iNEMI Report on the State of Metals Recycling
BY CAROL HANDWERKER, PURDUE UNIVERSITY, WAYNE RIFER, GREEN ELECTRONICS COUNCIL/EPEAT, MARK SCHAFFER, INEMI CONSULTANT
Metals recovery from electronic product recycling is focused on high-volume and most valuable metals that are recoverable in an economically feasible way. Current electronics contain small quantities of metals that are available for recovery but are recovered at a very low rate, or not at all in today’s recycling infrastructure. There are a number of different causes of this. Moreover, current and imminent technology trends will make recovery more complex. These trends include miniaturization, increase of functionality and performance, product dematerialization, and the introduction of new heterogeneous materials systems. These factors create increasing challenges with respect to materials supply, recovery, and recycling.
The iNEMI Metals Recycling Project was organized to analyze the existing recycling systems, identify unmet needs for current materials recovery and assess the readiness of the current system for meeting future materials recovery needs. The project focused on metal recovery, as it applies to consumer electronics, enterprise electronics and future information and communications technology (ICT). This article reviews some of the team’s findings re: the state of metals recovery, encompassing the extraction of rare earth metals and disposal of harmful battery materials.
Current status of metals recovery from electronics
The project team reviewed information provided by the United Nations Environment Programme (UNEP) International Resource Panel’s (IRP’s) working group on metals recycling, drawing primarily on the report, “Metal Recycling: Opportunities, Limits, Infrastructure (2013).1
This report emphasizes that the supply of metals will be critical to the green economy. With demand projected to grow by 3–9 times by 2050 and, with the quality of primary ores decreasing, the amount of ore mined annually is expected to increase dramatically to meet demand Moreover, uncertain geopolitical forces will control future supply of a wide range of metals. Of particular concern is the accelerating demand for metals, specifically precious metals, platinum group metals and rare earths.
The UNEP study “focuses on the recycling of high-value, low-volume metals that are essential elements of existing and future high-tech products, … [which are] essential for sustainable growth, though typically lost in current recycling processes.” The report notes that metals recycling is becoming more difficult due to increasingly complex combinations of materials and the trend toward miniaturization, and concludes that far too much valuable metal is lost because of the imperfect collection of end-of-life (EoL) products, improper practices, or structural deficiencies within the recycling chain.
Three interrelated factors are identified as as important to successful recycling and maximizing resource efficiency: (1) recycling processes and the major physical and chemical influences on the metals and other materials in the processing stream, (2) collection and pre-sorting of waste, and (3) the physical properties and design of the EoL products in the waste streams. Clearly, one of the challenges is to address the causes of low recovery for electronics. Looking at the metals recovery system generally, the report calls for a number of innovations to improve recovery:
- Ways to set up better collection systems.
- Means to trace and track EoL products or fractions thereof along the recycling chain.
- Alloy-specific sorting technologies (where products, scrap, etc., are not too complex).
- Improved and adapted liberation methods.
- Identification and separation of metal-containing components, though complex products with complex material linkages may make this superfluous and impossible.
- New mechanical, chemical and thermal separation and concentration techniques for metals, complementing the large body of existing metallurgical separation know-how.
- Additional final-recovery processes for end-refining metals and metal products, in case these are not yet available or being developed and implemented at this moment.
Metals recovery from electronics poses some very specific challenges, particularly as designs and metals content of products change quickly. Some of the dimensions of those challenges are discussed below.
Are all metals equal from a recycling perspective for ICT products?
Not only are metals key components of ICT that produce the functionality of the products, but the number of metals that are being called upon has been increasing in the last decades. As products are miniaturized and power and diversity of functions are increased, different metals are being incorporated for their physical, chemical and electrical properties. The schematic from Intel shown in Figure 1 depicts the growth in the number of individual elements incorporated in ICT circuits over the last 30+ years.
The estimate is that currently approximately 60 elements are found in a typical ICT product, the great majority of them being used as metals. Industry, including other sectors such as energy and transportation, is calling increasingly on scarce metals or unusual combinations of metals that they use in small quantities, but contribute much to product functionality.
