Effect of additive BaO on corrosion resistance of xCu/(10NiO-NiFe2O4)
cermet inert anodes for aluminum electrolysis
cermet inert anodes for aluminum electrolysis
(1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Hunan University, Changsha 410082, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
2. School of Materials Science and Engineering, Hunan University, Changsha 410082, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract: xCu/(10NiO-NiFe2O4) cermet and 1BaO-xCu/(10NiO-NiFe2O4) cermet (x=5, 10, 17) inert anodes were prepared as potential inert anodes for aluminum electrolysis and their corrosion resistance to traditional electrolyte was studied with anodic current density of 1.0 A/cm2 in laboratory electrolysis. The substantial corrosion of metal Cu was observed, many pores appeared on the surface of anode and electrolytes infiltrated inside anodes during the electrolysis. The wear rates of 5Cu/(10NiO-NiFe2O4), 10Cu/(10NiO-NiFe2O4), 17Cu/(10NiO-NiFe2O4), 1BaO-5Cu/(10NiO-NiFe2O4), 1BaO-10Cu/(10NiO-NiFe2O4) and 1BaO-17Cu/ (10NiO-NiFe2O4) are 2.15, 6.50, 8.30, 4.88, 4.70 and 4.48 cm/a, respectively. The addition of BaO to 10Cu/(10NiO-NiFe2O4) cermet and 17Cu/(10NiO-NiFe2O4) cermet is advantageous because BaO can effectively promote densification and thus improve corrosion resistance. But the addition of BaO to 5Cu/(10NiO-NiFe2O4) cermet is unfavorable to corrosion resistance because additive BaO at the grain boundary of anode accelerates possibly the corrosion of cermet.
Key words: BaO; inert anode; aluminum electrolysis; cermet; corrosion resistance; wear rate