HIGHER PULVERIZED COAL INJECTION OPERATION METHOD FOR IMPROVING HEAT TRANSFER IN LOWER PART OF BLAST FURNACE

摘要

PURPOSE: A higher pulverized coal injection operation method is provided to increase temperature of dead man and prevent accumulation of non-burnt carbon by blowing pure oxygen along with air into the blast furnace when increasing injection ratio of pulverized coal to improve heat transfer efficiency in the lower part of blast furnace. CONSTITUTION: In a method for performing blast furnace operation by injecting higher pulverized coal into blast furnace, the higher pulverized coal injection operation method for improving heat transfer in the lower part of the blast furnace comprises the steps of determining level of injection ratio of pulverized coal; obtaining an oxygen enrichment ratio according to the determined pulverized coal injection ratio; judging whether an injection ratio of pulverized coal exceeds 150 kg/t-P or not; and blowing oxygen into the blast furnace using lance, wherein the oxygen enrichment ratio is determined by the following table 1 in the step of obtaining an oxygen enrichment ratio according to the determined pulverized coal injection ratio: and wherein a lower limit value of the oxygen enrichment ratio in the step of obtaining an oxygen enrichment ratio according to the determined pulverized coal injection ratio is determined by the following expression 1:£{(VBx0.21)+(O2/60)}/{VB+(O2/60)}|-0.21x100, where VB is blowing amount (m¬3/min), and O2 is supply amount of oxygen (m¬3/hr).