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Article
Looking Down Under for a circular economy of indium Tim T. Werner, Luca Ciacci, Gavin Mark Mudd, Barbara K. Reck, and Stephen Alan Northey Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b05022 • Publication Date (Web): 04 Jan 2018 Downloaded from http://pubs.acs.org on January 4, 2018
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Environmental Science & Technology
Looking Down Under for a circular economy of indium
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Tim T. Werner1,4*, Luca Ciacci2, Gavin Mark Mudd1, Barbara K. Reck3, Stephen Alan Northey4
6 7
1 Environmental Engineering, School of Engineering, Building 10, Level 13, Room 5a, RMIT University, Melbourne, VIC, Australia
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2
Dipartimento di Chimica Industriale "Toso Montanari", University of Bologna, Viale del Risorgimento 4, Bologna, Italy
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3
Center for Industrial Ecology, School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA
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4
Faculty of Engineering, Monash University, Clayton, VIC, Australia
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*
Corresponding author: Tim.Werner@rmit.edu.au
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Abstract
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Indium is a specialty metal crucial for modern technology, yet potentially critical due to its by-
16
product status in mining. Measures to reduce its criticality typically focus on improving its
17
recycling efficiency at end-of-life. This study quantifies primary and secondary indium
18
resources (“stocks”) for Australia through a dynamic material flow analysis. It is based on
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detailed assessments of indium mineral resources hosted in lead-zinc and copper deposits,
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respective mining activities from 1844-2013, and the trade of indium-containing products
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from 1988-2015. The results show that Australia’s indium stocks are substantial, estimated
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at 46.2 kt in mineral resources and an additional 14.7 kt in mine wastes. Australian mineral
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resources alone could meet global demand (~0.8 kt/year) for more than five decades.
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Discards from post-consumer products, instead, are negligible (43 t). This suggests that the
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resilience of Australia’s indium supply can best be increased through efficiency gains in
26
mining (such as introducing domestic indium refining capacity), rather than at end of product
27
life. These findings likely also apply to other specialty metals such as gallium or germanium,
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and other resource-dominated countries. Finally, the results illustrate that national circular
29
economy strategies can differ substantially.
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Highlights
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1.
A product-level dynamic material flow analysis of indium in Australia is presented.
2.
Australia hosts large quantities of indium in mineral deposits, tailings and slags.
3.
Australia’s in-use stocks of indium are minor in comparison to mineral resources, tailings and slags. On a per-capita basis, our results show that recycling will not provide adequate quantities of indium even in other developed countries with higher populations than Australia’s. Policies to improve primary refining capacity should instead be favoured.
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1.
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Introduction
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Critical metals are those that are important to society, but which are problematic to supply.
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This can be due to their supply chains being at risk of some constraint (e.g. geopolitical in
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nature or due to concentrated supply chains), and/or their production being environmentally
50
harmful1, 2. A number of studies have quantified these factors to establish ratings of metal
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criticality, generally agreeing that the specialty metals used in modern technologies like
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indium, germanium, gallium, antimony and the rare-earth elements are typically the most
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critical3-9. Despite this classification, these metals often remain less economic to extract for
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mining and/or metal refining companies than major metals such as zinc, copper, gold or
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silver. The lesser economic value of the critical metals means that of the many mines and
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processing facilities that could produce these metals, only a select few actually do so. Global
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mining activities therefore result in the continuous extraction of rock containing critical metals,
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but with large portions of these metals being lost during various stages of mineral processing
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and separation8.
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Indium is one such metal that is often considered critical (e.g. European Commission
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is poorly studied and remains inefficiently produced and recycled. Given its primary uses in
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LCD/LED displays and solar panels, it is projected that indium demand (currently ~800 t/year)
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will continue to increase for the foreseeable future11. Recent estimates of the global mineral
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resources of indium show that mineral resources are not a limiting factor for demand this
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century12. However, while large resources exist even outside of the current suite of
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producing countries, the production of refined indium remains concentrated in China and a
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small number of other producers, placing risks and limitations on the actual supply of refined
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indium to the global market in the short to medium term. This was highlighted in a recent
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study by Frenzel, et al.13, who found that indium is at risk of reaching its full production
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potential sooner than other critical metals such as germanium and gallium. The pertinent
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question around future indium supply is therefore not whether we as a society will run out of
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indium, but which pathway for supply is the most resilient and sustainable in the medium to
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long term. It is here that material flow analyses can shed new light, namely by highlighting
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how this metal is currently used, and where it accumulates as a waste or potential resource
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(e.g. Chen & Graedel14). This study examines the stocks and flows of indium in Australia, a
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resource-rich economy which exports large quantities of indium’s hosts zinc and copper, but
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produces no critical metal by-products of these metals. We employ a detailed product-level
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dynamic material flow analysis to analyse quantities of indium within mineral resources,
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through to end of life wastes and draw conclusions on Australia’s potential to become a
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major supplier of refined indium in future.
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2.
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Methods
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A national scale material flow analysis involves the characterisation of a number of stocks
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and flows along the life cycle of a metal. In Fig. 1, a generalised life cycle for indium in
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Australia is shown. The stocks (shown in blue and green) represent locations of interest for
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their future resource value. The flows (grey arrows) are of interest because they determine
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the rates of stock accumulation. The nodes shown in orange are processing stages where
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materials are transformed, which ultimately affect the direction and magnitude of the flows.
