EDITOR: | November 9th, 2015 | 1 Comment

Ucore’s promise for clean and efficient technology metals recycling

| November 09, 2015 | 1 Comment
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Ucore and IBC Advanced Technologies outline MRT’s role in recycling as an Aid to Metal Sustainability in Global Society

recycling2The amount of waste generated annually on this planet is huge. Williams [1] cites one estimate that 41.8 million metric tonnes of electrical and electronic products were discarded globally in 2014, with a rise to 50 million metric tonnes predicted by 2018. The number beyond that date is expected to continue to rise due to global population increase, greater consumer affluence, and increased production of new products to replace old ones. Although the quantity of technology metals (precious plus specialty) is small (mg) in each item, the amount in 50 million metric tons is enormous.

Hagelüken [2] reports that 80 percent of the global mine production of platinum group metals PGM), rare earth metals (REE), In, and Ga since 1900 has occurred in the past three decades. Global REE production increased from about 5,000 metric tons in 1956 to about 140,000 metric tons in 2010 to meet the product demand for these metals [3]. Since most of these technology metals are used only once before being discarded with their end-of-life products (recycling rates for REE are <1%) and REE are not retrievable following discard using present technology, new virgin ore must be mined to replace them in the new products constantly being produced to meet customer demand. The number of metals used in high-tech products has increased dramatically in the past few decades. The average computer chip today contains 61 different elements compared to the 12 elements that were used in the 1980s [1].

The thrust of this article is to demonstrate that recycling is a valuable and effective means of preserving Earth’s technology metal resources and of reducing the amount of virgin ore mined, with its accompanying environmental challenges. Articles in coming months will amplify on the subject of recycling metals. Effective recycling is of crucial importance in maintaining Earth’s metal supply for current and future generations. Yet, those who use these products are, generally, not aware of the technology metals they contain or of the importance of conserving this metal resource.

Recycling involves multiple steps. Technology metals, for example, are usually components of products that eventually have decreased function or are replaced by new products with discard of the old. These discarded products may be stored, placed in landfill, incinerated, or disassembled for the value they contain, usually in the form of precious metals [4]. Incorporated into these operations may be collection procedures, legislative mandates, shredding, re-sale of old products, and other steps. Hagelüken [2,5] has treated in detail the operations that precede actual separation and recovery of target metals.

My intent in this series of articles is to discuss the technologies available for separation and recovery of target metals from end-of-life materials, with particular emphasis on the capability and versatility of Molecular Recognition Technology (MRT) in accomplishing these tasks using green chemistry procedures. Examples will be given to illustrate the variety of technology metals that have been recovered using MRT and the wide range of products or systems for which these metals are used. Background for MRT can be found in previous Investor Intel articles [6-8] and in published papers [4,9,10].

Recycling of Technology Metals has Many Benefits for Global Society

The benefits to the global community of recycling are numerous. Understanding these benefits by stakeholders should lead to greater interest in preserving Earth’s valuable technology metal resources. These beneficial features, as summarized by Hagelüken [2], are given in Table 1. The following discussion draws from the points presented in this Table.

Table 1

Technology metals, as by-product or accompanying metals, are present in much lower concentrations. The environmental burden of the mining process is large and is increasing as the need for metals increases. As ore is mined to meet the demands of society, grades of available ore decrease prompting the need to find new deposits, to develop technology to mine economically deposits having lower grades, and/or go to greater depths of existing deposits increasing waste generation and energy and water use [11].The environmental burden of mining can be reduced by effective recycling programs. Mining is inherently a process which generates large amounts of waste. This waste derives from the fact that most ore bodies contain a few percent of the target metal, necessitating the removal of a large overburden and separation from this gangue material of a few percent, at most, of the desired metal.

Increasingly stringent environmental regulations in Organization for Economic Cooperation and Development (OECD) nations have resulted in recent decades in the movement of much mining and ore beneficiation processing to non-OECD nations, which have less strict regulations. However, as the global consumer increasingly demands ethical and responsible production, manufacturers now require traceable and responsibly produced input material.

