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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo do efeito do ?xido de b?rio no comportamento de massas para porcelanato

Cavalcanti, Daniel Jatoba de Holanda 23 February 2012 (has links)
Made available in DSpace on 2014-12-17T14:57:52Z (GMT). No. of bitstreams: 1 DanielJHC_TESE.pdf: 5059546 bytes, checksum: d026fcca3b608eb8f8318d620f8e0f29 (MD5) Previous issue date: 2012-02-23 / In this work, it is proposed the study of the effect of barium oxide acting as synthetic flow in the behavior of masses for stoneware from the use of raw materials found in the deposits of minerals of the Rio Grande do Norte that it makes use of a great natural potential for the industrialization of the product. The porcelanato is a sophisticated product with excellent final properties being applied as ceramic coating in buildings of high standard of engineering. The raw materials selected for the development of the study had been two types of argilas, two types of feldspatos, dolomita, talco, barium carbonate and silica, being characterized by X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis and thermal analysis. Thus, it is intended to define four formulations using the cited raw materials that will be processed, conformed and sintered in the temperatures of 1150 ?C, 1175 ?C, 1200 ?C, 1225 ?C e 1250 ?C. From the physical characterizations, chemical and morphologic of the formed formulations, the effect of barium oxide is determined in the physical and mechanical properties of the studied system carrying water absorption tests, linear retraction, apparent porosity, apparent specific mass, compacting curve, flexural strength and microstructural analysis by XRD and SEM. After analyzing the results, indicated that barium oxide acts as a flux of high temperature and as the ordering of structure, where the embedded glass phase has the nucleating effect phase potassium silico-aluminum reacting with free silica which together with the high content of potassium concentrated form a new crystalline phase called microcline. The masses studied with the addition of barium oxide present physical-mechanical properties highly satisfactory in reduced firing temperatures, which implies a saving in energy given off in the production and increased productivity / Neste trabalho, prop?e-se o estudo do efeito do ?xido de b?rio atuando como fluxo sint?tico no comportamento de massas para porcelanato a partir da utiliza??o de mat?rias-primas encontradas no estado do Rio Grande do Norte que disp?e de um grande potencial natural para industrializa??o do produto. O porcelanato ? um produto com excelentes propriedades finais, sendo aplicado como revestimento cer?mico em diversos empreendimentos da constru??o civil. As mat?rias-primas selecionadas para o desenvolvimento do estudo foram dois tipos de argilas, dois tipos de feldspatos, dolomita, talco, carbonato de b?rio e s?lica, sendo caracterizadas por an?lises de fluoresc?ncia de raios X, difra??o de raios X, an?lise granulom?trica e an?lises t?rmicas. Assim sendo, procede-se o processamento, conforma??o e sinteriza??o de quatro formula??es utilizando as mat?rias-primas citadas nas temperaturas de 1150 ?C, 1175 ?C, 1200 ?C, 1225 ?C e 1250 ?C. A partir das caracteriza??es f?sicas, qu?micas e morfol?gicas das formula??es, determina-se o efeito do ?xido de b?rio nas propriedades f?sicas e mec?nicas do sistema estudado realizando ensaios de absor??o de ?gua, retra??o linear, porosidade aparente, massa espec?fica aparente, curva de compacta??o, tens?o de ruptura a flex?o, difra??o de raios X e microscopia eletr?nica de varredura com a microan?lise por EDS. Ap?s a an?lise dos resultados, verifica-se que o ?xido de b?rio atua como fundente de alta temperatura e como ordenador de estrutura, onde incorporado ? fase v?trea, possui efeito nucleante da fase sil?cio-alum?nio-pot?ssio reagindo com a s?lica livre que juntamente com o alto teor de pot?ssio concentrado forma uma nova fase cristalina denominada microcl?nio. As massas estudadas com o acr?scimo do ?xido de b?rio apresentam propriedades f?sico-mec?nicas extremamente satisfat?rias em temperaturas de queima reduzidas, o que implica em uma economia na energia desprendida para a produ??o e aumento de produtividade / 2020-01-01
2

Produ??o de gr?s porcelanato a partir de mat?rias-primas do estado da Bahia

Brito, Jorge Ferreira 19 October 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:53Z (GMT). No. of bitstreams: 1 JorgeFB.pdf: 2466045 bytes, checksum: 390a8dfd299d465779890586b1bd5be1 (MD5) Previous issue date: 2009-10-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The State Bahia, Brazil, presents different geological sites it with a very expressive variety minerals. It is situated among the very important States which produces minerals for industries, such as pointed aggregate, ornamentals stones and ceramics raw materials. Nowadays only four companies producting ceramics tiles. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. For this purpose, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis, thermal differential analysis and dilatometric analysis. Admixtures containing different compositions were prepared and fired at four temperatures, 1100 ?C, 1150 ?C, 1200 ?C and 1250 ?C with isotherm for 60 minute and heathing rate of 5 oC/min. After firing the samples, they were characterized by water absorption tests, linear retraction, analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by X-ray diffraction and scanning electron microscopy . The results revealed three ceramics with porcelainized stoneware tiles characteristics and porcelain tile will be produce from raw materials originated in the State of Bahia / O Estado da Bahia apresenta uma diversidade de terrenos geol?gicos que encerra uma expressiva dota??o mineral e est? situado entre os mais importantes Estados produtores de minerais industriais, ressaltando-se agregados, rochas ornamentais e mat?rias-primas cer?micas. Atualmente somente quatro empresas produzem placas cer?micas. O gr?s porcelanato ? uma das mais nobres cer?micas de revestimento devido a sua baixa absor??o d ?gua (tipicamente abaixo de 0,5%), al?m de apresentar excelentes caracter?sticas t?cnicas, destacando-se pelas elevadas resist?ncias mec?nica, ao risco e ao manchamento. O presente trabalho tem a finalidade de avaliar o potencial das mat?rias-primas, feldspato, argila e caulim, utilizado na produ??o de gr?s porcelanato no estado da Bahia. Para isso, foi feita a caracteriza??o das mat?rias-primas por fluoresc?ncia de raios X (FRX), difra??o de raios X (DRX), an?lise granulom?trica (AG), an?lise t?rmica gravim?trica (TG), an?lise t?rmica diferencial (DTA) e an?lise dilatom?trica, elaborando-se sete formula??es que foram queimadas nas temperaturas: 1100 ?C, 1150 ?C, 1200 ?C e 1250 ?C, com isoterma de 60 minutos e taxa de aquecimento de 5 oC/ min. Ap?s a queima, os corpos-de-prova foram submetidos a ensaios de absor??o de ?gua, retra??o linear, an?lise dilatom?trica, porosidade aparente, massa espec?fica aparente, resist?ncia ? flex?o, difra??o de raios X e microscopia eletr?nica de varredura. Em tr?s formula??es foram obtidas, propriedades compat?veis com as exigidas para a produ??o do gr?s porcelanato com mat?rias-primas oriundas do Estado da Bahia

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