Contributed by Ashley Baker, Research Assistant, ACS Green Chemistry Institute®
Slowly but surely the world is waking up to the reality and consequences that come with a disposable tech culture. In May 2009, The Atlantic revealed “clean energy’s dirty little secret,” the story of how green technologies are currently made possible through the use of rare earth elements. Just last year, the BBC featured an article detailing the disturbing conditions in and around an Inner Mongolia rare earths processing factory.
While the efforts of journalists and scientists seeking to raise awareness about the environmental and geopolitical issues surrounding rare earth elements have not inspired broad action, many different groups are seeking sustainable solutions.
Despite their name, these materials are not especially “rare;” certainly, many of them are more abundant in the Earth’s crust than commonly used platinum group metals. The challenges surrounding rare earths have more to do with their geographic concentrations and the difficulty in separating the desired elements from the ore in which they’re bound.
To add to the physical challenges of obtaining these materials, politics and global economics play key roles in the world’s supply. China has the largest concentration of rare earths in the world, enabling the country to exert significant influence on the rare earths market. Last year, the World Trade Organization determined that China was violating international trade agreements with its export restrictions. The fact that the U.S., which has struggled to compete with foreign rare earth prices, filed the claim demonstrates the scale of these concerns.
Despite the challenges of mining and processing rare earths, our growing dependence on them – for everything from texting to national security – means avoiding them is no straightforward task. This is where green chemistry can play a key role by re-imagining the processes and chemistries involved and innovating towards more sustainable solutions. All over the world, chemists and engineers are seeking – and finding – ways to make sure that people throughout the world have access to technology that enables a higher standard of living, and for many years to come.
Alternatives, Innovation and Mitigation
Because of the market’s uncertainty associated with the distribution of rare earths, businesses have good reason to seek alternatives to buffer themselves against sudden price changes. Companies such as Honda, Dell and Solvay are just a few that are innovating and seeking more sustainable ways of using rare earth elements or developing alternative approaches to delivering similar functionality.
Designing for recovery and recycling can cut down on the amount of rare earths a company needs to buy. The Electronics TakeBack Coalition promotes green design and recycling of electronics. That’s the route Dell is taking. The theory is that by building products such that rare earth-containing components are easily identifiable and removable, the likelihood of the materials being either collected and reused increases. Likewise, car manufacturer Tesla teamed up with Umicore to get as many rare earth metals as possible back from their electric engines. Partnerships that enable more sustainable approaches while reducing operating costs are certainly a win-win.
While some companies look downstream for solutions like recycling, others are investigating opportunities for improvement closer to the beginning of the process. Researchers at the Oak Ridge National Laboratory, for example, are seeking ways to improve the harsh processing steps. They’ve found that ionic liquids may prove to be a safer alternative way to extract rare earths from mineral ores like bastnaesite, which is conventionally repeatedly treated with strong acids. Further research into greener rare-earths processing methods could reduce the environmental impact of using them.
While mitigating the effects of using rare earths after the fact is certainly a step in the right direction, it would be ideal to avoid their use in the first place. IRENA is an international collaborative project with the mission of replacing indium and gallium in flat panel displays by using single-walled carbon nanotubes. Similarly, novel metal alloys with computationally-predicted magnetic properties may just be the way forward. With the help of computer programs that are more powerful than ever, there’s a chance novel compounds and materials could usurp permanent magnets made from rare earths.
The demand for these materials and products is great, and funding opportunities for more extensive research are emerging in response. The Engineering and Physical Sciences Research Council (EPSRC) in the UK began a £10 million program to support alternative, sustainable materials and to accelerate their commercialization. Stateside, the Advanced Research Projects Agency-Energy (ARPA-E) created the REACT program (Rare Earth Alternatives in Critical Technologies) to likewise fund research into substitute materials.
The current shortcomings of clean energy are certainly fixable; moreover, the methods we use now are hopefully just to tide us over as we transition from fossil fuels. Projects and organizations all over the world – like the Critical Materials Institute and the Critical Raw Materials Innovation Roadmap – are initiating collaborative efforts to create and implement technology that will work today and for many tomorrows. In addition, despite the bad environmental reputation of rare earths mining in China – by far the largest global supplier - there has been a buzz in clean production research over the past few years (reference: section 7.3.7). Changes in Chinese mining regulation specifically target the most environmentally harmful mining methods, such as those that produce large quantities of radioactive slurry or facilities that fail to treat wastewater, gas and solid waste. Encouraging results from research institutes and universities across China point to a future of safer and more efficient rare earths mining worldwide.
While the challenges may seem insurmountable, assuming there are no viable alternatives is a sure way to not find them, and believing something is impossible is a sure way to inhibit innovation. The future of rare earth element use will certainly require thinking far outside the box, and that could mean anything from mining the moon to undiscovered biochemical routes.
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