Recycling of metals is an important activity that, if effectively done, has the potential to reduce significantly the need to mine new ore to fill the continuing need to replace the metals discarded in end-of-life (EOL) products [12]. Since EOL products do not contain the plethora of metals that virgin ore does, recycling avoids release of toxic or other metals into the environment, as is the case in mining and beneficiation processes.

mining

Mining has high energy and water requirements [3,13]. Obtaining metals through recycling can reduce significantly the amount of mining required with associated reduction in carbon dioxide emissions, waste generation, and land and water use. Impacts on the biosphere, e.g.,in rain forests, Arctic regions, ocean floors, and so forth could be reduced by effective recycling. A further important benefit of recycling is the reduction in the generation and discard of solid, liquid, and/or gaseous waste into surrounding land, streams, and atmosphere which is common in many mining processes where environmental regulations either do not exist or are poorly enforced.

The literature and internet are replete with examples of waste generation associated with mining activities, past and present. Lichti and Mulcahy [14] estimate that in the U.S. alone there are over 250,000 abandoned acid mine drainage sites. One of these sites, the Gold King Mine near Silverton in southwest Colorado, failed in the summer of 2015, attracting a great deal of attention worldwide as the released waste turned the rivers downstream yellow and orange for all to see via television coverage. A major waste site is the Berkeley Pit, in Southwest Montana, near Butte. This site is large enough to “swallow all of central Melbourne,

Australia and contains 100 billion litres of water contaminated with acids and heavy metals” [LIC98]. Severe pollution of the surrounding environment from mining of heavy rare earth metals in south China has been documented by Yang, et al. [15]. The list could go on and on. A future Investor Intel article will describe the successful use of MRT in separating and recovering contaminating metals, including Cu, Fe, Al, Zn, Mn, Cd, and As, from Berkeley Pit and other acid mine drainage sites; and the potential use of MRT for separation and recovery of REE from spent products.

Depletion of Earth’s Technology Metal Resources

Continued use of Earth’s metal supply without replenishing it can lead only to eventual depletion of this resource. This result is of greater significance in the case of some metals than others. A major effect will be that the cost of metals will increase as supply diminishes. Another is that, in some cases, such as for certain technology metals deemed critical, demand may exceed supply resulting in major price fluctuations. Indium is an example of a metal that, in the form of indium-tin-oxide (ITO), is critical to the function of flat screen devices, which, in turn, are critical to a whole host of modern high-tech products. As a result of consumer demand, primary production of In increased a staggering 1675% from 1975 to 2012 [12].

saltsIndium is one of the rarest of metals in Earth’s crust. Its sole commercial source is sphalerite, ZnS, from which it is recovered as a by-product [3]. Eighty percent of global Zn is mined and processed in China, making this Nation a major source of In, producing 390 tonnes in 2012, about 70% of the world’s supply. Canada, Japan, and South Korea each produced about 35 tonnes of In in 2012.

Indium is of interest because it is a critical metal, but one of low economic value. Hence, there is little incentive to recycle In from EOL products containing it. The recycle rate of In from EOL products is <1% [16]. Forecast consumption growth rates for LCDs and solar cells project that supplies of In from primary mined Zn sources will be severely depleted by the early 2020s [3]. Estimated global reserves of In [IZA14] range from 2,800 (2006) to 11,000 (2007) tons with an annual consumption of 510 tons. Consumption is expected to grow to 1,900 tons annually by 2030. Nassar, et al, [12] have discussed the relationship between Zn and its companion metal In.

Active programs are underway to find material that can replace ITO in flat screens, but so far none can match the function of ITO. Since the demand for In is projected to continue unabated into the future, it is desirable that an effective recycling program be developed to stem the loss of this valuable resource. In a future article, I will describe successful applications of MRT in separating and recovering In; as well as several other metals that are in a similar situation, such as Re, Mo, and Ge; from EOL products.

Geopolitical and Supply Concerns Regarding Earth’s Technology Metal Supply

Effective recycling programs could reduce the geopolitical concerns that exist regarding our technology metal supply. It is not wise to be dependent on other nations for this supply. Examples are China, which controls nearly 100% of Earth’s (REE) supply [3] and 70% of the global In supply; South Africa and Russia who together control a very high percentage of the PGM supply [17]; and the Copper Belt of Congo (Kinshasa) and Zambia of Africa where over half of the recoverable global Co supply is located [18]. Effective recycling programs for these metals could significantly reduce this dependency.

