Sintering behaviour of MgAl 2O 4—a prospective anode material

Abstract

Awareness in environmental hygiene and escalation in the energy cost in electrometallurgical industries have necessitated a reauditing of the production technologies, more so in the case of aluminium as it is a highly energy intensive process. Metal aluminates are of interest due to their technological applications in aggressive environments. The preparation of the metal aluminates usually involves the solid state reaction (SSR) of the corresponding metal oxides or sulphates at high temperatures. The present investigation is the preparation of MgAl 2O 4 using the metal oxides by solid state synthesis. The compacts were sintered at high temperatures and their properties such as particle size, density, porosity, hardness, ac electrical conductivity and dielectric behaviour were evaluated. The phase formation and structural properties have been ascertained by XRD, FTIR, TG/differential thermal analysis (DTA) and scanning electron micrograph (SEM) studies. The sinterability characteristics of the materials strongly dependent on the temperature of the processing. The XRD patterns confirm the phase formation of MgAl 2O 4. The FTIR spectra show the structural details of the synthesized compound. From the SEM micrographs, it is revealed that the agglomeration process progresses with the increasing temperature. The ac electrical conductivity and dielectric behaviour of aluminates strongly depend upon sintering time, temperature and spinel formation.