Distribution Characteristics of Phosphorus in the Metallic Iron during Solid-State Reductive Roasting of Oolitic Hematite Ore

Abstract

The distribution characteristics of phosphorus in the metallic iron, and the reduction behaviors of hematite and fluorapatite during solid-state reductive roasting of a phosphorus-rich (1.3 mass%) oolitic hematite ore were investigated in the temperature range of 900°C–1200°C. Experimental results show that phosphorus in the iron is present in the forms of αFe and Fe₃P, resulted from the simultaneous reduction of fluorapatite and hematite at temperatures up to 1100°C. The phosphorus content in the metallic iron particles decreases from the edge to the center in the pellet cross-section. For the aim of phosphorus removal, the selective reduction of hematite and fluorapatite should be achieved; while for the enrichment of phosphorus as ferrophosphorus, the reduction of fluorapatite, and affinity of P₂ and Fe should be guaranteed. These findings could provide guidance for technique development for the utilization of phosphorus-rich oolitic iron ores via pyro-methods.