METHOD FOR PRODUCING HEMATITE FOR IRONMAKING

摘要

Provided is a method for producing hematite for ironmaking, wherein high purity hematite, which can be used as an iron-making raw material, is cheaply and efficiently recovered from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process. This method for producing (high purity) hematite for ironmaking in a process of adding a mineral acid and an oxidant to ore containing iron and valuable metals and then leaching the valuable metals under high pressure and high temperature includes (1) a neutralization step of adding a neutralizer to a leachate obtained under high pressure and high temperature to form a leach slurry, (2) a solid-liquid separation step of separating the leach slurry obtained in the neutralization step (1) into a leach residue and the leachate, and (3) a classification step of classifying the leach residue into the hematite and gangue components. (145 words)

主权项

1. A method of producing high-purity hematite for ironmaking by a process of adding a mineral acid and an oxidant to ore containing iron and valuable metals and then leaching the valuable metals under high pressure and high temperature, the method further comprising the following steps (1) to (3):
(1) a neutralization step of performing a two-stage neutralization process on a leachate obtained under high pressure and high temperature to form a leach slurry, the two-stage neutralization process having a first neutralization process in which the magnesium oxide is used as the neutralizer, and following the first neutralization process, a second neutralization process in which the magnesium hydroxide is used as the neutralizer depending on a concentration of a free acid of the leachate; (2) a solid-liquid separation step of separating the leach slurry obtained in the neutralization step into a leach residue and the leachate; and (3) a classification step of classifying the leach residue into the hematite and gangue components.