銅陽極電位に及ぼす不純物の影響 (第2報)

ヒ素, アンチモン, ビスマス及びスズの影響

抄録

Effect of Impurities such as arsenic, antimony, bismuth and tin on the copper anode potential has been studied.
By the presence of β-Cu₃As in anode copper the anode potential is extremely raised, but a large portion of arsenic dissolves in electrolyte to form arsenic or arsenious acid. The raise in potential of antimony containing anode is caused by formation of Sb₂O₃ (ortho) slime. Bismuth does not dissolve in copper but presents at grain boundaries. Effect of bismuth on anode potential is quite different depending on Cl^-ion. The absence of Cl^-ion leads to raise in potential according to copper slime formed by the reducing reaction of bismuth. On the contrary, the presence of it brings about the fall in anode potential by means of a formation of bismuth oxychloride slime. Tin forms SnO₂ slime, but has no effect on anode potential. When the temperature of electrolyte is low, arsenic, antimony and tin lower anode potentials during the first stage of electrolysis. These phenomena can be explaind as the results of the decrease of activation polarization.