Surplus Cost Potential as a Life Cycle Impact Indicator for Metal Extraction

Marisa Vieira,Mark Huijbregts,Thomas Ponsioen,Mark Goedkoop

doi:10.3390/resources5010002

Marisa Vieira, Mark Huijbregts + Show 2 more

Open Access

https://doi.org/10.3390/resources5010002

Copy DOI

Abstract

In the evaluation of product life cycles, methods to assess the increase in scarcity of resources are still under development. Indicators that can express the importance of an increase in scarcity of metals extracted include surplus ore produced, surplus energy required, and surplus costs in the mining and the milling stage. Particularly the quantification of surplus costs per unit of metal extracted as an indicator is still in an early stage of development. Here, we developed a method that quantifies the surplus cost potential of mining and milling activities per unit of metal extracted, fully accounting for mine-specific differences in costs. The surplus cost potential indicator is calculated as the average cost increase resulting from all future metal extractions, as quantified via cumulative cost-tonnage relationships. We tested the calculation procedure with 12 metals and platinum-group metals as a separate group. We found that the surplus costs range six orders of magnitude between the metals included, i.e., between $0.01–$0.02 (iron) and $13,533–$17,098 (rhodium) USD (year 2013) per kilogram of metal extracted. The choice of the reserve estimate (reserves vs. ultimate recoverable resource) influenced the surplus costs only to a limited extent, i.e., between a factor of 0.7 and 3.2 for the metals included. Our results provide a good basis to regularly include surplus cost estimates as resource scarcity indicator in life cycle assessment.

Highlights

The need for reduction of greenhouse gas emissions will most likely shift energy generation from fossil fuels to alternative sources of energy such as solar, wind and nuclear power [1]
We demonstrated how the method can be applied in practice for 12 metal commodities including uranium, which is an energy resource, and platinum-group metals as a group
A number of metals and platinum-group metals (PGM) indicate relatively high costs with low costs compared to other mines

Summary

Introduction

The need for reduction of greenhouse gas emissions will most likely shift energy generation from fossil fuels to alternative sources of energy such as solar, wind and nuclear power [1]. Renewable energy production technologies often require significantly more metals in their construction, such as copper, indium, lead, and molybdenum, compared to fossil energy [2]. It is, important to understand the trade-offs in using different types of mineral, metal, and fossil resources. Life cycle assessment (LCA) is a method that is capable of quantifying trade-offs in terms of potential impacts on human health, natural environment and natural resources [3]. For fossil resources the same is observed, with costs being the limiting factor for fossil resource extraction [15].

Objectives

Methods

Results

Discussion

Conclusion