低温电解质[K_3AlF_6/Na_3AlF_6]-AlF_3-Al_2O_3熔体中TiB_2-C复合阴极的耐腐蚀性能

Corrosion resistance of TiB_2-C cathode composites for aluminum electrolysis in [K_3AlF_6/Na_3AlF_6]-AlF_3-Al_2O_3 melts

采用模压-焙烧技术制备沥青、呋喃、酚醛和环氧基TiB2-C复合阴极,研究其在[K3AlF6/Na3AlF6]-AlF3-Al2O3熔体中的低温电解腐蚀行为。研究结果表明:TiB2-C复合阴极均有着良好的铝液润湿性;沥青基TiB2-C复合阴极耐腐蚀性能较差,其腐蚀率和碱金属(K和Na)渗透速率分别为8.09 mm/a和10.6 mm/h;相比之下,酚醛基TiB2-C复合阴极的耐腐蚀性能最好,其腐蚀率和碱金属的渗透速率分别为3.05 mm/a和4.72 mm/h,分别比沥青基TiB2-C复合阴极下降62.3%和55.5%;树脂基TiB2-C复合阴极的抗碱金属渗透能力较好,其中又以酚醛基TiB2-C复合阴极的抗碱金属渗透能力最强;树脂黏结剂的使用可以在一定程度上改善TiB2-C复合阴极的耐腐蚀性能。

Pitch,furan,phenolic aldehyde and Epoxy based TiB2-C cathode composites were prepared in the mould pressing-baking process,and their corrosion resistance in [K3AlF6/Na3AlF6]-AlF3-Al2O3 melts was studied.The results show that no matter what kind of binder is used,TiB2-C cathode composites have the good wetting property by liquid aluminum.Pitch based TiB2-C cathode composite has the poor corrosion resistance,and its corrosion rate and penetration rate of alkali metals（K,Na） is 8.09 mm/a and 10.6 mm/h respectively.In contrast,phenolic aldehyde based TiB2-C cathode composite has the stronger corrosion resistance,and its corrosion rate and penetration rate of alkali metal is 3.05 mm/a and 4.72 mm/h,respectively,which decreases by 62.3% and 55.5%.Compared with pitch,resin based TiB2-C cathode composites have stronger resistance ability to penetration of alkali metals.Among them,phenolic aldehyde based TiB2-C cathode composite exhibits the strongest resistance ability to penetration of alkali metals.The use of resin as adhesive can improve the corrosion resistance of TiB2-C cathode composites to some extent.