100% on both the crystallization heat treatment.<br>A fundição é a maneira mais rápida para a obtenção de peças metálicas através do vazamento do metal líquido em moldes de areia verde. Os principais componentes das areias de fundição são as areias bases, bentonita e pó de carvão. Durante o processo de fundição, os componentes perdem as suas características de mistura, além da diminuição de volume, tornando- se necessário o descarte de parte dessa areia de fundição, gerando a areia descartada de fundição (ADF). No Brasil são descartadas aproximadamente 2,76 milhões ton de areia anualmente e esse número passou a ser uma preocupação ambiental devido à dificuldade do descarte do resíduo. Nesse âmbito, diversas linhas de pesquisa que visam à reciclagem do resíduo vêm sendo estudadas, entre elas a utilização de ADF em vidros e vitrocerâmicos. Este trabalho estuda a incorporação de ADF calcinada em substituição a sílica pura nas porcentagens de 25, 50, 75 e 100% na fabricação de vidros e vitrocerâmicos pertencentes ao sistema quaternário SiO2 Cão MgO Al2O3. As amostras foram fundidas em cadinhos de alumina a 1400 °C durante uma hora. Após da obtenção, as amostras vítreas foram recozidas a 750 °C por meia hora e após, foram submetidas a análise de espectroscopia de ultravioleta visível e também a tratamentos térmicos a 900, 950 e 1000 °C durante 90 min. Após os tratamentos térmicos todas as amostras foram encaminhadas para a análise de difração de raios X, microscopia óptica e apenas as amostras 50 e 100% de ADF foram encaminhadas para a microscopia eletrônica de varredura, a fim de analisar a recristalização das amostras. Para o tratamento térmico de 900 °C, as fases cristalinas encontradas foram a akermanita e o diopsídio. À medida que a temperatura aumentou aos 950 °C começaram a surgir os primeiros cristais de gehlenita e melilita e a cristalização aumentou com a maior temperatura de tratamento térmico. As imagens obtidas por ambas às microscopias relatam a formação de uma estrutura dendrítica para as amostras 25, 50 e 75% ADF para os três tratamentos térmicos. Para o tratamento térmico a 900 °C a cristalização está relacionada com o diopsídio, e para os tratamentos a 950 e 1000 °C está relacionada à melilita. Para a amostra 100% ADF houve a cristalização em ambos os tratamentos térmicos.
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Geßwein, Holger. "Entwicklung hochfester Net-shape-Oxidkeramiken im System Al2O3-SiO2-ZrO2." Karlsruhe FZKA, 2005. http://bibliothek.fzk.de/zb/berichte/FZKA7186.pdf.
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Iriarte, Lecumberri Pedro Ignacio. "Synthèse de minéraux argileux dans le système SiO2-Al2O3-Fe2O3-MgO-Na2O-H2O entre 150 et 225°C." Poitiers, 2003. http://www.theses.fr/2003POIT2252.
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Dans le présent mémoire on a étudié la synthèse de minéraux argileux (kaolinites et smectites) sous diverses conditions hydrothermales de pH (5-10) et de températures (150-225 o̱C), dans le système SiO2-Al2O3-Fe2O3-MgO-Na2O-H2O. Les matériaux de départ utilisés étaient des gels amorphes avec des stoechiométries de smectite et différentes proportions de cations octaédriques (aluminium, fer et magnésium). Préalablement à la synthèse, on a réalisé une optimisation de la méthode de préparation des gels dans des conditions hydrothermales (pH). La kaolinite se forme dans des conditions de pH légèrement acide. En présence de fer, celui ci s'incorpore à la structure, et la teneur en FeVI peut atteindre 30 %. Dans la gamme de composition étudiée, le système se comporte comme une solution solide octaédrique Al-Fe3+ dans les kaolinites. A partir de gels riches en Al, avec du Fe3+ et avec ou sans Mg et sous des conditions de pH légèrement plus basiques (7-10), des smectites dioctaédriques ont été synthétisées. Dans toutes les séries, notamment dans les échantillons synthétisés pour les plus basses températures, la smectite est accompagnée d'une phase à 7 Å de type kaolinite. Toutes les phases smectitiques néoformées sont de type beidellite. A partir de gels riches en Mg et dans des conditions de pH légèrement alcalin (8-10), des argiles trioctaédriques de type saponite, stévensite et kérolite ont été synthétisées. Dans tous les cas, de la kérolite a été formée. Le gel purement magnésien, aboutissent á la formation d'interstratifiés stevensite/kerolite. Les gels riches en magnésium et contenant du Fe3+, aboutissent à la formation de stevensite et kerolite. Les gels riches en magnésium et contenant de l'aluminium aboutissent à la formation de saponite et de kérolite interstratifiés ou pas interstratifiés. . .
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Vieira, Luana de Aguiar. "Estudo da sinterabilidade de materiais aluminosos obtidos através da sinterização por fase líquida no sistema Al2O3-MgO-CaO-SiO2." Universidade do Estado de Santa Catarina, 2006. http://tede.udesc.br/handle/handle/1697.
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Previous issue date: 2006-08-29<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The use of aluminium ceramic materials is a reality in many industrial fields. Though, the research development to improve the products and processes that there are nowadays are the same that have been used for the last decade. The majority of the studies aim to explore the most the potencials of alumina that, in spite of having a wide range of applications, has a great deal of its properties. This research to has the objective to obtain ceramic pieces containing hight quantities of alumina, to obtained through the sintering of liquid phase, in addiction to magnesia, kaolin, calcium carbonate and shell of oyster. The raw materials concerning are low prices and are supplier of forming elements at liquid phase: magnesium oxide (MgO), silicium oxide (SiO2), calcium oxide (CaO) respectely. The shell of oyster was used in this research to substitute commercial calcium carbonate, it reduces the price of production as well as minimizing a problem of de are litoranea in special Florianópolis, wich is the dumping of this materials in environment. With the results, it s verified that the presence of liquid phase reduces sgnificantilly the temperature. Obtaining, in this way, one alumina with high density that can be used in many kinds of application. The results also show that the formation of liquid phase and sinterability depend strongly on composition control done through the ternário diagram MgO-CaO-SiO2.<br>O uso de materiais cerâmicos aluminosos é uma realidade em inúmeros setores industriais. Entretanto, o desenvolvimento de pesquisas para o aperfeiçoamento de produtos e processos já existentes se mantém nas últimas décadas. A maioria destes estudos busca explorar ao máximo os potenciais da alumina que, embora possua uma vasta gama de aplicações, tem suas propriedades aproveitadas parcialmente.Este trabalho tem por objetivo a obtenção de peças cerâmicas contendo elevados teores de alumina, obtida através da sinterização por fase líquida, pela incorporação de óxido de magnésio, caulim, carbonato de cálcio comercial e casca de ostra. As matérias-primas utilizadas são de baixo custo e fornecedoras dos elementos formadores de fase líquida: óxido de magnésio (MgO), óxido de silício (SiO2) e óxido de cálcio (CaO) respectivamente. A casca de ostra foi utilizada, nesta pesquisa, como substitutivo do carbonato de cálcio comercial. Sendo assim, além de reduzir o custo de produção, a utilização da casca de ostra minimiza o problema das regiões litorâneas, em especial Florianópolis, que é a deposição incorreta deste material no meio ambiente. Os resultados obtidos comprovam que a presença da fase líquida reduz significativamente a temperatura de sinterização, obtendo-se assim um material aluminoso com elevada densidade que pode ser usado para vários fins industriais. Além disso, os resultados também demonstraram que a formação da fase líquida e a sinterabilidade dependem significativamente do controle da composição realizado através do diagrama ternário MgO-CaO-SiO2.
