Environmental and economic implications of slag disposal practices by the ferrochromium industry: A case study

Abstract

A large volume of slag is annually produced by the ferrochromium industry and the slag has historically been dumped without any pollution prevention, control or remediation measures. The slag at the ASSMANG Chrome Machadodorp (ACM) plant in Mpumalanga (where this case study was conducted) contains elements that may pose a significant threat to human life and the environment. The objectives of this study were to assess the composition of the slag produced at the ACM plant and classify the slag in terms of the minimum requirements, as prescribed by the Department of Water Affairs and Forestry (DWAF), and to determine the economic implications of compliance with existing statutory requirements, and critically assess the implementation of the minimum requirements in practice. According to leachability results for the ACM slag, aluminium (Al), iron (Fe) and manganese (Mn) have the potential to leach from the slag in excess of the acceptable risk levels. Using the minimum requirements’ prescribed methods, the ACM slag was classified based on these three substances as Hazard Rating II.

Authors

Categories