Life cycle assessment of an industrial gold mining in Mali

In addition to its considerable economic benefits, mining generally has a significant environmental impact on the ecosystem and human health, despite the efforts made. Mali, the 13th gold producer in the world and 3rd in Africa, deserves very special attention. This paper aims to identify and assess the potential environmental impacts and environmental hotspots of gold mining in Mali, using a life cycle assessment (LCA) approach.

An industrial gold mine located west of Bamako in the Kéniéba circle in Mali exploiting two main underground deposits was considered in this paper. SimaPro software (v.9.0.0) is used for LCA by applying the ReCiPe 2016 Midpoint/Endpoint (H) V1.08 method to quantify the impacts generated. In addition, a sensitivity analysis of the scenarios proposed by Bjorklund is carried out to improve the reliability of the results obtained.

The results show that the main category of impact of gold mining that contributes most to the total environmental impact is human carcinogenic toxicity due to the production of electricity, the use of diesel, heavy fuel oil, hydrogen peroxide, sodium cyanide, aluminium chloride, and on-site emissions. In addition, the impacts of fossil resource depletion, terrestrial ecotoxicity, ozone formation in terrestrial ecosystems, mineral resource depletion, ozone formation in human health, terrestrial acidification, global warming, marine ecotoxicity, fine particle formation, and freshwater ecotoxicity also contribute considerably. Water consumption is identified as a positive impact of gold mining.

Following the identification of environmental hotspots by this paper, further research is strongly recommended into the efficient production and rational consumption of energy and the choice of less energy-intensive, green technologies to promote more environmentally efficient gold mining.