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Земляной, К. Г. "Влияние способов измельчения на спекание материалов в системе Al2O3 – MgO – SiO2 – CaO – Cr2O3 : автореф. дис. … канд. техн. наук : 05.17.11". Thesis, б. и, 2013. http://hdl.handle.net/10995/19827.
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Liu, Xiang Feng. "Signification pétrogénétique des micas trioctaédriques sodiques : modélisation expérimentale dans le système Na2O, K2O, MgO, Al2O3, SiO2, H2O, (TiO2, HF, D2O)." Orléans, 1989. http://www.theses.fr/1989ORLE2016.
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Aygun, Aysegul. "Novel Thermal Barrier Coatings (Tbcs) That Are Resistant To High Temperature Attack By Cao-Mgo-Al2o3-Sio2 (Cmas) Glassy Deposits." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1221589661.
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Soulard, Henri. "Evolution des laves basiques alcalines : étude expérimentale à 1 atmosphère du système analogue synthétique CaO-MgO-Al2O3-SiO2-Na2O (CMASN)." Clermont-Ferrand 2, 1992. http://www.theses.fr/1992CLF21424.
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Cette etude apporte des donnees experimentales sur les assemblages 4, 5 ou 6 phases de l'ensemble liquide-forsterite-diopside-plagioclase-spinelle-melilite-nepheline-orthoenstatite (liq-fo-di-pl-sp-mel-ne-oen). Apres avoir detaille les techniques experimentales et analytiques utilisees, la stchiometrie des phases minerales a ete verifiee: forsterite fo-mo-sp, diopside di-cats-en-jd, plagioclase an-ab-cms3#+s4, spinelle sp-os-ca, melilite ak-geh-sm-(ms3), nepheline nane-an-s4#+-(cms3)-(#+mas2) et orthoenstatite en-mgts-di#+jd. Nous proposons avec a. Provost, une methode descriptive numerique qui permet de quantifier les evolutions des compositions des phases dans les surfaces divariantes, et tient compte des incertitudes analytiques. Les relations de phases (donc les trajets de cristallisation) ont ete determines dans tout le systeme en utilisant (comme pour la verification de la stchiometrie) un programme de calcul de melange (inversion generalisee avec propagation des erreurs analytiques). L'assemblage cardinal des roches basaltiques (liq-fo-di-pl) possede un tres vaste domaine de stabilite reliant les compositions sursaturees a un modale et sous-saturees ou le sp, la mel, la ne et la wollastonite sont stables. Le domaine de compositions est subdivise sur la base de la norme cipw et d'un critere d'alcalinite (ne==2 na/na+al). Les limites ainsi definies correspondent a des changements drastiques dans la solution solide du di, du pl et de la mel. Des analogues synthetiques de la plupart des roches volcaniques naturelles ont pu etre definis, des basaltes aux rhyolites, phonolites et nephelinites. La relecture genetique de la classification internationale nous permet d'inclure les melilitites dans un modele d'evolution des magmas a b. P. : *les basaltes (s. L. ) produisent l'ensemble des magmas differencies par cristallisation de fodi-pl; *4 magmas parents suffisent a engendrer l'ensemble des roches volcaniques (les basaltes, nephelinites a ol, melanephelinites, melilitits a ol). Les melilitites evoluent totalement independamment de tous les autres magmas
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Souza, Filho Manoel Pereira de [UNESP]. "Vitrocerâmicas de alta resistência mecânica obtidas a partir da cristalização do sistema SiO2-Al2O3-MgO-Li2O com adição de ZrO2 e B2O3." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/103730.
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souzafilho_mp_dr_guara.pdf: 3300858 bytes, checksum: 28f848b21612cf810bf7d4ab1078db03 (MD5)<br>Neste trabalho estudou-se as vitrocerâmicas obtidas a partir de vidro base do sistema SiO2-Al2O3-MgO-Li2O com adição de ZrO2, como agente nucleante e do B2O3, que tem a função de reduzir a viscosidade do sistema durante o processo de fusão. Os vidros precursores foram obtidos por fusão na temperatura de 1650 ºC, em cadinhos de mulita-zirconia. Os vidros fundidos foram vertidos em molde de grafite para obtenção das amostras monolíticas, e em água para obtenção do material particulado. Este material foi moído e passou por processo de prensagem uniaxial e isostática, antes da sinterização. Para produção das vitrocerâmicas foram realizados tratamentos térmicos em duas condições diferentes. Na primeira as amostras foram aquecidas até 1100 ºC, com taxa de 10 ºC/min, e, na segunda, aquecimento inicial até a temperatura de 780 ºC, com taxa de 10 ºC/min e, em seguida, aquecimento até 1100 ºC, com taxa de 1ºC/min. Sobre os vidros foram feitas análises de dureza indicando valores em torno de 7,0 GPa. Com relação às vitrocerâmicas, os maiores valores de dureza, em torno de 9,2 ± 0,5 GPa, foram verificados nas amostras monolíticas cristalizadas no volume e que estiveram sob tratamento térmico com duas taxas de aquecimento (10 ºC/min até 780 ºC e 1 ºC/min até 1100 ºC)<br>This work presents the results of the study with glass-ceramics obtained from base glass of the MgO-Al2O3-SiO2-Li2O system with addition of ZrO2 as nucleating agent and B2O3, which has the function to reduce the viscosity of the system during the melting process. The parent glasses were obtained by fusing at the temperature of 1650 ºC in crucible zirconia-mullite. The molten glasses were poured into a graphite mold to obtain the monolithic samples and also in water in order to obtain particulate material. Such material was grinded and then pressed by the uniaxial and isostatic pressing method before being sintered. Both the monolithic and pressed samples were performed under two different conditions of heat treatment for their nucleation and crystallization. In the first one the samples were heated to 1100 ºC with a heating rate of 10 ºC/min In the second one there was an initial heating rate of 10 ºC/min until reaching 780 ºC. Such temperature was kept for 5 minutes. After that, the samples were heated to 1100 ºC at a rate of 1 ºC/min microhardness analysis showed that base glass presented values around 7.0 GPa. The glass-ceramics obtained from the sintering powder had microhardness values smaller than those obtained from the monolithic samples. The highest hardness values were obtained in samples that were treated (10 ºC/min to 780 ºC and 1 ºC/min to 1100 ºC) which reached values around 9.2 ± 0.5 GP
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Souza, Filho Manoel Pereira de 1952. "Vitrocerâmicas de alta resistência mecânica obtidas a partir da cristalização do sistema SiO2-Al2O3-MgO-Li2O com adição de ZrO2 e B2O3 /." Guaratinguetá, 2013. http://hdl.handle.net/11449/103730.