The traditional approach in recycling generally is to focus on commodity materials. Recycling success is typically measured in percentage by weight of actual recycled products relative to the estimated available EoL product and by total weight recycled. This mindset has been carried over to electronics recycling, and most electronics recycling programs, including the EU WEEE legislation, are quantified in the same terms. However, this approach, while convenient due to the simple metric — i.e., weight — is overly simplistic. For example, collecting equal weights of refrigerators and desktop computers leads to very different metals mixes and recovery values. Recovering a kilogram of gold is obviously far more valuable in terms of financial return and environmental impact than a ton of steel.
Clearly, not all metals are equal in terms of recycling EoL electronics. In determining how to set priorities for recovery of individual metal species, there are alternative approaches that can be taken. Metals recovery may be prioritized to:
- Obtain the highest financial value of the recovered metal as measured by profit from metals recovery
- Prevent environmental and human health and safety impacts from hazardous materials by their being recycled rather than landfilled, such as mercury in TVs and displays or lead in Pb-acid batteries and Sn-Pb solder
- Reduce environmental and human health impacts by using “urban” mining rather than mining of primary ore as illustrated in the Table 2, even when the profit from metals recovery is low
- Increase the supply of metals considered “critical” from the perspective of reducing risks to long-term supply from primary sources, even when the profit from metals recovery is low or negative.
Of these four priorities profit, after considering all the recycling costs from collection through processing, is a dominant driver of metals recovery. For the other three to occur, someone must pay the cost of recovery. The second priority is typically accomplished through legislation, including landfill and household waste bans, fees charged for proper disposal by certified recyclers, and mandatory up-front charges to consumers for recycling and recovery at product EoL. The same could be used for the third and fourth and, again, there would have to be a source of funding for recycling and metals recovery if the profit from metals recovery is not sufficient.
Identifying the priorities for metals recovery and the sources of funding for reaching specific goals provides insight into why the current state of metals recycling from electronics is the way it is and how well the systems will adapt with changes in products, materials and technologies.
Value of metals available for recovery in a product
The large suite of technology metals in electronics includes commodity metals such as iron, aluminum and copper, precious metals such as gold, silver and palladium, specialty metals such as cobalt and indium, and “critical metals” such as the rare earth elements neodymium and dysprosium. Although the quantities of metals per individual product can be small, the large number of products makes the quantities significant.
Metals, particularly precious and specialty metals that have the greatest value and the greatest environmental impact in products, are being recovered from electronics at a surprisingly low rate. There are several reasons for low metals recovery.
In urban mining, metals recovery value (MRV) is determined by the quality, concentration and commodity value of all the metal in the product, and by the efficiencies and costs of collection, separation, sorting, processing/extraction and appropriate treatment of waste products. This leads to two straightforward equations that are needed to understand the
current state of metals recycling. The first is that the final recovery efficiency ( Efinal ) from urban mining a particular metal can be found by multiplying the efficiencies of the individual steps such that Efinal = Ecollection * Eseparation * Esorting * Eprocessing/extraction
Because the final efficiency is determined by the product of the efficiencies of the individual steps, the amount yielded during successive steps is determined by the efficiencies of each of the previous steps. If only half the possible electronic products are collected, the total efficiency will be 50% at most, and likely less depending on the efficiencies of the subsequent steps.
A second financial equation is then used to determine the economic value of the recycled metal where the profit is equal to recycled metal sales minus the cost of recovery. As the economic value of metals in products decreases, the cost of recovery must likewise decrease for a profit to be made.
These are coupled equations since the cost of recovery depends of the efficiencies of, and costs for, performing the individual steps. Both equations must be considered in analyzing the existing recycling supply chain for electronics and its ability to meet current and future needs.
Undercollection of EoL consumer and enterprise electronics in the US
According to a 2011 IDC survey and report,2 only 3.4 million tons of EoL electronics were recycled in 2011 compared with an estimate of EoL electronics of 6 million tons. This represents an efficiency of 57%. indicating a large loss of metal assets that could be recovered. In those 3.4 million tons, 26% by weight was obtained from consumers and 74% from businesses.
This under-collection has many causes, particularly as a reflection of people’s attitudes toward the products they use, the resources their products contain, and the act of recycling. For example, in a 2014 Harris survey of US consumers, 6% stated they never recycle anything and 62% stated that they would not recycle if it were inconvenient to do so. In a second Harris report specifically on US adults recycling small electronics, 31% of Americans stated that they have never recycled any of their small electronics. The remaining 68% recycled at least one small electronic product, a category that includes supplies such as ink cartridges for printers.
