| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing hematite capable of manufacturing a hematite of a low sulfur quality during a high pressure acid leach (HPAL) process of nickel oxide ores.SOLUTION: Magnesium oxide manufactured through steps (1) through (5) is used as a neutralizer for a pre-neutralizing treatment targeting an exudate slurry exuded and obtained at a high temperature and a high pressure from nickel oxide ores by adding thereto sulfuric acid: (1) impurities are separated from an exudate obtained as a result of exudation of nickel oxide ores by adding thereto a neutralizer, and after sulfides of nickel and cobalt have been obtained by adding a sulfurizing agent to the neutralized liquid, the sulfurized liquid is separated; (2) a to-be-discharged effluent obtained by separating aluminum and manganese from the sulfurized liquid by adding thereto a neutralizer is concentrated so as to induce the deposition and separation, as calcium sulfate, of calcium included within the to-be-discharged effluent; (3) the obtained solution is further concentrated so as to induce the deposition, as magnesium sulfate, of magnesium within the solution; (4) manganese oxide and a sulfurous acid gas are obtained by roasting the magnesium sulfate together with a reductant; and (5) the magnesium oxide is washed. |
