Steel Slags in Cement-Making-The Current Status of Development

In the production of iron and steel, two different types of slags are generated - one, the blast-furnace slag obtained at the time of iron extraction and the other, the steel slag generated during the conversion of iron to steel in the steel melting shop. The blast-furnace slag, after proper granulation, is used extensively as a supplementary cementitious material in the cement and concrete industry. The steel slag, however, has not found much use and is mostly dumped as a waste material after removing scrap steel. In order to explore the avenues for economical utilization of this slag in cement-making, an extensive literature and patent survey has been carried out. Further, based on the steel slags available from some of the integrated steel plants in India, the material has been characterized in detail and its hydraulic behavior has been studied. Studies relating to the potential use of this slag as a raw material in the production of portland cement clinker as well as in the manufacture of special cements like the calcium suphoaluminoferrite type have been experimentally carried out at a pilot scale. Blended cement formulations with maximized incorporation of steel slag have been prepared and studied. Based on available literature and experimental findings, an attempt has been made to look at the potential scenario of steel slag usage in cement-making with specific emphasis on environmental amelioration and greenhouse gas reduction.