Low-waste, single-step, sustainable extraction of critical metals from deep-sea polymetallic nodules.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41270155.
- Also identified by DOI 10.1126/sciadv.aea1223 and PMC identifier 12637279.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
To support the green energy transition, sustainable supplies of critical metals-60 million (metric) tons of copper, 10 million tons of nickel, and 1 million tons of cobalt-annually by 2050 are essential. These metals are currently sourced from declining terrestrial reserves, making deep-sea polymetallic nodules a promising alternative. However, current metal extraction methods are lengthy and energy and carbon intensive, emitting 45, 28, and 4 tons of carbon dioxide equivalent per ton of nickel, cobalt, and copper, respectively. We present a fossil-free hydrogen plasma-based reduction process, powered by green hydrogen and renewable energy, which condenses calcination, smelting, reduction, and refining into a single-step metal extraction, reducing direct carbon dioxide emissions by up to 90% and improving energy efficiency by up to 18%. In addition, we demonstrate selective copper recovery via a heat treatment requiring no acids or reducing agents, offering a more sustainable and cost-effective pathway for critical metal extraction from polymetallic nodules.