Penetrative and migratory behavior of alkali metal in different binder based TiB2-C composite cathodes
Affiliation of Author(s):
冶金工程学院
Journal:
Transactions of Nonferrous Metals Society of China
Key Words:
中文关键字:铝电解;渗透;迁移;碱金属;TiB2-C 复合阴极;耐腐蚀,英文关键字:aluminum electrolysis; penetration; migration; alk
Abstract:
In electrolyte melts containing K at low temperature, the penetrative and migratory path of alkali metals (K and Na) in
pitch, furan, phenolic aldehyde and epoxy based TiB2-C composite cathodes during the electrolysis process were studied by EDS
and self-made modified Rapoport apparatus. The electrolysis expansion rates, the diffusion coefficients of the alkali metals and the
corrosion rates of the composite cathode were also calculated and discussed. The results show that no matter what kind of binder is
used, alkali metals have the same penetrative path in composite cathodes: firstly in pore, then in binder and finally in carbonaceous
aggregates. K and Na penetrate into both binder and carbonaceous aggregates, which leads to the expansion of composite cathodes,
and K has stronger penetration ability than Na. Electrolysis expansion rate of resin based composite cathode is smaller than that of
pitch based composite cathodes, and so do the diffusion coefficient and corrosion rate. Resin based composite cathode has better
resistance ability to the penetration of alkali metals than pith based composite cathode, and phenolic aldehyde based composite
cathode exhibits the strongest resistance ability. The penetration rate, the diffusion coefficient of alkali metals in phenolic aldehyde
based TiB2-C composite cathode and the corresponding corrosion rate are 4.72 mm/h, 2.24×10-5 cm2/s and 2.31 mm/a, respectively.
First Author:
朱军,li linbo,yujuan,wuxiaolei,fangzhao