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This study aims to characterise, quantify and analyse each of these components for the
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years 1988-2015, although early stages in the indium cycle are characterised as far back as
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1844 due to the availability of detailed mining production data.
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The starting point of any metal cycle is its extraction (or mining) from stocks in mineral
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deposits. Indium mineral resources in Australia were determined using an approach of
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estimating contents of indium in individual deposits. For those deposits where contained
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indium was not explicitly reported by mining companies or in the literature reviewed, indium
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grades were inferred using a proxy method developed in previous work, which the reader is
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referred to for discussion of uncertainty 12.
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The trade of ore and concentrates over time was determined from various past and present
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Australian government agencies (e.g. Bureau of Mineral Resources (BMR), Australian
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Bureau of Agricultural and Resource Economic (ABARE), and the Office of the Chief
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Economist (OCE))15,
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deported to concentrates that would ultimately become domestic slag, or be exported to
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overseas refineries (of which only a portion is actually extracted17). These trade data allowed
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the present day resource estimate of indium to be backtracked to the beginning of mining
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activity in Australia. The relative proportions of mined indium appearing in various product
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and waste streams was determined from a review of individual deposits where indium
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deportment data were available. These indicated a range of deportment values, of which the
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average was taken (see Table S2), allowing for the accumulation of indium in mine tailings to
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be estimated. The wastage of indium in Australian refinery slags was not necessary to
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examine in detail, as a lack of domestic refining capacity for indium implies that all indium in
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domestically shipped concentrates is destined to appear in slag.
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In assessing the flows of indium beyond the mining and mineral processing sectors, the
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or direct company reporting, indicating the proportion of indium
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method broadly followed the retrospective dynamic MFA approach described by Müller, et al.
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, with the addition of a product-level analysis as described by Harper
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. A review was
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conducted to identify all of indium’s past and present applications in society, particularly in
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Australia. A set of trade tariff codes that encompass these applications was determined20-22,
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resulting in 8 semi-finished goods and 23 end use goods identified as relevant to Australia.
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Subsequently, Australia’s trade of indium-containing products was calculated by obtaining
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historical import/export data of these codes (notably from the United Nations Comtrade
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database, supplementary tables S3-4). An additional table of codes pertaining to indium
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which might be relevant for indium MFA of other countries is provided in Table S5. As
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multiple products can be traded under a singular tariff code, it was necessary to determine
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the market share of those products which do or do not contain indium. This information was
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obtained through a combination of literature review and direct industry contact. Estimates of
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the content of indium within the indium-containing products were also necessary, including
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considerations of how indium contents in a particular product might change over time (e.g.
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changing average screen sizes in a TV or computer monitor); these were obtained from a
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broad literature review and all assumptions and references are provided in the
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supplementary material (Tables S6-9). Contents were estimated using arithmetic averages,
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with upper and lower bounds representing three standard deviations of uncertainty. These
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uncertainty bounds were extended to estimates of in-use stocks. A detailed breakdown on
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the methods and assumptions used for the analysis of indium in solar photovoltaic cells is
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provided by Werner 23.
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In addition to the volumes of traded indium, domestic manufacturing potential was also
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considered. An approach of reviewing Australia’s manufacturing capacity in a number of
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indium-relevant sectors was employed, highlighting a number of key companies potentially
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producing indium-based products or requiring indium intermediates. This was cross checked
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with a general approach of reviewing literature which lists major producers of indium-
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containing products or intermediates. These sources often excluded Australia as a producer
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in many cases, allowing certain sectors or products to be ruled out for further analysis (e.g.
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24, 25
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producers of a particular indium-containing product/intermediate were not known, domestic
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production was assumed to exist at a level proportional to global production for that year
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(using total GDP or GDP per capita). Given Australia’s small population and estimated
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imports of semi-finished goods, this assumption had little effect, but is noted as a source of
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uncertainty. The apportionment of semi-finished goods for domestic manufacturing of
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indium-related products is shown in Fig. 2, alongside estimated production losses. The
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construction of this figure was based on global averages, except where more information
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about the Australian context was available (e.g. lack of indium tin oxide (ITO) manufacturing
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from unwrought indium). Losses in production may arise from the manufacture of LCD/LED
). Where actual production data were not available from individual companies, or the
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products architectural glass, and solar panels, but were assumed to be negligible for alloys
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and thermal interface materials for printed circuit boards. Further detail on the losses of
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indium during manufacturing processes is available from
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effect of these losses is minimal in the context of the overall Australian indium cycle. Given
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the prevalence of ITO recycling in recent years, it was assumed that ITO imports were also
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recycled. While this could not be independently verified, this assumption had minimal effect
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on the overall throughput of indium to end of life goods, and was maintained as a
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conservative overestimation of Australia’s potential indium use.
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Finally, the stages of product use and end of life were analysed using probabilistic lifetime
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functions which estimate the time a product spends in use before either being recycled or
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landfilled. Lifetime distribution variables and sources are listed in Table S10. Some
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estimates of in-use stocks were cross referenced with external data or bottom up studies to
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verify the validity of our assumptions around product stocks and lifetimes. Losses due to in-
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use dissipation were assumed to remain negligible as per Ciacci et al. 30.
26-29
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3.
