Phosphorus Removal of High Phosphorous Oolitic Iron Ore with Acid-Leaching Fluidized-Reduction and Melt-Separation Process

Abstract

A process with acid leaching followed by hydrogen-based fluidized reduction and melt separation is presented for recovering DRI (direct reduced iron) from high-phosphorus oolitic hematite in this study, and the aim of this study is to provide theoretical and technical basis for economical and rational use of high phosphorus oolitic iron ores. The reducibility of the ore can be improved by acid leaching, which is caused by the formation of voids in the ore particles after acid leaching and enhancing the internal gas diffusion. The phosphorus content in the DRI is still relative high even though there is no carbon in DRI, and it can be decreased to 0.087 wt% (raw ore 1.2 wt%) with the optimum condition in this study. It is proved that P exists in the DRI recovered from melt separation in the form of P₂O₅ inclusions or Fe_xP as solid solutions, while not in the form of Ca₃(PO₄)₂ inclusions. Finally, a combined flowsheet for the treatment of high phosphorus oolitic iron ore is designed in this study.