Production of porous ceramic materialusing different sources of alumina and calcia

Detalhes bibliográficos
Autor(a) principal: Oliveira,Ivone Regina de
Data de Publicação: 2015
Outros Autores: Leite,Vitoria Marques Cesar, Lima,Milene Paula Vargas Porto, Salomão,Rafael
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Matéria (Rio de Janeiro. Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762015000300739
Resumo: ABSTRACTNumerous papers and publications report the use of microporous calcium hexaluminate (CaO.6Al2O3; CA6) as a key raw material for high temperature insulating materials. This material has unique properties with respect to chemical purity and mineral composition. Another important property of CA6 is its structure, which consists of platelet-shaped crystals that interlock. The free distance between the crystals defines the microporous structure. The low density in combination with the micropores hampers heat transfer by radiation at temperatures exceeding 1000 oC and results in a low thermal conductivity. Given the advantages presented by this material, it is necessary to understand the formation mechanism of CA6 grains in order to better develop the potential applications of this material. CA6 can be fabricated using organic binders to consolidate the Al2O3-CaCO3 powder mixture and to provide green strength so that a green body can be formed and retains the desired shape before heating. However, these organic binders must be completely thermally decomposed so that they do not remain in the sintered body as carbon or ash. Moreover, the use of organic binders releases large volumes of gases such as carbon dioxide from the green body during heating. Therefore, an eco-friendly ceramic fabrication process has been developed that employs an inorganic binder (hydraulic alumina). The aim of the present work was to study the synthesis of porous calcium-hexaluminate ceramics using calcined alumina or hydraulic alumina combined with different sources of calcia (CaCO3 and Ca(OH)2) at different temperatures. The materials produced were characterized by X-ray diffraction, scanning electron microscopy, apparent porosity and mercury intrusion porosimetry. The materials produced by hydraulic alumina presented higher porosity and larger pores compared to those produced from calcined alumina
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spelling Production of porous ceramic materialusing different sources of alumina and calciaCalcium hexaluminatesynthesisinorganic binderpropertiesABSTRACTNumerous papers and publications report the use of microporous calcium hexaluminate (CaO.6Al2O3; CA6) as a key raw material for high temperature insulating materials. This material has unique properties with respect to chemical purity and mineral composition. Another important property of CA6 is its structure, which consists of platelet-shaped crystals that interlock. The free distance between the crystals defines the microporous structure. The low density in combination with the micropores hampers heat transfer by radiation at temperatures exceeding 1000 oC and results in a low thermal conductivity. Given the advantages presented by this material, it is necessary to understand the formation mechanism of CA6 grains in order to better develop the potential applications of this material. CA6 can be fabricated using organic binders to consolidate the Al2O3-CaCO3 powder mixture and to provide green strength so that a green body can be formed and retains the desired shape before heating. However, these organic binders must be completely thermally decomposed so that they do not remain in the sintered body as carbon or ash. Moreover, the use of organic binders releases large volumes of gases such as carbon dioxide from the green body during heating. Therefore, an eco-friendly ceramic fabrication process has been developed that employs an inorganic binder (hydraulic alumina). The aim of the present work was to study the synthesis of porous calcium-hexaluminate ceramics using calcined alumina or hydraulic alumina combined with different sources of calcia (CaCO3 and Ca(OH)2) at different temperatures. The materials produced were characterized by X-ray diffraction, scanning electron microscopy, apparent porosity and mercury intrusion porosimetry. The materials produced by hydraulic alumina presented higher porosity and larger pores compared to those produced from calcined aluminaLaboratório de Hidrogênio, Coppe - Universidade Federal do Rio de Janeiroem cooperação com a Associação Brasileira do Hidrogênio, ABH22015-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762015000300739Matéria (Rio de Janeiro) v.20 n.3 2015reponame:Matéria (Rio de Janeiro. Online)instname:Matéria (Rio de Janeiro. Online)instacron:RLAM10.1590/S1517-707620150003.0078info:eu-repo/semantics/openAccessOliveira,Ivone Regina deLeite,Vitoria Marques CesarLima,Milene Paula Vargas PortoSalomão,Rafaeleng2015-10-21T00:00:00Zoai:scielo:S1517-70762015000300739Revistahttp://www.materia.coppe.ufrj.br/https://old.scielo.br/oai/scielo-oai.php||materia@labh2.coppe.ufrj.br1517-70761517-7076opendoar:2015-10-21T00:00Matéria (Rio de Janeiro. Online) - Matéria (Rio de Janeiro. Online)false
