Rare Earth Elements
Rare Earth Elements (REEs) are key components of many new digital and e-mobility technologies. They are critical for the world’s economy, and demand for them has leapt from 30,000 tonnes in the 1980s to 120,000 tonnes in 2010 - higher than the world’s current annual production of 112,000 tonnes.
In 2011, it was reported that high concentrations of REEs (in particular the rarer heavy REEs) could be found in the top few metres of deep-sea clays. Although it is not clear whether the resource is commercially viable, deep-sea mud mining is being explored. The impacts will probably exceed those involved in the extraction of polymetallic nodules, because mining will occur deeper into the seabed and may be more severe in terms of operational and discharge plumes. REE mining operations in muds may include the application of weak acid during processing, and the residue may potentially be returned to the seafloor. Relatively high concentrations of REEs are also found in polymetallic nodules and cobalt crusts.