Direct Reduction of Liquid V2O5 in Molten CaCl2

Abstract

An alternative process of the reduction of V 2 O 5 was studied. It consists of thermochemical and electrochemical reactions in molten CaCl 2 + CaO. V 2 O 5 is thermochemically reduced by Ca. The by-product CaO is electrolyzed. Liquid V 2 O 5 was reduced to vanadium metal through intermediate CaV 2 O 4 , and oxygen concentration was 1860ppm at minimum. By deoxidation of the sample with a smaller specific surface area, the lowest oxygen concentration, 460ppm, could be achieved A major component of ejected gas from the anode was CO 2 at the initial stage and CO at the later stage. O 2 gas was not detected because its concentration was lower than detection limit.

A Facile Formation of Vanadium(0) by the Reduction of Vanadium Pentoxide Pelletized with Magnesium Oxide Enabled by Microwave Irradiation

“…Up to now an alternative process for the reduction of V 2 O 5 was reported by Oka et al . It consists of thermal reduction of V 2 O 5 with calcium metal and electrolysis of CaO, a by‐product of the thermal reduction reaction, in molten CaCl 2 + CaO.…”

(Invited) Metal Production in CaCl2-Based Melts

“…The appearance of Ca-containing phases such as CaNb 2 O 6 , CaTa 2 O 6 and CaV 2 O 4 in the way from Nb 2 O 5 , Ta 2 O 5 and V 2 O 3 to the corresponding metals indicates the important contribution of Ca and CaO (6)(7)(8)(9)(10)(11).…”

“…Once the carbonate ion was generated in the bath, it reacts at cathode as Eq. [9] to precipitate carbon powder. The gas bubbles were found at the cathode in Figure 4(b), and they are due to CO 2 gas as written in Eq.…”

“…[7] and also precipitate carbon on the cathode surface as Eq. [9]. Two kinds of carbon were reported as amorphous carbon with spherical morphology and carbon nano-fiber grown from the cathode surface with the assistance of iron particles (17).…”

Electrolytic reduction of V₃S₄ in molten CaCl₂

“…7,8) Oka and Suzuki investigated the reduction of vanadium by the OS (Ono Suzuki) process starting from vanadium oxide. 9) In this process, CaO dissolved in molten CaCl 2 is reduced to Ca at the cathode. The Ca present near the cathode undergoes a redox reaction with V 2 O 5 to produce V, while the Ca is oxidized to CaO and dissolves in the solution.…”