Impact analysis of gold[sbnd]silver refining processes through life-cycle assessment

© 2019 Elsevier Ltd Gold and silver are extracted through the gold-silver couple production process or the gold-silver-lead-zinc-copper combined production process. This paper aims to analyse and compare the life-cycle assessment (LCA)of the gold and silver refining processes. Two production routes are considered in this study: gold and silver refining through the gold-silver couple production process and gold and silver refining which are produced from the gold-silver-lead-zinc-copper combined production process. SimaPro software version 8.5 is used for the life-cycle assessment using the International Life Cycle Reference Data (ILCD)method and the cumulative energy demand method (CED). The geographic region considered in the original dataset is based on Papua New Guinea and Sweden. The major impact categories from the ILCD methods are climate change, human toxicity (cancer and non-cancer effects), ecotoxicity, ionising radiation (human health and ecotoxicity), eutrophication (freshwater, marine, and terrestrial), land use, water use, and mineral resources depletion. The impact categories where the results are analysed and presented here from the CED method are renewables, fossil fuels (oil, coal, and gas), biomass, nuclear, and embodied energy. The analysis results indicate that between gold-silver couple production and gold silver combined metal production process, refining through the gold-silver couple production process have greater environmental impacts. Furthermore, gold refining effects are larger as compared to the silver refining process. Among the significant impact categories, the most crucial is human toxicity (cancer and non-cancer). Results from the cumulative energy demand method shows that fossil-fuel consumption is larger than all other sources of energy demand in the precious-metal refining process.