We examined the kinetic and transport processes involved in Mg production from MgO via electrolysis at ca 1250 K with in a eutectic mixture of MgF2-CaF2, using a Mo cathode, and carbon anode. Exchange current densities, transfer coefficients, and diffusion coefficients of the electroactive species were established using a combination of cyclic and linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The cathode kinetics are described by a concentration dependent Butler-Volmer equation. The exchange current density and cathodic transfer coefficient are 11 +/- 4 A cm(-2) and 0.5 +/- 0.12 respectively. The kinetics of the anode are described by two Tafel equations: at an overvoltage below 0.4 V, the exchange current density is 0.81 +/- 0.2 mA cm(-2) with an anodic transfer coefficient of 0.5 +/- 0.1; above 0.4 V overvoltage the values are 0.14 +/- 0.05 mA cm(-2) and 0.7 +/- 0.2 respectively. The diffusion coefficients of the electroactive species are D(Mg2+)=5.2 +/- 0.6E-5 cm(2) s(-1) and D(Mg2OF42-)=7.2 +/- 0.2E - 6 cm(2) s(-1). The ionic conductivity of the electrolyte is ca 2.6 S cm(-1). A 3D finite element model of a simple cell geometry incorporating these kinetic and transport parameters suggest that up to 27% of the energy required to drive the electrolysis reaction can be supplied thermally for a current density of 0.5 A cm(-2), enabling a reduction in operating cost if the thermal energy is substituted for valuable electric work. (C) 2016 Elsevier Ltd. All rights reserved.