Life Cycle Assessment of Metals: A Scientific Synthesis

By P. Nuss, M. Eckelman. PLoS ONE, 2014

662 citations recorded by the source corpus.

We have assembled extensive information on the cradle-to-gate environmental burdens of 63 metals in their major use forms, and illustrated the interconnectedness of metal production systems. Related cumulative energy use, global warming potential, human health implications and ecosystem damage are estimated by metal life cycle stage (i.e., mining, purification, and refining). For some elements, these are the first life cycle estimates of environmental impacts reported in the literature. We show that, if compared on a per kilogram basis, the platinum group metals and gold display the highest environmental burdens, while many of the major industrial metals (e.g., iron, manganese, titanium) are found at the lower end of the environmental impacts scale. If compared on the basis of their global annual production in 2008, iron and aluminum display the largest impacts, and thallium and tellurium the lowest. With the exception of a few metals, environmental impacts of the majority of elements are dominated by the purification and refining stages in which metals are transformed from a concentrate into their metallic form. Out of the 63 metals investigated, 42 metals are obtained as co-products in multi output processes. We test the sensitivity of varying allocation rationales, in which the environmental burden are allocated to the various metal and mineral products, on the overall results. Monte-Carlo simulation is applied to further investigate the stability of our results. This analysis is the most comprehensive life cycle comparison of metals to date and allows for the first time a complete bottom-up estimate of life cycle impacts of the metals and mining sector globally. We estimate global direct and indirect greenhouse gas emissions in 2008 at 3.4 Gt CO2-eq per year and primary energy use at 49 EJ per year (9.5% of global use), and report the shares for all metals to both impact categories.

Subfields: Environmental Engineering, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/9f77604395d8016351f2ef97c12ececdeca780b5

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Environmental Engineering

1. Fu Zhao
2. J. Navarro
3. P. Nuss
4. Thomas E. Graedel

In Mechanical Engineering

1. E. Harper
2. Fu Zhao
3. J. Navarro
4. P. Nuss
5. N. Nassar
6. B. Reck
7. Thomas E. Graedel

Citations in the corpus

• Electroplating for Decorative Applications: Recent Trends in Research and Development (2018, background): “The demand for durable metals and adaptable manufacturing processes are needed across a wide range of applications, from automotive and aerospace to jewelry and machinery [3,4].”
• Life-Cycle Assessment of the Production of Rare-Earth Elements for Energy Applications: A Review (2014, methodology): “The default Ecoinvent inventory data was used but the energy/material inputs and emissions were re-allocated to all the 15 REOs based on Bayan Obo bastnasite composition provided in Chinese Rare-Earth Yearbook 2010 and 2006–2010 REO prices (Nuss and Eckelman, 2014).”
• Criticality of metals and metalloids (2015, background): “Crossmetal analyses of specific criticality indicators can also reveal properties of individual metals or metal groups, as we have shown in the cases of potential substitutability (23) and environmental implications (25).”