Reducing mining industry costs with molten salt technology

The University of South Australia (UniSA) has formed a collaborative research funding partnership with Centrex Metals in a bid to develop molten salt technology to significantly reduce energy and water usage, and therefore the cost of mineral processing using molten salts.

The research will expand current molten salt research for solar energy applications into minerals processing with a view to maximising successful technology development and commercialisation.

The research programme, led by UniSA associate research Professor Frank Bruno, will develop a minerals processing circuit to leach, extract and purify metals from silicate minerals in a solely molten salt environment, without the need for subsequent aqueous processing.

Centrex Metals will use the technology at its Oxley Potash Project to become the first commercial and cost competitive manufacturer of bulk potassium chloride fertiliser from potassium feldspar ore. The project is a rare 32km long shallow dipping and outcropping potash feldspar rich lava flow about 125km southeast of the port of Geraldton, Western Australia.

Molten salt technology has previously been used in the solar and nuclear energy industries at temperatures up to 600°C, including the 110MW Crescent Dunes Solar Energy Project in Nevada. The UniSA project will be the first to use salts at temperatures from 850°C and above.

Prof Bruno said the research could have broader implications for mineral refinement in the mining industry and provide valuable insights for its further development in the solar and nuclear industries.

“Salts at the higher temperatures are generally more corrosive and also because you’re at higher temperatures that in itself creates greater reactions,” said Prof Bruno. “Now that people know that we are working with a higher temperature molten salt they are coming to us with all sorts of applications they are wanting us to look at.”

Between Centrex, the Minerals Research Institute of Western Australia and the Mining Industry Participation Office of South Australia, $464,000 of external funding will support UniSA’s work on the first two stages of the proposed three stage research programme.