Testing of cement bonded briquettes under laboratory and blast furnace conditions Part 2 - Swelling of briquettes

Cement bonded agglomeration process is being considered as an economically and environmentally attractive method of recycling iron rich byproducts from iron and steel plant back to the blast furnace. In this method various iron rich byproducts are mixed with required amount of cement and agglomerated. On curing these agglomerates can be used as a burden material for blast furnace. When the agglomerates are subjected to high temperature reducing condition inside the blast furnace, the hydrated cement phases dissociate and the iron oxide phases undergo a series of phase transformations. As a result, these agglomerates disintegrate inside the blast furnace leading to operational problems. Hence, to improve the performance of the agglomerates the understanding of the reactions taking place in the agglomerates is essential. The present paper discusses the reactions that take place between the calcium silicates and lime from the cement and iron oxides from the byproducts at high temperature reducing conditions.