Oxidation and reduction of Cr(III) species originating from dissolution of Cr2O3 in cryolite-based melts at 900 degrees C was studied. The molar ratio n(NaF)/n(AlF3) was 1.4, which allowed us to perform electrochemical measurements at 900 degrees C. Cr(II) species were prepared in situ by the reduction of Cr2O3 with chromium powder. Saturation was achieved after several hours, the concentration of Cr(II) being (237 +/- 11) wt ppm. C(III) can be oxidized to Cr(VI) both chemically by oxygen present in the air and electrochemically when using an inert anode. When a carbon anode was used, the formation of Cr(VI) species was not observed. The solubility of Cr(VI) species in the above-mentioned melt was found to be (1395 +/- 22) wt ppm at a total amount of Cr species in the melt of (1574 +/- 16) wt ppm. (C) 2013 The Electrochemical Society. [DOT: 10.1149/2.024304jes] All rights reserved.