Abstract

VILLAQUIRAN-CAICEDO, Mónica Alejandra; RODRIGUEZ, Erich David  and  MEJIA-DE GUTIERREZ, Ruby. Microstructure Assessment of Metakaolin Based-Geopolymers Produced with Alternative Silica Sources Exposed to High Temperatures. Ing. invest. y tecnol. [online]. 2015, vol.16, n.1, pp.113-122. ISSN 2594-0732.

Ceramic materials more environment friendly and with similar or even better performance than traditional ones can be produced by alkali activation of natural minerals, wastes or industrial by-products. The present study assesses the effect of exposure at 600° and 1200°C of a MK-based geopolymers. Rice husk ash (RHA) and silica fume were modified chemically in order to obtain an alternative alkali activator. Exposure to elevated temperatures leads to dehydration of the reaction products and structural reorganization associated with the crystallization of the gel to leucite (KAlSi₂O₆) and kalsilite (KAlSiO₄). The structural changes associated with the thermal treatment also promote a densification and reduction of porosity. The unreacted MK particles embedded into the geopolymeric gel lead to the formation of mullite (2Al₂O₃ · SiO₂) after the thermal treatment at 1200°C.

Keywords : geopolymer; high temperatures; metakaolin; rice husk ash; silica fume.

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