Removal of chromium from cobalt

摘要

A process is disclosed for removing chromium from cobalt. The process involves first contacting an acidic cobalt chloride solution with an oxidizing agent, followed by adjusting the pH to from about 3.2 to about 5.5 with a base at a sufficient temperature to form a first solid containing essentially all of the chromium and a portion of the cobalt and a first liquor containing the balance of the cobalt, and then separating the first solid from the first liquor. The first solid is then heated at a sufficient temperature to remove essentially all of the water and form a second solid which is contacted with sufficient water and ammonium hydroxide to form a slurry which is at a pH of greater than about 3.8. The slurry is made up essentially of a second liquor which contains essentially all of the cobalt which was present in the second solid and a third solid which contains essentially all of the chromium which was initially present in the acidic cobalt chloride solution and which is then separated from the second liquor.