Environmental impact of high-value gold scrap recycling

Abstract

Purpose The gold routes satisfying the global gold supply are mining (74%), recycling of high-value gold (23%), and electronic scraps (3%). Besides its applications in the investment, jewelry, and industrial sector, gold also has a bad image. The gold production in industrial as well as artisanal and small-scale mines creates negative impacts such as resource depletion, extensive chemical use, toxic emissions, high energy consumption, and social concerns that are of great importance. On the other hand, almost all gold is recycled and has historically always been. In common life cycle assessment (LCA) databases, there is no data on recycling of high-value gold available. This article attempts to answer the question what the ecological benefits of this recycling are. Method In this study, we were able to collect process data on the most commonly used high-value gold scrap recycling process, the aqua regia method, from several state-of-the-art German refineries. With this data, life cycle inventories were created and a life cycle model was produced to finally generate life cycle impacts of high-value gold scrap recycling. Results This study contains the corresponding inventories and thus enables other interested parties to use these processes for their own LCA studies. The results show that high-value gold scrap recycling has a considerably lower environmental impact than electronic gold scrap recycling and mining. For example, high-value gold scrap recycling in Germany results in a cumulative energy demand (CED) of 820 MJ and a global warming potential (GWP) of 53 kg-CO2-Eq. per kg gold. In comparison, common datasets indicate CED and GWP levels of nearly 8 GJ and 1 t-CO2-Eq. per kg gold, respectively, for electronic scrap recycling and levels of 240 GJ and 16 t-CO2-Eq. per kg gold, respectively, for mining. Conclusion The results show that buying gold from precious metal recycling facilities with high technological standards and a reliable origin of the recycling material is about 300 times better than primary production.

Gold nanoclusters embedded in antimicrobial keyboard covers: life cycle assessment and environmental sustainability

“…recovered and recycled gold, as this would significantly help to reduce the environmental impacts of the system. 76 Specifically, it would help in decreasing the resource consumption and all the impacts linked to the mining of primary gold, as investigated by B. Fritz and colleagues. 76 To this end, if gold nanoclusters and nanoparticles were widely employed, it would be advisable to explore new techniques and methodologies for recovering nanomaterials from wastewater effluents and different solid matrices.…”

“…76 Specifically, it would help in decreasing the resource consumption and all the impacts linked to the mining of primary gold, as investigated by B. Fritz and colleagues. 76 To this end, if gold nanoclusters and nanoparticles were widely employed, it would be advisable to explore new techniques and methodologies for recovering nanomaterials from wastewater effluents and different solid matrices. 22 Comparison between the LCIA results of the antimicrobial keyboard covers with the ones from the production of alcohol wipes and gloves highlights the overall environmental benefits of antimicrobial keyboard covers being adopted in hospitals.…”

Turning waste into wealth: efficient and rapid capture of gold from electronic waste with a thiourea functionalised magnetic core stirring rod adsorbent and its application for heterogeneous catalysis

“…11 Once the recovery of gold from the e-waste can be realised, not only will resources be wisely used and the environment protected, but there will also be significant economic benefits that will have long-term and profound implications for sustainable development. 12 Unfortunately, due to the low percentage, the highly acidic environment and complex ionic interference, the sustainable and selective recovery of gold from e-waste remains a major challenge. 13 In recent years, various recovery technologies for gold ions from electronic waste leachate solutions have been developed, such as solvent extraction, 14 ion exchange, 15 chemical precipitation, 16 membrane separation, 17 photocatalytic dissolution 18 and adsorption.…”

“…11 Once the recovery of gold from the e-waste can be realised, not only will resources be wisely used and the environment protected, but there will also be significant economic benefits that will have long-term and profound implications for sustainable development. 12 Unfortunately, due to the low percentage, the highly acidic environment and complex ionic interference, the sustainable and selective recovery of gold from e-waste remains a major challenge. 13…”

Scrap Gold Recovery: Recycling, Fabrication and Electrochemical Characterization of Low-Cost Gold Electrode

“…It is a costly material, which limits its use in various fields, despite its superb performances compare to other metals. Mining (74%), high-value gold recycling (23%), and electronic scrap (3%) are the gold pathways that satisfy the world gold supply [22]. In 2018, the overall gold supply was 4670 tons, with 23% coming from the refinement of gold-containing debris like jewellery or coins, 3% from the recovering of waste electronic equipment, and the remainder coming from freshly mined gold [23].…”