14 research outputs found
Characterizing the Urban MineâChallenges of Simplified Chemical Analysis of Anthropogenic Mineral Residues
Anthropogenic mineral residues are characterized by their material complexity and heterogeneity, which pose challenges to the chemical analysis of multiple elements. However, creating an urban mine knowledge database requires data using affordable and simple chemical analysis methods, providing accurate and valid results. In this study, we assess the applicability of simplified multi-element chemical analysis methods for two anthropogenic mineral waste matrices: (1) lithium-ion battery ash that was obtained from thermal pre-treatment and (2) rare earth elements (REE)-bearing iron-apatite ore from a Swedish tailing dam. For both samples, simplified methods comprising âinhouseâ wet-chemical analysis and energy-dispersive Xray fluorescence (ED-XRF) spectrometry were compared to the results of the developed matrix-specific validated methods. Simplified wet-chemical analyses showed significant differences when compared to the validated method, despite proven internal quality assurance, such as verification of sample homogeneity, precision, and accuracy. Matrix-specific problems, such as incomplete digestion and overlapping spectra due to similar spectral lines (ICP-OES) or element masses (ICP-MS), can result in quadruple overestimations or underestimation by half when compared to the reference value. ED-XRF analysis proved to be applicable as semi-quantitative analysis for elements with mass fractions higher than 1000 ppm and an atomic number between Z 12 and Z 50. For elements with low mass fractions, ED-XRF analysis performed poorly and showed deviations of up to 90 times the validated value. Concerning all the results, we conclude that the characterization of anthropogenic mineral residues is prone to matrix-specific interferences, which have to be addressed with additional quality assurance measures.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität BerlinEC/H2020/641999/EU/ Prospecting Secondary raw materials in the Urban mine and Mining waste/ProSU
Long-Term Strategies for Increased Recycling of Automotive Aluminum and Its Alloying Elements
Aluminum
recycling currently occurs in a cascading fashion, where
some alloys, used in a limited number of applications, absorb most
of the end-of-life scrap. An expected increase in scrap supply in
coming decades necessitates restructuring of the aluminum cycle to
open up new recycling paths for alloys and avoid a potential scrap
surplus. This paper explores various interventions in end-of-life
management and recycling of automotive aluminum, using a dynamic substance
flow analysis model of aluminum and its alloying elements with resolution
on component and alloy level (<i>vehicle-component-alloy-element</i> model). It was found that increased component dismantling before
vehicle shredding can be an effective, so far underestimated, intervention
in the medium term, especially if combined with development of safety-relevant
components such as wheels from secondary material. In the long term,
automatic alloy sorting technologies are most likely required, but
could at the same time reduce the need for magnesium removal in refining.
Cooperation between the primary and secondary aluminum industries,
the automotive industry, and end-of-life vehicle dismantlers is therefore
essential to ensure continued recycling of automotive aluminum and
its alloying elements
The Global Anthropogenic Gallium System: Determinants of Demand, Supply and Efficiency Improvements
Gallium has been
labeled as a critical metal due to rapidly growing
consumption, importance for low-carbon technologies such as solid
state lighting and photovoltaics, and being produced only as a byproduct
of other metals (mainly aluminum). The global system of primary production,
manufacturing, use and recycling has not yet been described or quantified
in the literature. This prevents predictions of future demand, supply
and possibilities for efficiency improvements on a system level. We
present a description of the global anthropogenic gallium system and
quantify the system using a combination of statistical data and technical
parameters. We estimated that gallium was produced from 8 to 21% of
alumina plants in 2011. The most important applications of gallium
are NdFeB permanent magnets, integrated circuits and GaAs/GaP-based
light-emitting diodes, demanding 22â37%, 16â27%, and
11â21% of primary metal production, respectively. GaN-based
light-emitting diodes and photovoltaics are less important, both with
2â6%. We estimated that 120â170 tons, corresponding
to 40â60% of primary production, ended up in production wastes
that were either disposed of or stored. While demand for gallium is
