Rare Earth Metals and their Importance
Rare earth elements (REEs), also referred to as rare earth metals, include yttrium, scandium, and 15 metallic elements of the lanthanide series in the periodic table.
All REEs, such as high electrical conductivity, display similar chemical and physical properties. Although REEs are abundant in Earth’s crust, they are primarily available in low concentrations in minerals and cannot be separated easily from other elements.
REEs are used extensively as key ingredients in multiple products, including industrial catalysts, polishing powders, pigments, fiber optics, lasers, medical imaging machines, compact fluorescent lamps, cell phones/smartphones, and other electronics such as television, light emitting diode (LED) lights, flat screen monitors, hard drives, and computers. A few REEs are utilized in nuclear power and oil refining applications.
Moreover, REEs are an integral part of high-powered magnets and rechargeable batteries used in renewable energy technologies, such as solar panels, wind turbines, and electric vehicles, which are necessary to realize a zero- or low-carbon future.
In defense, REEs are used in global positioning system (GPS) equipment, satellites, missile defense and guidance systems, sonar and radar systems, lasers, electronic displays, and jet engines.
The innovation and development of emerging technologies, such as automation and green technology, that will increase efficiency in manufacturing processes and facilitate decarbonization primarily depend on the increasing extraction of REEs. For instance, a wind plant requires substantially more minerals as input than a gas-fired plant.
Increasing investments by individuals, organizations, and governments in clean/carbon-neutral technologies will increase the demand for REEs in the upcoming decades. Specifically, the demand for neodymium and dysprosium will increase more due to their extensive application in wind turbines and electric vehicles. However, REE extraction can adversely affect communities and contaminate the area surrounding the REE extraction sites..
Limitations of REE Extraction
Fulfilling the ever-rising demand for REEs is extremely challenging as REEs are not naturally available in the form of concentrated deposits. Miners must excavate substantial amounts of ore and then subject it to chemical and physical processes to concentrate the REEs and separate them.
REEs are primarily mined using two energy-intensive methods and possess a high risk of environmental and health hazards as they release toxic chemicals into the environment.
The first method involves removing the topsoil and creating a leaching pond where different chemicals are added to the extracted earth to separate the metals.
However, the toxic chemical-rich leaching ponds can leak into groundwater if not appropriately secured, negatively impacting waterways. In the second method, holes are drilled into the ground using rubber hoses and polyvinyl chloride (PVC) pipes to pump chemicals into the earth, creating a leaching pond with similar issues as the first method.
Both methods generate a substantial amount of toxic waste. Approximately 13 kg of dust, one ton of radioactive residue, 9,600-12,000 cubic meters of waste gas, and 75 cubic meters of wastewater are generated for mining one ton of rare earth.
When mixed with the leaching pond chemicals, REE ores have metals that contaminate soil, water, and air. Moreover, rare earth ores typically contain radioactive uranium and thorium, creating health hazards.
Several mechanisms are being considered to address these issues, including reducing waste generation during ore processing and improving the REE element separation efficiency to decrease toxic waste generation.
Recovering REEs from coal waste and recycling rare earths from discarded and old electronics are suitable alternatives to REE mining.
Recent Developments in the Rare Earth Mining Industry
China
The global production and processing of REEs remain concentrated, with China accounting for the leading share of REE production and processing. Several countries worldwide, including the industrialized nations in Europe and Japan, depend entirely on REE imports from China to meet their requirements.
However, the rising geopolitical tensions around Taiwan and China have spurred several countries, such as Canada, Australia, and the United States (US), to reduce their reliance on China for REEs by increasing domestic production or diversifying supply sources.
United States
The US Department of Energy (DoE) has recently announced a $30 million initiative to primarily secure the domestic supply chain in the US for rare earths and other minerals essential for battery manufacturing, such as lithium and cobalt. However, political, environmental, and business factors can increase the challenges of building the REE supply chain from mine to magnet over a short time frame. Rapidly scaling up the refining and processing of the mined rare earths cost-effectively is the key to reducing the overreliance on China.
Recently, MP Materials, based in the US, has restarted REE production from the Mountain Pass mine in California that was closed in 2015. Lynas Corporation, based in Australia, has received $30.4 million in funding to construct a light rare earths processing facility in Texas. The company has also partnered with Blue Line Corporation to build a heavy rare earths separation facility.
Australia
A critical mineral demonstration facility in Australia has been planned in North Queensland. It will process critical elements like vanadium, cobalt, and REEs.
Lynas Rare Earth has planned to invest $345m to expand the capacity of Mount Weld Mine and its concentration plant to significantly increase the production of praseodymium and neodymium in the upcoming years.
Vietnam
Vietnam strives to position itself as a critical source of REEs as the global REE supply chain is increasingly diversifying to other countries.
Although Vietnam has the second-largest reserves of exploitable rare earths after China, the country has significantly failed to increase its rare earth production. However, investments by Japanese companies in recent years to secure non-Chinese REEs have fueled the growth of the REE mining industry in that country.
Africa
Africa is considered a new source of REEs and a key alternative to China. Scaling up REE exploration in Africa can help to identify and extract REEs, with several REE-rich deposits being explored in the continent.
Mkango Resources, an exploration firm based in Canada, has planned to start REE production from its Songwe Hill rare earths mine in Malawi. Similarly, the Steenkampskraal Mine in South Africa has one of the highest grades of REEs, with large deposits of praseodymium and neodymium.
Europe
In Europe, LKAB, a mining company based in Sweden, has recently discovered the largest known REE deposit in Europe in Kiruna. It contains over one million metric tons of rare earth oxides.
The discovery can help Europe substantially increase REE production in the region.
Japan
Japan has announced it will mine rare earth from the seabed to become a self-sufficient nation in REEs by the end of the decade; huge quantities of rare earths are available on the sea floor.
The Future of Rare Earth Metal Mining
REEs are currently playing a critical role in several high-tech applications and will continue to witness a substantial demand with the development of emerging technologies, including carbon-neutral technologies. These are essential for attaining net-zero targets.
However, identifying sustainable, eco-friendly, and cost-efficient REE production methods and securing the global REE supply chain from geopolitical uncertainties are necessary to maintain the growth momentum in the REE mining industry.
Source: azo mining
