Basic oxygen furnace slag: Review of current and potential uses

Steel slag, in particular, basic oxygen furnace slag (BOF-S) – a by-product in the steelmaking industry – is an environmental challenge due both to the large volume of the material that is produced annually and its potentially detrimental environmental impacts. Globally, waste generation and management has become a critical issue with waste prevention and recycling rates reportedly too low to keep up with the growing rate of production. In this regard, considerable research has been done to improve traditional applications as well as explore possible reuse options of BOF-S. Multiple, innovative, new technologies and uses have emerged, including BOF-S reuse as a cement binder, a neutralizing agent, an anti-microbial additive or as a carbon sequestration material. Many applications involve the treatment or processing of other waste products such as wastewater, contaminated soils or thin film transistor liquid crystal display waste. Even so, much still needs to be done for sizeable implementations and noticeable differences to be made in the BOF-S reuse field. Large slag dumps continue to exist and grow in many parts of the world as the global steel production rate increases on an annual basis. This paper presents an overview of BOF-S characteristics and composition and discusses how these qualities contribute to the range of possible applications of the by-product. The applications for use of BOF-S presented herein, range from novel, small-scale applications and extends to well-established, large-scale uses.