Processing Effects on Properties of (Fe,Mg,Al)(3)O-4 Spinels as Potential Consumable Anodes for Pyroelectrolysis

Abstract

A promising concept of consumable anode materials for high-temperature pyroelectrolysis process, which is expected to overcome the environmental and economical impacts of classical extractive metallurgy, relies on substituted magnetite-based ferrospinels, presenting high electrical conductivity, appropriate refractoriness, and redox stability. The present work aims assessment of the processing effects on structural, redox, and electrical properties of Fe2.3Al0.2Mg0.5O4 spinel, prepared by conventional solid-state route (SSR) and laser floating zone (LFZ) method. The observed trends for high-temperature electrical conductivity behavior indicated that the electronic transport is only slightly affected by the preparation method, suggesting the minor effects from the grain boundaries. For scaled-up ferrospinel-based consumable anodes the impact of oxidation during thermal cycling on electrical properties and electrode integrity can be minimized even in air, by using relatively fast cooling/heating rates.