RESEARCH AND PRACTICE ON IMPROVING HIGH-PROPORTION LUMP ORE SMELTING IN BLAST FURNACE WITH COKE NUT
In response to the smelting issues of blast furnaces under high proportion lump ore conditions,such as decreased permeability and reduced melt dripping performance of the burden,this paper employs laboratory softening and melting dripping experiments.By adding different proportions of coke nuts and using different charging methods,the soft melting temperature range and permeability characteristic index of the burden during coke and ore mixing were obtained.The results indicate that the permeability of the burden increases significantly after the addition of coke nuts,with a notable improvement when the proportion of coke nuts reaches 10%.Mixing coke nuts with pellet ore or stratified mixing of coke fines with pellet ore can further improve the permeability of the burden structure.However,when the lump ore ratio reaches 20%,the permeability of the comprehensive burden deteriorates.The production practice shows that in the process of increasing the lump ore ratio from 14%to 18%,the addition of coke nuts is as high as 30 kg/tHM to 60 kg/tHM,and the pressure difference of the blast furnace can be stably maintained at about 142 kPa.When the pellets are mixed with coke,the ratio of the blast furnace is 18%,the loading capacity of coke is 50 kg/tHM,the pressure difference of the blast furnace is basically between 133 kPa~138 kPa,and the gas utilization rate is more than 44%.
blast furnacecoke nutburden structurelump orecoke and ore mixingmelt dripping performance