Low‐temperature synthesis of mullite‐based ceramics from Moroccan naturally occurring andalusite and marble waste.

The present work aims to prepare mullite‐based ceramics at low temperature mainly from andalusite and marble byproduct by a solid‐state interaction method. Marble powder byproduct was used, in the prospect of waste management, as a sintering aid. The influence of marble powder byproduct (5 wt.%) on the phase formation, microstructure‐temperature evolution, densification, and mechanical strength was evaluated by means of XRD, TGA‐DTA, and SEM. The results revealed that the andalusite remained present with mullite up to 1400°C, while the addition of 5 wt.% of marble byproduct involved its complete transformation into mullite and a trace of anorthite. The transformation of andalusite into mullite upon the heating in the range 1300–1400°C involved the densification of the matrix body and a significant increase in mechanical strength from 60 to 170 MPa, which promoted its application for refractory materials. [ABSTRACT FROM AUTHOR]