Physical and chemical characteristics of blast furnace, basic oxygen furnace, and electric arc furnace steel industry slags

Approximately 21 million tons of steel industry slag are produced each year in the United States, and many productive commercial uses of slag have bee n developed (e.g., road bed, fill material). However, because slag contains heavy metals at concentrations that are higher than in most soil, question s have been raised regarding the need to evaluate the potential human healt h and environmental hazards associated with current applications. To enhanc e general understanding of the physical and chemical characteristics of thi s material, slag samples from 58 active mills with blast furnaces, basic ox ygen furnaces, and/or electric are furnaces were examined. This study profi les the major and minor constituents of slag from each furnace type and rep orts the leachability of metals from slag under neutral and acidic conditio ns. Particle size distributions and partitioning coefficients (K-d) are als o reported. Although concentrations of metals in slag are elevated relative to concentrations in soil, the metals in slag are tightly bound to the sla g matrix and not readily leached. This study represents the most complete c haracterization of steel industry slag currently produced in North America, encompassing mills that collectively produce over 47% of steel industry sl ag. These data provide insights that may be useful for evaluating the marke tability of steel industry slag and for human and ecological health risk as sessment of environmental applications.