Electrolytic Copper and Refinery Slimes: Blister Anodes Dissolved in Bluestone and Acid (Barnett, in Peters 1905)

Blister copper is cast into thick anodes and hung in tanks of acid copper sulphate solution between thin copper starting sheets. A direct current carries copper from anode to cathode; the silver, gold and other insoluble matter of the anodes fall to the bottom as slimes. Result: cathode copper of conductivity grade, melted and cast into ingots, and about 20 lb of slimes per tank in the first month. Source: Maurice Barnett's design in Edward D. Peters, Modern Copper Smelting (1905), ch. XVIII. Not given: the working temperature of the electrolyte, the cathode purity. Picture drawn by Youblob. The electrolyte is a strong acid.