INFLUÊNCIA DA CONCENTRAÇÃO DE NaOH NA SÍNTESE DE GEOPOLÍMERO COM REAPROVEITAMENTO DE RESÍDUO INDUSTRIAL
INFLUENCE OF NaOH CONCENTRATION IN THE SYNTHESIS OF GEOPOLYMER WITH REUSE OF INDUSTRIAL WASTE
Woshington da Silva Brito, André Luis Mileo Ferraioli Silva, Kristoff Svensson, Herbert Pöllmann, Rozineide Aparecida Antunes Boca Santa, Humberto Gracher Riella, José Antônio da Silva Souza
Resumo
A concentração molar do ativador alcalino é um parâmetro importante na síntese de geopolímero com reaproveitamento de cinza volante e metacaulim. O trabalho de pesquisa tem como objetivo avaliar o desempenho mecânico dos geopolímeros com razão de Davidovits (SiO2 /Al2 O3 ) de 2,65, sintetizados com diferentes concentrações molares de NaOH (5, 15, 30 e 40 Molar) no ativador. A reação de geopolimerização foi conduzida a temperatura ambiente de 28°C e como ativador utilizou-se hidróxido de sódio (NaOH) e silicato de sódio (Na2 SiO3 ) alcalino 10 Molar. Os geopolímeros sintetizados com 5 e 15 molar de NaOH apresentaram alta resistência a compressão. Apresentando 40,8 MPa com 28 dias de cura para o geopolímero sintetizado com 15 molar. Os geopolímeros sintetizados com 30 e 40 molar de NaOH apresentaram baixa resistência a compressão.
Palavras-chave
Abstract
The molar concentration of the alkaline activator is an important parameter in the synthesis of geopolymer with reuse of fly ash waste and metakaolin. The objective of this work was to evaluate the mechanical performance of the Davidovits (SiO2 /Al2 O3 ) geopolymers of 2,65 synthesized with different concentrations of NaOH (5, 15, 30, 40 Molar) in the activator. The geopolymerization reaction was conducted in ambient temperature of 28°C and 15 Molar sodium hydroxide (NaOH) and 10 Molar sodium silicate (Na2 SiO3 ), were used as the activator. The geopolymers synthesized with 5 and 15 molar NaOH showed high compressive strength. Featuring 40.8 MPa with 28 days cure for the 15 molar synthesized geopolymer. The geopolymers synthesized with 30 and 40 molar NaOH showed low compressive strength.
Keywords
Referências
1 Davidovits, J. Geopolymer Chemistry e Aplication. 2. ed. Saint-Quentin: Institute Geopolymere; Polymers and Geopolymers. 2008; p.9
2 Duxson P, Provis JL, Lukey GC, Mallicoat SW, Kriven WM, Deventer JSJ. Understanding the relationship between geopolymer composition, microstructure and mechanical properties. Colloids and Surfaces. A, Physicochemical and Engineering Aspects. 2005;269:47-58.
3 Salih MA, Abang A A A, Farzadnia N. Characterization of mechanical and microstructural properties of palm oil fuel ash geopolymer cement paste. Construction & Building Materials. 2014;65:592-603.
4 Duxson P, et al. Geopolymer technology: the current state of the art. Journal of Materials Science. 2007;42(9):2917-2933.
5 Wang MR, Jia DC, He PG, Zhou Y, Lett M. Influence of calcination temperature of kaolin on the structure and properties of final geopolymer. Materials Letters. 2010;64:2551-2554.
6 Cioffi R, Maffucci L, Santoro L. Optimization of geopolymer synthesis by calcination and polycondensation of a kaolinitic residue. Resources, Conservation and Recycling. 2003;40:27-38.
7 Castro GJP, Silva AP, Cano RP, Durán SJ, Albuquerque A. Potential for reuse of tungsten mining waste-rock in technical-artistic value added products. Journal of Cleaner Production. 2012;25:34-41.
8 Sakulich AR. Reinforced geopolymer composites for enhanced material greenness and durability. Sustainable Cities and Society. 2011;1:195-210.
9 Karthik A, Sudalaimani K, Vijayakumar CT. Durability study on coal fly ash-blast furnace slag geopolymer concretes with bio-additives. Ceramics International. 2017;43:11935-11943.
10 Zhang J, He Y, Wang YP, Mao J, Cui XM. Synthesis of a selfsupporting faujasite zeolite membrane using geopolymer gel for separation of alcohol/water mixture. Materials Letters. 2014;116:167-170.
11 Davidovits J. Geopolymers based on natural and synthetic metakaolin – A critical review. New York: Elsevier; 2015.
12 Medri V, Fabbri S, Dedecek J, Sobalik Z, Tvaruzkova Z, Vaccari A. Role of the morphology and the dehydroxylation of metakaolins on geopolymerization. Applied Clay Science. 2010;50:538-545.
13 Narayanan A. An Experimental Investigation on Flyash-based Geopolymer Mortarunder different curing regime for Thermal Analysis. Energy and Buildings. 2017;138:539-545.
14 Salehi S, Khattak MJ, Bwala AH, Karbalaei FS. Characterization, morphology and shear bond strength analysis of geopolymers: Implications for oil and gas well cementing applications. Journal of Natural Gas Science and Engineering. 2017;38:323-332.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email