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Orientador: Elson de Campos<br>Coorientador: Francisco Cristóvão Lourenço de Melo<br>Banca: Rogério Pinto Mota<br>Banca: Antonio Jorge Abdalla<br>Banca: Luiz Antonio Genova<br>Banca: Francisco Piorino Neto<br>Resumo: Neste trabalho estudou-se as vitrocerâmicas obtidas a partir de vidro base do sistema SiO2-Al2O3-MgO-Li2O com adição de ZrO2, como agente nucleante e do B2O3, que tem a função de reduzir a viscosidade do sistema durante o processo de fusão. Os vidros precursores foram obtidos por fusão na temperatura de 1650 ºC, em cadinhos de mulita-zirconia. Os vidros fundidos foram vertidos em molde de grafite para obtenção das amostras monolíticas, e em água para obtenção do material particulado. Este material foi moído e passou por processo de prensagem uniaxial e isostática, antes da sinterização. Para produção das vitrocerâmicas foram realizados tratamentos térmicos em duas condições diferentes. Na primeira as amostras foram aquecidas até 1100 ºC, com taxa de 10 ºC/min, e, na segunda, aquecimento inicial até a temperatura de 780 ºC, com taxa de 10 ºC/min e, em seguida, aquecimento até 1100 ºC, com taxa de 1ºC/min. Sobre os vidros foram feitas análises de dureza indicando valores em torno de 7,0 GPa. Com relação às vitrocerâmicas, os maiores valores de dureza, em torno de 9,2 ± 0,5 GPa, foram verificados nas amostras monolíticas cristalizadas no volume e que estiveram sob tratamento térmico com duas taxas de aquecimento (10 ºC/min até 780 ºC e 1 ºC/min até 1100 ºC)<br>Abstract: This work presents the results of the study with glass-ceramics obtained from base glass of the MgO-Al2O3-SiO2-Li2O system with addition of ZrO2 as nucleating agent and B2O3, which has the function to reduce the viscosity of the system during the melting process. The parent glasses were obtained by fusing at the temperature of 1650 ºC in crucible zirconia-mullite. The molten glasses were poured into a graphite mold to obtain the monolithic samples and also in water in order to obtain particulate material. Such material was grinded and then pressed by the uniaxial and isostatic pressing method before being sintered. Both the monolithic and pressed samples were performed under two different conditions of heat treatment for their nucleation and crystallization. In the first one the samples were heated to 1100 ºC with a heating rate of 10 ºC/min In the second one there was an initial heating rate of 10 ºC/min until reaching 780 ºC. Such temperature was kept for 5 minutes. After that, the samples were heated to 1100 ºC at a rate of 1 ºC/min microhardness analysis showed that base glass presented values around 7.0 GPa. The glass-ceramics obtained from the sintering powder had microhardness values smaller than those obtained from the monolithic samples. The highest hardness values were obtained in samples that were treated (10 ºC/min to 780 ºC and 1 ºC/min to 1100 ºC) which reached values around 9.2 ± 0.5 GP<br>Doutor
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Simon, Hellgren. "Secondary Steel Metallurgy Slag Design and MgO-C Refractory Implications : Theoretical and Practical Considerations." Thesis, Luleå tekniska universitet, Industriell miljö- och processteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-76339.
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MgO-C based refractory materials, often used in secondary steel making, are exposed to variouswear mechanisms in its application. The wear could be divided into oxidative, chemical andabrasive categories, all behaving differently and all being influenced by different factors. Dueto the importance of minimizing material loss and to the environmental challenges to run asustainable industry, it is of interest to gain more knowledge of the behavior of the refractorymaterial in use. The present thesis work specifically investigated slag designed of the CaOSiO2-Al2O3-MgO (CSAM) system as well as the chemical and oxidative wear mechanisms ofthree different MgO-C based refractory materials from Höganäs AB, Halmstadverken, whichcontained 5, 10 and 12 wt% carbon (labeled T05, T10 and T12). Different CSAM slags weredesigned to meet certain process criteria such as MgO and CaO saturations and wereinvestigated through thermodynamic calculations using the FactSage software and throughlaboratory scaled slag smelting experiments. The oxidation effect on the refractory material wasalso studied through pre-heating simulations in chamber furnaces, similar to the pre-heating ofa re-built ladle furnace.The thermodynamic calculations made in FactSage 7.0, using the FactPS and FToxid databases, resulted in a few different slag designs with different properties. A few different slagsfulfilled the CaO and MgO saturation limits proposed by Höganäs AB and could be consideredto test experimentally for further evaluation. The simulations also showed trends on how theliquid viscosity behaved with different slag compositions and how the solids content changedwith temperature.The oxidation experiments were performed on the different MgO-C refractory types, where thebricks with 10% carbon also contained Al2O3 antioxidants. The experiments showed that themass loss during the pre-heating is greater for refractory with higher carbon content, withexception to T10, where the mass losses were measured to 3.76 – 4.01%, 1.06 – 1.28% and6.28 – 6.33% for T05, T10 and T12 respectively. Further, the oxidation depth of each materialwas measured to 9-10 mm, 2-3 mm and 2-5 mm for the T05, T10 and T12. The experimentsalso showed that T12 refractory in particular was very susceptible to abrasive wear after beingoxidized.The slag smelting experiments were carried out through two different methods, by melting slagin MgO-C crucibles and by melting pressed slag briquettes on top of refractory bricks. Theformer tests mainly showed that the methodology was not suitable for this type of refractorymaterial due to the crucibles cracking during the experiments. The latter experiments showedsome general behaviour of the different components in the slag, where Ca, Al and Fe stayednear the surface, and Si and Mg penetrated deeper. The spinel formation at the refractory surfacewas then concluded to be the reason for Al not penetrating deeper. Further it was concludedthat no significant difference in refractory dissolution was seen between slags with- and withoutMgO, other than possibly a small increase in refractory dissolution for the latter.
