METHOD FOR PRODUCING HEMATITE FOR IRON MAKING

摘要

PROBLEM TO BE SOLVED: To provide a production method in which purification of iron oxide (hematite) contained in a leach residue produced in a HPAL (High Pressure Acid Leach) process, to a degree that a resultant hematite contains a small amount of sulfur constituent so that the resultant hematite can be used as a raw material for iron making.SOLUTION: There is provided a production method of (high purity) hematite for iron making in a process of adding an oxidant and sulfur acid to a nickel oxide ore to leach nickel. The production method includes steps of: adding a neutralizer to leaching slurry formed by mixing leachate obtained after leaching nickel with leach residue, the neutralizer generating gypsum by acting with free sulfuric acid as excess acid contained in the leaching slurry; then performing solid-liquid separation to form neutralization residue whose sulfur content exceeds 1.0 wt.%; then performing heating process of the neutralization residue in a temperature range of 600°C to 1,400°C to form hematite whose sulfur content is 1.0 wt.% or less.