BEHAVIOR OF IMPURITIES IN ANODE DURING COPPER ELECTROREFINING - EFFECT OF ARSENIC AND OXYGEN IN ANODE.

In this study the behavior of arsenic and oxygen on the anode during copper electrorefining has been investigated. The form of anode slime and the dissolution state of anode surface after electrolysis as well as the effect of dissolved oxygen in electrolyte have been revealed. The arsenic concentration in the anode was lower than 3% The major part of it was homogeneously distributed in the copper matrix, and then that was dissolved as As**3** plus ions into the electrolyte during electrolysis. These ions produced concurrently anode slime on the anode surface. These slime delayed the diffusion of the As**3** plus ions in the vicinity of the anode to the short distance area from the anode, and the anode was passivated after the drastic increase of the As**3** plus ions in the vicinity of the anode. The anode passivation was greatly accelerated with increasing concentration of the arsenic in the anode and the As**3** plus ions in electrolyte. The form of anode slime showed mostly Cu//3As and a slight amount of the copper powder, irrespective of the concentration of arsenic and oxygen in the anode or dissolved oxygen in the electrolyte.