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Yazhenskikh, Elena. "Development of a new database for thermodynamic modelling of the system Na2O-K2O-Al2O3-SiO2." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=977928454.
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Pina, Sandra Cristina de Almeida. "Preparação de vidros e vitro-cerâmicos do sistema SiO2-AL2O3-B2O3-CaO-MgO-Li2O-(K, NA)2O-F para potenciais aplicações em medicina dentária." Master's thesis, Universidade de Aveiro, 2005. http://hdl.handle.net/10773/2275.
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Mestrado em Engenharia de Materiais<br>O presente trabalho teve por finalidade investigar a influência da
substituição catiónica em vidros e vitro-cerâmicos à base de Ca-mica e
a produção de materiais com propriedades adequadas para aplicações
de interesse tecnológico.
Considerou-se como referência a composição CaMg3Al2Si2O10F2 e
investigou-se a influência da substituição (parcial ou completa) de Mg
por Li e de Al por B no processo de cristalização e nas propriedades
dos vitro-cerâmicos resultantes.
Os materiais produzidos foram caracterizados por recurso a diversas
técnicas experimentais, nomeadamente, análises térmicas (ATD e
dilatometria), difracção de raios X, espectroscopia de Raman,
microscopia electrónica de varrimento e espectroscopia de energia
dispersiva. A densidade e as propriedades mecânicas foram avaliadas
pelo de método de Arquimedes, microdureza de Vickers e ensaios
mecânicos à flexão, respectivamente, enquanto para o estudo da
durabilidade química se recorreu à imersão em ácido acético.
Os resultados experimentais mostraram que o vidro de referência só
funde adequadamente a cerca de 1550ºC, enquanto todos os vidros
dele derivados puderam ser facilmente fundidos e vazados a
temperaturas baixas (≈1350ºC).
A cristalização e propriedades dos vitro-cerâmicos obtidos a partir dos
vidros base mostraram-se muito sensíveis à substituição dos catiões. O
início da cristalização foi deslocado para temperaturas mais baixas na
presença de B e de Li. Por outro lado, a substituição completa de Al por
B causou um decréscimo da cristalinidade dos vitro-cerâmicos, uma
fusão parcial após tratamento térmico a temperaturas acima de 850ºC,
e tornou os vidros mais propensos a uma cristalização em volume.
Os vidros apresentaram unidades Q1, Q2, e Q3 do silício e ligações
Al∅4
- na presença de Al, e/ou unidades triangulares B∅2O- e
tetraédricas B∅4
- na presença de B. A presença de Li não causou
alterações significativas a nível estrutural, enquanto que a presença de
fósforo favoreceu a formação de unidades isoladas de coordenação
tetraédrica do tipo PO4
4-.
A composição de referência foi a única em que se formou a mica
(xantofilite) após tratamento térmico a 650ºC. A substituição, parcial ou
completa, de Mg por Li e de Al por B levou à formação de variadas
fases, tais como, inossilicatos (piroxenas e anfíbolas), nesossilicatos
(humite e forsterite) e, num caso, feldspato de Ca (anortite). Os vitrocerâmicos
com P na sua composição apresentaram fases variadas, tais
como, diopsido, borato de Mg, fosfito de B, SiO2e CaF2.
O uso de uma rocha natural à base de Li incorporou inevitavelmente
outros metais alcalinos, como K e Na. O vidro contendo todos os
catiões (Li, Na, K, Al) mostrou-se mais propenso a uma cristalização
homogénea em volume. Os vitro-cerâmicos apresentaram diversas
fases cristalinas a diferentes temperaturas (anfíbolas, Ca-mica,
forsterite, espinela e KLi-mica. Estes materiais são mais baratos e
apresentaram boas propriedades ópticas de brancura, translucidezopacidade,
e propriedades químicas e mecânicas promissoras para
diversas aplicações.
ABSTRACT: The present work aimed at investigating the influence of cation
substitution in glass and glass-ceramics based on Ca-mica and at the
production of materials with suitable properties for applications of
technological interest.
Considering the composition CaMg3Al2Si2O10F2 as reference, the
influence of substitution (partial or complete) of Li for Mg and B for Al on
crystallization process and on the properties of the resulting glassceramics,
was investigated.
Several experimental techniques were employed for the characterization
of the produced materials, such as thermal analysis (DTA and
dilatometry), X-ray diffraction, Raman spectroscopy, scanning electron
microscopy and energy dispersive spectroscopy. The density and the
mechanical properties were measured by the Archimedes method, and
Vickers microhardness and flexural strength measurement, respectively,
while the study of chemical durability was made by imersion in acetic
acid.
The experimental results showed that the reference glass was melted at
near 1550ºC, while all the other glasses derivated from it were easily
melted and cast at lower temperatures (≈1350ºC).
The crystallization and the properties of glass-ceramics crystallized from
the base glasses were very sensitive on cations substitutions. Initial the
onset of crystallization was shifted to lower temperatures in the
presence of B and Li. On the other hand, the complete substitution of B
for Al caused significant lowering of crystallinity in the glass-ceramics,
partial melting after heat treatment at temperatures higher than 850ºC,
and the resulting glasses became prone to bulk crystallization.
The glasses showed Q1, Q2, eQ3 silicon units and Al∅4
-, in the
presence of Al, and/or triangular, B∅2O-, and tetrahedral units B∅4
- in
the presence of B. The presence of Li didn’t cause significative
modifications in the structure, while the presence of P favoured the
formation of isolated tetrahedral coordinated units of type PO4
4-.
The formation of mica (xanthophyllite) only occurred in the case of
reference composition after heat treatment at 650ºC. Substitution,
partial or complete, of Li for Mg and B for Al showed the formation of a
variety of phases such as, inosilicates (pyroxenes and amphiboles),
nesosilicates (humite and forsterite) and, in a particular case, Cafeldspar
(anortite). The glass-ceramics with P in their composition
showed different phases, such as, diopside, Mg-borate, B-phosphite,
silica and CaF2.
The use of a natural rock based on Li inevitably introduced other alkalis
metals, such as K and Na. The glasses which contain all the cations (Li,
Na, K, Al) were prone to homogenous bulk crystallization. The glassceramics
showed different crystalline phases at different temperatures
(amphiboles, Ca-mica, forsterite, spinel and KLi-mica). These materials
are cheaper and exhibited good optical properties of whiteness,
translucency-opalescence, and chemical and mechanical properties
which are promising for several applications.
