Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/7429 |
Resumo: | Calcination is an important step in the alumina production process, affecting the final properties of the resulting powder and the attained product. Over the previous decades, attempts have been conducted to understand this process aiming to decrease the calcination temperature and time, additionally to the improvement of the alumina properties. In this sense, the use of additives is promising as these mineralizers, like fluorides, act decreasing the transformation temperature from the transition alumina to the alpha phase. In this context, this study addressed the understanding of the influence of three different additives (solid fluoride, soluble fluoride and seeds) on the properties of the calcined alumina, considering the actual condition of the industry and focusing in technical aspects such as morphology, surface area, primary crystal size, alpha content and the soda decrease. There are several theories about the working reaction of these additives, however, no experimental procedure was carried out to prove those mechanisms. In this work, the AlF3 and the soluble fluoride's mechanism reaction were investigated by using DTA-TG-MS techniques. The results showed that the presence of fluoride in transition aluminas leads to the generation of gaseous compounds which are responsible for speeding up the mass transportation, thus, decreasing the temperature and energy required for obtaining the alpha phase. These mineralizers also influenced the alumina properties, such as an increase in the primary crystal size and a decrease in the surface area. The optimum properties can be attained by the right balance between temperature and mineralizer content. Other additives sources, such as NH4Cl, can be used for decreasing the soda content. This work highlights that their efficiency is directly related to a suitable gas confinement inside of the calciner. |
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Oliveira, Daniela Riello Gomes dePandolfelli, Victor Carloshttp://lattes.cnpq.br/7369376873984839http://lattes.cnpq.br/8034337197861293d1d9f2db-a6b4-438c-bdf0-1afadc012efa2016-09-26T18:40:40Z2016-09-26T18:40:40Z2015-08-31OLIVEIRA, Daniela Riello Gomes de. Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas. 2015. Dissertação (Mestrado em Ciência e Engenharia de Materiais) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7429.https://repositorio.ufscar.br/handle/ufscar/7429Calcination is an important step in the alumina production process, affecting the final properties of the resulting powder and the attained product. Over the previous decades, attempts have been conducted to understand this process aiming to decrease the calcination temperature and time, additionally to the improvement of the alumina properties. In this sense, the use of additives is promising as these mineralizers, like fluorides, act decreasing the transformation temperature from the transition alumina to the alpha phase. In this context, this study addressed the understanding of the influence of three different additives (solid fluoride, soluble fluoride and seeds) on the properties of the calcined alumina, considering the actual condition of the industry and focusing in technical aspects such as morphology, surface area, primary crystal size, alpha content and the soda decrease. There are several theories about the working reaction of these additives, however, no experimental procedure was carried out to prove those mechanisms. In this work, the AlF3 and the soluble fluoride's mechanism reaction were investigated by using DTA-TG-MS techniques. The results showed that the presence of fluoride in transition aluminas leads to the generation of gaseous compounds which are responsible for speeding up the mass transportation, thus, decreasing the temperature and energy required for obtaining the alpha phase. These mineralizers also influenced the alumina properties, such as an increase in the primary crystal size and a decrease in the surface area. The optimum properties can be attained by the right balance between temperature and mineralizer content. Other additives sources, such as NH4Cl, can be used for decreasing the soda content. This work highlights that their efficiency is directly related to a suitable gas confinement inside of the calciner.A calcinação é uma etapa importante no processo de produção da alumina alfa, influenciando várias propriedades do particulado e do produto que a contém. A utilização de aditivos durante esta etapa tem-se mostrado promissora, uma vez que estes agentes mineralizadores, como é o caso dos fluoretos, atuam diminuindo a temperatura de transformação de aluminas de transição para a fase alfa. Diante deste cenário, este trabalho teve como objetivo compreender a influência de três diferentes aditivos (fluoreto sólido fluoreto solúvel e sementes) nas propriedades da alumina calcinada, por meio de uma abordagem sistêmica que se assemelhasse às condições reais da indústria e focando em aspectos técnicos como morfologia e tamanho de cristais primários, área superficial, teor de alumina alfa e possível redução da concentração de sódio. Na literatura podem ser encontradas diversas teorias sobre a atuação de tais aditivos, entretanto, nenhuma avaliação experimental foi realizada para comprovar seus mecanismos. Neste trabalho, o comportamento do mineralizador AlF3 , bem como do fluoreto solúvel, foi investigado pela utilização das técnicas DTA-TG-MS. Os resultados indicaram que a presença de fluoreto em aluminas de transição leva a formação de compostos gasosos que são responsáveis por acelerar o transporte de massa, reduzindo assim a temperatura e energia de calcinação necessária para obtenção da fase alfa. Estes mineralizadores também apresentaram influência nas propriedades da alumina, como aumento do tamanho do cristal primário e redução da área superficial. Propriedades ótimas podem ser obtidas balanceando-se o teor de aditivo em relação à temperatura empregada. Outros aditivos, como o NH4Cl, podem ser utilizados para redução do teor de sódio. Este trabalho evidencia que a eficiência dos mesmos está diretamente relacionada a um bom confinamento de gases dentro do ambiente de calcinação utilizado.