When most people hear rare earth minerals, their minds immediately think it refers to the rarest minerals in the world. However, that is not the case. Rare earth minerals are among the most abundant minerals in the world. The word “rare” refers to their scarcity at the time of their discovery.
Rare earth minerals are essential manufacturing components in the world. That is because they can help transition from a fossil fuel-powered global economy to an economy reliant on renewable energy. You can find parts made from rare earth minerals in numerous technologies considered vital to the transition to sustainability, like electric motors and wind turbines.
Read on for a detailed account that defines rare earth minerals, highlights their importance to the EV manufacturing industry, and the potential hazards associated with their extraction.
What Are Rare Earth Minerals?
The name “rare earths” is a product of their time of discovery. Scientists first discovered the complex ores containing rare earth elements towards the end of the 18th century. They were known “earths” at the time. These elements were hard to find and separate from the ores, hence their categorization as rare.
Rare earth minerals are a group of 17 metals which include scandium, yttrium, and 15 elements from the lanthanide group. The 15 lanthanides are lanthanum, cerium, praseodymium, terbium, samarium, europium, neodymium, promethium, gadolinium, holmium, erbium, dysprosium, thulium, lutetium, and ytterbium.
Not Rare at All
Unlike their name suggests, rare earth minerals are not rare at all. There are numerous deposits of rare earth minerals around the globe on all continents. However, they often exist in low concentrations within ore deposits.
In total, rare earth element deposits are more abundant in the earth’s crust than other widely used metals like copper, zinc, gold, and platinum. For example, cerium is the 28th most naturally abundant element in the world, while thulium, the least abundant rare earth element, is the 63rd most abundant element.
Rare earth elements have strong magnetic properties that make them ideal for making alloys with other metals like iron. They also exhibit electrical conductivity and fluorescent properties.
Rare earth elements are also incandescent, meaning they emit light when exposed to heat, which was beneficial in the manufacture of lamps in the late 19th century. They also oxidize when exposed to air, although the lighter rare earth elements oxidize faster than the heavier ones.
Why Do EVs Need Them?
EVs need rare earth elements because car manufacturers use them to make components vital to the functioning of the vehicles. For instance, rare earth metals are necessary for the manufacturing of electric motors that help in the powering of the engine. Rare earth metals are also present in EV batteries because of their electrical conductivity properties.
However, in recent years, sourcing rare earth minerals has become more challenging because of the fluctuations in pricing on the global market caused by China, the biggest global producer of minerals. The issues in sourcing rare earth minerals are attributable to several factors.
They include China investing heavily in boosting rare earth mineral production in the final decades of the 20th century. The country proceeded to dump substantial amounts of the minerals on the global market, thus destabilizing prices and forcing other major producers to shut down some of their mining facilities.
That’s because it was no longer profitable for them to keep mining rare earths. Once competitors started lowering production, Chinese companies were able to fill the void, resulting in them almost monopolizing the market.
Consequently, China has used its dominance in the rare earth metals market as leverage during disputes with other countries. For example, in 2010, during a maritime border dispute between China and Japan, Chinese officials held a shipment of rare earth metals destined for Japan, resulting in a spike in global prices.
On the other hand, recent tensions between China and the United States have forced EV manufacturers to seek alternatives, as they fear China might impose export quotas or restrict exports entirely. The options include buying from other rare earth metal producers and redesigning EVs to use little to no rare earth minerals.
Common Rare Earth Minerals Used in EVs
In the early years of EV production, companies like Toyota and Honda used rare earth minerals as components for their car batteries. The kind of EV batteries used in said cars were nickel metal hydride-based.
The batteries consisted of an anode made from lanthanum pentanickel alloy, with the lanthanum accounting for about 10 kilograms of the batteries. In the absence of the lanthanum compound, the battery contained a cerium compound as the anode.
However, with time, EV manufacturers have moved away from nickel-based batteries and adopted lithium-ion batteries. That is because they offer better performance and are cheaper to produce though vehicles that use the nickel battery still exist.
The other use of rare earth minerals in EV production is the manufacturing of high-power magnets essential to producing permanent electric motors. The electric motor generates electricity that magnetizes the permanent magnets and coils, creating a magnetic force by the magnets’ repelling poles. The magnetic force drives the axles, thus causing the vehicles’ wheels to turn.