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Geßwein, Holger [Verfasser]. "Entwicklung hochfester Net-shape-Oxidkeramiken im System Al2O3-SiO2-ZrO2 / Forschungszentrum Karlsruhe GmbH, Karlsruhe. Holger Geßwein." Karlsruhe : FZKA, 2005. http://d-nb.info/978996968/34.
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Kirsten, Armin [Verfasser]. "Oberflächenfunktionalisierung dentaler Zirkonoxid-Implantate mittels bioaktiver Glasbeschichtungen aus dem System SiO2-Na2O-K2O-CaO-MgO-P2O5 / Armin Kirsten." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1076065813/34.
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Walk-Lauffer, Bernd. "Untersuchung des Einflusses von Sulfaten auf das System CaO-SiO2-Al2O3-K2O-H2O mittels Wärmeflusskalorimetrie und In-situ-Neutronenbeugung unter hydrothermalen Bedingungen." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=967520762.
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Schultze, Dina [Verfasser], Gerhard [Akademischer Betreuer] Franz, Gerhard [Gutachter] Franz, Max [Gutachter] Wilke, and Wilhelm [Gutachter] Heinrich. "Dissolution-precipitation reactions in the system Al2O3-SiO2-H2O and the formation of Al2SiO5 / Dina Schultze ; Gutachter: Gerhard Franz, Max Wilke, Wilhelm Heinrich ; Betreuer: Gerhard Franz." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1161007016/34.
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Choi, Ellen Eun-Ha. "Multicomponent diffusion in the system K2O-Na2O-FeO-MgO-TiO2-P2O5-Al2O3-SiO2." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=95070&T=F.
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Su, Yu-Lang, and 蘇育瑯. "Effect of FeO content on High-temperature properties in FeO-CaO-SiO2-Al2O3-MgO system." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/48217471126918834976.
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碩士<br>國立中興大學<br>材料科學與工程學系所<br>105<br>In this study, FeO-CaO-SiO2-5% MgO-5% Al2O3 slag system (C / S = 2.5 and 3.0, FeO = 10 ~ 40 wt. (%)) with different basicity and FeO ratio was designed by Thermo-Calc thermodynamics simulation. The Actual composition of slag was confirmed by WDS-XRF analysis, the Fe chemical titration and XRD phase identification. In the high temperature characteristic analysis, using DV III RV viscometer, the high temperature optical image observation, and pre-thermodynamics simulation investigate the softening, melting and flow properties. Finally, the actual dephosphorization test and foaming height analysis were carried out to find out optimum composition range of dephosphorization agent and foaming agent in FeO-CaO-SiO2-5% MgO-5% Al2O3 slag system.
The x-ray diffraction results revealed that the composition of the FeO content (9.9-43.2 wt. (%)) at different basicity is composed of FeO, Ca2SiO4 and CaMoO4. It was found that the viscosity of slag was affected by Ca2SiO4 solid particles, and the viscosity increased with the increase of basicity or the decrease of FeO content, and thus C/S=2.1-9.9%FeO and C/S=2.6-20.6%FeO have a higher viscosity. Through the high temperature optical image observation, it found that the viscosity of 1300cP above and Ca2SiO4 solid fraction rate of 20% of the formula, high temperatures to maintain structural stability and slow down the softening rate enhance the melting temperature as well; and the viscosity of 183cP below and Ca2SiO4 solid fraction ratio were less than 10% of the formula, due to a large number of FeO melting in advance leading to rapid disintegration of the structure, which significantly reduce the melting temperature, making slag flow better.
The results show that the viscosity is between 25cP and 1810cP, and the foaming index is linearly proportional to the viscosity, and the foaming index of C/S=2.6-20.6%FeO is 109.7% at 1560oC, which is the best performance of the foam formulation. In the dephosphorization capacity assessment, the thermodynamic empirical formula that in the high basicity and the appropriate FeO content of the dephosphorization agent can effectively improve the ability of dephosphorization. The results showed that the dephosphorization rate of C/S=2.1-20.0%FeO was up to 89.2% at 1530-1550oC.
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Ganesha, A. V. "An experimental study of the stability and melting relations of some anhydrous silicates in the system K20-Mgo-Al2o3-Sio2-H20." Thesis, 1995. http://hdl.handle.net/2009/2075.
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Hunger, Anja [Verfasser]. "Gläser und Glaskeramiken im MgO-Al2O3-SiO2-System mit hoher Mikrohärte und hohem Elastizitätsmodul : Anwendung als Substrat für Festplatten / von Anja Hunger." 2006. http://d-nb.info/980027764/34.
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Chen, Kai-Chun, and 陳凱群. "The effect of TiO2 and K2O addition on the crystallization of Cr doped glass-ceramic from glasses in the system SiO2/Al2O3/MgO." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/20421434259106682911.
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碩士<br>國立中山大學<br>光電工程學系研究所<br>101<br>We studied the magnesium silicate glass Oxides TiO2, and the added K2O, general literature to increase the quantity produced crystal and glass phase separation effects and optical properties of the crystalline phase, so I hope by changing its composition the content of the crystalline phase to produce the correct fluorescence intensity increase, and increase the number of crystallization and reduce the scattering loss crystalline particle size reduction, research on chromium doped Ti and K glass and glass-ceramic material properties of the optical and the impact on the composition and thus make improvements to enable fluorescence excitation wavelength of 1.1 to 1.6 microns of Cr4 + ions in the crystal internal content increases and reaches the crystallization of nanometer-scale crystals reduce excessive scattering loss incurred unnecessary.
For the experiments were changes in chromium-doped TiO2 and K2O content of the glass composition, and its optical measurement of material properties. And to infer the characteristics of each post, and then deploy the mixing proportion, culminating in the modulation of the closest to the target characteristics of the samples in this experiment, and its composition formulations fiber spinning process, application and production expectations having broadband fluorescence characteristics chromium-doped glass ceramic fibers. Experimental results show that, TiO2 generally the compound as a nucleating agent for crystallization crystalline phase had no effect, and its main function is to help the formation of crystals from the XRD results. The main impact of the crystalline phase of K2O, add it or not is the impact of Mg2SiO4 crystal phase formed the most important reason. Commissioned by the optical pumping system, and its characteristics are the same as with chromium-doped glass ceramics, glass ceramics research evidences can be used in MCVD and pumped into fiber for future research may use and improvement of orientation.
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Shin, Jin-Wook [Verfasser]. "The experimantal and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 / vorgelegt von Jin-Wook Shin." 2004. http://d-nb.info/975613715/34.
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Liu, Xi. "Effect of K2O, Cr2O3, H2O and CO2 on the partial melting behaviour of spinel lherzolite in system CaO-MgO-Al2O3-SiO2+/-K2O+/-Cr2O3+/-H2O+/-CO2 at 11 kbar." Phd thesis, 2003. http://hdl.handle.net/1885/151809.
