Reactions of liquid sodium with transition-metal oxides. Part V. The oxides Fe3O4, Co3O4, and NiO; stoicheometry and reaction rates

Abstract

The stoicheiometry and rates of reaction of liquid sodium with the oxides Fe₃O₄, Co₃O₄, and NiO have been studied by measuring the quantity of sodium consumed over a range of reaction times and temperatures. The nickel oxide reaction becomes rapid above 150°, and the sodium consumed corresponds precisely to complete reduction to nickel metal. Reaction of Fe₃O₄ is slow below 250°; reduction to metallic iron is only 80% complete at 250°, and this is attributed to ternary oxide formation. The oxide Co₃O₄ reacts rapidly below 120°, and explosively above this temperature. Reduction to cobalt metal is about 90% complete at 120°.