Numerical analysis of sodium diffusion in aluminum electrolysis cathode carbon blocks based on a microstructure...

Area of Science:

• Materials Science
• Chemical Engineering
• Electrochemistry

Background:

• Current research on sodium penetration in aluminum cathode carbon blocks focuses on macroscopic expansion curves, neglecting microscopic structural influences.
• The pore structure of cathode carbon blocks significantly impacts their sodium diffusion performance as porous media.

Purpose of the Study:

• To investigate sodium diffusion in cathode carbon blocks from a microstructural perspective.
• To develop a predictive model for sodium diffusion considering key influencing factors.

Main Methods:

• A random aggregate model was developed using Python.
• Finite element software was employed to simulate sodium diffusion based on Fick's second law.
• The model incorporated porosity, temperature, binding effects, current density, and molecular ratio.

Main Results:

• Increased porosity, temperature, current density, and molecular ratio enhance sodium infiltration.
• These factors reduce diffusion resistance and increase the sodium diffusion coefficient.
• The simulation results showed good agreement with experimental data.

Conclusions:

• The developed microstructural model accurately predicts sodium diffusion in cathode carbon blocks.
• Understanding microstructural effects is crucial for optimizing cathode performance in aluminum electrolysis.
• The model provides a reliable tool for analyzing and improving cathode carbon block properties.