Experimental study on the coal-based method to deal with pyrite cinder for preparing sulfur-bearing steel

Using pyrite cinder with low melting point and bituminous coal as raw materials,carbonized pyrite cinder pellets were made and introduced to the reduction smelting process. The effects of basicity,roasting temperature,roasting time and C/O molar ratio on the iron recovery rate were investigated to search the optimum experimental parameters. It was found that iron nuggets with the iron recovery of 93.1% were obtained when the basicity was 1.2,the roasting temperature was 1450℃,the roasting time was 20 min and the C/O molar ratio was 1.2. Iron oxides and iron-bearing sulfides in pyrite cinder were reduced,thus a higher iron recovery rate was achieved. From X-ray diffraction analysis on the slag tailings,short smelting time caused high amount of iron in metallic state retained in the slag. Because of high sulfur in iron nuggets from pyrite cinder by reduction and melting separation,the iron nuggets can be used as raw materials to product sulfur-bearing free-cutting steel.