Síntesis de cerámicas de mullita 3:2 a partir de residuos de torta de filtración enriquecida en sílice mediante el...

Mullite ceramics were synthesized from filter cake waste following the diphasic gel method. Filter cake waste, with over 65% silica content, and aluminum nitrate nonahydrate were utilized as the sources of silica and alumina, respectively. The prepared samples were sintered at various temperatures of 1150, 1250, and 1350 °C. The sintered bodies were then evaluated for porosity, density, compressive strength, and dielectric strength. Differential Thermal Analysis (DTA) revealed exothermic peaks at 970 °C and 1147 °C, corresponding to spinel and mullite formation, which was also confirmed by X-ray diffraction (XRD) analysis. The XRD result also showed single-phase mullite crystallization at 1250 °C. Field Emission-Scanning Electron Microscopy (FESEM) and Energy Dispersive Spectroscopy (EDS) demonstrated morphological changes, grain growth, and uniform elemental distribution in sintered mullite ceramics. The mullite ceramics sintered at 1350 °C exhibited a density of 2.615 g/cm³, compressive strength of 420 MPa, and dielectric strength of 10.2 kV/mm. These findings highlight the potential of the diphasic gel method to produce high-quality mullite ceramics from industrial waste, contributing to cost-effective, eco-friendly materials with promising applications, including electronic devices, electrical power transmission systems, and other structural and functional advanced ceramics.