Removal of Phosphorus from High-phosphorus Iron Ore with Preliminary Reduction Treatment and Physical Concentration

Fundamental experiments were conducted with the aim of crude separation of the phosphorus contained in high-P iron ore prior to the ironmaking process. By reducing high-P iron ore with lime and graphite at an appropriate blending ratio and temperature, a reduction product was obtained consisting of a P-concentrated phase, metallic Fe with low P, and an Fe oxide-containing phase. The reduction product was pulverized by electrical pulse disintegration, and a magnetic separation experiment was performed for each particle group. As a result, 57.5% of the P contained in the reduction product was removed by removing particles of 250 µm or less. Samples simulating the constituent phases of the reduction products were synthesized and subjected to magnetization measurement. It was assumed that the Fe oxide-containing phase was paramagnetic and the P-concentrated phase was diamagnetic. We calculated the magnetic and drag forces acting on the paramagnetic particles in wet magnetic separation. When the magnetic field gradient was low, the magnetic forces acting on the fine particles were low, and attraction was difficult due to the drag force of water.