‘Vacuum-cleaner’ could collect rare metals from the deep sea floor

‘Blue Harvesting’ - a collaboration between five European countries - has designed a way to collect rare metals from the bottom of the ocean. 

The sea floor boasts one of the world’s largest untapped collections of rare-earth elements, including copper, manganese, nickel and cobalt — materials crucial for accelerating the energy transition.

In order to meet this rising demand for rare earth minerals, a team of scientists has developed Apollo 2, which they described as a "vacuum cleaner" driven by water pressure and powered entirely by electricity. The device is able to collect raw materials without causing the clouds of fine sediment which are often harmful to marine life.

"The novelty of the new design is that we reduce the extent of the sediment cloud by recirculating it back into the collector. The new device has been thoroughly tested," said project co-ordinator Rudy Helmons. "The results are promising for the future.”

Helmons has recently returned from three weeks of successful field experiments in the Mediterranean Sea, where the team tested Apollo 2. 

The tests took place in Malaga Bight, 15-20km south of Malaga itself and at a depth of around 300m where the conditions are very similar to the deep sea.

"We created a test-field of strips around 50 metres, which we installed with artificial nodules and used remotely operated and autonomous underwater vehicles to carry out measurements using cameras and sonar devices," Helmons said. 

The mining vehicle was also equipped with various sensors which measured how much sediment was disturbed during the 'mining' operation, as the nodules were gathered from the sea floor.

The team was able to carry out all the tests planned, in which Apollo 2 "proved extremely efficient at picking up the nodules without causing large dust clouds of sediment", the team said. In fact, some of the 'plumes' seemed to be smaller than usual and contained significantly less sediment than the researcher's expectations. 

The results of the experiment, described by Delft University of Technology, proved quite promising for the development of the technology and could solve one of the largest challenges of the energy transition. 

In April 2022, researchers from KU Leuven University in Belgium found that Europe will require 35 times more lithium and seven to 26 times the amount of increasingly scarce rare earth metals compared to its limited use today in order to meet the EU’s ‘Green Deal’ goal of climate neutrality by 2050. 

These resources are all essential for the production of electric vehicles and batteries, renewable wind, solar and hydrogen energy technologies, and the grid infrastructure needed to achieve climate neutrality.

For this reason, is estimated that Europe could face problems around 2030 from global supply shortages for five metals, especially lithium, cobalt, nickel, rare earths and copper.