DESULFURIZATION IN REDUCTION OF IRON ORE IN HEAT MEDIUM PARTICLE-CIRCULATED FLUIDIZED BED

PURPOSE:To suppress the migration of sulfur into reduced iron to a minimum by charging effectively a solid desulfurizer into at least one of a reduction tower and a combustion tower in the reduction of iron ores in a heat medium-circulated fluidized bed. CONSTITUTION:A carbonaceous material 6a as a heat medium particle heated in a combustion tower 2 is moved to a reduction tower 1 through a pipe 3, where it gives a heat necessary for the reduction of iron ores supplied in the apparatus 4 and returns to the tower 2 through a pipe 15 and a cyclone 11. The carbonaceous material 6a, e.g., coal, etc., supplied in the apparatus 6 is burned with O2 or air blown from a nozzle 8, and heavy oil and coal blown from the nozzle into the tower 1 are gasified to reduce the iron ores. Most of waste gas from the towers 1 and 2 is again supplied through a carbonic acid remover 14. C and S present in the carbonaceous material 6a are converted into combustion gases and also gasified S is generated even in the tower 1 when the carbonaceous matieral 6a is moved. Thus, a solid reducing agent, e.g., lime stone, etc., is charged into at least one of the towers 1 and 2. The particle size of the solid reducing agent is almost the same as that of packings. By this, the classifying phenomenon of particles in the fluidized bed can be prevented and the mixing effect of the fluidized bed can be raised.