Abstract
Hydrometallurgical process involving the electrodeposition of iron-group metals such as Fe, Ni and Co can be found in various industrial fields. An anomalous codeposition behavior in which less noble metal deposits preferentially appears frequently in the codeposition of iron-group metals with others. In the present paper, the examples of the preferential deposition of less noble metal was demonstrated in the electroplating of Zn-iron-group metal alloys and the hydrometallurgical processes of electrowinning of Zn and electrorefining of Fe in sulfate solutions. The electrodeposition behavior of iron-group metals in above three processes was discussed based on the hydroxide suppression mechanism proposed for the anomalous codeposition.