expected to rise in the future, our results indicated that it is possible
to increase primary production substantially with conventional technology,
as well as improve the system-wide material efficiency
Historical Penetration Patterns of Automobile Electronic Control Systems and Implications for Critical Raw Materials Recycling
Car electronics form a large but poorly utilized source for secondary critical raw materials (CRMs). To capitalize on this potential, it is necessary to understand the mechanism in which car electronics enter and exit the vehicle fleet over time. We analyze the historical penetration of selected car electronic control systems (ECS) in 65,475 car models sold in the past 14 years by means of statistical learning. We find that the historical penetration of ECS tends to follow S-shaped curves, however with substantial variations in penetration speed and saturation level. Although electronic functions are increasing rapidly, comfort-related ECS tend to remain below 40% penetration even after 14 years on the market. In contrast, safety regulations lead to rapid ECS penetration approaching 100%, while environmental emission regulations seem to indirectly push related ECS to a medium penetration level (e.g., growing to 60% after six years). The trend towards integration of individual ECS poses long-term challenges for car electronics dismantling and recycling. Monitoring the ECS embedded in new cars, such as carried out in this study, can inform timely updates for such strategies. The results also provide a framework for developing scenarios to identify related future CRM stocks and flows
Byproduct Metal Availability Constrained by Dynamics of Carrier Metal Cycle: The GalliumâAluminum Example
Future availability
of byproduct metals is not limited by geological
stocks, but by the rate of primary production of their carrier metals,
which in turn depends on the development of their in-use stocks, the
product lifetimes, and the recycling rates. This linkage, while recognized
conceptually in past studies, has not been adequately taken into account
in resource availability estimates. Here, we determine the global
supply potential for gallium up to 2050 based on scenarios for the
global aluminum cycle, and compare it with scenarios for gallium demand
derived from a dynamic model of the gallium cycle. We found that the
gallium supply potential is heavily influenced by the development
of the in-use stocks and recycling rates of aluminum. With current
applications, a shortage of gallium is unlikely by 2050. However,
the gallium industry may need to introduce ambitious recycling- and
material efficiency strategies to meet its demand. If in-use stocks
of aluminum saturate or decline, a shift to other gallium sources
such as zinc or coal fly ash may be required
Global Carbon Benefits of Material Substitution in Passenger Cars until 2050 and the Impact on the Steel and Aluminum Industries
Light-weighting
of passenger cars using high-strength steel or
aluminum is a common emissions mitigation strategy. We provide a first
estimate of the global impact of light-weighting by material substitution
on GHG emissions from passenger cars and the steel and aluminum industries
until 2050. We develop a dynamic stock model of the global car fleet
and combine it with a dynamic MFA of the associated steel, aluminum,
and energy supply industries. We propose four scenarios for substitution
of conventional steel with high-strength steel and aluminum at different
rates over the period 2010â2050. We show that light-weighting
of passenger cars can become a âgigaton solutionâ: Between
2010 and 2050, persistent light-weighting of passenger cars can, under
optimal conditions, lead to cumulative GHG emissions savings of 9â18
gigatons CO<sub>2</sub>-eq compared to development business-as-usual.
Annual savings can be up to 1 gigaton per year. After 2030, enhanced
material recycling can lead to further reductions: closed-loop metal
recycling in the automotive sector may reduce cumulative emissions
by another 4â6 gigatons CO<sub>2</sub>-eq. The effectiveness
of emissions mitigation by material substitution significantly depends
on how the recycling system evolves. At present, policies focusing
on tailpipe emissions and life cycle assessments of individual cars
do not consider this important effect
Elaborating the History of Our Cementing Societies: An in-Use Stock Perspective
Modern
cities and societies are built fundamentally based on cement
and concrete. The global cement production has risen sharply in the
past decades due largely to urbanization and construction. Here we
deployed a top-down dynamic material flow analysis (MFA) model to
quantify the historical development of cement in-use stocks in residential,
nonresidential, and civil engineering sectors of all world countries.
