You may have heard of kaolin — an industrial clay often referred to as ‘China Clay’ after its discovery more than 1,000 years ago.
Kaolin has a broad spectrum of applications and is most notably used as an additive in a wide range of everyday products, including paper, ceramics, paints and rubber.
New uses for kaolin continue to come to light, ensuring the material will garner strong global demand for years to come.
But it’s halloysite, a mineral that’s part of the same subgroup of clay minerals as kaolinite, that has researchers (and investors) interested.
Halloysite is coming to the fore in specialised green technologies and other cutting-edge applications, exposing the material to lucrative and exciting new markets including batteries, supercapacitors, and cancer therapeutics.
It is now also highly sought after in the medical field for biomedical applications with uses for drug delivery, gene delivery, tissue engineering, cancer and stem cells isolation, and bioimaging.
What’s the deal with halloysite?
Halloysite’s tubular microstructure – naturally occurring hollow nanotubes that are imperceptible to the human eye — make halloysite a unique mineral with highly desirable properties.
Features such as a high surface area to unit weight ratio, high porosity and differential charge capabilities between inner and outer surfaces have led researchers to discover its suitability in high-tech processes and end-uses such as carbon capture and conversion, hydrogen storage, water remediation and nanotechnology.
Pure kaolinite, hybrid kaolinite-halloysite and pure halloysite. Source: Minotaur Exploration.
What should get potential investors excited is that halloysite and hybrid halloysite-kaolin is far more valuable than regular kaolin, as well as the scarcity of large, commercial deposits of halloysite nanotubes.
Pure halloysite sells for up to US$5,000/tonne, compared to a kaolin/halloysite hybrid, which fetches between A$500 and A$1,000/tonne, and pure kaolin going for A$300/tonne.
The Andromeda effect
One company looking to fill the gap in the market is Andromeda Metals Ltd (ASX:ADN), an Australian exploration company that, in a joint venture partnership with Minotaur Exploration Ltd (ASX:MEP), owns the Great White Project.
Great White is described as a world-class deposit with a JORC estimated resource of 34.6 million tonnes, hosting rich quantities of both halloysite and kaolinite on the Eyre Peninsula in South Australia.
The resource at Great White includes 17.4 million tonnes of minus 45-micron quality kaolin product and contains two sub-domains: a halloysite zone of 15.9 million tonnes and an ultra-bright high-purity kaolin zone of 1.2 million tonnes.
In an interview with Proactive, Andromeda Metals managing director James Marsh said that while it has been difficult educating the Australian market about the product, there’s been a recent surge in interest following work on new avenues to market.
Halloysite-kaolin refined noodles. Source: Andromeda Metals
Back in March, Andromeda and Minotaur signed a binding offtake agreement with Japanese porcelain manufacturer Plantan Yamada, which has factories in Japan and China.
The agreement covers 5,000 tonnes per annum of Great White CRM high-quality halloysite-kaolin, priced at A$700/tonne.
Nevertheless, in the fast-moving nanotechnology market, prices are exponentially higher.
Nano-technology and green-technology applications
According to Grand View Research, the nanotechnology space was worth US$8.5 billion in 2019 and is expected to grow at a compound annual growth rate (CAGR) of 13.1% from 2020 to 2027.
Natural Nanotech (NNT), a research vehicle jointly formed by Andromeda Metals and Minotaur Exploration, has spent the last few years looking into new and emerging applications for halloysite-kaolin nanotubes (HNT) with the University of Newcastle’s Global Innovation Centre for Advanced Nanomaterials (GICAN).
Marsh said: “For pure halloysite itself, it will sell for about $5,000 per tonne and we are now working on research with Natural Nanotech, our joint venture company with Minotaur on new technologies for halloysite composites and there we are talking about several million dollars per tonne.”
NNT’s testing on halloysite-derived carbon nanomaterials has shown excellent absorption potential and recyclability for carbon capture and conversion purposes, with more than 1.1 tonnes of CO2 capture per tonne absorbent.
Minotaur non-executive director Tony Belperio said the scientists at GICAN were blown away when they came across the halloysite material from Great White.
“They are used to dealing with carbon nanomaterials, which are very expensive to produce.
“But if nanomaterials could be provided much more cheaply, then the market will explode.”
Belperio said the Great White Kaolin Project contained the greatest known global accumulation of halloysite nanotubes in variable admixtures of around 10% and 80% with kaolinite.
He said NNT was now asking: “Can halloysite serve as a natural alternative for highly expensive and hazardous carbon nanotubes?”
Research activity is underway with GICAN under two specific agreements:
- Halloysite-derived nanomaterial for environmental applications, such as water remediation and hydrogen storage; and
- Halloysite based materials for carbon capture and conversion, which is aiming to optimise the processing route and development of carbon capture and conversion pilot plants.
The idea is to capture the carbon and strip it back off the nanotubes — “a bit like a swimming pool filter,” Belperio said.
“You would be passing all the gasses through, capturing the C02, backflushing it whenever it fills up and then refreshing the nanotubes numerous times until one day you might have to replace them.”
Once the CO2 has been captured, the next step would be to convert it into a clean energy source such as methane or methanol.
Belperio added: “Demand for this would be global and would come mostly from industrial users such as cement plants, refineries, brick plants and plasterboard factories – these are the sort of companies looking for a method of capturing CO2 that is reasonably cheap and efficient.”
A pilot carbon capture plant has been designed by Natural Nanotech and delivery is expected by November – December 2021.
With the likes of Elon Musk encouraging the world to create the best carbon capture technology with a $100 million reward, the timing could not have been better.
Am donating $100M towards a prize for best carbon capture technology— Elon Musk (@elonmusk) January 21, 2021
Which ASX-listers have halloysite-kaolin and where is it found?
The Great White Kaolin Project on the Eyre Peninsula, South Australia. Source: Andromeda Metals
Only a handful of ASX-listers have discovered commercially viable halloysite-kaolin resources, further proving why it is so rare.
Latin Resources Ltd (ASX:LRS) is undertaking a pre-feasibility study on its Cloud Nine resource at the Noombenberry Kaolin Halloysite Project in Western Australia after announcing a mineral resource estimate in May.
The Noombenberry project comprises 207 million tonnes of kaolinised granite, which includes separate domains of 123 million tonnes of bright-white kaolinite and 84 million tonnes of kaolin/halloysite bearing material.
Okapi Resources Ltd (ASX:OKR, FRA:260) acquired two large-scale kaolin-halloysite projects back in May – the Holly Kaolin Project in Western Australia, where exploration is underway, and the White Knight Kaolin-Halloysite Project in South Australia.