Cerâmica estrutural: efeitos da incorporação de cinzas provenientes da queima de madeira
Carregando...
Data
2022-11-18
Autores
Matsumoto, Danielly Thiemy
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A utilização de resíduos industriais em materiais destinados à construção civil vem sendo um relevante foco de estudos nos últimos anos e o setor de cerâmica estrutural têm utilizado diversos resíduos que podem atuar como fundentes e/ou desplastificantes, substituindo os materiais naturais. Neste trabalho, foi realizado um estudo sobre o aproveitamento de cinzas pesadas, provenientes da queima da madeira, em uma matriz cerâmica coletada em uma indústria ceramista da região de Panorama/SP. Duas cinzas foram utilizadas: a primeira, denominada de cinza A, proveniente da madeira de eucalipto e pinus da própria indústria ceramista, e a segunda, cinza B, de eucalipto coletada em uma indústria de papel e celulose, localizada em Três Lagoas/MS. As cinzas com composição, predominantemente, de óxido de silício e cálcio, foram adicionadas à massa cerâmica, composta de quartzo, caulinita e mica. A adição foi realizada nas proporções de 0, 5, 10, 15 e 20%, em massa. A sinterização ocorreu nas temperaturas de 900 a 1200ºC. Posteriormente, os corpos de prova foram caracterizados quanto às suas propriedades físicas e mecânicas. Os resultados mostraram que a resistência à flexão foi superior ao limite mínimo recomendado para fabricação de tijolos maciços (2 MPa) para ambas as composições, sinterizadas acima de 1150ºC. As demais propriedades físicas, como absorção de água, massa específica aparente e retração linear de queima, apresentaram valores dentro dos limites recomendados para a fabricação de blocos, as quais são decorrentes da formação de fase líquida e da mulita em temperaturas a partir de 1000ºC. A fase líquida, auxiliada pelos óxidos fundentes presentes nas cinzas, pode ser observada em algumas imagens de microscopia óptica. Conclui-se, portanto, que ambas as cinzas podem ser incorporadas à matriz cerâmica utilizada neste estudo, até o teor máximo estudado para fabricação de tijolos maciços, desde que a peça cerâmica seja sinterizada em temperaturas acima de 1150ºC.
The use of industrial waste in materials intended for civil construction has been a relevant focus of studies in recent years. In the structural ceramics sector, many works has used various residues that can act as fluxes and/or deplasticizers, replacing natural materials. In this work, a study was carried out on the use of bottom ash, from the burning of wood, in a ceramic matrix collected in a ceramic industry in the region of Panorama/SP. Two ashes were used: the first, called ash A, from eucalyptus and pine wood from the ceramic industry itself, and the second, ash B, from eucalyptus collected in a pulp and paper industry, located in Três Lagoas/MS. The ashes, predominantly composed of silicon and calcium oxide, were added to the ceramic mass, composed of quartz, kaolinite and mica. The addition was carried out in proportions of 0, 5, 10, 15 and 20% by mass. Sintering took place at temperatures from 900 to 1200ºC. Subsequently, the specimens were characterized as to their physical and mechanical properties. The results showed that the flexural strength was higher than the minimum limit recommended for the manufacture of solid bricks (2 MPa) for both compositions, sintered above 1150ºC. The other physical properties, such as water absorption, apparent specific mass and linear firing shrinkage, showed values within the recommended limits for the manufacture of blocks, which are due to the formation of the liquid phase and mullite at temperatures from 1000º C. The liquid phase, aided by the fluxing oxides present in the ashes, can be observed in some optical microscopy images. It is concluded, therefore, that both ashes can be incorporated into the ceramic matrix used in this study, up to the maximum content studied for the manufacture of solid bricks, provided that the ceramic piece is sintered at temperatures above 1150ºC.
The use of industrial waste in materials intended for civil construction has been a relevant focus of studies in recent years. In the structural ceramics sector, many works has used various residues that can act as fluxes and/or deplasticizers, replacing natural materials. In this work, a study was carried out on the use of bottom ash, from the burning of wood, in a ceramic matrix collected in a ceramic industry in the region of Panorama/SP. Two ashes were used: the first, called ash A, from eucalyptus and pine wood from the ceramic industry itself, and the second, ash B, from eucalyptus collected in a pulp and paper industry, located in Três Lagoas/MS. The ashes, predominantly composed of silicon and calcium oxide, were added to the ceramic mass, composed of quartz, kaolinite and mica. The addition was carried out in proportions of 0, 5, 10, 15 and 20% by mass. Sintering took place at temperatures from 900 to 1200ºC. Subsequently, the specimens were characterized as to their physical and mechanical properties. The results showed that the flexural strength was higher than the minimum limit recommended for the manufacture of solid bricks (2 MPa) for both compositions, sintered above 1150ºC. The other physical properties, such as water absorption, apparent specific mass and linear firing shrinkage, showed values within the recommended limits for the manufacture of blocks, which are due to the formation of the liquid phase and mullite at temperatures from 1000º C. The liquid phase, aided by the fluxing oxides present in the ashes, can be observed in some optical microscopy images. It is concluded, therefore, that both ashes can be incorporated into the ceramic matrix used in this study, up to the maximum content studied for the manufacture of solid bricks, provided that the ceramic piece is sintered at temperatures above 1150ºC.
Descrição
Palavras-chave
Cinza de eucalipto, Resíduos, Reaproveitamento, Cerâmica vermelha, Eucalyptus ash, Waste, Reuse, Red ceramics