Peptides are short chains of amino acids, the same building blocks that make up proteins. While proteins can be hundreds or thousands of amino acids long, peptides are usually between 2 and 50 amino acids in length. They have medical and therapeutic uses and can be used to fight bacteria, viruses, and fungi by disrupting their membranes, and certain peptides are being explored as targeted drug carriers or inhibitors of cancer growth.
But could peptides have the potential for a new paradigm in mineral processing? Traditional mineral processing relies heavily on physical separation methods and harsh chemicals which are effective but environmentally challenging. Peptides, because of their specificity, tunability, and mild operating conditions, could provide a biomolecular alternative or complement to these methods.
We first heard mention of peptides in mineral processing seven years ago at Biohydromet '18 in Namibia. Robert Braun, of Helmholtz Institute Freiberg for Resource Technology, Germany, highlighted the potential of artificial peptides that are able to bind metal ions and combine unique sensitivity and high specificity. He described the development of peptide-based biosorptive materials for heavy metal removal, including identification, adaptation and characterisation of specific peptides binding nickel and cobalt. The study provided a system that can be adapted to other materials and knowledge about the nature of metal-peptide interaction, which he predicted might lead to the discovery of novel metal-interacting biomolecules, e.g. enzymes and peptides.
At Sustainable Minerals '18 which followed, Robert's colleague, Sabine Matys, looked at the development of metal ion binding peptides using phage surface display technology, a powerful laboratory method used to study protein-protein, protein-peptide, and protein-DNA interactions.
At Flotation '21, Wonder Chimonyo, of The University of Queensland, examined the potential of new peptides as biocompatible alternatives to amine collectors in iron ore flotation and at Flotation '23 Mayeli Alvarez Silva, a researcher at Corem, Canada, presented the development of novel bio-collectors for sulphides, specifically chalcopyrite. Testwork on chalcopyrite and quartz proved the effectiveness of the peptide-base collectors comparable to xanthate. Mayeli concluded that the work opened interesting alternatives in the selection and development of peptide-type collectors (or depressants and other reagents) having great affinities towards different minerals.
Also at Flotation '23, Lam Ian Ku, of Australia's JKMRC presented a paper, co-authored by Chun-Xia Zhao, of the University of Adelaide, on the separation of arsenic minerals in flotation using a novel peptide collector, concluding that the findings will contribute to the ongoing effort of the mining industry to process complex ores efficiently, while minimising the environmental impact.
There are challenges, however, in the use of peptides. Synthesising peptides cheaply enough for bulk mineral processing is a barrier, though biotech advances are rapidly reducing peptide production costs. Many peptides degrade in harsh pH, temperature, or chemical conditions, so would need stabilisation strategies and replacing entrenched flotation reagents requires not just performance gains but also regulatory acceptance and operational compatibility.
However, peptide-based technologies could reduce reliance on toxic chemicals, enable selective, low-energy, water-based processing and allow recovery of critical minerals from low-grade ores and mine waste, opening new possibilities in the circular economy of metals.
A central core to this work is the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals (CoEMinerals), where researchers at the University of Adelaide are developing designer peptides and proteins tailored for specific mineral binding and flotation applications, mimicking cancer-targeting drug logic to "fit" specific mineral surfaces like a jigsaw puzzle
Led by Professor Chun-Xia Zhao and Dr. Guangze Yang, the team uses phage display technology to discover peptide sequences that bind selectively to target minerals. They characterise how these peptides perform under varying conditions such as pH, temperature, salinity, and sequence modifications.
 |
| Prof. Chun-Xia Zhao |
This research demonstrates how biologically inspired molecular tools can offer highly selective, sustainable, and scalable alternatives to traditional mineral processing methods. The peptide-based platform holds potential for revolutionising how we extract critical minerals, especially from complex ores and tailings, while significantly reducing the environmental and economic costs.
Prof. Zhao's team has applied learnings from multiple scientific disciplines to mimic how a cancer-targeting drug finds cancer cells but in this case finding a one-in-a-billion peptide molecule targeting a given mineral or metal. This advancement has the potential to unlock the equivalent of a ‘DNA code’ for every mineral and metal on Earth and revolutionise mineral processing. It also heralds environmental benefits.
We are extremely pleased that Prof. Zhao will be presenting a keynote lecture on developments in this field at Critical Minerals '26 in Cape Town.
Prof. Zhao is a Leadership Fellow in the School of Chemical Engineering at the University of Adelaide, and the Deputy Director of the Australian Research Council (ARC) Centre of Excellence at the university. She has built extensive collaborations with scientists at top universities such as Harvard University, Brown University, etc. She serves as Editor and Editorial Board member for several journals.
Prof. Zhao will show how bioinspired molecules can selectively separate valuable metals and minerals, including precious metals and rare earth elements. This approach offers broad applicability, from primary mineral separation to urban mining applications such as recycling photovoltaic panels, magnets, and batteries. delivering significant environmental, economic, and operational benefits. She will demonstrate the transformative potential of biomolecule-based separation strategies to redefine the future of mineral processing and resource recovery.
#CriticalMinerals26
