Production of Iron Powder by Solid-Phase Reduction of Fine Magnetite

Abstract

It is shown that the effectiveness of processes in fluidized-bed reactors is limited by the low rate of reaction at low temperatures rather than by the small size of the particles. Low-temperature reduction by hydrogen is associated with low use of gas and high energy consumption of the gas treatment system. Temperature increase is impossible due to bonding of iron particles causing destruction of the fluidized bed, but mechanical activation can increase the rate of reaction without increasing the temperature of the process. Since sulfur and phosphorus bond with iron in the reduction of iron oxides, iron and magnetite can be separated from iron sulfides and phosphides using the difference in the Curie points in different iron compounds and magnetic separation at ~500 °C. The possibility to form high-temperature magnetic separators for fine materials is pointed out.