3al2o3 2sio2
Mostrando 1-12 de 272 artigos, teses e dissertações.
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1. Microstructural characteristics, properties, synthesis and applications of mullite: a review
Abstract Mullite, an intermediate phase of the binary alumina-silica system, is one of the most important phases of ceramic products containing alumina and silica in the initial composition. Its stoichiometry ranges from 3Al2O3.2SiO2 (3:2) to 2Al2O3.SiO2 (2:1) and its crystalline structure is orthorhombic, characterized by the presence of octahedral chains o
Cerâmica. Publicado em: 2022
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2. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
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3. Adsorption of Calcium(II), Cadmium(II) and Copper(II) Ions from Water by Prepared Silicon-Aluminum-Zirconium Oxide Using Sol-Gel Process
Ternary oxide silica-alumina-zirconia (SiO2/Al2O3/ZrO2) obtained by the sol-gel process was applied as novel adsorbent of ions in aqueous solution. Batch isotherms were performed using standard CuII, CdII and CaII solutions at variable pH and different concentrations. Adsorption capacity was best at weakly acidic pH. The maximum adsorption capacities were 2.
J. Braz. Chem. Soc.. Publicado em: 2021-07
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4. Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material
Abstract The use of supplementary cementitious materials (SMCs) is one of the three essential factors for the sustainability of the cement industry. To reduce CO2 emissions, several studies have introduced new methods for the utilization of industrial wastes such as the addition into cementitious materials. The objectives of this study were to chemically and
Cerâmica. Publicado em: 2021-06
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5. QUANTIFICAÇÃO DE MULLITA PROVENIENTE DE RESÍDUOS DE CAULIM DA REGIÃO AMAZÔNICA: USO DO MÉTODO DE RIETVELD
Mullite is used to obtain a refractory material, there are several factors that influence the synthesis process of mullite: the preparation of the mixture, the precipitation and the reaction of SiO2 and Al2O3. For the synthesis of mullite, samples of kaolin processing residues were used as precursor material, because it presents SiO2 and Al2O3 in its composi
Quím. Nova. Publicado em: 2021-04
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6. Use of rice husk ash to produce alternative sodium silicate for geopolymerization reactions
Abstract This study investigated the feasibility of synthesizing sodium silicate from rice husk ash (RHA) and its application to produce geopolymers. Samples were prepared at different SiO2/Al2O3 molar ratios (3.0, 3.5, and 4.0) for both sodium silicates (commercial and from RHA). They were underwater cured at 60 ºC for 1 h and then at room temperature (25
Cerâmica. Publicado em: 2021-03
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7. Thermal decomposition and reaction sintering for synthesis of mullite-zirconia composite using kaolin, γ-alumina and zirconia
Abstract The refractory materials used in the wall of the furnaces for glass melting can be prepared from mullite-zirconia composite material. The composite of mullite/zirconia was synthesized from Iraqi kaolin, γ-alumina, and zirconia using thermal decomposition with reaction sintering at 1600 °C. Several batches were prepared with various ratios of kaoli
Cerâmica. Publicado em: 2021-03
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8. Influence of Mn2+ ions on depression of quartz and spessartine in gondite ore
Abstract Low-grade manganese ores that are composed of manganese oxides, wad, quartz, iron oxides, gibbsite, and especially of spessartine (Mn3Al2(SiO4)3) are known as gondite. Spessartine is a mineral with a high content of silica (SiO2) and alumina (Al2O3) that causes a decrease of the enrichment in manganese oxide concentrates by flotation, giving this o
REM, Int. Eng. J.. Publicado em: 2021-01
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9. Síntese e caracterização de zeólita tipo sodalita obtida a partir de resíduo de caulim
Resumo Produtos zeolíticos foram sintetizados a partir de um resíduo industrial do processo de beneficiamento de caulim. O material de partida foi submetido a tratamento térmico a 700 °C durante 2 h. As sínteses foram realizadas com a reação do resíduo com NaOH e uma fonte adicional de sílica, em condições hidrotermais, para relações molares de
Cerâmica. Publicado em: 2020-12
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10. Síntese e caracterização de pó de mulita monofásico derivado de sol-gel
Resumo Pó precursor de mulita microfina de alta pureza de composição estequiométrica, 3Al2O3.2SiO2, foi sintetizado por rota sol-gel usando isopropóxido de alumínio e tetraetoxissilano. O pó precursor de mulita foi caracterizado por área de superfície BET, distribuição de tamanho de partícula, espectroscopia no infravermelho por transformada de F
Cerâmica. Publicado em: 2020-09
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11. Produção de geopolímeros utilizando cinza da casca de arroz como fonte complementar de sílica
Resumo O silicato de sódio é a fonte complementar utilizada na reação de geopolimerização. Entretanto, esse reagente é produzido em alta temperatura ou em autoclave a alta pressão, o que gera muito impacto ambiental. Visando a produção de geopolímeros mais ecológicos, produziu-se um silicato de sódio alternativo (ASW) a partir da dissolução da
Cerâmica. Publicado em: 2020-06
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12. Influência das propriedades microestruturais e morfológicas de argilas in natura na reatividade de resíduos de tijolos em uma matriz cimentícia
Resumo Características físicas, químicas e mineralógicas das argilas in natura utilizadas nas indústrias interferem no processo produtivo e produto cerâmico final. Foram caracterizadas argilas in natura de 4 indústrias do Sul do Brasil pelas técnicas de DRX, FRX, FTIR, DSC e MEV. Além disso, o potencial pozolânico também foi verificado com base no
Cerâmica. Publicado em: 2020-06