Processing Effects on Properties of (Fe,Mg,Al)3O4 Spinels as Potential Consumable Anodes for Pyroelectrolysis.

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 Fe_2.3Al_0.2Mg_0.5O₄ 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. [ABSTRACT FROM AUTHOR]