Results and Discussion
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3.1 Resources, mining and mineral processing
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Mineral resources of indium in Australia are estimated at ~46,213 t In among 247 mineral
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deposits, mapped in Fig S1. Such quantities, if extracted and refined, would be sufficient on
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their own to meet global demand for many decades, although at present the infrastructure
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and economic drive within the Australian mining industry does not exist to support such
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activities. The apportionment of indium in various Pb-Zn and Cu mineral processing wastes
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over time (namely, mine tailings and smelter/refinery slags) was also assessed (Fig S2).
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Information on indium deportment was necessary to determine the proportion of indium in
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these flows, however indium deportment is poorly understood at a global level. Only studies
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listing these values on a case study basis were identified (Table S2). These suggested that
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some 65% of milled indium typically appears in Pb and Zn concentrates, with ~19%
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deporting to tailings and the remaining ~%16 to other various concentrates. Given
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Australia’s lack of domestic refining capacity for indium, the indium content of locally
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processed concentrates reported annually was assumed to remain in slag. This leads to the
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first finding that at least ~14,750 (±3,062) t In has accumulated in Australian slags and
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tailings, a very large figure in relation to Australian or even global demand. Notably, as there
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are significantly fewer refineries than mines, the quantities present in slag are concentrated
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in a handful of locations (e.g. Risdon and Townsville). It is possible that the economic value
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of indium and other unprocessed critical metals present in these wastes provides some
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incentive for recovery or rehabilitation in future. However, the reprocessing of tailings and
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slags presents new technical challenges (e.g. the remaining minerals are often more
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refractory31) meaning the indium contained is largely uneconomic to extract. It is perhaps
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more likely that if Australia did produce indium in future, it would be as a by-product during
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the initial processing of Zn and Cu. However, this will be dependent on whether increasing
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indium criticality or prices arise to foster a better strategic or economic case for recovery.
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Past economic conditions have led to at least 18,600 t In in mined ore and concentrates
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being exported since 1844, without the apparent need for consideration of these quantities
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by Australian mining companies.
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For the majority of the trade history assessed, large portions of indium-laden concentrates
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would not have reached smelters capable of extracting indium (even only ~30% in recent
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years). For the remaining portion, a typical recovery rate of 50% is assumed, suggesting that
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~35% of indium in concentrates will end up being refined17. However, as shown in Table 1 of
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Werner, Mudd and Jowitt 11, other studies estimate a much lower proportion only a few years
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prior. Using these fluctuating published values of processing efficiency, it is possible to
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estimate what percentage of indium exported in Australian concentrates was refined at
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overseas facilities over time. Using global production data available from the USGS32 we
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estimate that some 20% of global indium production in recent years has been initially
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sourced from Australia (Fig. 3). The calculated peak in the 1980’s is attributable to a decline
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in global indium production coinciding with a period of substantial reported Australian zinc
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concentrate exports. This peak is possibly a result of limited location-specific data for
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concentrate exports. Considering the annual price of refined indium and accounting for
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inflation to 2015 dollars, it is estimated that at least US$1.19 billion
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production has originated from Australian exports since 1972. Nearly all of this value can be
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attributed to the companies operating the refineries in which indium separation took place,
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as the price of specialty metal by-products are rarely (if ever) accounted for in the sale of
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concentrates8.
of refined indium
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3.2
Net imports of semi-finished and finished products
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The analysis of trade volumes, market shares, domestic manufacturing capacity, and indium
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contents in products over time enabled an estimation of Australia’s net imports of semi-
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finished and finished goods. Large uncertainties arise from market share and indium content
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estimates. This is mainly due to limited data and issues with aggregated reporting of HS
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codes which contain multiple products, only some of which contain indium. Additional
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uncertainties of applying the dynamic MFA methodology to a metal with as little data
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available as for indium are discussed in Ciacci et al. 33. Our results for net imports have been
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checked against other studies (e.g. Ciacci et al.
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remain reasonable by these standards. While we perform product level analyses of trade
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flows (see Fig S3), it is possible to aggregate these to end-use sectors to enable a
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comparison with prior studies of indium usage at this scale. Such a comparison is given in
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supplementary figure S4.
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It is estimated that Australia now imports 1328-6566 (avg. 3606) kg In/yr in semi-finished
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forms and ~2293-5226 (avg. 3707) kg In/yr in finished products, representing a significant
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increase in recent years. LCD/LED screens for TVs, laptops, tablets and desktop computers
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account for the majority of imported indium to Australia (at least since 1995). This is rather
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unsurprising, given the rapid increase in the use of these products in recent years. The
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indium contained in solar panels has become a major factor since 2009/10, which is
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consistent with industry statistics showing an exponential increase in solar photovoltaic (PV)
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installations on Australian households from this time35. The imports of solders, alloys and
33
, Zhu, et al.
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, see also section 3.3) and
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miscellaneous chemicals contribute only marginally to Australian indium use.
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3.3 Stocks in use and assessment of uncertainty
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In addition to the direct imports of semi-finished and finished goods, domestic manufacturing
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was considered and apportioned as per Fig. 2. It was found to be particularly difficult to find
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production statistics for goods containing indium in Australia. Hence, for the most part, it was
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necessary to review literature to verify whether Australia was listed as a source for any
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indium products, and whether manufacturing capacity existed in Australia for products
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containing indium (see supplementary Table S11). Quantities imported for domestic
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manufacturing were assumed to be processed at global average processing efficiencies as
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per Fig. 2, and then added to direct imports of finished goods. For the production of products
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containing refined indium, rates of dissipation may be assumed to range from 5% for ITO-
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containing goods (as per Ciacci, et al.
