EVALUATION OF THE QUALITIES OF RAW MATERIALS FOR GASEOUS DIRECT REDUCTION.

Raw materials should have high iron content with small amounts of phosphorous, sulphur and alkali; high reducibility to make retention time of the burden in the furnace shorter; a low fines generation characteristic to decrease the furnace pressure drop and low clustering tendency to guarantee smooth descent of the burden. To evaluate these properties, the static bed reduction test, Linder rotating reduction test and clustering test were adopted.