Iron - Wikipedia- iron solid state reduction with coal ,Direct iron reduction. ... These gases are then treated with iron ore in a furnace, producing solid sponge iron: ... When loss of iron is not adequately compensated by adequate dietary iron intake, a state of latent iron deficiency occurs, which ...Solid State Reduction of Preoxidized Chromite-iron Ore ...A comparative study on coal-based solid state reduction of preoxidized chromite pellets and chromite-iron ore pellets was conducted to investigate the reduction behavior of these two types of pellets.