Exergy analysis of silicon content in hot metal and its temperature influence on energy efficiency of “BF shop – BOF shop” complex operation

Application of pulverized-coal fuel in BF production results in changes of blast furnace heat operation, in particular, in hot metal temperature and silicon content in it changes, that effects the energy efficiency of “BF shop – BOF shop” complex operation. Isolated consideration of energy utilization by facilities (blast furnace, basic oxygen furnace) without taking into account their energy-technological ties does not provide steel smelting rational solutions obtaining. An exergy analysis of silicon content in hot metal and its temperature influence on energy efficiency of “BF shop – BOF shop” complex operation accomplished by application of the elaborated method of calculation of complete energy balance of “BF shop – BOF shop” system under existing conditions of pulverized-coal fuel application in Ukraine. It was shown, that silicon content decreasing down to level, which does not allow malfunctions of BF heat operation is strategically important for improving of energy efficiency of “BF shop – BOF shop” complex operation under conditions of pulverized-coal fuel application in BF production. It was determined, that under conditions of pulverized-coal fuel application in “BF shop – BOF shop” system, silicon content in hot metal decrease by 0.1% results in decreasing of exergy losses by 18–180 MJ/ton of steel, which is equivalent to standard fuel consumption decrease by 0.5–6.0 kg/ton of steel, increase of hot metal production by ~0.3–1.2 %. Hot metal temperature in blast furnace increase by 50 °С results in exergy losses decrease by 26–29 MJ/ton of steel, which is equivalent to standard fuel decrease by 0.9–1.0 kg/ton of steel.