Chase Mining Corporation’s (ASX:CML) subsidiary Topfibre Pty Ltd has completed a collaborative topaz research project with the University of New South Wales (UNSW), with the company deciding to seek a financial or commercial partner to progress its proof-of-concept outcomes with the best commercial application potential.
The research was co-funded through an Australian Research Council (ARC) Linkage Grant, with the aim to develop the means of fabricating single-crystal mullite fibres from topaz sourced from the large Torrington deposit in NSW that are suitable for reinforcement of metal and ceramic matrix composites.
As single-crystal mullite is the most sought-after fibrous additive but is not available commercially, CML expects to attract an immediate clientele in laboratories and companies servicing the aviation industry and the military.
Notably, a secondary commodity, which will utilise all of the fluorine by-product, is sodium silicofluoride, which is used widely in water fluoridation.
Torrington topaz proof-of-concept
Project work concentrated on the development of single-crystal mullite fibres because this was complex and difficult while the recovery of sodium silicofluoride was relatively straightforward.
The work on fibre reinforcement was focused on metal matrix composites (MMCs) as these represent a much larger market and the processing technology is less complex than for ceramic matrix composites (CMCs).
However, it was recognised that there were some strong technical and commercial advantages to the fabrication of MMCs by metal infiltration of porous compacts and the work was supplemented to investigate the feasibility of the fabrication of porous mullite preforms and infiltration by promising metal alloys.
This resulted in the demonstration of proof-of-concept that Torrington topaz derived mullite-fibre reinforced composites can be processed into MMCs using different alloys suitable for different products applicable across the automotive, mining, chemical and military industries.
Commercial applications
A range of commercial trajectories became apparent over the course of the research project, including:
- Fibres for Laboratory Development: As single-crystal mullite fibres long have been considered the holy grail of fibre reinforcements but they are not available commercially, there are hundreds of industrial and research laboratories that are potential customers - however, this product would require coarsening of the fibres so that they are not respirable;
- Impact and Wear Pads: The transfer of minerals by the mining industry during processing results in high deterioration rates of conveyancing systems. Small MMC tiles with aluminium infiltration, even with some residual porosity, are likely to have considerable commercial potential;
- Brake Pads: The replacement of existing braking systems by copper-infiltrated mullite has considerable market potential. The metal must be pure copper owing to its high thermal conductivity.
- Military Armour: The military industry is an important potential customer as cost is less important than performance. Small MMC tiles with aluminium infiltration are ideal for body, vehicular and possibly aircraft armour as they are lightweight and have the potential to compete technically and economically with existing armour;
- Catalytic Convertors: Although palladium products are established in the automotive industry, this application is attractive because no precious metal is required, reducing the price significantly - and the engineering is relatively straightforward as it requires only a sufficient gas flow rate. There are many other chemical processes that require catalytic converters.
- Filters: The chemical industries have little choice with high-temperature high-throughput filters and as this product involves only a preform, the engineering would appear to be straightforward. However, early experimentation has shown that it is not easy to engineer a controlled pore size distribution.
Going forward
Although the initial goal included Pilot Plant Design and commercial studies, no work in this area was formalised partly due to COVID-19 restrictions, but also due to lack of suitable equipment availability at the UNSW.
Conceptually, however, the design, even for full commercial production, is straightforward owing to the present program’s exposure of the key technical issues that must be overcome.
Going forward, the company and its advisors have decided to seek either a financial or commercial partner to progress the proof of concept outcomes with the best commercial application potential.