Papers by Keyword: Electro-Deoxidation

Abstract: The reaction mechanism of electrochemical extraction of Fe_xTi alloys direct from natural ilmenite in molten CaCl₂ has been investigated. The electrochemical deoxidation experiment process was carried out at 1000 °C and 3.8 V, and a solid oxide oxygen-ion-conducting membrane (SOM) filled with carbon-saturated liquid metal was served as the inert anode of the electrolytic cell. The macro-/micro-structure variations of the samples during electrolysis were investigated. The reaction routes from natural ilmenite to Fe_xTi alloys are proposed and discussed. It is found that element Fe is reduced firstly from ilmenite and thus serves as electronic conductor to accelerate subsequent deoxidation, Fe_xTi alloys can be produced directly from natural ilmenite by electrolysis in molten salt. It is suggested that Fe_xTi phase can be formed directly from Fe_xTiO_y compounds and/or from deoxidation-generated Ti and Fe through various reaction routes.

Abstract: Powders of tantalum, niobium and an alloy thereof have been prepared by the electro-deoxidation of their oxide precursors in a eutectic melt of CaCl2-NaCl at 1098 K. The reduced products were characterised by X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray analysis, and quantitative oxygen analysis. All metallic materials were of high purity and had porous nodular microstructures. The alloy powders were single phase, with a relatively wide particle size distribution and some variation in the local Ta-to-Nb ratio. The oxygen contents of the products were below 5000 ppm by mass.

Abstract: The FFC-Cambridge process is a molten salt electrochemical deoxidation method that was invented at the Department of Materials Science and Metallurgy of the University of Cambridge one decade ago. It is a generic technology that allows the direct conversion of metal oxides into the corresponding metals through cathodic polarisation of the oxide in a molten salt electrolyte based on calcium chloride. The process is rather universal in its applicability, and numerous studies on metals, semimetals, alloys and intermetallics have since been performed at the place of its invention and worldwide. The electro-winning of titanium metal is a particularly rewarding target because of the disadvantages of the existing extraction methods. This article summarises the research work performed on the FFC-Cambridge process at the University of Cambridge and its industrial partners with a focus on the electro-winning of titanium metal from titanium dioxide. Topics addressed encompass the invention of the process, early proof-of-concept work, the identification of the reaction pathway, and the investigation and optimisation of the key process parameters. Also discussed are aspects of technology transfer and some of the development work undertaken to date.