As many scientists experienced, a novel technology is never properly new. Indeed, patents that report iron extraction from oxides or sulphides exists since 1889 (Siemens). My research focussed on two completely different electrolytic principles, both genuine innovation in the underlying electrochemistry and corresponding engineering development.

    When I started this process study in 2004, the challenge was to better understand its electrochemical features (cathode and anode reaction mechanism, identification of transport phenomena influence) to lead to an industrial pilot-scale proposal relevant for iron production with optimized energy consumption. The pace of progress has been fair enough to lead to the development of a pilot cell in 2008 (1kW) that readily produces iron samples of several kilograms and an overall energy efficiency of 80%. This fast development has primary been possible thanks to the fundamental understanding of reaction mechanism, notably the identification of the conversion mode of iron oxide particles in direct contact with the cathode. The engineering of key transfer phenomena to obtain an equirepartition of entropy production has been used, leading to an energy consumption close to optimum.

    The other technology, at the embryonal stage of development, needs fundamental and technological studies to move to the laboratory-scale pilot cell. The principle is to produce liquid metal at 1600°C in a mixture of molten oxides (molten slag, molten glass) as proposed already by Aiken in 1906, and put forward by Professor D. R. Sadoway. The process is commonly compared to an electric arc furnace, an electro-slag refining reactor or a Hall-Héroult cell. In reality, it is a genuine new tool for handling, producing refining or studying liquid metal, or alloys in interaction with a mixture of oxides. Because of the absence of carbon, it is foreseen as an ideal platform to produce C-free metals and alloys.