Smelters: limits on recovery
Not all smelters recover everything. The most integrated smelter is Umicore (Belgium), with 17 metals recovered, but this is not the typical case.
Electronic scrap is recycled by smelters with the main focus on the recovery of bulk metals such as Cu, Al or Fe, and a secondary focus on precious metals. The smelting process extracts a metal from an ore or oxides by involving heat and melting. An example of the process is the smelting of tin from cassiterite, the tin oxide mineral, SnO2. Most smelters first use a smelting process to initially reduce the scrap to metals and then use a refining process, removing impurities or unwanted elements to recover the precious metals. Some major recyclers engaged in the recovery of precious metals from electronic scrap are Umicore (Belgium), Boliden (Sweden), Aurubis (Germany) and Dowa (Japan).
Recycling of electronic scrap is based upon the copper (Cu) system due to the high amount of copper in electronics, especially printed circuit boards and the fact that recovery of precious metals is compatible with Cu-based streams. They ride-along or dissolve in the Cu based streams and not in iron (Fe) or aluminum (Al) streams. An example of the technology for a Cu-based smelting stream is as follows: the material goes into an anode furnace that removes the oxygen and leaves 99% pure Cu which also contains the precious metals. The smelted material then goes to an electrolytic refining process that grows a pure Cu cathode with the precious metals on the anode. The precious metals then go through further refining processes. Each recycler has developed unique smelting and refining technologies. Up to 17 elements may be recovered, but typically gold (Au), the highest value, palladium (Pd), platinum (Pt), silver (Ag) and copper (Cu) are paid. Tin (Sn), lead (Pb), nickel (Ni) and zinc (Zn) are also recovered.
Incoming scrap can come in various forms — complete products, complete printed circuit boards, components, shredded products and industrial by-products.
Batteries usually must be removed prior to shipment to the smelter and are processed in their own stream. Even small button batteries typically should be removed from circuit boards such as mainboards but can be processed if they are not removed. Some smelters process industrial dust, ash and industrial by-products. All scrap must be free of hazardous materials.
Smelters do not currently recover rare earth elements (REE) as they have no affinity to copper and do not dissolve in copper. Since they are not recovered, they end up in the slag from Cu smelters along with aluminum, iron and other elements not being recovered. Currently, there is no technology available that allows the recovery of the few parts-per-million (ppm) of rare earth elements from the huge amounts of smelter slag. Since most of the rare earth elements in electronic scrap are used as magnets, particularly in products such as hard-disk drives or speakers, the components have to be removed prior to smelting and processed in a separate stream in order to recover any rare earth elements.
Specialty and “critical” metals – battery materials and rare earth magnets in electronics
Several studies3,4,5,6 have developed lists of “critical” or “near critical” metals, indicating that these metals have both high supply vulnerabilities and low likelihood of substitution by other metals if supply is limited.
The following section explores two examples of potentially critical materials contained in electronics: Li, Co and other metals in batteries, and Nd and Dy in magnets.
Recycling of battery materials in electronics
As mobile devices become ever-more prevalent, there is a proportional increase in lithium-ion (Li-ion) batteries. This increase introduces new challenges in the e-waste recycling stream, including variable material content, undeveloped recycling infrastructure, safety concerns in handling and transportation, and a lack of consistent policy guidance. These issues will continue to grow as the battery waste stream also begins to receive used batteries from electric vehicles, some of which will have similar chemistry and form factor as those in consumer electronics while others are very different. Conversely, battery packs coming from electric vehicles will also introduce new electronics, due to the circuitry (PCB, wiring, etc.) needed as part of the battery management system (BMS), which is used to control the depth and rate of battery charge-discharge cycles within a safe operating range.
Currently, only a limited amount of Li-ion battery material is recycled, despite the fact that it may be environmentally beneficial and technologically viable to do so in some circumstances. Other important technology metals contained in Li-ion batteries, including cobalt, nickel, aluminum and steel, are recycled from products other than Li-ion batteries at the levels noted in Table 3, but are currently not recycled from Li-ion battery material. The primary barrier to Li-ion battery recycling appears currently to be economic.
Preliminary analysis conducted at Rochester Institute of Technology (RIT) using a material flow analysis method illustrates the predicted growth in cell phone and laptop battery waste shown in Figure 2. The uncertainty in these graphs is estimated by developing multiple scenarios of battery waste. Top-down A and B are projections based on product sales data and the bottom-up projection is based on household product penetration rates, which are alternate ways of estimating material flows.
