Hematite manufacturing method and hematite manufactured by same

摘要

Provided is a hematite manufacturing method by which hematite with a low sulfur level can be manufactured using a high-pressure acid leaching (HPAL) process with a nickel oxidized ore. Magnesium oxide manufactured by steps (1) through (5) is used as a neutralizer for a preliminary neutralization process performed on a leached slurry obtained by adding sulfuric acid to a nickel oxidized ore and leaching the ore at a high temperature and high pressure. The present invention involves the following: (1) the neutralizer is added to a leachate obtained by leaching the nickel oxidized ore to separate impurities, a sulfating agent is added to the neutralized liquid to obtain nickel and cobalt sulfides, and then the sulfated liquid is separated; (2) effluent waste water from which aluminum and manganese have been separated by adding the neutralizer to the sulfated liquid is concentrated and calcium contained in the effluent waste water is made to precipitate as calcium sulfate and is separated; (3) the solution obtained is further concentrated and the magnesium in the solution is made to precipitate as magnesium sulfate; (4) the magnesium sulfate is roasted along with a reducing agent to obtain magnesium oxide and sulfurous acid gas; and (5) the magnesium oxide is washed.