A team from the Max Planck Institute developed an innovative method for sustainable extraction of critical metals from the seabed.
The technology uses hydrogen plasma and reduces CO2 emissions by more than 90% compared to traditional mining.
The procedure recovers copper, nickel, and cobalt from polymetallic nodules.
These materials are essential for batteries and electrical systems in the energy transition.
How the new sustainable metal extraction process works
Under the direction of Dierk Raabe and Ubaid Manzoor, the method reduces polymetallic nodules in an electric arc furnace with hydrogen plasma.
The nodules mainly come from the Clarion-Clipperton zone in the Pacific.
“We reduce the dry minerals with a hydrogen plasma directly in an electric arc furnace powered by renewable energy,” explained Manzoor.
The sustainable metal extraction process first separates copper as a pure metal.
Then it obtains a nickel alloy and cobalt, along with manganese oxides useful for manufacturing batteries.
The proportion of metals in the alloy can be adjusted according to the duration of the process. This facilitates its further processing and industrial application.
The environmental benefits of sustainable metal extraction
The research, presented in the journal Science Advances, highlights multiple environmental advantages of sustainable metal extraction:
- Over 90% reduction in CO2 emissions using green hydrogen and renewable electricity
- Requires about 20% less energy than conventional processes
- Fewer treatment stages compared to traditional mining
- Generates significantly less waste: 9 billion tons compared to 63 billion
According to the Max Planck Institute, producing materials for a billion batteries using marine nodules generates seven times less waste than terrestrial mining.
The method also eliminates child labor and deforestation associated with cobalt and nickel mining on land.
The strong comparison with traditional mining
Terrestrial mining of copper, nickel, and cobalt involves the removal of extensive forests.
This generates annually between 4 billion and 5 billion tons of rock waste and slag.
Terrestrial deposits have a low concentration of metals, which requires extracting more material.
In contrast, polymetallic nodules for the seabed contain higher proportions of these metals.
Future demand justifies the search for alternatives. By 2050, 60 million tons of copper, 10 million tons of nickel, and 1.4 million tons of cobalt will be needed.
This means that the demand for copper and nickel will double. The demand for cobalt could increase fivefold compared to current levels.
The pending challenges of the project
The Max Planck Institute acknowledges that underwater mining entails ethical and environmental challenges to be resolved.
Dierk Raabe warns that “the extraction of these nodules from the seabed also leaves an environmental footprint“.
Raabe, who previously rejected the exploitation of these resources, changed his position given the possibility of minimizing damage.
Ubaid Manzoor noted that the team’s goal is “to provide a sustainable method to extract critical metals from seabed nodules and the data to make informed decisions”.
Currently, the future of mining polymetallic nodules remains a subject of international debate.
However, moving towards a less carbon-dependent economy will require solutions that balance resource demand with environmental protection.
