Development of Iron Recovery Technique from Steelmaking Slag by Reduction at High Temperature

In order to recycle iron in steelmaking slag, a new process concerning mechanical separation of iron from slag, slag reduction at high temperature, and slag recycle after iron separation has been developed. In the mechanical separation, more than 90% of metallic iron was collected from steelmaking slag by improving methods of magnetic separation and gravity separation. In the slag reduction at high temperature, 92% of FetO in separated slag was reduced by heating the slag of basicity (%CaO/%SiO2) = 2.0 at 1 643 K with rotary kiln. In the slag recycle after iron separation, alkaline elution from the slag was decreased to less than one tenth by coating slag with chitosan. Moreover, cooling conditions for direct casting of molten slag to rock shape were investigated.