As the consideration of value recovery from electronic waste continues, parallel effort should aim to proactively develop new recycling technologies and infrastructure, business models and effective policies to improve the potential for cost-effective and environmentally effective Li-ion battery recycling.
Recycling rare earth magnets in hard disk drives
Certain rare earth elements have been identified as critical materials and are being considered as new priorities for EoL electronics recycling. Rare earth elements have a number of applications in electronics, including magnets in hard disk drives (HDDs) and speakers in ICT products, and in phosphors. A 2015 paper by Ueberschaar et al9 effectively describes the economic and logistical difficulties of recycling hard disk drives in desktop and notebook computers. This paper’s most significant findings are:
1. For HDD the ranking of intrinsic metal value is weighted toward precious metals (Au, Pd, Ag) – 80%, with Al – 10%, and REE – 8%, with the precious metals foun d on the circuit board
2. There are typically two to three magnets per HDD (voice-coil and spindle), with the Dy content varying by use and year of manufacture, and the spindle magnet usually containing a high Nd concentration
3. Both magnet types are integrated into the design and, hence, very difficult to remove from the assembly
4. Even if they can be removed, the magnets will need to be reprocessed for recovery of the REEs; they cannot be reused due to the processes needed to remove coatings, potential damage during removal and contamination
5. Shredding appears to currently be a preferred option to prepare the HDD metals for metals recovery, but the focus on recovery has typically been for precious metal recovery and not for the REEs
These findings are, of course, based on current product design and recycling systems. Two additional issues limiting the viability of REE recovery from HDD are the logistics for collection of HDD from widely dispersed sources and the current methods, i.e. shredding, for local and traceable HDD data destruction. A challenge of this report is to identify changes to these existing conditions that would facilitate future REE recovery.
From this and other assessments, recovery of rare earth elements could become commercially viable if:
1. New, innovative, highly efficiency recycling technologies were created specifically for REEs
2. Significantly higher efficiencies were obtained for collection, as well as for other processing steps
3. Prices for commodity REEs and magnets were higher, hereby making REE from recycling more competitive
Summary of metals recovery issues, including specialty and critical metals
Both battery and magnet recycling, and especially the latter, are nascent technologies. The development of an economically viable recovery system for battery and magnet metals, especially for REEs, lithium, and cobalt will require innovation at each stage of the lifecycle to make recycling cost-effective, safe and practical. A metals recovery system can operate most effectively and cost efficiently if, and only if, it becomes integrated into a broader electronics asset management and metals recovery strategy. This strategy would include the following:
• Products are designed to facilitate recovery of different metals. (The issues of metals recovery when various metals are mixed are described in the UNEP reports.)
• Effective communication is established between producers and the recycling industry regarding material content and design for recovery. Design for disassembly principles create triage and pre-processing steps to facilitate separation of the proper fractions for further processing.
• Logistics of collection, transportation and safe handling of battery and magnet material must be established.
• Simple and efficient processes are developed to recover high-value sub-components, e.g., magnets and battery components.
• Cost-effective processing technologies at all stages in recovery are created and implemented to recover the metal elements and convert them to products
There are possible incentives to encourage the development of integrated systems. Voluntary standards such as EPEAT, and other eco-labels such as those in Europe and Asia, could have parallel requirements for design features, thus providing a market reward for recovery-system-compatible design, and they could reward inclusion of post-consumer metals in products, thus increasing their market value.
The stages of the recycling system can be improved through standards that address two additional parts of the system. One is corporate performance requirements of producers. In this age of increasing expectation of producer responsibility for EoL electronics, manufacturers/producers have close relationships with recyclers and others in the supply chain. Second is in standards for recyclers such as R2, eStewards, the CENELEC EN 50625 standard for collection, logistics and treatment requirements for WEEE, and others.
The final element separation and purification technologies for several of the specialty metals are being researched and piloted by organizations such as the DOE Critical Materials Institute led by Ames Laboratory, with a team from three other DOE laboratories, seven universities, and numerous companies and affiliate members.
The greatest need now is for the development of the “rules of the game,” that is, a comprehensive model of how different components of value recovery systems for EoL electronics function; how products, costs and revenues will be exchanged based not only on the economics of metals recovery but also on environmental and societal factors; and what kinds of incentive systems will contribute most to encourage specific behavior.