30
) and 10% in all other cases (as per Zimmermann
36
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and Gößling-Reisemann
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losses occurring during use, and so these were assumed to remain negligible. Following the
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top-down approach for in-use stock estimation (described in Gerst and Graedel
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and Graedel
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should be noted that the majority of these functions have been assigned based on studies
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conducted outside of Australia, and hence may not reflect Australian consumer behaviour
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with respect to indium-containing goods. The exception is Golev, et al.
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mobile phone lifetimes based on Australian consumer survey data. The resulting annual
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estimation of in-use stocks of indium in Australia is provided in Fig. 4. It shows that Australia
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might be approaching saturation of in-use stocks from around 2012, had it not been for the
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boom in solar PV installations occurring around this time, which contributed to the estimate
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of approx. 25 t In in use by 2015. The apparent saturation of indium stocks in LCD displays
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is consistent with the phase out of cathode ray tube (CRT) screens, and the introduction of
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newer generation TVs now largely replacing LCD screens. The introduction of tablet
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technologies in recent years can be seen to have had a noticeable influence on in-use
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stocks, however the dominant reservoir of indium is in flat panel TV’s, due to their larger
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screen size. Thus, if policies were implemented to explore recycling as an avenue for indium
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supply, TV’s would present the most obvious target for collection. This may change in
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coming decades as solar panels have a longer assumed lifetime (~28 years40).
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It should be noted that there are considerable uncertainties associated with the in-use stock
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estimates shown in Fig. 4. While the error bars indicating the uncertainty due to prior market
38
), however there is little information pertaining to dissipative 37
and Chen
), lifetime probability functions were used for each product (see Table S10). It
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, which estimates
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share and product content estimates appear reasonable, they do not encapsulate the
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uncertainty associated with other possible estimates for product lifetimes. In many cases, it
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was only possible to find one reference for relevant product lifetime parameters, and hence
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the exploration of the effect of varying these parameters was limited and could not be
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quantified to the extent that they could be incorporated into these error bars. It appears that
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these results are more sensitive to product lifetime estimates than to product content
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estimates. To at least partially address this source of uncertainty, these results have been
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compared with Zhu et al.
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survey data of Australian households, and Ciacci et al.
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indium in Europe using a similar approach to this study. Table 1 shows the comparison of
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our results in four product categories to that of Zhu et al.
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uncertainties, and considerably different approaches taken, it is encouraging that our results
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are in the same order of magnitude, and reflect the same relative scale between product
34
, who assess in-use stocks of indium in Australia using based on 33
, who assess in-use stocks of 34
. Given the large number of
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categories. That our estimates are higher on average is perhaps explained in that Zhu et al.
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34
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We can compare to Ciacci et al. 33 in terms of per-capita stocks as the population and hence
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total in-use indium stocks in Europe are considerably higher. We found that in-use stocks of
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indium appears to have grown to around 1.1 g In per capita in recent years, which is highly
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consistent with an assessment of ~1 g In per capita in Europe. While stocks in LCD displays
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have quadrupled in recent years, Fig. 4 shows that this has somewhat plateaued. However,
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solar PV installations remain as a growing category. Certainly the cost of installing solar PV
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has decreased41, suggesting that installations will continue to push growth in in-use stocks of
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indium in this category. Australia’s solar PV capacity has been projected to increase tenfold
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from 2017 to 204042, suggesting that in use indium stocks in this category could increase
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accordingly. If it is assumed that all other product categories are in fact saturated, and
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indium in solar panels increased to this level, a new high of ~2.3 g In/cap is calculated (Fig
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S5). As Australia ranks second on the human development index43 (HDI), this value might
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feasibly represent a higher end estimate for what other countries might achieve as they
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develop further (pending no major changes to indium’s applications in society). If China were
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to sit at this upper estimate, its current population (~1.382 Billion) would result in an
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estimated 3,179 t In in use. Similarly, the global population of ~7.5 Billion at this high end
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figure equates to ~17,250 t In in use. These resources are of course dispersed among
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millions of products, making this indium resource difficult to collect and process as a whole.
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Furthermore, only ~20% of this is currently recyclable30, suggesting global in-use stocks
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might provide 3,450 t In if collected and processed. This value is less than 1% of estimated
do not consider stocks in use for commercial applications.
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global indium mineral resources of over ~356,000 t In44, and unlikely to foster significant
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changes in the supply security of this critical metal if recovered.
