REDUCTION KINETICS OF MAGNETITE CONCENTRATE PARTICLES WITH HYDROGEN AT 1150 - 1600 °C RELEVANT TO A NOVEL FLASH IRONMAKING PROCESS

摘要

A novel ironmaking process is under development at the University of Utah aimed at producing iron directly from iron oxide concentrate in a flash reactor. This process will reduce hazardous emissions and save energy. The kinetics of magnetite reduction with hydrogen was previously investigated in our laboratory in the temperature range 1150 to 1400 °C at large temperature increments (~100 °C increments). Due to the significant melting that occurs above 1350 °C, the reduction kinetics was measured and analyzed in two distinct temperature ranges of 1150 to 1350 °C and 1350 to 1600 °C (-50 °C increments). Experiments were performed using magnetite concentrate particles of different sizes under various hydrogen partial pressures and residence times. Reduction degrees of more than 90 % were achieved in a few seconds at temperatures as low as 1250 °C. Different rate expressions were needed to obtain reliable agreement with experimental data.