Much of the apparent scarcity is because China, the largest consumer of rare earth metals, is one of the few countries where REE currently are mined. China sits on approximately 40 percent of global reserves, but was responsible for 85 percent of global rare earth production in 2012.
From the mid-1960s through the 1980s, the United States provided the bulk of the world’s REEs from Molycorp’s Mountain Pass mine in California. But the mine was shut down in 2002 due to environmental violations and competition from China. The United States then became 100 percent reliant on imports.
China began reducing its exports of rare earth metals in 2008 to preserve supplies and protect its environment, causing prices to rise dramatically. This was a wake-up call for the international community, as it realized how dependent it was on China.
Countries around the world have geared up to develop alternative REE sources. But new mines can take up to 10 years to become productive.
In 2012, the total world capacity for producing rare earths was estimated at approximately 155,000 tons, but as more countries develop rare earth mining operations, 386,000 tons could be available by 2017. The supply of rare earth metals from the rest of the world outside of China is projected to increase by more than 27 percent per year between 2014 and 2020.
The problem with the current boom in REE mining, however, is the environmental damage left in its wake. REEs are bound up with low-level radioactive elements, which are lethal to humans and can contaminate the environment.
Also, mining and processing rare earth metals can leave behind toxic wastewater and tailings ponds that could leak into groundwater. A 2012 Chinese white paper on the country’s rare earth industry said that, “Excessive rare earth mining has resulted in landslides, clogged rivers, environmental pollution emergencies, and even major accidents and disasters, causing great damage to people’s safety and health and the ecological environment.”
Moreover, because rare earth metals are difficult to mine and separate, the processes require a significant amount of electricity, water, and chemicals.
It’s ironic that REEs account for much of the carbon footprint of green energy, and that such a highly energy-intensive process is needed to produce products (such as wind turbines and vehicles with electric motors) meant to reduce carbon emissions.
The Department of Energy’s strategy for dealing with critical materials is to facilitate mining and processing in the United States and abroad in an “environmentally sound manner.” Moreover, they are to develop substitute materials and promote more efficient use, reuse, and recycling of REEs.