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3.4 Australian indium cycle and future research
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The combined results of our analyses are presented in Fig. 5. It can be seen that the
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quantities in both stocks and flows occupying earlier stages of the Australian indium cycle
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are significantly greater than that of end of life, largely due to low recovery rates in mining
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and mineral processing. This is not particularly surprising for a relatively resource rich and
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low population country like Australia. However, as a developed nation, the magnitude of
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stocks in use on a per-capita basis is notably low. Alongside similar per-capita results
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estimated for Europe33, this highlights that other developed countries are likely to also
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possess low in use stocks of indium. Globally, the end-of-life recycling rate for indium is
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estimated to be less than 1%45, which has led some to suggest that recycling rates of indium
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must be improved45-50. Some studies go on to highlight that a focus on product design and
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waste management strategies are virtually essential to managing the future supply of
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indium49-51. Our study presents an alternative view that efforts to secure future indium
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supplies would be better focussed on the construction of new indium circuits in existing zinc
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processing facilities. Following this, any efforts to improve the technical or economic
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feasibility of extracting critical metals from mine wastes appear worthwhile, given the large
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quantities that could potentially become unlocked. .
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Potentially thousands of tonnes of indium are estimated for the slags of the zinc processing
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facilities in Port Pirie, Hobart and Townsville alone, which represent far more concentrated
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and higher tonnage sources of indium than end of life goods. Indium is rarely reported as a
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potential resource in slag, with Zeehan, Tasmania noted as a particular exception for
331
Australia (Table S1). That this particular location is reported using the joint ore reserves
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committee (JORC) codes in Australia (see Mudd et al.8), suggests that the indium contained
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in this slag was in fact considered potentially economically extractable by the reporting
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company Intec, however there remain many technical and economic barriers to mine and
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processing waste recovery which still need to be addressed if these quantities are to
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become available to the broader indium market (see also Werner et al.
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assaying of mining and processing wastes for critical metals, and a more detailed
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assessment of the ways in which processing facilities can be adapted to facilitate critical
339
metal by-products would be beneficial to understand the true supply potential of the
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). Increased
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quantities estimated in this study. A starting point for Australia may be to further study the
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zinc refinery at Risdon, which the owner Nyrstar has indicated may be adapted to include
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indium capacity in the near future53, pending the right market conditions.
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While our results suggest that recycling for indium is not a priority for Australia (at least in
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terms of contributing meaningfully to global supplies), we must be clear that we do not
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propose an end to recycling of electronics altogether. Indeed, the recycling of e-waste will be
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an important process in reducing landfill-related hazards, and may be economically viable for
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the recovery of other resources like gold, silver and copper 54. Nonetheless, some change in
348
rhetoric around the circular economy, and how a circular economy for other by-
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product/critical metals might be achieved, is warranted. That Australia’s best contributions to
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a circular economy can be made through efficiency gains in mining highlights that circular
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economy strategies can be quite country-specific.
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Given that other critical metals like gallium and germanium are also produced as by-products
353
of zinc, are not currently produced in Australia and have low-concentration applications in
354
electronic devices, it is possible that they exhibit similar cycles. The similarity of Australia
355
and Europe’s per-capita estimates of indium in use suggests that other industrialised
356
resource-rich nations would also exhibit a similar overall structure to their cycles of gallium,
357
germanium and other critical metals. This raises questions about the viability of recycling
358
critical metals more broadly. Additional MFA studies of by-product/critical metals at a
359
national level for other industrialised nations would help to verify this, and hopefully better
360
guide decision makers interested in securing significant sources of critical metal supply in
361
future. In the meantime, it is clear that Australia has some potential to reduce the risks of
362
indium supply disruptions in future.
363
Acknowledgements
364 365 366
A portion of this work was conducted as a component of the ‘Wealth from Waste’ research
367
cluster, a collaborative program between the Australian Commonwealth Scientific Industrial
368
Research Organisation (CSIRO); the University of Queensland, the University of Technology,
369
Sydney; Monash University, Swinburne University of Technology and Yale University. The
370
authors would like to thank Ermelinda Harper for sharing her experience in MFA
371
methodology, and Brian O’Neill of AIM Minor Metals for his valuable discussions and data on
372
the indium market.
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Supporting Information Available
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Additional information on the methodology employed and detailed data used in the
375
estimation of indium stocks and flows are available as supporting information. This
376
information is available free of charge via the Internet at http://pubs.acs.org.
377 378 379
References
380 381 382 383 384
1.
Dewulf, J.; Blengini, G. A.; Pennington, D.; Nuss, P.; Nassar, N. T., Criticality on the international scene: Quo vadis? Resources Policy 2016, 50, 169-176; DOI 10.1016/j.resourpol.2016.09.008
385 386 387 388
2.
Graedel, T. E.; Barr, R.; Chandler, C.; Chase, T.; Choi, J.; Christoffersen, L.; Friedlander, E.; Henly, C.; Jun, C.; Nassar, N. T.; Schechner, D.; Warren, S.; Yang, M.-Y.; Zhu, C., Methodology of metal criticality determination. Environmental Science and Technology 2012, 46, (2), 1063-1070; DOI 10.1021/es203534z
389 390 391
3.
Ciacci, L.; Nuss, P.; Reck, B.; Werner, T.; Graedel, T., Metal Criticality Determination for Australia, the US, and the Planet—Comparing 2008 and 2012 Results. Resources 2016, 5, (4), 29; DOI 10.1021/es203534z
392 393 394 395 396
4.
European Commission Report on critical raw materials for the EU: Report of the Ad hoc Working Group on defining critical raw materials; DG Enterprise and Industry: Brussels, Belgium, May, 2014. https://ec.europa.eu/docsroom/documents/10010/attachments/1/translations/en/renditi ons/pdf
397 398 399
5.
