Experimental Study On The Effect Of Ferro-coke And Iron Ores Mixing Charging On Primary Slag Formation In The Blast Furnace

The profile and position of the cohesive zone is one of the key factors affecting theblast furnace stable operation. The effect of ferro-coke mixing into the burden materialson primary slag formation process in the blast furnace and the hightemperature_reduction of sinter as well as pellet was experimentally studied. The resultsdemonstrated that the addition of ferro-coke can lower the compression startingtemperature of all samples. This is because ferro-coke starts to react with CO2at lowertemperatures and increases the difference between the CO concentration in gas and theequilibrium content, accelerating the indirect reduction of iron ore. Moreover, theaddition of ferro-coke would generally increase the softening-end temperature anddecrease the melt-down temperature, leading to smaller softening-melting temperaturerange by a large margin, as well as a significant decrease of permeability index.Thissuggests that the mixing of ferro-coke into iron ores can remarkably improve thepermeability of blast furnace stock, which will be very beneficial for the actual blastfurnace operation.The effect of No.4ferro-coke mixed into the burden materials on the hightemperature reduction of sinter and pellet was studied, and the results demonstrated thatthe addition of ferro-coke can improve the high temperature reduction degree of sinterand pellet. Moreover, as the ratio of ferro-coke blended increased, the reduction degreewent up regularly. This means that ferro-coke can promote the reduction of iron ore,which is good for strengthening smelting, also it can reduce reductant consumption andcoke ratio. Besides, the smaller the particle size of ferro-coke is, the greater the area ofiron ore contacting with ferro-coke is. Thus, it can improve the high temperaturereduction of sinter and pellet.