The Future Of Renewable Energy May Depend Heavily On Rare Earth Mining. Yet At What Price?
Three prospectors went out to look for wealth in the parched mountains of southern Nevada and southeast California in the spring of 1949 equipped with Geiger counters.
Those mountains produced gold, silver, copper, and cobalt during the previous century. However, the guys were seeking uranium, a different type of wealth. Following World War II, the Cold War was about to break out. To create its stockpile of nuclear weapons, the US required uranium. Mining domestic resources turned become a national security issue.
After many weeks of looking, the group found what they believed to be gold. Their equipment picked up strong radioactivity in brownish-red ore veins exposed on a granite outcrop in the Clark Mountain Range of California. The brownish-red substance, however, turned out to be bastnaesite, a mineral containing fluorine, carbon, and 17 unusual elements collectively known as rare earths, rather than uranium. The ore included radioactive thorium traces that caused the Geiger detectors to ping.
The prospectors sold their claim to the Molybdenum Corporation of America, afterwards known as Molycorp, notwithstanding how depressing that must have been since the bastnaesite still had value. The rare earths mining was of interest to the firm. The usage of rare earth elements increased dramatically in the middle of the 20th century. For instance, cerium served as the foundation for a glass-polishing powder, while europium provided luminosity for newly developed fluorescent lights and colour television displays.
The location, afterwards known as the Mountain Pass mine, served as the world’s top supplier of rare earth elements for the next several decades until two pressures proved to be too great. China began actively mining its own rare earths in the late 1980s and selling them for less. Additionally, Mountain Pass’ production was shut down in 2002 as a result of a string of hazardous waste accidents.
But the narrative didn’t stop there. Mountain Pass, which subsequently reopened and is now the sole rare earths mine in the United States, received fresh interest as a result of the green-tech revolution of the twenty-first century.
Today, a variety of carbon-neutral technologies as well as a wide range of tools that power the contemporary world are all made using rare earths. These components serve as the foundation for tiny, very effective permanent magnets that power electric cars, wind turbines, cellphones, and other devices.
President Joe Biden’s government declared in February 2021 that mining U.S. deposits of rare earth elements is an issue of national security.
Although they are not really rare on Earth, rare earths do tend to be dispersed at low quantities across the crust. And without the intricate, often dangerous processing required to transform the ore into a marketable form, the ore itself is worth very little, according to Julie Klinger, a geographer at the University of Delaware in Newark. As a consequence, the mining of rare earths is dealing with a history of environmental issues.
Large open pits are dug in the ground to extract rare earths, which may damage the environment and disturb ecosystems. When mining is not properly controlled, wastewater ponds containing acids, heavy metals, and radioactive substances may flow into the groundwater. It takes a lot of time, water, and possibly hazardous chemicals to process the raw ore into a form that can be used to build magnets and other types of technology. This process also generates a lot of trash.
The shift to a climate-safe future requires rare earth elements, according to Michele Bustamante, a sustainability researcher at the Natural Resources Defense Council in Washington, D.C. However, Bustamante claims that “everything we do while we are mining is impactful ecologically.”
Thomas Lograsso, a metallurgist at the Ames National Laboratory in Iowa and the head of the Critical Materials Institute, a Department of Energy research facility, thinks there are methods to lessen mining’s environmental impact. Everything from minimising the amount of trash generated during the ore processing to increasing the effectiveness of rare earth element separation—which may reduce the quantity of harmful waste—is being studied by researchers. Researchers are also exploring mining substitutes, such as extracting rare earths from coal ash or recycling them from obsolete devices.
The mining sector is a major collaborator in this study, and Lograsso stresses the need of getting its support. Mining businesses must be willing to make changes and invest in them. To avoid creating solutions that no one actually wants, he adds, “we want to make sure that the research and innovations we conduct are driven by industry demands.”
If these ideas are widely implemented, Klinger says she is cautiously hopeful that the rare earth mining business can become less harmful and more sustainable. The low-hanging fruit offers the most potential rewards, she asserts. The amount of fuel needed to generate the high temperatures necessary for certain procedures may be decreased by making even simple hardware improvements to increase insulation. You take action as you can.
The Effects Of Rare Earth Mining On The Environment
Ivanpah Dry Lake is a wide, flat basin that is located between the craggy peaks of the Clark range in California and the Nevada border. The valley had water in it all year round about 8,000 years ago. The lake is now ephemeral, appearing only after a heavy rain and flash flood, like many similar playas in the Mojave Desert. Beautiful and desolate, it is the habitat of uncommon desert flora including Mojave milkweed and endangered desert tortoises.
The Ivanpah Dry Lake served as a storage area for sewage pumped in from Mountain Pass from around 1984 until 1998. Wastewater was created as a byproduct of chemical processing used to concentrate rare earth elements in mined rock, increasing its marketability to businesses that could subsequently extract those elements to create certain goods. The mine sent effluent to evaporation ponds in and around the dry lake bed, 23 kilometres distant, through a hidden conduit.
