Emergy-based environmental accounting of gold ingot production in China

Abstract

Gold production has brought serious environmental impacts on the natural ecosystem. Thus, it is critical to evaluate such impacts so that appropriate mitigation measures can be initiated. Derived from thermodynamics and systems ecology, emergy synthesis is one evaluation method widely used for environmental accounting. This study employs emergy-based indicators to evaluate gold ingot production based on regional data so that the holistic environmental performance of gold production in China can be examined. Sensitivity analysis on gold concentration, dominant contributors, labor & services is conducted so that more reliable results can be obtained. Results show that the total emergy (without labor & services) used for per gram gold ingot production was 9.63E + 13 sej, in which energy and chemicals were the dominant contributors. Specially, the unit emergy value of gold in the ground based on local gold enrichment was 3.67E + 12 sej/g. Results also indicate that gold production is extremely unsustainable because it’s heavily dependent on nonrenewable resources during its whole production life cycle. Finally, several recommendations were proposed to mitigate its overall environmental impacts by considering the local realities.