A major benefit of recycling is that it would partially decouple the production of the by-product technology metal from that of the major metal. Examples include the following companion or by-product metals whose primary supply depends on production of a particular major metal (given in parentheses): In (Zn); Mo, Re, and Te (Cu); Ga (Zn or Al); and Pd, Ru, Ir, and Rh (Pt) [12]. The main objective of the producer of commercial metals is to produce the major metals, not by-product metals.

Nassar, et al. [12] have pointed out that the dependence of companion metal availability on the production of host metals introduces a new facet of supply risk to modern technology. Several essential technology elements, such as germanium, terbium, and dysprosium, are further characterized as having geopolitically concentrated production and extremely low rates of end-of-life recycling. Any success in decoupling the link between major metals and companion technology metals by recycling is advantageous to the security of the technology metal supply and, hence to the continued performance and growth of our high-tech society. The effectiveness of MRT in separating and recovering a number of these technology metals from EOL products and other wastes will be treated in a future Investor Intel article.

Recovery of Toxic Metals and Radioactive Species a Challenge to Recycling

Toxic metals, including Pb, Hg, Cd, As, and Tl, are generated in considerable amounts in many mining and beneficiation processes. These metals are usually released into the environment as discarded waste and often become a severe environmental concern. They, typically, are not recovered since they are nuisance metals and have little economic value. In addition, several of these metals are present in electronic and other waste, such as Pb in cathode ray tubes (~2.2 pounds Pb per tube), and Cd in batteries.

Recovery or recycling of toxic metals from e-waste is not being done. Their recovery rate is <1% [16]. The result is widespread environmental and human health damage when EOL products are improperly discarded. Separation and recovery of these metals from EOL products would provide a way to dispose of them in an environmentally acceptable manner. MRT has reported effective means of separating and recovering these toxic metals from various systems at mg/L or lower levels. In a future article, examples of the use of MRT to achieve these separations will be given.

Contamination of the environment from radioactive species derived from U, Th, and their daughter products is prevalent in many areas. Three of these areas are in mining of rare earth metals, particularly monazite sands; in wastes from generation of electricity in nuclear power plants; and in accidental spills of radioactive species as a result of natural or man-caused disasters, such as that at Fukishima Bay, Japan. In addition, there is an on-going concern over radioactive emissions entering the environment from stored wastes generated during World War II and the post-World War II era, such as those at Hanford, Washington.

The use of MRT products to make green chemistry separations and recovery of a variety of these radioactive metal isotopes including Cs, Sr, Ra, U, Ra, Pu, and Tc will be described in a forthcoming Investor Intel article. These examples will include successful projects involving MRT separations of radioactive Cs, Sr, and Tc from Hanford wastes and of Cs and Sr from simulated Fukishima Bay solutions.

Urban Mining: A ’Gold’ Mine Awaiting the Harvesters

There are significant economic incentives to recover precious metals and Cu from EOL waste in so-called above-ground or urban mining [3]. Precious metal amounts in multi-ton quantities of these wastes are significantly higher than those found in virgin ores, where the Au or PGM content on average is ~10g/ton. In a future article, the factors involved in urban mining will be discussed. This activity has great promise, but there are challenges in implementing it. Successfully carried out, urban mining can make significant contributions to metal sustainability.

Summary

Metal recycling approaching 100% is achieved in modern integrated smelters [5]. But there are few such smelters in the world and waste must be transported to them, causing other real and potential liabilities.At the other extreme, informal recycling, primarily in non-OECD nations, involves large numbers of individuals who manually disassemble electronic EOL products and inefficiently retrieve the valuable components, such as Au, using unsafe methods [3].

Between these extremes, there are efforts, some successful on small scale, to develop formal methods for recycling technology metals from specific EOL products, such as Dy and Nd, which are present in high strength magnets. However, compared to the 50,000 metric tons of electronic waste generated annually, the cumulative recovery of technology metals by presently used methods is small, indeed.

There is great opportunity and, certainly, need for the development of green chemistry processes capable of large scale separation and recovery of these metals from EOL products. MRT holds tremendous promise for clean and efficient metals recycling, and the intention is to expand its use to make a significant contribution to the recycling of these valuable metals.

