Co-Ni-xNiFe_2O_4惰性阳极的电导率及耐腐蚀性能

Electric Conductivity and Corrosion Resistance of Co-Ni-xNiFe_2O_4 Inert Anodes

采用冷等静压-烧结的方法制备了铝电解用Co-Ni-xNiFe2O4(x=5%,10%,15%,20%,质量分数,下同)金属基惰性阳极,并对试样的导电性和抗腐蚀性进行了研究。结果表明:阳极试样的电导率随NiFe2O4含量的增加和温度的升高而降低,在900℃时惰性阳极47.5Co+47.5Ni+5.0NiFe2O4和42.5Co+42.5Ni+15.0NiFe2O4的电导率分别为550S·cm-1和300S·cm-1。SEM照片表明试样的抗腐蚀性随着NiFe2O4含量的增加而增强。由于氧化作用和铝热反应,电解极化腐蚀速率要比静态腐蚀速率大。

Cold isostatic press sintering is adopted to prepare Co-Ni-xNiFe2O4 （x=5 %, 10 %, 15 % and 20 wt%） metal based inert anodes for aluminum electrolysis. The electric conductivity and corrosion resistance of electrolyte are investigated. The experimental results show that the electric conductivity of anode decreases with increasing the content of NiFe2O4 and temperature. The electric conductivities of 47.5Co＋47.5Ni＋5.0 NiFe2O4 and 42.5Co＋42.5Ni＋15.0NiFe2O4 are 550 S·cm^-1 and 300 S·cm^-1 at 900 ℃, respectively. Scanning electron microscopy （SEM） shows that the corrosion resistance increases with increasing the content of NiFe2O4. The polarization corrosion rate is bigger than the static corrosion rate due to the oxidation and thermit reaction.