Abstract
The preparation of high-purity chromium from commercial, aqueous electrolytic chromium has been investigated. Factors influencing the refining process, such as cell design, electrolyte components, chromium concentration in electrolytes, and cell operating parameters, have been studied. An improved molten-salt electrolytic refining process has been developed for the preparation of high- purity chromium with total impurity contents of less than 70 ppm, using a KCl-LiCl-CrCl2 electrolyte at 520 deg C. High-purity chromium deposits ranging from 0.2 to 0.3 kg have been routinely prepared with initial cathode current densities of 40 to 210 A/ft2 with average current efficiency of 96 percent. The chromium recovery in the process was 99 percent.