We found that global cement production spreads unevenly among 184
countries, with China dominating the global production and consumption
after the 1990s. Nearly all countries have shown an increasing trend
of per capita cement in-use stock in the past century. The present
per capita cement in-use stocks vary from 10 to 40 tonnes in major
industrialized and transiting countries and are below 10 tonnes in
developing countries. Evolutionary modes identified from historical
patterns suggest that per capita in-use cement stock growth generally
complies with an S-shape curve and relates closely to affluence and
urbanization of a country, but more in-depth and bottom-up investigations
are needed to better understand socioeconomic drivers behind stock
growth. These identified in-use stock patterns can help us better
estimate future demand of cement, explore strategies for emissions
reduction in the cement industry, and inform CO<sub>2</sub> uptake
potentials of cement based products and infrastructure in service
Stocks, Flows, and Distribution of Critical Metals in Embedded Electronics in Passenger Vehicles
One
of the major applications of critical metals (CMs) is in electrical
and electronic equipment (EEE), which is increasingly embedded in
other products, notably passenger vehicles. However, recycling strategies
for future CM quantities in end-of-life vehicles (ELVs) are poorly
understood, mainly due to a limited understating of the complexity
of automotive embedded EEE. We introduce a harmonization of the network
structure of automotive electronics that enables a comprehensive quantification
of CMs in all embedded EEE in a vehicle. This network is combined
with a material flow analysis along the vehicle lifecycle in Switzerland
to quantify the stocks and flows of Ag, Au, Pd, Ru, Dy, La, Nd, and
Co in automotive embedded EEE. In vehicles in use, we calculated 5<sub>â2</sub><sup>+3</sup> t precious
metals in controllers embedded in all vehicle types and 220<sub>â60</sub><sup>+90</sup> t rare
earth elements (REE); found mainly in five electric motors: alternator,
starter, radiator-fan and electronic power steering motor embedded
in conventional passenger vehicles and drive motor/generator embedded
in hybrid and electric vehicles. Dismantling these devices before
ELV shredding, as well as postshredder treatment of automobile shredder
residue may increase the recovery of CMs from ELVs. Environmental
and economic implications of such recycling strategies must be considered
Carbon Emissions of Infrastructure Development
Identifying
strategies for reconciling human development and climate
change mitigation requires an adequate understanding of how infrastructures
contribute to well-being and greenhouse gas emissions. While direct
emissions from infrastructure use are well-known, information about
indirect emissions from their construction is highly fragmented. Here,
we estimated the carbon footprint of the existing global infrastructure
stock in 2008, assuming current technologies, to be 122 (â20/+15)
Gt CO<sub>2</sub>. The average per-capita carbon footprint of infrastructures
in industrialized countries (53 (Âą6) t CO<sub>2</sub>) was approximately
5 times larger that that of developing countries (10 (Âą1) t CO<sub>2</sub>). A globalization of Western infrastructure stocks using
current technologies would cause approximately 350 Gt CO<sub>2</sub> from materials production, which corresponds to about 35â60%
of the remaining carbon budget available until 2050 if the average
temperature increase is to be limited to 2 °C, and could thus
compromise the 2 °C target. A promising but poorly explored mitigation
option is to build new settlements using less emissions-intensive
materials, for example by urban design; however, this strategy is
constrained by a lack of bottom-up data on material stocks in infrastructures.
Infrastructure development must be considered in post-Kyoto climate
change agreements if developing countries are to participate on a
fair basis
Variability and Bias in Measurements of Metals Mass Fractions in Automobile Shredder Residue
The treatment of end-of-life vehicles generates large amounts of automobile shredder residue (ASR), a potential source of recycled metals. Reliable measurement methods are required to determine the composition of ASR and evaluate the resource potential. We reported on research undertaken to investigate bias and variability in the process of measuring trace metals in ASR. Two primary samples of shredder light fraction (SLF) underwent extensive physical sample preparation and chemical analysis. The samples were spiked to control random variations and systematic effects during physical sample preparation. Chemical analysis was conducted using wavelength-dispersive X-ray fluorescence spectrometry (WD-XRF), a fully validated wet-chemical analysis, and a wet-chemical analysis representing an “in-house” lab procedure. Physical sample preparation introduced deviations up to a factor of 2, likely due to preferential losses and heterogeneity. Deviations for WD-XRF measurements of elements were in the range +100%/−50%. In-house chemical analysis produced results that were in good agreement with validated results for Al, Fe and Sn, but led to biased results or high variability for Cd, Dy, La, Nd, Pb, Pd, Pt and Sb. To improve the chemical analysis of trace metals in SLF, we recommended reducing particle size to less than 0.1 mm before chemical analysis and using a larger number of repeated digestions