The rare earth metals used in permanent magnet production are neodymium, praseodymium, terbium, and dysprosium. Neodymium is the primary element used in the process because of its magnetic coercivity, which refers to the magnetic field strength required to magnetize or demagnetize a material.
However, neodymium operates at very low temperatures, meaning it cannot sustain magnetism in the motor for long periods. Therefore, EV manufacturers use dysprosium or terbium to create an alloy with neodymium.
This leads to a higher operating temperature that maintains magnetism for as long as necessary. A modern EV will contain about one or two kilograms of rare earth minerals.
Departure from Rare Earths
EV manufacturers are, however, trying to avoid dependence on electric motors because of the uncertainty surrounding rare earth access. Some companies have resorted to using induction motors that rely on aluminum and copper. They include Tesla, which has used induction motors on its Model S and Model X, as well as BMW and Renault.
Why Is Ecology at Stake?
Despite their name, rare earth minerals are relatively abundant. However, they are widely dispersed in the Earth’s crust, thus making them challenging and expensive to extract. The primary method used in rare earth metal mining involves removing rare earth ores from the ground and leaching them in chemicals to dissolve the rare earth elements, thus separating them from other compounds in the ore.
Once dissolved, the solvent gets concentrated before the individual rare earth elements get separated from each other. Though they are vital to the global economy, mining rare earth minerals can be very harmful to the environment because of the processes used and the materials generated.
For instance, one of the chemicals used in the leaching of rare earth ores is concentrated sulphuric acid, which can cause water contamination if it seeps into groundwater. Consumption of such water can cause health difficulties in humans, livestock, and wildlife.
Water contaminated with sulphuric acid can also affect plant life by damaging seed embryos, thus hampering germination. Seepage of concentrated sulphuric acid into the soil can also increase soil pH, making the soil too acidic to facilitate the growth and development of plants.
Toxic Waste Gasses
Moreover, the leaching process releases toxic waste gasses into the environment, which can cause medical conditions, like respiratory issues, when inhaled. Other chemicals in the wastewater and residue generated during and after the leaching process include magnesium oxide and hydrochloric acid, which can present similar ecological problems.
In addition, some rare earth mineral ore deposits contain radioactive materials like uranium and thorium that are highly toxic. Medical practitioners associate radioactive elements with increased chances of developing cancerous cells. The most common cancers associated with rare earth metal mining are lung and pancreatic cancer.
Another ecological issue of rare earth mining is the waste the processes generate. Mining rare earth elements requires extracting substantial amounts of rare earth ores spread across a wide area instead of concentrated in one location.
The result is the production of large quantities of waste that gets heaped onto landfills, whereby extraction of one ton of rare earth produces 2,000 tons of waste. Such dumps are susceptible to landslides during rain storms, spreading the toxic waste onto other lands outside the mine. This eventually causes soil and water contamination.
“Cancer Villages” in China
People can find the most disastrous examples of rare earth mining pollution in China. Chinese authorities have acknowledged the existence of so-called “cancer villages,” in which many residents have received cancer diagnoses. Others have succumbed to the disease because of exposure to toxic wastes.
However, in recent years, as environmentalists and communities near mines have exposed the amount of pollution mining towns suffer from, companies and regulators have begun to keep a close eye on pollution levels. In some places, mining companies have established wastewater treatment facilities to prevent the leakage of toxic materials into the environment.
The effects of toxic chemicals and waste on the environment get exacerbated by lax waste disposal regulations in some of the world’s foremost rare earth mineral producers like China, Brazil, and India. Without proper regulation and monitoring of mining and waste disposal methods, pollution from rare earth element mining will continue to be a significant problem in various countries.
It is evident that rare earth minerals are integral to producing EVs. However, they are not compulsory. For a long time, EV companies relied on rare earth minerals as they were affordable and readily available from China. However, recent political issues between China and the U.S. have risked the once reliable rare earth minerals supply.
Additionally, there is increasing pressure on EV companies to reduce their reliance on rare earth minerals because of the associated environmental implications. Consequently, EV companies are resorting to other alternatives in their commitment to conserve the environment. Currently, it is impossible to tell whether EV companies will phase out rare earth minerals for good. We’ll have to wait and see.