Over the years, the pipeline broke several times. The valley received an estimated 2,000 metric tonnes of radioactive wastewater from at least 60 different accidents. Federal authorities were concerned that exposure to that thorium may put neighbouring inhabitants and guests of the Mojave National Preserve at danger of developing lung, pancreatic, and other malignancies.
In 1997, it was mandated that the leak be cleaned up by Unocal Corporation, which had bought Molycorp in 1977. The corporation paid penalties and settlements totaling more than $1.4 million. The raw ore’s chemical processing came to an end. Soon after, mining activities came to an end.
Another environmental crisis was developing halfway across the globe. Since the 1990s, between 80 and 90 percent of the rare earth elements available on the market have originated in China. The huge Bayan Obo mine in Inner Mongolia, which is only one location, produced 45 percent of all rare earths in 2019.
Approximately half the size of Florida’s Walt Disney World resort, Bayan Obo is spread over 4,800 hectares. Additionally, it is among the most polluted locations on the planet. In a region that was already prone to desertification, clearing the soil to look for ore meant destroying flora, which allowed the Gobi Desert to advance southward.
Authorities in the neighbouring city of Baotou discovered radioactive, arsenic- and fluorine-rich mining waste, or tailings, being dumped on farms, into surrounding water sources, and into the Yellow River in 2010. Fumes and poisonous particles in the air made it difficult to see. Residents reported experiencing headaches, dizziness, nausea, and arthritis. According to Klinger, others showed indicators of skeletal fluorosis, including brittle bones and skin lesions, as well as discoloured teeth and brittle bones.
China’s State Council declared in 2010 that the nation’s rare earth sector was creating “serious harm to the natural environment.” “The loss of vegetation and contamination of surface water, groundwater, and farmland” were caused by the emission of heavy metals and other pollutants during mining. The council said that “excessive rare earth mining” caused landslides and blocked waterways.
In response to these intensifying environmental catastrophes and worries that it was using its rare earth resources too quickly, China drastically reduced its export of the elements in 2010 by 40%. The new restrictions caused costs to skyrocket and sparked worries that China had a too tight grip on these essential components. This then encouraged investment in rare earth mining in other locations.
There were not many additional locations mining rare earths in 2010, and Malaysia, India, and Brazil produced very little. The mining corporation Lynas opened a new mine in 2011 in a remote area of Western Australia. The business delved through petrified lava that had been preserved within Mount Weld, an extinct volcano.
According to Saleem Ali, a professor of environmental planning at the University of Delaware, Mount Weld didn’t have anything like the same kind of environmental effect as that seen in China because of its isolated location and the mine’s small size compared to Bayan Obo. While this was going on, Mountain Pass was still the greatest option for the United States, which was keen to have its own supply of rare earths once again.
Reviving Mountain Pass Mine
The Mountain Pass mine changed ownership once again after the Ivanpah Dry Lake incident. Although Chevron bought it in 2005, it never started up again. Then, in 2008, a newly established business named Molycorp Minerals bought the mine with grand aspirations to establish an entire rare earth supply chain in the US.
In addition to mining and processing the ore, the objective included sorting out the valuable components and even turning them into magnets. Currently, the manufacture of magnets and separations is done elsewhere, mostly in China. The business has put out a strategy to prevent wastewater from leaking into surrounding sensitive ecosystems. With the “dry tailings” technique, which removes 85% of the water from mine waste to create a thick paste, Molycorp restarted mining. On its own property, the business would then store the immobilised, pasty residue in lined pits and reuse the water within the factory.
According to Matt Sloustcher, senior vice president of communications and policy at MP Materials, the current owner of Mountain Pass mine, Molycorp “was an awful failure” from an economic standpoint. In 2015, Molycorp filed for Chapter 11 bankruptcy as a result of poor management. After purchasing the mine in 2017, MP Materials started mining again. In 2022, Mountain Pass Mine was generating 15% of the rare earths in the world.
The ambitious ambition of MP Materials includes aims to establish a whole supply chain. And the business is committed to learning from the errors of the past. According to Michael Rosenthal, chief operating officer of MP Materials, “We have a world-class… amazing deposit, an untapped potential.” “We aim to be the magnetics champion in the United States and promote a strong and varied U.S. supply chain.”
Problems In Separating Rare Earths
On a steamy August morning, Sloustcher stands at the brink of the Mountain Pass mine, an enormous crater in the earth that is up to 183 metres deep and 800 metres broad. It’s a striking vista and a wonderful vantage point from which to sketch a future vision. He shows out the numerous structures, including those that house the ore crushing and grinding, the chemical treatment of the ground rocks to remove as much non-rare earth material as possible, the water extraction from the waste, and lined ponds for the waste.
