ABx models up proprietary aluminium fluoride process

ABx Group’s chemical refining subsidiary, Alcore Limited has modelled up a processing flowsheet designed to produce aluminium fluoride using cheap smelter waste as the feedstock. Alcore’s engineers have proposed a commercial 10,000 tonne per year aluminium fluoride plant using the new technology’s proprietary process which the company believes will deliver benefits for Australasian smelters currently reliant on imports of material, mainly from China. Importantly, the process is proprietary to Alcore and therefore also to the ASX-listed ABx.

Using the results of thermodynamic modelling combined with laboratory test work the company has identified another, potentially even more effective process for aluminium fluoride production and this will be further investigated at Alcore NSW’s research centre in the coming months.

An international process engineering company was recently engaged by ABx’s 87 per cent owned subsidiary Alcore to do the modelling. The outputs included mass and energy balances, process flow diagrams and a mechanical equipment list.

Results from the modelling have provided Alcore with increased confidence in the development of the process. The modelling results will assist it to increase the yield of aluminium fluoride from the metal refining waste, also known as “dross”.

Dross is a waste by-product that forms on top of molten aluminium in casting furnaces and consists of aluminium oxide, aluminium metal and aluminium nitride, with trace cryolite and other impurities. Most aluminium metal can be physically recovered, however the non-metallic component is sold at a loss and at times cannot be sold. Many smelters have significant stockpiles of dross which represents an ongoing storage cost to satisfy environmental and community standards.

Alcore has been evaluating using dross due to its low acquisition cost and its potential to increase recycling of aluminium waste in smelters. The company has previously reported the development of a process to produce aluminium fluoride from 100 per cent dross and this is now proprietary to Alcore and will deliver significant economic and environmental benefits according to the company.

Despite the constraints of COVID-19 lockdowns and supply chain issues, development of all aspects of the Alcore process has continued uninterrupted and Alcore says it has managed to improve the precipitation process in the laboratory and can now produce aluminium fluoride of comparable particle size to existing commercial aluminium fluoride.

Alcore Limited CEO, Dr Mark Cooksey said: “Process modelling confirms the Alcore process for producing aluminium fluoride from dross is feasible and attractive because it is substantially lower cost, delivers higher operating margins and recycles waste from the smelting process. Alcore will continue to engage with third party experts to accelerate development and commercialisation of the process.”

To assist with the accelerated development, Alcore recently increased its team by appointing a new Senior Engineer from the University of Sydney who has worked on technology development projects on the NSW Central Coast for several years before joining Alcore.

Aluminium fluoride is a strategically important mineral that is an essential ingredient for aluminium smelting and is intriguingly also being investigated for use in advanced lithium-ion batteries.

The company says all commercial aluminium fluoride production currently comes from aluminium hydroxide. ABx itself has previously used a two-stage approach combining dross and aluminium hydroxide. Alcore reports the new single-stage process has delivered numerous samples of aluminium fluoride with chemical compositions in line with industry specifications that contains low-level silicon, sodium and calcium impurities.

However, Australian aluminium smelters currently rely entirely on imported aluminium fluoride, typically more than 70 per cent of which comes from China. Australian imports from China in 2020 alone totalled 21,000 tonnes at an average purchase price of US$1,180 per tonne, according to Alcore.

The company is confident the commercialisation of this proprietary technology and the subsequent development of what will be Australia’s first production plant, would provide much-needed security of supply for Australasian aluminium smelters.

The latest developments could bode well for the Sydney-based ABx as it looks to advance aluminium fluoride production towards commercialisation. The company believes its process will be a key contributor to improving the environmental performance of aluminium smelters globally.

ABx is also riding on the success of its heavy rare earth discovery at its Tasmanian bauxite project and it appears the stars are aligning well for this innovative company.

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