Frenzel, M.; Kullik, J.; Reuter, M.; Gutzmer, J., Raw material "criticality" - Sense or nonsense? Journal of Physics D: Applied Physics 2017, 50, (12); DOI 10.1088/13616463/aa5b64
400 401
6.
Graedel, T. E.; Gunn, G.; Tercero Espinoza, L., Metal resources, use and Criticality. In Critical Metals Handbook, Gunn, G. Ed.; John Wiley & Sons: 2014; pp 1-19.
402 403 404
7.
Harper, E.; Kavlak, G.; Burmeister, L.; Eckelman, M. J.; Erbis, S.; Sebastian Espinoza, V.; Nuss, P.; Graedel, T., Criticality of the geological zinc, tin, and lead family. Journal of Industrial Ecology 2014, 19, (4), 628-644; DOI 10.1111/jiec.12213
405 406 407 408
8.
Mudd, G. M.; Jowitt, S. M.; Werner, T. T., The world's by-product and critical metal resources part I: Uncertainties, current reporting practices, implications and grounds for optimism. Ore Geology Reviews 2017, 86, 924-938; DOI 10.1016/j.oregeorev.2016.05.001
ACS Paragon Plus Environment
Environmental Science & Technology
409 410 411 412 413
9.
Skirrow, R. G.; Huston, D. L.; Mernagh, T. P.; Thorne, J. P.; Dulfer, H.; Senior, Anthony B. Critical commodities for a high-tech world: Australia's potential to supply global demand; Geoscience Australia: Canberra, 2013. https://data.gov.au/dataset/critical-commodities-for-a-high-tech-world-australiaspotential-to-supply-global-demand
414 415 416
10.
European Commission Study on the review of the list of Critical Raw Materials; DG for Internal Market, Industry, Entrepreneurship and SMEs. Raw Materials: Brussels, Belgium, 2017; p 93.
417 418 419
11.
Werner, T. T.; Mudd, G. M.; Jowitt, S. M., Indium: key issues in assessing mineral resources and long-term supply from recycling. Appl. Earth Sci. (Trans. Inst. Min. Metall. B) 2015, 124, (4), 213-226; DOI 10.1179/1743275815Y.0000000007
420 421 422
12.
Werner, T. T.; Mudd, G. M.; Jowitt, S. M., The world's by-product and critical metal resources part II: A method for quantifying the resources of rarely reported metals. Ore Geology Reviews 2017, 80, 658-675; DOI 10.1016/j.oregeorev.2016.08.008
423 424 425
13.
Frenzel, M.; Mikolajczak, C.; Reuter, M. A.; Gutzmer, J., Quantifying the relative availability of high-tech by-product metals–The cases of gallium, germanium and indium. Resources Policy 2017, 52, 327-335; DOI 10.1016/j.resourpol.2017.04.008
426 427 428
14.
Chen, W.-Q.; Graedel, T. E., Dynamic analysis of aluminum stocks and flows in the United States: 1900–2009. Ecological Economics 2012, 81, (0), 92-102; DOI 10.1016/j.ecolecon.2012.06.008
429 430
15.
BMR, Bureau of Mineral Resources, Australian Mineral Industry Reviews. Australia. Various. https://trove.nla.gov.au/work/21703868?selectedversion=NBD2947291
431 432 433 434
16.
OCE, Office of the Chief Economist, Resources and Energy Statistics. Department of Industry. Commonwealth Government of Australia: Canberra, 2014; Vol. 4. https://industry.gov.au/Office-of-the-Chief-Economist/Publications/Pages/Resourcesand-energy-statistics.aspx
435
17.
Mikolajczak, C. Availability of Indium and Gallium; Indium Corporation: 2009.
436 437 438
18.
Müller, E.; Hilty, L. M.; Widmer, R.; Schluep, M.; Faulstich, M., Modeling Metal Stocks and Flows: A Review of Dynamic Material Flow Analysis Methods. Environmental Science & Technology 2014, 48, (4), 2102-2113; DOI 10.1021/es403506a
439 440
19.
Harper, E. M., A Product-Level Approach to Historical Material Flow Analysis. Journal of Industrial Ecology 2008, 12, (5-6), 768-784; DOI 10.1111/j.1530-9290.2008.00070.x
441 442
20.
Chagnon, M. J., Indium and Indium Compounds. In Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc.: 2000.
443 444
21.
Felix, N., Indium and Indium Compounds. In Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA: 2000.
445 446
22.
Schwarz-Schampera, U., Indium. In Critical Metals Handbook, Gunn, G., Ed.; John Wiley & Sons: 2014; pp 204-229.
ACS Paragon Plus Environment
Page 14 of 24
Page 15 of 24
Environmental Science & Technology
447 448
23.
Werner, T. T. Indium and the Future of Critical Metals in Autralia. Doctoral Thesis, Monash University, 2017.
449 450
24.
Jorgenson, J. D.; George, M. W. Indium: Mineral Commodity Profile; Unites States Geological Sruvey: 2004.
451
25.
Tolcin, A. C. Indium; United States Geological Survey: 2016; pp 80-81.
452 453
26.
Chang, T.-C.; Yen, F.-C.; Xu, W.-H., Substance Flow Analysis of Indium in Taiwan. Materials transactions 2015, 56, (9), 1573-1578; DOI 10.2320/matertrans.M2015165
454 455 456 457
27.
