SOM (Solid-Oxide Oxygen-Ion-Conducting Membrane) Process
for Electrolysis of Metals and Alloys from their Oxides
(Funded by DOE, NSF, and Metal Oxygen Separations Technology)
|Prof. Uday B. Pal and Dr.
Eric Gratz, Alex Roan, Jiapeng Xu, Wenjie Tu, Yihong Jiang, Xiaofei
Guan, and Jarrod Millshtein
View a PDF presentation on Magnesium
Production From Magnesium Oxide
The research work demonstrates the technical viability of employing
zirconia-based inert SOM anodes for environmentally sound and cost-effective
production of metals such as magnesium, tantalum, titanium, rare
earths, silicon, retc., by directly reducing them from their oxides.
The inert anode consists of the oxygen-ion-conducting stabilized
zirconia membrane in intimate contact on one side with a catalytically
active electronic phase. The opposite (other) side of the zirconia
membrane is placed in contact with an ionically conducting solvent
phase containing the desired oxide for reduction. A cathode is placed
in the solvent and an appropriate electric potential is applied
between the electrodes to electrolyze the metals from their oxides.
The full-benefit of the process can be realized if it is
conducted at temperatures between 1000-1400°C. At these temperatures
the ohmic resistance drop across the stabilized zirconia membrane
are low and therefore high current densities on the order of 1 A/cm2
or greater can be obtained. In addition, the process efficiency
can be further increased by directly reforming hydrocarbon fuel
over the anode.
Topics covered in this research include: stability of the
zirconia membrane in the selected molten solvent (flux), volatility
of the flux, transport processes, potentiodynamic sweeps, electrolysis
experiments, metal recovery and analysis and process scaleup.