Abstract:
The anode effect can occur during neodymium and didymium oxide electrowinning, causing a surge in the electrochemical cell voltage, interrupting the process, and increasing the greenhouse gas emissions. In this work, we develop a mathematical model, based on the mass balance of gas bubbles evolving from the anode, to understand the influence of some process parameters on the anode effect. The anode effect occurs due to bubble coverage and limitations on the mass transfer of the oxide species. Variables such as current density, oxide content, viscosity, and electrolyte composition play an important role in the anodic process. Finally, we propose a mechanism for the occurrence of the anode effect during Nd or Di (Nd–Pr) oxide electrolytic reduction based on models used in aluminum electrolysis.
Reference:
SILVA, Andre Luiz Nunis (8653); SANTOS, Celia Aparecida Lino dos (8757); ARAÚJO, Rogério de Melo Riberio de; FELDHAUS, Dominic; FRIEDRICH, Bernd; LANDGRAF, Fernando José Gomes; GUARDANI, Roberto. Model and mechanism of anode effect an electrochemical cell for Nd or (Nd, Pr) reduction. Metals, v.12, n.3, 498, 2022. 15 p.
Access to the article on the Journal website:
https://www.mdpi.com/2075-4701/12/3/498
The anode effect can occur during neodymium and didymium oxide electrowinning, causing a surge in the electrochemical cell voltage, interrupting the process, and increasing the greenhouse gas emissions. In this work, we develop a mathematical model, based on the mass balance of gas bubbles evolving from the anode, to understand the influence of some process parameters on the anode effect. The anode effect occurs due to bubble coverage and limitations on the mass transfer of the oxide species. Variables such as current density, oxide content, viscosity, and electrolyte composition play an important role in the anodic process. Finally, we propose a mechanism for the occurrence of the anode effect during Nd or Di (Nd–Pr) oxide electrolytic reduction based on models used in aluminum electrolysis.
Reference:
SILVA, Andre Luiz Nunis (8653); SANTOS, Celia Aparecida Lino dos (8757); ARAÚJO, Rogério de Melo Riberio de; FELDHAUS, Dominic; FRIEDRICH, Bernd; LANDGRAF, Fernando José Gomes; GUARDANI, Roberto. Model and mechanism of anode effect an electrochemical cell for Nd or (Nd, Pr) reduction. Metals, v.12, n.3, 498, 2022. 15 p.
Access to the article on the Journal website:
https://www.mdpi.com/2075-4701/12/3/498