The establishment of such “rules” will require broad stakeholder engagement with individuals willing to examine new scenarios, generate and share data, and collaborate in research. This work can be undertaken in several forums, which, as they develop, can each contribute portions to the full system model. iNEMI has consistently provided a platform for such collaborative research. Additionally, at least one research project that is currently in start-up mode under the European Commission Horizon 2020 research program could also contribute. Called the Sustainably SMART project, it includes a large team being led by Fraunhofer IZM and will focus specifically on the impact and opportunities of product miniaturization on product life span, reuse, remanufacturing and recycling.
A key bottom line question is: Could a more integrated system ever be cost effective? Will it be technically as well as economically feasible? Could it, under reasonably expected technical feasibilities and market conditions, generate sustainable profits to make it a market-driven system? Answers to these questions are not known. To refine such assumptions will be part of the challenge ahead.
To download the complete iNEMI Report on the State of Metals Recycling, go to:
A follow-on effort — the iNEMI Value Recovery from End-of-Life Electronics Project — is working to develop a community-based approach to establish the groundwork for developing an implementable plan for a value recovery system for HDDs. For additional information: http://community.inemi.org/value_recovery
ABOUT THE AUTHORS
Carol Handwerker is the Reinhardt Schuhmann Jr. Professor of Materials Engineering at Purdue University and Director of the NSF-funded Purdue- Tuskegee IGERT program in Globally Sustainable Electronics. She was previously Chief, Metallurgy Division, National Institute of Standards and Technology (NIST). Carol chaired the iNEMI Metals Recycling Project and is currently co-chair of iNEMI’s Value Recovery from End-of-Life Electronics Project. (firstname.lastname@example.org)
Wayne Rifer is Senior Advisor, Green Electronics Council/EPEAT. Wayne leads research in electronics recycling and has participated in e-waste recycling efforts including negotiation to develop a national solution — the National Electronics Product Stewardship Initiative (NEPSI) — and the drafting of the Oregon e-waste bill. (email@example.com)
Mark Schaffer is a consultant with iNEMI and staff manager of several of iNEMI’s environmental and recycling projects. In addition to his work with iNEMI, he is the owner and primary consultant for Schaffer Environmental LLC, which provides leading supply chain, environmental and sustainability consulting, advisory and project management services to organizations around the world. (firstname.lastname@example.org)
1. UNEP (2013) Metal Recycling: Opportunities, Limits, Infrastructure, A Report of the Working Group on the Global Metal Flows to the Inter- national Resource Panel. Reuter, M. A.; Hudson, C.; van Schaik, A.; Heiskanen, K.; Meskers, C.; Hagelüken. http://www.unep.org/resourcepanel/Publications/tabid/54044/Default.aspx
2. Filing Information: September 2011, IDC #229786, Volume: 1 eWaste and Environmental Opportunities: Survey.
3. “Strategic and Critical Materials, 2013 Report of Stockpile Requirements, Office of the Undersecretary of Defense for Acquisition, Technology and Logistics, U.S DOD, January 2013.
4. Critical Materials Strategy, U.S. Department of Energy, December 2011.
5. Critical Materials for the EU, Report of the Ad-hoc Working Group on defining critical raw materials, European Commission, July 2010.
6. Communication from The Commission To The European Parliament, The Council, The European Economic And Social Committee And The Committee Of The Regions, Tackling The Challenges In Commodity Markets And On Raw Materials, European Commission, February 2011.
7. Bailey, C., Babbitt, C.W., Gaustad, G. 2011. “Tracking the material, energy, and value flow for end-of-life lithium-ion batteries in the US.” Proceedings of the 2011 IEEE International Symposium on Sustainable Systems and Technology.
8. Wang, X., Gaustad, G., Babbitt, C.W., Bailey, C., Ganter, M., Landi, B. 2014. “Economic and environmental characterization of an evolving Li-ion battery waste stream.” Journal of Environmental Management 135, 126-134.
9. Enabling the recycling of rare earth elements through product design and trend analyses of hard disk drives. Maximilian Ueberschaar Vera Susanne Rotter, J Mater Cycles Waste Manag (2015) —17:266–281, DOI 10.1007/s10163-014-0347-6.