Abstract: NiFe2O4 spinel was synthesized via solid-state sintering technology using NiO and Fe2O3 as raw materials, and ZrO2(f)-NiFe2O4 inert anode was prepared by adding ZrO2 fibers [ZrO2(f)] into NiFe2O4. The static thermal corrosion rate and electrolytic corrosion rate of inert anode samples in cryolite molten salt were measured by weight-loss method, and their corrosion mechanism was examined by SEM, EDX and XRD analysis. The experimental results indicate that the porosity of anode samples is increased from 4.9% to 5.8% with the increase of ZrO2(f) from 0 to 4%(w), which leads to the increase of static thermal corrosion rate from 3.8 to 4.3 mg/(cm2×h). The dissolution reactions of oxides in cryolite molten salt are inhibited in the electric field. The electrolytic corrosion rate of anodes samples containing 3%(w) ZrO2(f) is 2.2 mg/(cm2×h), which is much lower than its static thermal corrosion rate, and both corrosions are controlled by physicochemical dissolution. ZrO2(f) has excellent stability in cryolite molten salt at high temperature, and can be used for the reinforcement of NiFe2O4 based inert anodes in aluminum electrolysis.

Key words: ZrO2 fiber, NiFe2O4 spinel, inert anode, molten salt, corrosion rate

摘要： 以NiO和Fe2O3为原料，采用固相烧结法合成了NiFe2O4尖晶石，通过添加ZrO2纤维[ZrO2(f)]制备了ZrO2(f)-NiFe2O4惰性阳极材料. 采用失重法测量了阳极试样在冰晶石熔盐中的静态热腐蚀率和电解腐蚀率，并对腐蚀机理进行了探讨. 结果表明，ZrO2(f)添加量由0增加至4%(w)时，阳极试样的气孔率从4.9%上升到5.8%，导致其静态热腐蚀率由3.8 mg/(cm2×h)增大到4.3 mg/(cm2×h)；在电场作用下，氧化物在冰晶石熔盐中的溶解反应受到抑制，含3%(w) ZrO2(f)阳极试样的电解腐蚀率为2.2 mg/(cm2×h)，远小于其静态腐蚀率，腐蚀均为物理化学溶解过程；高温下ZrO2(f)在冰晶石熔盐中稳定性良好，可作为铝电解NiFe2O4基惰性阳极的强韧化材料.

关键词: ZrO2纤维, NiFe2O4尖晶石, 惰性阳极, 熔盐, 腐蚀率