As countries look to reduce their carbon emissions, the focus is on cleaning up fossil-fuel-powered transportation. Electric vehicles (EV) are a major part of this strategy but the production of electric vehicles requires the mining of rare earth elements (REEs). Now, Japanese automobile manufacturer Nissan claims to have co-developed a technology that allows for easier and faster recovery of rare-earth elements.
The environmental impact of EVs is largely measured in terms of lithium that goes into its battery and how it is sourced. Apart from the batteries, the electric motor, itself, is magnetic and uses rare elements such as neodymium and dysprosium. With the sharp uptick in the acceptance of EVs, the mining of these elements is bound to increase, working against the purpose of shifting to EVs.
Attempts have been made to design batteries as well as motors that do not use these rare-earth elements, but they need to be tested heavily before being put into practical use. The current demand for EVs will be met by REEs but future demand for EVs can be met with alternately manufactured components or by using improved recycling methods like the one Nissan has developed.
To ensure that its EVs are sustainable, Nissan has already been working on reducing the use of REEs in its cars. The company claims that its 2020 model uses up to 85 percent lesser REEs than its popular 2010 EV, Leaf. In addition to this, the automobile maker also recycles low-quality motors to recover REEs. To do so, it dissembles the motor and then removes the magnets. But this procedure is time-consuming. So, it partnered with Waseda University to develop a new method.
Developed over a period of three years, the new technique does not require manual motor disassembly. Instead, a carburizing material and pig iron are added to it and then the mixture is heated to 2552 degrees Fahrenheit (1400 degrees Celsius). Once the mixture is molten, iron oxide is added to it, which oxidizes the REEs. Borate-based flux is then added, which then dissolves the oxidized REEs and rises to the top, and can be easily separated from the heavier iron-carbon alloy at the bottom.
Nissan claims that its tests showed up to 98 percent of REE recovery using this process which required 50 percent lesser time. The company now plans to set up a larger facility to further test this method and even use retired EVs at its facility.