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Purwin, Horst. "Eine experimentelle Studie des Oxidationszustandes von Eisen in Granat und Klinopyroxen als Funktion der Temperatur im System CaO-FeO-Fe2O3-MgO-Al2O3-SiO2: Implikationen für die Granat-Klinopyroxen-Geothermometrie." Phd thesis, 2012. http://tuprints.ulb.tu-darmstadt.de/3246/1/Dissertation_Purwin.pdf.
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Das Granat-Klinopyroxen-Geothermometer ist eines der am häufigsten angewandten Methoden um Equilibrierungstemperaturen von Eklogiten, Granat-Peridotiten und anderen (ultra)basischen, granat- und klinopyroxenhaltigen metamorphen Gesteinen zu bestimmen. Obwohl das Thermometer auf einer Kationenaustauschreaktion von Fe2+ und Mg2+ zwischen Granat und Klinopyroxen beruht, basieren alle bisherigen Kalibrierungen auf dem Gesamteisengehalt, bei dem nicht zwischen Fe2+ und Fe3+ unterschieden wird. Das Hauptziel dieser Arbeit war herauszufinden, ob das Thermometer durch Nichtdifferenzierung des Fe-Oxidationszustandes mit einem systematischen Fehler behaftet ist, welcher eine Neukalibrierung des Thermometers unter Berücksichtigung des Oxidationszustandes erforderlich macht.
Die Synthese von Proben eklogitischer Zusammensetzung im System CaO-FeO-Fe2O3-MgO-Al2O3-SiO2 (CFFMAS) erfolgte in einer Stempelzylinder- oder Belt-Apparatur bei einem Druck von 2,5-3,0 GPa und Temperaturen von 800°C bis 1300°C, wobei in Platin eingeschweißte Graphitkapseln zum Einsatz kamen. Die synthetisierten Granate und Klinopyroxene wurden mittels Elektronen-Energieverlust-Spektroskopie (electron energy-loss spectroscopy – EELS) hinsichtlich ihres Fe-Oxidationszustandes untersucht und auf ihre chemische Zusammensetzung hin mit Hilfe der Elektronenstrahl-Mikrosonde (EMS) und am Transmissionselektronenmikroskop (TEM) ausgeführter energiedispersiver Röntgenspektroskopie (EDX) analysiert.
Die mit dem Gesamteisengehalt berechneten Equilibrierungstemperaturen reproduzieren die experimentelle Temperatur innerhalb von ±60°C. Nutzt man nur den Fe2+-Gehalt für die Temperaturberechnung, welcher durch Kombination der EMS- mit den EELS-Ergebnissen ermittelt wurde, weichen die berechneten Temperaturen von den experimentellen systematisch ab. Da der systematische Fehler relativ gering ist (kleiner als ±100°C), besteht für das System CFFMAS unter den hier untersuchten Bedingungen keine Notwendigkeit das Thermometer unter Berücksichtigung des Fe-Oxidationszustandes neu zu kalibrieren.
Aus dem Vergleich der Oxidationszustände der experimentellen Phasen mit denen natürlicher Granat-Peridotite, wobei auf Literaturdaten zurückgegriffen wurde, ist zu schließen, dass für natriumarme Granat-Peridotite ebenfalls keine Neukalibrierung erforderlich ist.
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Talapaneni, Trinath. "Physicochemical Properties of CaO-MgO-SiO2-Al2O3 Synthetic Slag." Thesis, 2019. http://ethesis.nitrkl.ac.in/10010/1/2019_PhD_TTalapaneni_513mm1060_Physicochemical.pdf.
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Blast furnace slag composition has a very important bearing on its physicochemical characteristics which affects the degree of desulphurization, coke consumption, smoothness of operation, gas permeability, heat transfer and fluidity which in turn affects the softening and melting behavior in the cohesive zone. Due to the diminution of high-quality iron ores, blast furnaces are running with iron ores having a high Al2O3/SiO2 ratio (as high as 4.17 in case of Sierra Leone ores, but the ideal Al2O3/SiO2 ratio should be in the order of 0.6-0.7) and this produce slag containing Al2O3 25-30%. Al2O3 being a refractory oxide will increase the liquidus temperature of the slag, due to this, the furnace has to operate at high temperatures, and this involves high coke consumption, which ends up with high silicon content in hot metal. Whereas, silicon pick up in the hot metal can be reduced by lowering the position of cohesive zone (CZ). This is possible with slags having a high softening temperature, coupled with a relatively low flow temperature increases the formation of a narrow cohesive zone at the lower part of the blast furnace, and this will increase the permeability in the CZ. Also, these slags are highly viscous and show less efficient desulphurization. The former is due to the network forming ability of Al2O3 and later is due to the increase in the activity of sulphur in slag. All the above factors will influence the working condition of a blast furnace and diminish the quality of hot metal. Apart from this the volume of the slag also increases. The Overall production of blast furnace slag may be estimated as equivalent to 25% to 30% of crude (pig) iron production compared to steel furnace slag as about 10% to 15% of crude steel output [217].
Therefore, the present work is focused on the study of physicochemical properties like liquidus temperature, viscosity and desulphurization ability of CaO-MgO-SiO2-Al2O3 quaternary slag system.
The effect of Al2O3, MgO and CaO/SiO2 ratio on flow characteristic temperatures are carried out using a high-temperature microscope in accordance with German standard 51730. Slag with Al2O3 (25-30 %), C/S (0.9-1.4) and MgO (4-12 %) ensures Al2O3 (30 %), C/S ratio of 1.4 and MgO (8 %) as short slag. Whereas, slags with C/S (0.8-1.6) and MgO (8-16 %) are showing Al2O3 (30 %), C/S ratio 1.2 and MgO (12%) as short slag. Also, phase diagrams and XRD analysis for slag samples reveals that all the slags are falling in Anorthite-Melilite-Spinel region.
Viscosity experiments are carried out for slag composition of Al2O3 (25-30 %), C/S (0.8-1.6) and MgO (8-16 %) using vertical rotating type (Model VIS 403 HF) high-temperature viscometer in the temperature range of 1748 K to 1848 K. A relationship between viscosity and the slag structure is intent by Fourier Transform Infrared (FTIR) and Raman spectroscopy. Chemical thermodynamic software FactSage 7.0 is used to predict viscosity of slags. It is observed that an increase in CaO/SiO2 ratio and MgO content in the slag depolymerizes the silicate structure. This leads to a decrease in viscosity and activation energy of the slag. Also, an addition of Al2O3 content increases the viscosity and activation energy of slag by polymerization of aluminosilicate structure.
