| 摘要 |
<p>Manganese is removed from a cobalt solution containing manganese as an impurity by an oxidative neutralization process. The process comprises 2 stages for producing a cobalt solution of low manganese concentration, the first stage being for oxidative neutralization of the cobalt solution controlled at an oxidation-reduction potential of 900 mV or more (based on an Ag/AgCl electrode) and pH of 3 or less to remove most of the manganese in the form of oxide precipitate having a Co/Mn ratio of 0.3 to 1.0 by weight, and the second stage being for the continued oxidative neutralization of the cobalt solution produced in the first stage to remove a small quantity of the residual manganese in the form of oxide precipitate and thereby to produce the high-purity cobalt solution containing manganese at 0.05g/L or less, while keeping the same oxidation-reduction potential and pH conditions for the cobalt solution. The cobalt solution containing the Mn impurity may be cobalt chloride. The oxidant may chlorine, hypochlorous acid and/or ozone. The neutralizer may be a hydroxide or carbonate of an alkali metal or alkaline earth metal, or cobalt carbonate.</p> |
