The Effect of the Fe2: Fe3 Ratio upon the Current Efficiency in the Electrolysis of a Copper Sulfate Solution Containing Iron Sulfate

In the treatment of copper ores by hydro-electro-metallurgical methods, not only is copper deposited, but other metals are also dissolved. In practice it has been found* that iron, under certain conditions, causes the copper to deposit on the cathode as a nonadherent precipitate and also that the iron in solution causes a great decrease in current efficiency, es­pecially when the electrolysis is conducted by operating with a higher current density at the cathode than at the anode. The present investigation deals with the effects of the two valences of iron on the current efficiency and endeavors to determine whether or not there is a ratio of the two at which point the efficiency becomes zero or approaches it.

The Staining Effect of the Hydrochloric Acid-Chromate Trioxide Solution on the Minerals of the Chalcocite-Stibnite-Galena Ternary System.

The object of this work has been to devise a method by which the different phases in the chalcocite-stibnite-galena ternary system may be identified. As the mineralogists have no precise methods for the identification of these phases, a hydrochloric acid-chromate trioxide staining solution was employed.