Licht, C.; Peiró, L. T.; Villalba, G., Global Substance Flow Analysis of Gallium, Germanium, and Indium: Quantification of Extraction, Uses, and Dissipative Losses within their Anthropogenic Cycles. Journal of Industrial Ecology 2015, 19,(5), 890-903; DOI 10.1111/jiec.12287
458 459 460
28.
Nakajima, K.; Yokoyama, K.; Nakano, K.; Nagasaka, T., Substance Flow Analysis of Indium for Flat Panel Displays in Japan. Materials Transactions 2007, 48, (9), 23652369; DOI 10.2320/matertrans.MAW200702
461 462
29.
Yoshimura, A.; Daigo, I.; Matsuno, Y., Global Substance Flow Analysis of Indium. Materials Transactions 2013, 54, (1), 102-109; DOI 10.2320/matertrans.M2012279
463 464
30.
Ciacci, L.; Reck, B. K.; Nassar, N. T.; Graedel, T. E., Lost by Design. Environmental Science & Technology 2015, 49, (16), 9443-51; DOI 10.1021/es505515z
465 466 467
31.
Mudd, G. M.; Jowitt, S. M.; Werner, T. T., The World’s Lead-Zinc Mineral Resources: Scarcity, Data, Issues and Opportunities. Ore Geology Reviews 2017, 80, 1160-1190; 10.1016/j.oregeorev.2016.08.010
468 469
32.
USGS, United States Geological Survey, Indium Minerals Yearbooks and Mineral Commodity Summaries. Various.
470 471
33.
Ciacci, L.; Werner, T. T.; Vassura, I.; Montanari, T., Backlighting the European Indium Cycle. Journal of Industrial Ecology 2017, (Accepted).
472 473 474 475
34.
Zhu, X.; Lane, R.; Werner, T. T., Modelling in-use stocks and spatial distributions of household electronic devices and their contained metals based on household survey data. Resources, Conservation and Recycling 2017, 120, 27-37. 10.1016/j.resconrec.2017.01.002
476 477 478
35.
Solar Directory Australian PV installations since April 2001: total capacity (kW). https://www.solardirectory.com.au/images/solar-uptake-graph.png (Accessed 7 September)
479
.
480 481 482
36.
Zimmermann, T.; Gößling-Reisemann, S., Critical materials and dissipative losses: A screening study. Science of The Total Environment 2013, 461–462, 774-780; DOI 10.1016/j.scitotenv.2013.05.040
ACS Paragon Plus Environment
Environmental Science & Technology
483 484
37.
Gerst, M. D.; Graedel, T. E., In-use stocks of metals: status and implications. Environ Sci Technol 2008, 42, (19), 7038-45; DOI 10.1021/es800420p
485 486 487
38.
Chen, W.-Q.; Graedel, T. E., Improved Alternatives for Estimating In-Use Material Stocks. Environmental Science & Technology 2015, 49, (5), 3048-3055; DOI 10.1021/es504353s
488 489 490
39.
Golev, A.; Werner, T.; Zhu, X.; Matsubae, K., Product flow analysis using trade statistics and consumer survey data: a case study of mobile phones in Australia. Journal of Cleaner Production 2016, 133, 262-271; DOI 10.1016/j.jclepro.2016.05.117
491 492
40.
Zimmermann, T., Dynamic material flow analysis of critical metals embodied in thinfilm photovoltaic cells. Artec paper No. 194. 2013.
493 494 495
41.
Candelise, C.; Winskel, M.; Gross, R. J. K., The dynamics of solar PV costs and prices as a challenge for technology forecasting. Renewable and Sustainable Energy Reviews 2013, 26, 96-107; DOI 10.1016/j.rser.2013.05.012
496
42.
(BNEF), Bloomberg New Energy Finance, New Energy Outlook 2017. 2017.
497 498 499
43.
Jahan, S.; Jespersen, E.; Mukherjee, S.; Kovacevic, M.; Bonini, A.; Calderon, C.; Cazabat, C.; Hsu, Y.; Lengfelder, C.; Lucic, S., Human development report 2015: Work for human development. UNDP: New York, NY, USA 2015.
500 501 502
44.
Werner, T. T.; Mudd, G. M.; Jowitt, S. M., The world’s by-product and critical metal resources part III: A global assessment of indium. Ore Geology Reviews, 2017, 86, 939-956; DOI 10.1016/j.oregeorev.2017.01.015
503 504 505
45. Graedel, T. E.; Allwood, J.; Birat, J.-P.; Buchert, M.; Hagelüken, C.; Reck, B. K.; Sibley, S. F.; Sonnemann, G., What Do We Know About Metal Recycling Rates? Journal of Industrial Ecology 2011, 15, (3), 355-366; DOI 10.1111/j.1530-9290.2011.00342.x
506 507 508
46.
Buchert, M.; Manhart, A.; Bleher, D.; Pingel, D. Recycling critical raw materials from waste electronic equipment; Institute for Applied Ecology: Darmstadt, 24 February 2012, 2012.
509 510 511
47.
Cucchiella, F.; D’Adamo, I.; Lenny Koh, S. C.; Rosa, P., Recycling of WEEEs: An economic assessment of present and future e-waste streams. Renewable and Sustainable Energy Reviews 2015, 51, 263-272; DOI 10.1016/j.rser.2015.06.010
512 513 514
48.
