Simulation of the Creep Strain of Carbon-Based Cathode Material in the Aluminum Electrolysis

Different stresses can occur in the carbon cathodes due to melting and penetration of sodium during aluminum electrolysis. Under high temperatures and elevated stress, carbon blocks experience primary creep, which can be extended to the secondary and tertiary creep stages. It is quite necessary to characterize the creep behavior of carbon cathodes. Therefore, uniaxial compressive creep testing devices have been used for measuring the creep strain of a semi-graphitic cathode material during aluminum electrolysis under various stress levels. The Graham creep equation is applied for the evaluation of the creep curves and the relationship between creep coefficient and stress is determined. The creep properties of carbon cathode are obtained via numerical simulation. The extracted model effectively supports the obtained experimental results. This work introduces a new insight into the development of cell design and quality control of carbon cathode materials.