Produção de geopolímeros utilizando cinza da casca de arroz como fonte complementar de sílica

Apolonio, P. H.; Lima, Juliana Silva de; Marinho, E. P.; Nóbrega, Ana Cecília Vieira da; Freitas, Júlio Cézar de Oliveira; Martinelli, A. E.

doi:10.1590/0366-69132020663782914

Cited by 11 publications

(9 citation statements)

References 26 publications

(56 reference statements)

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“…The appearance of peaks between 600 and 800 cm -1 indicated the dissolution of species for the formation of the proper bonds of the geopolymer structure. Results obtained were in accordance with the literature [44,[48][49][50].…”

Section: Resultssupporting

confidence: 91%

Evaluation of the properties of a foamed geopolymer developed with different types of metakaolin

et al. 2021

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The physical and mechanical properties of foamed geopolymers were determined. The geopolymers were made with two different metakaolins (from Metacaulim do Brasil -MB, and Pantano Grande/RS -MPG) as precursors, with NaOH and Na 2 SiO 3 as activators, and with the addition of foam, which was produced with the foaming agent diethanolamide of coconut fatty acid with a minimum of 80% concentration. Also, two times (2.5 and 4 h) were used for the calcination of MPG at 750 °C. The results showed that all factors (precursors type, alkali content, silica modulus, and foam content) had a significant influence on the response variables, which presented the following variations: compressive strength of 0.36 to 3.23 MPa; thermal conductivity from 0.22 to 0.42 W/(m.K); saturated bulk density from 1176 to 1364 kg/m 3 ; dry bulk density of 619 to 864 kg/m 3 ; air void from 46.4% to 62.5%; and water absorption from 55.7% to 95.4%. It was also concluded that the precursor type was the factor that had the most influence on the properties of foamed geopolymers, with MPG calcined for 4 h being the best, as greater compressive strength and low thermal conductivity were obtained.

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Section: Resultssupporting

confidence: 91%

Evaluation of the properties of a foamed geopolymer developed with different types of metakaolin

et al. 2021

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“…The increase in species such as Na 2 O and SiO 2 favors the dissolution and polymerization of a greater number of fly ash particles. According to Apolonio et al [12] and Liew et al [34], the increase in compressive strength is associated with the greater dissolution of aluminosilicates with the later formation of N-A-S-H gel in the hardened specimens. The greater amount of Na 2 O promotes an increase in the alkalinity of the system after adding water.…”

Section: Characterization Of Aam Produced By the One-part Methodsmentioning

confidence: 97%

“…In order to promote the improvement of AAM to substantially be applied in various sectors, researchers have focused on the use of agro-industrial residues as a mechanism to improve the circular economy [11,12]. These residues, generated by different industrial activities, are currently one of the great challenges faced by large urban centers.…”

Section: Introductionmentioning

confidence: 99%

Physical-mechanical behavior of alkali-activated materials produced by the one-part method based on fly ash and rice husk ash

2022

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The study on the physical-mechanical properties of alkali-activated materials (AAM) produced by the 'one-part' method was carried out. For this, residues such as fly ash and rice husk ash (RHA) were used. The alkaline activator (NaOH) was calcined together with RHA for 2 h at 750 °C. Dry mixes were prepared by replacing fly ash with 10%, 20%, and 30% by weight of the calcined material. The samples produced were characterized after 7 and 28 days of curing. The results showed that the investigated variables (calcined material content and curing time at room temperature) were responsible for important variations: compressive strength from 2.40 to 24.92 MPa, modulus of elasticity from 0.90 to 12.32 GPa, water absorption from 2.92% to 13.64%, apparent porosity from 4.82% to 20.02%, and density from 1.48 to 1.71 g/cm 3 . It was concluded that these variations were due to the high concentration of Na 2 O and SiO 2 in the dry mixtures.

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“…A Figura 08 apresenta as imagens de MEV em um aumento de 500 vezes das CBC's. Ao analisar a Figura 08 é possível constatar que as CBC's possuem uma superfície áspera e de formato irregular, ainda é possível observar que as cinzas dos resíduos possuem uma superfície porosa [4]. Ainda a maior presença de partículas alongadas na amostra de 500°C expressa que o processo de calcinação não foi suficiente para a queima completa do bagaço de cana-de-açúcar [18].…”

Section: Microscopia Eletrônica De Varreduraunclassified

“…Dentro deste contexto, estudos visando a redução da produção de clínquer ou até mesmo buscando alternativas para substituição parcial e/ou total deste produto, atrelados a uma melhor durabilidade e resistência, vem se intensificando nos últimos anos [4,10,13,16,22].…”

Section: Introductionunclassified

Análise da viabilidade do uso de resíduos de cana-de-açúcar para produção de aglomerantes sustentáveis

et al. 2021

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RESUMO A cinza de bagaço de cana-de-açúcar é um subproduto oriundo do processo de cogeração de energia elétrica. Este resíduo é composto principalmente por sílica, desta forma, podendo ser reutilizado como agregado e/ou como aglomerante em matrizes cimentícias. O presente trabalho tem como objetivo principal analisar as propriedades físico-químicas da cinza do bagaço de cana-de-açúcar, quando calcinada em diferentes temperaturas, visando a sua aplicação como aglomerante em uma matriz sustentável. O resíduo (bagaço de cana-de-açúcar) utilizado na presente pesquisa, foi coletado no município de Porto Xavier, localizado no estado do Rio Grande do Sul. Para a análise, o resíduo foi separado em quatro amostras e então calcinado em uma mufla com temperatura controlada, sendo respectivamente: 500°C, 600°C, 700°C e 800°C, por um período de uma hora. O processo de calcinação do resíduo tem como finalidade a remoção da matéria orgânica presente. Para a análise das propriedades físico-químicas das amostras, utilizou-se as técnicas de Difração de Raio-X (DRX), Análise Termogravimétrica (TGA), reatividade pozolânica e Microscopia Eletrônica de Varredura (MEV). Os resultados indicam um maior grau de amorfismo na amostra calcinada a 500 °C e maior grau de cristalinidade em 800°C. Se mostrando um material com ótimas características para o uso na produção de aglomerantes sustentáveis.

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Produção de geopolímeros utilizando cinza da casca de arroz como fonte complementar de sílica

Cited by 11 publications

References 26 publications

Evaluation of the properties of a foamed geopolymer developed with different types of metakaolin

Evaluation of the properties of a foamed geopolymer developed with different types of metakaolin

Physical-mechanical behavior of alkali-activated materials produced by the one-part method based on fly ash and rice husk ash

Análise da viabilidade do uso de resíduos de cana-de-açúcar para produção de aglomerantes sustentáveis

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