| 摘要 |
PROBLEM TO BE SOLVED: To provide a method which can suppress variations of an oxidation-reduction potential (ORP) to stably retain in an optimum area in chlorine leaching treatment, and stabilize a Ni leach rate from the raw material.SOLUTION: A leaching control method is included in a chlorine leaching step S1 in an electrical Ni production process which has: the chlorine leaching step S1 of subjecting leaching treatment by chlorine gas to a Ni mixed sulfide MS in a reaction tank so as to obtain a leachate from which Ni is leached; a cementation step S2 of stabilizing copper in the leachate so as to obtain a cementation final solution and cementation residue CMR; and an electrolysis process S4 of purifying the cementation final solution followed by generating electrical Ni by electrolysis. A leaching control system calculates an amount of blow of chlorine gas in the chlorine leaching step S1, determines a MS treatment capacity to subject leaching treatment based on the calculated amount of blow so as to supply MS to the reaction tank, measures ORP in the reaction tank, and determines an amount of CMR to be added based on the measured ORP value followed by adding CMR.SELECTED DRAWING: Figure 1 |
