Hebei Messi Biology Co., Ltd. stated that in the industrial test of efficient recovery of cobalt by active magnesium oxide, the following steps are included in sequence:
The first step is leaching: add water to adjust the ore to a slurry concentration of 25%, then add concentrated sulfuric acid and reducing agent, and react for 420 minutes under the conditions of controlling the sulfuric acid mass concentration of 10g/l and the redox potential of 360mv in the leaching process. After the reaction, solid-liquid separation is completed to obtain cobalt-containing liquid 1 and leaching slag, and the leaching slag is sent to the slurry warehouse for storage;
The second step is iron removal: first add the second-stage cobalt precipitation slag to the cobalt-containing liquid 1, react for 40 minutes under air filling conditions, and then add low-grade cobalt ore with a mass percentage of 80% of the particle size of -0.074mm, and react for 60 minutes under air filling conditions. The end pH value of the iron removal reaction is controlled to be 4.0. After the reaction, solid-liquid separation is completed to obtain cobalt-containing liquid 2 and iron removal slag, the iron removal slag returns to the first leaching process;
The third step is manganese removal: add a special oxidant to the cobalt-containing liquid 2, control the redox potential at 1100mv, carry out manganese removal reaction for 120min, and separate the solid and liquid after the reaction to obtain cobalt-containing liquid 3 and manganese removal slag, and the manganese removal slag is sent to the slag slurry for storage;
The fourth step is two-stage cobalt precipitation: one-stage cobalt precipitation, add 15% active magnesium oxide milk to the cobalt-containing liquid 3, and carry out a cobalt precipitation reaction for 300min under the condition of controlling the pH value to 8.15. After the reaction, solid-liquid separation is completed to obtain cobalt hydroxide product and cobalt precipitation liquid 1, two-stage cobalt precipitation, add lime milk to the first cobalt precipitation liquid, and carry out a second cobalt precipitation reaction for 60min under the condition of controlling the pH value to 8.45. After the reaction, solid-liquid separation is completed to obtain the second cobalt precipitation slag and cobalt precipitation liquid 2, the second cobalt precipitation slag returns to the second step of iron removal process, and the cobalt precipitation liquid 2 is discharged after the treatment meets the standards.