The importance of Halloysite
The mineral takes the form of small hollow tubes, known as nanotubes. This shape gives it unique properties and a wide variety of industrial uses beyond the more common kaolinite, particularly in the emerging fields of batteries and nano-technology. This potential application of the natural halloysite nano-clay has been demonstrated by an all-solid-state lithium-sulfur battery over a wide temperature range of 25–100 °C. These results reveal the possibility of realizing sustainable high energy storage at a reduced cost.
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.
Halloysite's market value
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 can be sold for a price between A$500 and A$1,000/tonne, and pure kaolin can sell for A$300/tonne.
Halloysite is an aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. The key constituents are Oxygen (55.78%), Silicon (21.76%), Aluminium (20.90%), and Hydrogen (1.56%). Halloysite is usually formed by hydrothermal adjustment of alumino-silicate minerals.