Abstract: In order to provide mineralogical basis for the iron concentration from gas quenching slag of Tangshan Iron and Steel Company, the process mineralogy of the slag was studied by the means of chemical analysis, iron phase analysis, X-ray diffraction analysis, polarizing microscope analysis to identify the material composition, occurrence, dissemination feature and particle size distribution of the iron ore. The study results point out that the target minerals in the dressing tests are limonite, magnetite and metallic iron, among which limonite separation requires the magnetic roasting or direct reduction method. Magnetite and metallic iron can be separated by the conventional physical beneficiation method, but the process needs stage grinding with the final grinding fineness of less than 40 μm.

Key words: Gas quenching steel slag, Process mineralogy, Iron mineral, Occurrence situation, Dissemination feature, Particle size distribution