Phosphorus migration mechanism between iron and high phosphorus gangue phase at high temperatures

The phosphorus migration mechanism during melting separation of non-carbon-reduced high phosphorus iron ore was investigated. Firstly, the equilibrium compositions of hydrogen-reduced high phosphorus iron ore at different temperatures were simulated by the use of equilibrium composition module of HSC Chemistry software. Then, thermodynamic calculation was verified by the real heat treatment of simulated hydrogen-reduced high phosphorus iron ore with several pure reagents including self-made pure fluorapatite. The iron particles in the simulated samples gathered and grew up during heat treatment. Meanwhile, the hypoeutectic structure of Fe-P with grid shape of high phosphorus phase and circular shape of low phosphorus phase emerged within those iron particles. With the penetration of phosphorus from the periphery into the iron particles, the grid structure became denser and denser. It proves that the elemental phosphorus can be reduced from the gangue phase by metallic iron without solid carbon at high temperatures.