Blast furnace slag cement clinker production using limestone-hot blast furnace slag mixture

Abstract

The higher production of steel lead to increase in blast furnace slag (BFS) waste which is the by-product of pig iron production. It is due to the demand of steel and concrete around the world for residential and corporate office. The tapping temperature of BFS waste is 1500 °C, hence the amount of heat ex- posed to the atmosphere is enormous. Reusing slag and heat waste from hot slag contributes to green economy. Using appropriate mixing composition, BFS and limestone mixture can be used for green cement production. This works explores the potential to convert slag waste into cement clinker using heat recovered from blast furnace of iron production. BFS and limestone was mixed at specific ratio according to their phase diagram for mentioned purpose. The mixing composition of BFS and limestone is varied at weight percentage of 60, 70 and 74% calcium oxide (CaO). The results show the alite and belite phase present in the slag clinker under XRD characterization and the percentage of weight loss increase after annealing process. BET analysis shows the higher addition of CaO results in higher pore volume, which is proving the high percentage of weight loss. It is observed from the annealing process that the final composition of slag clinker changed. This study shows that by heating BFS with limestone has potential to produce cement clinker at the mixing composition of 74% CaO.