Desulfurization ability of slags is determined for slag composition of Al2O3 (25-30 %), C/S (0.8-1.6) and MgO (8-16 %) at a temperature of 1773 K using slag-metal equilibrium technique. The sulphur content in the slag as well as in metal after desulfurization reaction is analyzed using XRF (X-ray Fluorescence Spectroscopy) for calculating sulphur partition ratio (Ls) of the slags. The influence of Al2O3, CaO/SiO2 ratio and MgO content on Ls has been studied. It is observed that Ls increase with an increase in CaO/SiO2 ratio and MgO content, but it reduces as the Al2O3 content increase in slag. Also, the amount of bridge oxygen (Oo) decreases with increase in basicity and MgO content. However, Oo increases with increase in Al2O3. It is witnessed that the experimental values closely fit with the values obtained from the corrected optical basicity model.
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Tsai, Wei-Che, and 蔡維哲. "Phase Transformation and Properties of MgO-ZnO-Al2O3-SiO2 Glass-Ceramics." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/31186589245862168119.
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碩士<br>大同大學<br>材料工程學系(所)<br>93<br>Nanocrystalline glass-ceramics with high elastic modulus, moderate strength, extremely smooth polished surface, and toughness have been developed recently for potential use as magnetic disk substrate in computer hard drives. The major objective of this study is to explore the effect of TiO2 on the crystallization and properties of MgO - ZnO - Al2O3 - SiO2 glass-ceramics. The parent glasses was formed by a melt-quench process, then subjected to nucleation and crystallization heat-treatment to convert it into glass-ceramics containing spinel and enstatite as the major crystalline phases.
The experimental results indicate that while increases in the TiO2 amount enhanced the phase separation of glass, the glass formation ability was reduced. In this study, a three-stage crystallization heat treatment was proposed to decrease the TiO2 amount that is required for fabricating spinel + enstatite glass-ceramics, and inhibiting the precipitation of high-quartz s.s..
The Vickers hardness and Young’s modulus of the glass-ceramics increased obviously with the increase in the heat-treatment temperature. The highest Young’s modulus that can be reached is 155 GPa.
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HU, CHIA-WEI, and 胡嘉維. "Effect of Adding Strontia on MgO-CaO-Al2O3-SiO2-P2O5 Bioactive Glass." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9vq33b.
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碩士<br>中臺科技大學<br>牙體技術暨材料系碩士班<br>107<br>Strontium is believed to contribute to the growth of bone cells. By the way of degradation, strontium-containing bioactive glass would release strontium ions into the surrounding environment, to promote the growth of bone tissue. In this study, strontia-containing bioactive glass with composition of MgO 3%, CaO (35-x)%, Al2O3 8.6%, SiO2 41.4%, P2O5 12%, SrO x% (x = 0, 1, 3, 5, 10 wt.%), denoted by xSrAA, respectively, were synthesized using conventional melting-quenching technique. The effects of strontia on glass transition temperatures, apatite-forming ability, degradation in physicochemical solution, and ion release were investigated. The experimental results showed that the glass transition temperatures were in the range of 741-770°C. The strontia would widen the sintering window, which means the glass could maintain the glass phase condition with longer sintering duration. The test specimens were immersed in PBS solutions to evaluate the terms of degradation. It revealed that the pH value increased gradually with immersion duration. However, the more strontia content, the steadier pH values were in immersing PBS solutions. In addition, strontia also reduced the apatite deposition in PBS solutions. All these results revealed that SrAA glasses were more stable than AA glasses in PBS solutions. After co-cultured with MG-63 cells, 5SrAA showed the best cell activity.
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Lin, Kun-Hsien, and 林坤賢. "The study of physical and chemical properties of CaO-Al2O3-SiO2-MgO-CaF2 slags." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/68533133807376426555.
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碩士<br>國立中興大學<br>材料科學與工程學系所<br>102<br>The desulfurization reactions in steel making are associated with basicity, melting point, viscosity. In this study, design six groups (A-F) with a low melting point,different basicity, and different composition phase. In order to make a comparison, three control groups which are similar to steelworks slag waste (A1-A3) were designed. The three control groups are content 10% CaF2. By identify the physical and chemical properties of these groups, to discuss the impact of the desulfurization reaction.
In this experiment, using the frequency induction furnace to pre-melting the nine groups, simulating the patterns after the high-temperature reaction of nine groups. After
pre-melting, conducted a series of experiments as viscosity, F-CaO, XRD, XRF, DTA,Raman. Simulate the sulfur distribution ratio and desulfurization rate by using Thermo-Calc software.
In the results and discussions, it is confirm the pre-melting is success by XRD and XRF. In F-CaO testing, the group of Al-killed steel has higher F-CaO. The content of
F-CaO increase when the percent of Al2O3 increase. The melting point of the six groups are about 1470-1510°C, the three control groups are about 1400°C. The viscosity of Si-killed steel is higher, because of higher SiO2 content. But, when the CaF2 is add, it will break the cross-linked network of SiO2 and Al2O3 and reduce the viscosity. As the SiO2 decrease, the group of Al-killed steel has lower viscosity.
After the thermodynamic simulation, The group E has the best desulfurization rate and Ls of six testing groups. The group E has the best efficiency (desulfurization rate：
56%), because it has high value of Cs, enough F-CaO, low viscosity. The efficiency is closest to control group. High optical basicity has good properties, such as low viscosity,high F-CaO, Ls and desulfurization rate. It is helpful for desulfurization.
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Chuang, Chen-Yao, and 莊振堯. "Effect of glass composition (Mg0.5Zn0.5)Al2O4/ SiO2 ratio on the crystallization and properties of MgO-ZnO-Al2O3-SiO2 glass-ceramics." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/35926661422045100533.
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CHIEN-TING, CHEN, and 陳建庭. "Influence of Sodium Fluoride on the Crystallization Behavior of Machinable MgO-Al2O3-SiO2 Glass-Ceramics." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/66137980746204035557.
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碩士<br>國立臺灣科技大學<br>材料科技研究所<br>92<br>Abstract
Mica-containing glass-ceramics are unique because they possess the unusual property of machinability, they can be machined to precise tolerance and surface finish with conventional metal-working tools.
Transparent and clear glasses were prepared from the MAS system (based on MgO-Al2O3-SiO2) with different fluorine contents. Their crystallization behavior to giving mica glass-ceramics upon heat treatment was studied as a function of the source of fluorine and its concentration.