References

  1. Williams, I.D., Global Metal Reuse, and Formal and Informal Recycling from Electronic and Other High-Tech Wastes, In Metal Sustainability: Global Challenges, Consequences, and Prospects, Izatt, R.M. (Ed), Wiley, Oxford, Publication date early 2016.
  2. Hagelὕken, C., 2014, Recycling of (Critical) Metals: In Critical Metals Handbook, Gunn, G., Ed., Wiley, Oxford, pp 41-69.
  3. Izatt, R. M., Izatt, S. R., Bruening, R. L., Izatt, N. E., Moyer, B. A. (2014). Challenges to achievement of metal sustainability in our high-tech society. Chemical Society Reviews, 43, 2451-2475.
  4. Izatt, R. M., Izatt, S. R., Izatt, N. E., Krakowiak, K. E., Bruening, R. L., Navarro, L; (2015). Industrial applications of Molecular Recognition Technology to green chemistry separations of platinum group metals and selective removal of metal impurities from process streams. Green Chemistry, 17, 2236-2245.
  5. Hagelὕken, C., Grehl, M., 2012, Recycling and Loop Concept for a Sustainable Usage, In Precious Materials Handbook, Sehrt, U., (Ed), Umicore D Et Co, KG, Hanau-Wolfgang, Germany.
  6. Izatt, R.M., Molecular Recognition Technology: Clean Chemistry Applied to 21st Century Rare Earth Separation, InvestorIntel, May 15, 2015, Accessed 23 October 2015.
  7. Izatt, R.M., Green Chemistry in Modern Mining and Rare Earth Beneficiation, InvestorIntel, July 9, 2015,  Accessed 23 October 2015.
  8. Izatt, R.M., How Molecular Recognition Developed into Molecular Recognition Technology, InvestorIntel, September 12, 2015, Accessed 23 October 2015.
  9. Izatt, N. E., Bruening, R. L., Krakowiak, K. E., Izatt, S. R. (2000). Contributions of Professor Reed M. Izatt to Molecular Recognition Technology: From laboratory to commercial application. Industrial & Engineering Chemistry Research, 39, 3405-3411.
  10. Izatt, S. R., Bruening, R. L., Izatt, N. E. (2012). Status of metal separation and recovery in the mining industry. Journal of Metals, 64, 1279-1284.
  11. Mudd, G.M., 2012, Sustainability Reporting and the Platinum Group Metals: A Global Mining Industry Leader, Platinum Metals Reviews, 56, 2-19.
  12. Nassar, N.T., Graedel, T.E., Harper, E.M., 2015, By-product Metals are Technologically Essential but have Problematic Supply, Science Advances, 1, e1400180 (2015). doi: 10.1126/sciadv.1400180, 3 April 2015.
  13. Norgate, T.E., 2010, Deteriorating Ore Resources, In Linkages of Sustainability, Graedel, T.E., van der Voet, E., Eds., The MIT Press, Cambridge, MA, pp. 131-148.
  14. Lichti, G., Mulcahy, J., 1998, Acid Mine Drainage—Environmental Nightmare or Asset?, Chemistry in Australia, January/February, 10-13.
  15. Yang. X. J.; Lin, A.; Li, X.-L.; Wu, Y.; Zhou, W.; Chen, C. Q. (2013). China’s ion-adsorption rare earth resources, mining consequences and preservation, Environmental Development, 8, 131-136.
  16. Reck, B. K.; Graedel, T. E. (2012). Challenges in metal recycling, Science, 337, 690-695.
  17. Wilburn, D.R., 2012, Global Exploration and Production Capacity for Platinum-Group Metals from 1995 through 2015 (version 1.1), U.S. Geological Survey Scientific Investigations Report 2012–5164, 2012, 26 pp., Accessed October 23, 2015.
  18. Wilburn, D.R., 2012, Cobalt mineral exploration and supply from 1995 through 2013: U.S. Geological Survey Scientific Investigations Report 2011–5084, 16 p. Accessed October 24, 2015.

Reed M. Izatt, PhD

Editor:

Reed M. Izatt received a BS degree in Chemistry from Utah State University (1951) and a PhD degree in Chemistry with an Earth Sciences minor ... <Read more about Reed M. Izatt, PhD>


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Comments

  • Raj Shah

    Ucore is addressing a very serious problem of e-waste with its revolutionary recycling technology at the same time reducing dependence on other nations for supply of technology metals. Recycling is the way forward.

    November 10, 2015 - 11:51 AM

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