Development of Removal Technology of Attached Iron Ore Fine

Improvement of gas permeability in the blast furnace is strongly needed to realize lower coke rate blast furnace operation which can reduce CO2 exhaust dramatically. In the upper part of the blast furnace, it is known that removal of fine particles is very effective to improve gas permeability. Especially wet raw iron ore brings a lot of fine iron ore into blast furnace because the wettability of iron ore is quite higher than sinter ore, coke, and other raw materials. Then removal of attached ore fines from wet raw iron ore was tried using conventional screen. At first screening condition was changed, then it was shown that the extension of screening time was effective to remove fine ore. Next, screening of wet iron ore with additional reagent which can reduce the adhesion force by water was tested. Water absorbent polymers and surface acting agents were prepared and added to wet iron ore. Addition of these reagents was very effective to remove ore fines from wet iron ore.