Green Critical Minerals positions Torrington mine to advance global mullite fibre strategy

Green Critical Minerals (ASX: GCM) is banking on a flagship topaz-tungsten project in Queensland to deliver on its mine-to-market strategy for single-crystal mullite fibre technology.

The project is owned by subsidiary Torrington Minerals, which acquired the tenements from Resolve Geo in 2015 after Resolve had outlined a shallow combined indicated and inferred resource of 2,247 tonnes of tungsten oxide grading 0.2% and 198,500t of topaz at 17% at the Wild Kate and Mount Everard prospects.

The company is planning to review and assess the potential for topaz sales to underpin its mining activities, opening the door to produce the high-value mullite fibre—high-end non-oxide ceramic fibres that can sell for up to US$11,000 per kilogram.

Exceptional properties

Following the appointment of Professor Andrew Ruys to head of research and development, Green Critical said it is well-equipped to continue research into developing single-crystal mullite fibres from Torrington, providing a valuable mine-to-market opportunity.

Single-crystal mullite fibres are highly sought after for their exceptional properties, including high-temperature stability, low thermal expansion and excellent mechanical strength.

Previous research by Green Critical subsidiary TopFibre, in collaboration with the University of New South Wales, has focused on fabricating mullite fibres for reinforcing metal and ceramic matrix composites, with potential applications across a range of industries.

Green Critical believes the research may lead to a potentially disruptive beneficiation technology that could transform low-value topaz feedstock into high-value single-crystal mullite fibres for use in metal matrix and ceramic matrix composites.

Global market

The global metal matrix composites market was valued at approximately US$810 million in 2023 and is projected to reach over US$2.29 billion by 2032.

The market is driven by increasing demand from the aerospace, automotive, defence and industrial sectors seeking materials that offer performance advantages over traditional options.

“As single-crystal mullite fibres have long been considered the holy grail of fibre reinforcements but are not available commercially, there are literally hundreds, if not thousands, of industrial and research laboratories that are potential customers,” the company said.

Work program

Green Critical is now planning a work program for single-crystal mullite fibre technology.

The program will focus on the optimisation of fibre production, exploration of metal and ceramic matrix composites, environmental impact studies, pilot plant design and market assessment.

It will also investigate the production of commercial quantities of individual single-crystal mullite fibres from topaz, with dimensions suitable for implementation as reinforcements for metal matrix and ceramic matrix composites.