Assessment of Blast Furnace Slag Transformation into Value Added By-Products on Basis on Knowledge of Slag Characteristics

Slags are the main by-products generated during iron and crude steel production and the steel industry is committed to increasing and improving their recycling. Today the quantity of slag produced and its utilization are one of the important indicators of sustainable steel industry. There are different forms of BF slag by-products depending on the method used to cool the molten slag. The byproducts can be an excellent source of constructional materials, finding applications in road building, concrete aggregate, as thermal insulation (mineral wool), and as a clinker substitute in cement production, biological filter media, glass making etc. In addition to products obtained from fresh slag, the possibility to utilize the old and the stockpiled blast furnace slags was studied. A key role in their utilization plays the knowledge of the chemical, mineralogical, and morphological properties of BF slag. This paper summarizes the characteristics of BF slag and its possible application.