LOW FUEL RATIO OXYGEN BLAST FURNACE OPERATION METHOD BY HIGH BLENDING OF LOW REDUCIBILITY RAW MATERIAL

摘要

PURPOSE:To increase using quantity of a raw material, which had been extremely limited to a small amount, and to execute oxygen blast furnace operation at low fuel ratio by specifying high blending limited value for low reducibility raw material. CONSTITUTION:The charging material of iron-contained raw material having low reducibility, such as =60% JIS-RI index is blended in high ration to 50-90%, and charged in the blast furnace 1 from furnace top. Furnace gas is fed to a gas holder 3 through furnace top gas cleaning mechanism 2 and branched enroute and passed through a booster 4, to generate high temp. gas by a preheating gas generator 5 and blown in the furnace 1 from gas blowing holes 6. A part of the furnace gas is passed through a booster 4' to be blown in the furnace 1 from tuyeres 9 as temp. adjusting gas in front of the tuyeres 9. On the other hand, oxygen is fed to the above generator 5 and tuyeres 9 from an oxygen source 7, but ordinarily blown from the tuyeres 9 together with fine powdered coal from a fine powdered coal storing vessel 8 as a part of substitute for the coke. In this way, the low reducibility raw material can be reliably used at low fuel ratio.