Felix, J.; Tunell, H.; Letcher, B.; Mangold, S.; Jiaxu, Y.; Retegan, T.; Grammatikas, A.; Rydberg, T.; Ljungkvist, H. In Increasing the sustainability of LCD recycling, Electronics Goes Green 2012+ (EGG), 2012, 9-12 Sept. 2012, 2012; 2012; pp 1-6.
515 516
49.
Hagelüken, C., Recycling of (critical) metals. In Critical Metals Handbook, Gunn, G., Ed., John Wiley & Sons: 2014; pp 41-69.
517 518 519
50.
Ylä-Mella, J., Pongrácz, E., 2016. Drivers and Constraints of Critical Materials Recycling: The Case of Indium. Resources 2016, 5(4), 34; DOI 10.3390/resources5040034
520
ACS Paragon Plus Environment
Page 16 of 24
Page 17 of 24
Environmental Science & Technology
521 522 523
51.
Ueberschaar, M.; Schlummer, M.; Jalalpoor, D.; Kaup, N.; Rotter, V., Potential and Recycling Strategies for LCD Panels from WEEE. Recycling 2017, 2, (7), 1-19; DOI 10.3390/recycling2010007
524 525 526 527
52.
Duan, H.; Wang, J.; Liu, L.; Huang, Q.; Li, J., Rethinking China's strategic mineral policy on indium: implication for the flat screens and photovoltaic industries. Progress in Photovoltaics: Research and Applications 2016, 24, (1), 83-93; DOI 10.1002/pip.2654
528 529 530
53.
Nyrstar, Nyrstar proceeds with Port Pirie Redevelopment: reaching a pivotal milestone. 2014. http://www.nyrstar.com/~/media/Files/N/Nyrstar/results-reports-andpresentations/english/2014/port-pirie-transformation-presentation.pdf
531 532
54.
Golev, A.; Corder, G., Modelling metal flows in the Australian economy. Journal of Cleaner Production 2016, 112, (5), 4296-4303; DOI 10.1016/j.jclepro.2015.07.083
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Looking Down Under for a circular economy of indium
Figures and Tables Tim T. Werner1,4+, Luca Ciacci2, Gavin Mark Mudd1, Barbara K. Reck3, Stephen Alan Northey4 1
Environmental Engineering, School of Engineering, RMIT, Melbourne, VIC, Australia
2
Dipartimento di Chimica Industriale "Toso Montanari", University of Bologna, Viale del Risorgimento 4, Bologna, Italy 3
Center for Industrial Ecology, School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA 4
Faculty of Engineering, Monash University, Clayton, VIC, Australia
+
Corresponding author: Tim.Werner@rmit.edu.au
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Other regions Slag
Met. proc.
Concentrates
Refined In
Met. proc.
(no In capacity)
International mines
Concentrates
Slag
Slag
Manufacturing
Australia Slag
Direct ore export
Semifinished forms
Slag Concentrates
Ore
Bulk rock
Met. proc.
Milling
Mining
Low grade ore + waste rock
Mineral deposits
No domestic refining
Tailings
Finished goods
In-use Finished goods
End of life goods
Process waste
Manufacturing
Waste mgmt.
No domestic recycling Not recovered
Mine waste
Landfill
Figure 1: Domestic and international stocks, flows and processes considered in this study (Met. proc. = metal processing).
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Stockpiles No stockpiling in Aust.
1224
167 (100%)
167 (14%)
355 (29%)
695 (57%)
Unwrought indium No primary ITO manuf. in Aust.
85 (7%)
PCBs
1042 (86%) Other alloys
Thermal interface materials
85 (7%) Dental alloys
857
Alloys 2658 (19%)
1774 (6%)
15509
26616 (90%)
LCD products
Solar panels
27 (0.2%)
126 (0.3%)
Architectural glass
29426 (70%)
3428 (8.9%)
336 (0.8%)
ITO
1232 (4%)
Production losses
Elec. compounds & semiconductors
Recycling
9757 (69%)
13465
1717 (12%)
Direct Imports
Added to direct finished good imports
8407 (20%)
LED products
Added to direct finished good imports
10000
1000-5000 >15000
Figure 2: Apportionment of semi-finished imports to finished goods, taking into account production efficiencies. Apportionment estimates are derived as an average of Chang, et al. 26, Licht, et al. 27, Nakajima, et al. 28 and Yoshimura, et al. 29 modified to represent the Australian context. All units are in kg, with cumulative flows from 1988-2015 depicted.
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900 800
80% Global Production Australian sourced Australian sourced (%)
700
60%
600
t In
70%
50%
500 40% 400 30%
300
20%
200
10%
100
0 0% 1972 1977 1982 1987 1992 1997 2002 2007 2012 Figure 3: Proportion of global indium production estimated to originate from Australian zinc concentrates 1972-2012, in absolute and percentage terms.
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40,000
Solar Panels Flat Panel TV's
35,000
Laptops + Tablets LCD/LED Screens - PC
30,000
Mobile Phones Research samples, standards and glass Batteries
25,000
Locally manufactured LCD Products
kg In
PCBs / Thermal interfaces
20,000
LED Semiconductors Motor Vehicles Cameras for Film >16 mm
15,000
Cameras for Film