Rare Earth Elements: A Review of Production, Processing ...

More documents

Recommendations

Info

Rare Earth Elements Review Section 5 – Rare Earth Element Recovery/Alternative Material Use Figure 5-1. Representative rare earth oxide prices from 2007–2010 (The 2007–2010 figures are fourth-quarter [Q4] average prices. The 2011 numbers represent spot prices on February 25). (from: http://www.osa-opn.org/OpenContent/Features/Rare-Earth-Elements-High-Demand-Uncertain-Supply-3.aspx) Information from the literature indicates that large amounts of REEs are currently in use or available in waste products and would be able to support recycling operations. Specifically, a recent study by the Japanese government-affiliated research group National Institute for Material Science (NIMS) estimated that Japan has 300,000 tons of REEs and 6,800 tons of gold currently sitting in e-wastes (Tabuki, 2010). A recent study by Yale University estimated that 485,000 tons of REEs were in use globally in 2007 (Du and Graedel, 2011). The study further states that four REEs (cerium, lanthanum, neodymium, and yttrium) constituted more than 85 percent of the global production, and that recycling the in-use stock for each of these is possible, but remains a challenge. The research concludes that for the other rare earths that are generally used in much lower quantities, recycling would be difficult primarily due to technical challenges associated with separating the rare earths from the product. On an individual basis, cerium is mostly concentrated in catalytic converters and metal alloys; neodymium is used in permanent magnets, computers, audio systems, cars, and wind turbines; lanthanum is used in catalysts, metal alloys, and batteries; and yttrium is used in lasers and superconductors. A newly published report by the USGS provides additional information on the end uses of REEs and the potential for recyclability by end use (Goonan, 2011). To put use quantities in perspective, a Toyota Prius uses 2.2 pounds of neodymium (Wheeland, 2010) and over 10 pounds of lanthanum (Koerth-Baker, 2010); a typical air conditioner unit includes 4 magnets that contain about 30 grams of rare earths (Montgomery, 2011); and a new-generation windmill requires 1,500 pounds of neodymium (REVE, 2011). 5-2
Rare Earth Elements Review Section 5 – Rare Earth Element Recovery/Alternative Material Use A recent United Nations (UN) report on recycling rates of metals estimates that the end-of-life functional recycling (i.e., recycling in which the physical and chemical properties that made the material desirable in the first place are retained for subsequent use) for rare earths is less than 1 percent (UNEP, 2011). Another study estimates that world-wide, only 10 percent to 15 percent of personal electronics are being properly recycled (Dillow, 2011). Of the items that are sent for recycling, the European Union (EU) estimates that 50 percent of the total is illegally exported, potentially ending up in unregulated recycling operations in Africa or Asia. These recycling operations frequently result in environmental damage and worker exposure, as documented in a separate UNEP report (Schluep et al., 2009) and discussed further in Section 6. The increasing prices of REEs (as well as other recyclable metals), along with the knowledge of the quantities available in discards and the increased worldwide demand, have led to the concept of “urban mining.” Urban mining is defined as the recovery of elements and compounds from waste materials and products. Consumer electronics are increasingly becoming subject to urban mining practices— and with over 6.5 million metric tons of personal computers, computer monitors and peripherals, televisions, and mobile “If the United States committed itself to meeting its critical materials needs in large part through recycling, there is no nation on earth that could match American resources. The United States has the largest "above-ground" mines of critical materials in the world, in the sense that this country's supply of industrial scrap and end-of-life automobiles, electronics, and electronic appliances - whether they are in wreckers' yards, land-fills, or Americans' basements and attics - can't be matched by any other nation. In essence, these "above-ground mines" make the United States the Saudi Arabia of critical materials. A well-developed recycling system could tap these mines for U.S. critical materials security without limit.” Waste Management World, 2011 devices being generated in 2007 in the United States, Europe, China, and India—the supply available for “mining,” or recycling, is large and increasing (ICF International, 2011). A short introductory video on urban mining, with a focus on efforts in Japan, is available on the Internet (http://english.ntdtv.com/ntdtv_en/ns_offbeat/2010-10-19/822469802087.html). Some small electronics such as cell phones reach their end of life after a few years, while many of the products that contain larger amounts of REEs have useful lives of well over one decade. The recycling of the REEs contained within products will occur many years in the future and is not a short-term solution to the current demand. Another factor that will impact one of the recycling drivers is that as additional REE mines begin operation outside of China, global production will increase, costs may decrease, and the urgency behind the push to recycle may be reduced. 5.2 Recycle Processing Steps The recycling process for post-consumer, end-of-life products typically involves four key steps, as illustrated by Figure 5-1: (1) collection; (2) dismantling; (3) separation (preprocessing); and (4) processing. As previously noted, a 2011 status report (UNEP, 2011) states that the end-of-life recycling rates, defined as the “percentage of a metal in discards that is actually recycled,” for REEs is less than 1 percent. As cited by Meyer and Bras (2011), the consumer products with the most rare earth recycling potential are the ones that contain high levels of rare earths and an established collection or recycling infrastructure, such as fluorescent lamps, magnets, car batteries, and catalytic converters. Three factors noted as contributing to the effectives of recycling efforts are the following (UNEP, 2011): 1. Economics – The value of the materials to be recycled must be greater than the cost of recycling. In situations where this is not the case, laws and incentives can be effective in increasing recycling rates. 5-3
Page 1 and 2:
Rare Earth Elements Review Table of
Page 3 and 4:
Foreword The U.S. Environmental Pro
Page 5 and 6:
Abstract Rare earth elements (REEs)
Page 7 and 8: Table of Contents List of Acronyms
Page 9 and 10: List of Tables 2-1. Abundance of El
Page 11 and 12: Rare Earth Elements Review List of
Page 13 and 14: Rare Earth Elements Review Section
Page 57: Rare Earth Elements Review Section
Page 109 and 110:
Rare Earth Elements Review Section
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Rare Earth Elements Review Appendix
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
show all

Rare Earth Elements: A Review of Production, Processing ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?