For this study, glasses having weight-percentage compositions of；SiO2 34.7-38.1；B2O3 10.2-11.3；Al2O3 14.8-16.3；MgO 22.5-24.7；K2CO3 4.1- 4.5；CaCO3 0.1 and sodium fluoride (NaF) as additive, and added with 5wt﹪，9.5wt﹪，13.6wt﹪separately，The batch ingredients were gotten together and thereafter melt in close crucible for about 5 hours in an electrically fired furnace operating at 1450℃. Preparing three groups all contained those samples, and having two of them expose to heat treatment for four hours at 700℃ and 1100℃ individually, while the other one maintained the original form. Trying to find out influence of sodium fluoride on crystallization behavior machinable glass-ceramics.
SEM observation shows that sample contained crystalline mica platelets that range in diameter from about 1.2μm to 2.5μm. The Vickers hardness data clearly show that the hardness of these glass-ceramics decrease as the mica platelets increased. The sodium fluoride (NaF) contents increased while the values of thermal expansion coefficient increased. Temperature of heat treatment also increased while the values of thermal expansion coefficient increased. Two kinds of content（9.5wt﹪,13.6wt﹪） heat treated for 4 hours at 1100℃.It can be found that the experimental samples have machineability, or the fluorophlogopite mica crystals make the material machinable.
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Lin, Pei-Hsiang, and 林貝香. "Evaluation of MgO-CaO-Al2O3-SiO2-P2O5 Bioglass Immobilized with OMP Peptide as Bone Substitute In vivo." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/07328127080583726539.
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碩士<br>中臺科技大學<br>醫學工程暨材料研究所<br>103<br>The modifications induced on the surfaces of biomaterials aimed at promoting cell growth have been widely studied in the recent years for their potential application in the tissue engineering and regenerative medicine fields. Osteointegration and bone growth can be improved by biomimetic modification achieved by immobilization of selected proteins or peptides on the device surface. Previous studies have suggested that osteopontin play a role in bone resorption, tumorigenesis, and metastasis. In addition, osteopontin contains several interesting structural domains, including RGD (arginine-glycine-aspartic acid) adhesive domain. Therefore, the purpose of our study was to investigate the dose-dependent response and sequence- dependent response of recombinant human osteopontin fragment peptide (contain RGD) enhances osteogenic capability in vivo.
In this study, MgO-CaO-Al2O3-SiO2-P2O5 bioglass (AA) and recombinant human osteopontin fragement peptide (OMP) were manufactured from our lab. and used as raw materials. The covalent immobilization of OMP peptides on AA surface was carried out according to Iucci et al. and designed three different sequences and concentrations of OMP peptide: OMP-Ⅰ (50 μg/ml, OMP-Ⅰ50), OMP-Ⅲ(50 μg/ml, OMP-Ⅲ50), OMP-Ⅲ(250 μg/ml, OMP-Ⅲ250) as biomolecules for biomimetic modification, respectively. For animal study, AA discs immobilized with and without OMP peptides were implanted in the tibia of New Zealand white mature rabbits under general anaesthesia. Each rabbit received 4 implants, 2 in the left tibia and 2 in the right tibia. At the experimental times of 4, 8, and 12 weeks, rabbits were sacrificed, tibias were harvested and surrounding soft tissue was stripped. All the specimens were examined by radiographic, histology and histomorphometry analysis.
According to the macroscopic observation, all bone substitutes show good biocompatibility and no abnormal inflammation either infection was observed at the implantation sites. Radiographic images of implant sites at 4, 8, and 12 weeks showed in all groups that included OMP-immobilized AA substitutes were well incorporated with host bone tissue compared with control groups. In the histological, newly formed bone directly contacts the surface of OMP-immobilized AA substitutes, even growing into the center of material. After 4 weeks of implantation , the amount of newly formed bone by histomorphometrical data was 28.80% in OMP-Ⅲ250, 24.95% in OMP-Ⅲ50, 22.10% in OMP-Ⅰ50 and 18.37% in control group. After 8 weeks of implantation , the percentage of newly bone was 38.84% in OMP-Ⅲ250, 35.13% in OMP-Ⅲ50, 30.03% in OMP-Ⅰ50 and 26.86% in control group. After 12 weeks of implantation , more new bone was increased to 70.19% in OMP-Ⅲ250, 66.28% in OMP-Ⅲ50, 55.68% in OMP-Ⅰ50 and 50.49% in control group. Significant the percentage of newly formed bone in OMP-Ⅲ250 greater than all group in the same period.
Base on above results, we concluded that OMP-immobilized AA bioglass showed well biocompatibility and osteointegration characteristic comparing with AA bioglass. The sequence and concentration increase enhances new bone formation in this study. Therefore, OMP-immobilized AA bioglass could be served as a great bone substitute for the repair of bone defect.
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Chen, Hsuan-Yu, and 陳炫妤. "Materialization Study on Transformation of MgO-Al2O3-SiO2 Glass Ceramic from TFT-LCD Waste Glass with Additives." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/07651641485055594440.
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碩士<br>國立臺灣大學<br>環境工程學研究所<br>99<br>This study aimed to use TFT-LCD (Thin Film Transistor Liquid Crystal Display) waste glass from optoelectronics industrial wastes with MgO, Al2O3, and ZrSiO4 additives to produce excellent mechanical and dielectric properties through thermal treatment.
There were three experimental stages in this study. The first stage was cone test of TFT-LCD waste glass with additives, in order to obtain the blending ratio of the components for the melting temperature. The second stage was to determine the thermal treatment conditions based on glass transition temperature and crystallization temperature of the differential thermal analysis at various blending ratio and temperatures to crystallization, and then to observe crystal phase by X-ray powder diffraction analysis. The third stage was for selected ratio of MAS (MgO-Al2O3-SiO2) glass-ceramic system in order to assess the potential of insulting glass-ceramic produced from TFT-LCD waste glass with additives as raw materials to analyze the dielectric properties, compressive strength and flexural strength.
The experimental results showed that the temperature of cone test of TFT-LCD waste glass with MgO additive has been decreased, and the MgO in the glass-ceramic system has positive effect on melting. Crystal phase analysis showed that the TFT-LCD waste glass added 20 wt.% MgO and 15~20 wt.% Al2O3 via 1000℃ of thermal treatment could produce Cordierite phase, and the additive of ZrSiO4 in the TFT-LCD waste glass could help crystal phases to be generated at lower thermal treatment temperature. It demonstrated that the additive of ZrSiO4 plays a key role to energy saving and crystallization of cordierite.
The TFT-LCD waste glass added 20 wt.% MgO, 15 wt.% Al2O3 and 15 wt.% ZrSiO4 at heat temperature 920℃ showed the density of 2.78 g/cm3, the flexural strength of 172.820 MPa, compressive strength of 402.34 MPa, dielectric constant of 10.290 and the dielectric loss factor of 0.0172. It has good mechanical and dielectric properties, and in accordance with the required standard of insulated glass ceramics.