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.

The Effect of Cobalt Upon Current Efficiency in the Electrolysis of Zinc Sulphate Solutions

The detrimental effect of the presence of cobalt upon the current efficiency, in the commercial production of zinc by electrolysis, has been recognized for some time. Most authorities differ upon the maximum amount of cobalt allowable. This is due to the fact that the presence of other impurities either increases or diminishes the detrimental effects of the cobalt. The following tests were made with the object in view of ascertaining the relation, if any, between the amount of cobalt present and the current efficiency during the electrolysis of an otherwise pure zinc sulfate solution. The results obtained from these observations indicate that there is little apparent relation between the cobalt concentration of a given solution of zinc sulfate and the current efficiency that may be obtained on the electrolysis of that solution. For certain cobalt concentrations, however, it was noted that the time factor played an important part.

Effect of Impurities upon Current Efficiency in the Electrolysis of Zinc Sulphate Solution

There are many elements which are detrimental to the current efficiency in the electrolysis of zinc sulphate solution. Fortunately the majority of these elements are easily removed in the purification process and cause no further trouble. The elements that are likely to cause trouble in ordinary plant operations are antimony, arsenic, cobalt, nickel, manganese and germanium. The following tests were made to determine the mutual effect on the current efficiency when several of the impurities were present in the electrolyte.