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEMUFSCarAluminasAlF3MineralizadoresÁrea superficialCIENCIAS EXATAS E DA TERRA::QUIMICAENGENHARIASAgentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadasMineralizers and their effects on morphological and physicochemical properties of calcined aluminasinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisOnline600390bd4d1-c505-4015-b043-b075d197c61finfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissDRGO.pdfDissDRGO.pdfapplication/pdf4739026https://repositorio.ufscar.br/bitstream/ufscar/7429/1/DissDRGO.pdf0719fb9298e748f2acda9b76f191fbb3MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://repositorio.ufscar.br/bitstream/ufscar/7429/2/license.txtae0398b6f8b235e40ad82cba6c50031dMD52TEXTDissDRGO.pdf.txtDissDRGO.pdf.txtExtracted texttext/plain238316https://repositorio.ufscar.br/bitstream/ufscar/7429/3/DissDRGO.pdf.txt24a837086178682c625e108fca7113faMD53THUMBNAILDissDRGO.pdf.jpgDissDRGO.pdf.jpgIM Thumbnailimage/jpeg6368https://repositorio.ufscar.br/bitstream/ufscar/7429/4/DissDRGO.pdf.jpgfca203bacf339f20bb433d5711bd08ddMD54ufscar/74292023-09-18 18:30:51.436oai:repositorio.ufscar.br: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Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:30:51Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
dc.title.alternative.eng.fl_str_mv |
Mineralizers and their effects on morphological and physicochemical properties of calcined aluminas |
title |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
spellingShingle |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas Oliveira, Daniela Riello Gomes de Aluminas AlF3 Mineralizadores Área superficial CIENCIAS EXATAS E DA TERRA::QUIMICA ENGENHARIAS |
title_short |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
title_full |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
title_fullStr |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
title_full_unstemmed |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
title_sort |
Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas |
author |
Oliveira, Daniela Riello Gomes de |
author_facet |
Oliveira, Daniela Riello Gomes de |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/8034337197861293 |
dc.contributor.author.fl_str_mv |
Oliveira, Daniela Riello Gomes de |
dc.contributor.advisor1.fl_str_mv |
Pandolfelli, Victor Carlos |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/7369376873984839 |
dc.contributor.authorID.fl_str_mv |
d1d9f2db-a6b4-438c-bdf0-1afadc012efa |
contributor_str_mv |
Pandolfelli, Victor Carlos |
dc.subject.por.fl_str_mv |
Aluminas AlF3 Mineralizadores Área superficial |
topic |
Aluminas AlF3 Mineralizadores Área superficial CIENCIAS EXATAS E DA TERRA::QUIMICA ENGENHARIAS |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA ENGENHARIAS |
description |
Calcination is an important step in the alumina production process, affecting the final properties of the resulting powder and the attained product. Over the previous decades, attempts have been conducted to understand this process aiming to decrease the calcination temperature and time, additionally to the improvement of the alumina properties. In this sense, the use of additives is promising as these mineralizers, like fluorides, act decreasing the transformation temperature from the transition alumina to the alpha phase. In this context, this study addressed the understanding of the influence of three different additives (solid fluoride, soluble fluoride and seeds) on the properties of the calcined alumina, considering the actual condition of the industry and focusing in technical aspects such as morphology, surface area, primary crystal size, alpha content and the soda decrease. There are several theories about the working reaction of these additives, however, no experimental procedure was carried out to prove those mechanisms. In this work, the AlF3 and the soluble fluoride's mechanism reaction were investigated by using DTA-TG-MS techniques. The results showed that the presence of fluoride in transition aluminas leads to the generation of gaseous compounds which are responsible for speeding up the mass transportation, thus, decreasing the temperature and energy required for obtaining the alpha phase. These mineralizers also influenced the alumina properties, such as an increase in the primary crystal size and a decrease in the surface area. The optimum properties can be attained by the right balance between temperature and mineralizer content. Other additives sources, such as NH4Cl, can be used for decreasing the soda content. This work highlights that their efficiency is directly related to a suitable gas confinement inside of the calciner. |
publishDate |
2015 |
dc.date.issued.fl_str_mv |
2015-08-31 |
dc.date.accessioned.fl_str_mv |
2016-09-26T18:40:40Z |
dc.date.available.fl_str_mv |
2016-09-26T18:40:40Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
OLIVEIRA, Daniela Riello Gomes de. Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas. 2015. Dissertação (Mestrado em Ciência e Engenharia de Materiais) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7429. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/7429 |
identifier_str_mv |
OLIVEIRA, Daniela Riello Gomes de. Agentes mineralizadores e seus efeitos nas características morfológicas e físico-químicas de aluminas calcinadas. 2015. Dissertação (Mestrado em Ciência e Engenharia de Materiais) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7429. |
url |
https://repositorio.ufscar.br/handle/ufscar/7429 |
dc.language.iso.fl_str_mv |
por |
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por |
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600 |
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390bd4d1-c505-4015-b043-b075d197c61f |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
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openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEM |
dc.publisher.initials.fl_str_mv |
UFSCar |
publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFSCAR instname:Universidade Federal de São Carlos (UFSCAR) instacron:UFSCAR |
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