Formation and Structural Evolution of Metallic Iron During Fluidized Bed Hydrogen Reduction of Boron-Bearing Iron Concentrate

Boron-bearing iron concentrate is a refractory composite resource, and metallization reduction is a prerequisite for the pyrometallurgical separation of boron and iron. This study proposed a novel method for the efficient and clean reduction of boron-bearing iron concentrate using hydrogen as a reductant under fluidized bed conditions. At 500 550 degrees C, the magnetite was directly reduced to porous metallic iron. Above 600 degrees C, magnetite was first reduced to w & uuml;stite, and then to dense metallic iron, resulting in a rapid drop in metallization degree at 600 650 degrees C. When the reduction temperature was further increased to 700 degrees C, the metallization degree gradually increased due to the formation of cracks and the gradual reduction of ludwigite. Under the optimal conditions of reduction temperature of 800 degrees C, H2 concentration of 80 % and reduction time of 40 min, the metallization degree of the reduced product was 82.95 %, providing an alternative way for the efficient and clean reduction of boron-bearing iron concentrate. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.