dc.title.none.fl_str_mv Production of porous ceramic materialusing different sources of alumina and calcia
title Production of porous ceramic materialusing different sources of alumina and calcia
spellingShingle Production of porous ceramic materialusing different sources of alumina and calcia
Oliveira,Ivone Regina de
Calcium hexaluminate
synthesis
inorganic binder
properties
title_short Production of porous ceramic materialusing different sources of alumina and calcia
title_full Production of porous ceramic materialusing different sources of alumina and calcia
title_fullStr Production of porous ceramic materialusing different sources of alumina and calcia
title_full_unstemmed Production of porous ceramic materialusing different sources of alumina and calcia
title_sort Production of porous ceramic materialusing different sources of alumina and calcia
author Oliveira,Ivone Regina de
author_facet Oliveira,Ivone Regina de
Leite,Vitoria Marques Cesar
Lima,Milene Paula Vargas Porto
Salomão,Rafael
author_role author
author2 Leite,Vitoria Marques Cesar
Lima,Milene Paula Vargas Porto
Salomão,Rafael
author2_role author
author
author
dc.contributor.author.fl_str_mv Oliveira,Ivone Regina de
Leite,Vitoria Marques Cesar
Lima,Milene Paula Vargas Porto
Salomão,Rafael
dc.subject.por.fl_str_mv Calcium hexaluminate
synthesis
inorganic binder
properties
topic Calcium hexaluminate
synthesis
inorganic binder
properties
description ABSTRACTNumerous papers and publications report the use of microporous calcium hexaluminate (CaO.6Al2O3; CA6) as a key raw material for high temperature insulating materials. This material has unique properties with respect to chemical purity and mineral composition. Another important property of CA6 is its structure, which consists of platelet-shaped crystals that interlock. The free distance between the crystals defines the microporous structure. The low density in combination with the micropores hampers heat transfer by radiation at temperatures exceeding 1000 oC and results in a low thermal conductivity. Given the advantages presented by this material, it is necessary to understand the formation mechanism of CA6 grains in order to better develop the potential applications of this material. CA6 can be fabricated using organic binders to consolidate the Al2O3-CaCO3 powder mixture and to provide green strength so that a green body can be formed and retains the desired shape before heating. However, these organic binders must be completely thermally decomposed so that they do not remain in the sintered body as carbon or ash. Moreover, the use of organic binders releases large volumes of gases such as carbon dioxide from the green body during heating. Therefore, an eco-friendly ceramic fabrication process has been developed that employs an inorganic binder (hydraulic alumina). The aim of the present work was to study the synthesis of porous calcium-hexaluminate ceramics using calcined alumina or hydraulic alumina combined with different sources of calcia (CaCO3 and Ca(OH)2) at different temperatures. The materials produced were characterized by X-ray diffraction, scanning electron microscopy, apparent porosity and mercury intrusion porosimetry. The materials produced by hydraulic alumina presented higher porosity and larger pores compared to those produced from calcined alumina
publishDate 2015
dc.date.none.fl_str_mv 2015-09-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762015000300739
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dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S1517-707620150003.0078
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Laboratório de Hidrogênio, Coppe - Universidade Federal do Rio de Janeiro
em cooperação com a Associação Brasileira do Hidrogênio, ABH2
publisher.none.fl_str_mv Laboratório de Hidrogênio, Coppe - Universidade Federal do Rio de Janeiro
em cooperação com a Associação Brasileira do Hidrogênio, ABH2
dc.source.none.fl_str_mv Matéria (Rio de Janeiro) v.20 n.3 2015
reponame:Matéria (Rio de Janeiro. Online)
instname:Matéria (Rio de Janeiro. Online)
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reponame_str Matéria (Rio de Janeiro. Online)
collection Matéria (Rio de Janeiro. Online)
repository.name.fl_str_mv Matéria (Rio de Janeiro. Online) - Matéria (Rio de Janeiro. Online)
repository.mail.fl_str_mv ||materia@labh2.coppe.ufrj.br
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