THERMODYNAMIC AND ELECTROCHEMICAL STUDY OF VANADIUM SOLUTIONS: TOWARDS VANADIUM RECOVERY FROM A SPENT CATALYST

Abstract

Due to the low abundance of vanadium in nature (about 135 g/t), the feasibility to recover it from industrial wastes has highly attracted scientific and technological attention. The main recovery routes reported are associated with chemical or thermochemical processes. However, the electrochemical recovery of vanadium from industrial wastes has been poorly investigated. In this work, a thermodynamic and electrochemical study for the possible vanadium recovery from a spent catalyst generated in the petrochemical industry was conducted. The study was divided into two stages using low vanadium concentrations. In the first stage, the recovery of vanadium was possible in its V4+ state at low reduction potentials, whereas for the second stage, cyclic voltammetry was used to calculate the diffusion coefficient and the heterogeneous velocity coefficient of the V5+/V4+ redox pair. The obtained values are similar to those reported in the literature for aqueous solutions at high vanadium concentrations and would allow the design of the system at large scale. This report aims to set the conditions for the possible vanadium recovery from a spent catalyst by means of electrochemical processes, although the optimization of such conditions must be further explored.