高温活性化された粗銅陽極の溶解特性

銅陽極不働態化の研究 (第10報)

抄録

Various commercial copper anodes were heat treated by an annealing/slow cooling process, and their dissolution characteristics were extensively examined using copper electrorefining electrolytes.
The results obtained indicate that the following major beneficial effects could beachieved through this heat treatment;
1) The dissolution activity dramatically increases, which is responsible for the combined effect of anode slime layer becoming significantly more porous, thus making the diffusion of Cu²⁺ ions much easier, and also of the, anode itself being rendered very active.
2) As its consequence, cell voltages of the so heat treated anodes become significantly lower than those obtained for the untreated.
3) Slime fall dramatically decreases by 24 to 43% for all the anode samples tested, and
4) The colloidal (or amorphous) nature of anode slimes is considerably reduced, which results it a reduced incidence of the suspended slime particles to be formed in copper electrolyte, which, in turn, reduces a risk of the copper anodes to be contaminated with such impurities as As, Sb, Bi, Se etc.
It has also been shown that the distribution of slime-forming compounds dramatically changes as a result of this heat treatment.