The final product is a highly concentrated rare earth oxide ore, which is still far from being ready to produce magnets. Nevertheless, Rosenthal claims that the corporation has a three-step strategy “to restore the whole rare earth supply to the United States,” from “mine to magnet.” The first stage, which started in 2017, included resuming ore mining, crushing, and concentration. The chemical separation of the rare earth elements will complete Stage 2. Magnet manufacture will be stage 3, he adds.
Since going into operation in 2017, MP Materials has sent its concentrated ore to China for the next phases, which include the laborious and dangerous process of separating the components from one another. But the business informed investors in November that it had started the first steps for stage 2, a “significant milestone” in realising its mine-to-magnet objectives.
The business is constructing two separate facilities with funding from the US Department of Defense. One facility will extract the rare earth elements known as lighter rare earth elements, or those with lower atomic numbers, such as neodymium and praseodymium, which are both essential components of the permanent magnets used in many consumer gadgets and electric cars. In order to develop and construct a second processing facility to separate the heavier rare earth elements such as dysprosium, which is also a component of magnets, and yttrium, which is used to manufacture superconductors and lasers, MP Materials has received additional grant funding from the DOD.
Stage 3 is now underway, the same as stage 2. The business started construction on a neodymium magnet manufacturing plant in Fort Worth, Texas, in 2022. It has signed a contract with General Motors to provide such magnets for the motors of electric vehicles.
However, Dividing The Components Has Its Own Set Of Environmental Drawbacks
The procedure is challenging and produces a lot of garbage. Due to their high chemical similarity, rare earth elements have the propensity to adhere to one another. They must be forced apart one by one using several successive procedures and a range of strong solvents. Cerium, for instance, is removed from the mixture by caustic sodium hydroxide. Other procedures include the use of fluids containing ligands, organic compounds with a strong affinity for metal atoms. The ligands have the ability to selectively attach to certain rare earth elements and remove them from the mixture.
The inefficiency of this extraction method, however, is one of the main problems, according to Santa Jansone-Popova, an organic chemist at Oak Ridge National Laboratory in Tennessee. These metals are scavenged slowly and inadvertently, and it takes a number of extraction procedures for businesses to collect enough of the elements to be commercially viable. According to Jansone-Popova, the needed separation requires “many, many, many steps” when using the present chemical procedures. This increases the cost, complexity, and amount of trash produced by the whole process.
Jansone-Popova and her coworkers have been looking for a method to make the process more efficient by omitting several of those processes under the auspices of the DOE’s Critical Materials Institute. The researchers discovered a ligand in 2022 that they claim is far more effective than the ligands now used in the industry in capturing specific rare earths. She claims that industry partners are on board to test the new procedure this year.
There are ongoing issues about the possible effects of radioactivity on human health in addition to worry about heavy metals and other harmful chemicals in the trash. According to Ali, the issue is that there is still a dearth of epidemiological data about the effects of rare earth mining on human and environmental health, most of which is based on the toxicity of heavy metals like arsenic. Due to the low concentration of radioactive elements in rare earth mining waste, it is also unclear, in his opinion, how much of the worries about radioactive waste are substantiated by science.
However, these issues draw attention from throughout the world. A rare earth separation factory located close to Kuantan, Malaysia, created what campaigners referred to as “a mountain of poisonous trash” in 2019, amounting to roughly 1.5 million metric tonnes. Lynas, which owns the plant, transports its rare earth ore to the location from Mount Weld in Australia. The ore is heated with sulfuric acid and then diluted with water to dissolve the rare earths. There may be radioactive thorium residues in the leftover debris.
Lynas piled the rubbish on the hills close to Kuantan since he lacked permanent storage for it. However, scientists think that the concern about the possible radioactivity in those slopes may be overstated. According to Lynas, employees at the facility are exposed to less than 1.05 millisieverts of radiation annually, which is far less than the 20 millisievert limit for workers imposed by the International Atomic Energy Agency.
“Thorium is one of several byproducts about which there is a lot of false information. According to Ali, the thorium produced during the production of rare earths emits relatively little radiation. As a devoted environmentalist, I believe that there isn’t currently any decision-making on these issues that is based on research.
Environmental think tanks like the World Resources Institute have been advocating for more recycling of current rare earth minerals in order to decrease the demand for new mining and processing due to worries about new mining.
According to Bustamante of the NRDC, “getting the most out of what we take out of the earth has to do with the way to the future.” “In the end, production and what we do with those materials at the end of their useful lives are the largest levers for change,”
This entails not just recycling rare earths made from already-existing materials, but also utilising mined resources as effectively as feasible. She adds that getting greater use out of these resources may lessen the total environmental effects of mining.
Recycling is a good first step, but Ali argues that it is not a magic solution. One issue is that there aren’t currently enough used rare earth-containing batteries and other materials accessible for recycling. We won’t have enough supply at this time, therefore some mining will be required. And as demand rises, he continues, the supply issue will only become worse.
