Mining industry funds molten salt technology

A COLLABORATIVE research partnership between academia, government and industry in Southern Australia is funding a molten salt technology project that will reduce energy and water usage, and the cost of mineral processing using molten salts.

The University of South Australia (UniSA) is partnering with the South Australian and Western Australian governments and Centrex Metals to expand current molten salt research for solar energy applications into minerals processing.

The project aims to develop and commercialise technologies which use the liquid properties of molten salt to not only convert metals within silicate ore to an extractable form, but also separate and purify them without the need for aqueous processing. The research will be based around the Oxley Potassium Project which will allow Centrex to make fertilisers based on potassium instead of dwindling reserves of phosphates.

UniSA says its research focuses on overcoming the challenges of transferring and separating solids from highly-reactive molten salts at high temperatures to deliver a proof-of-concept and development of molten salt separation technologies.

Molten salts are currently being used in the solar and nuclear industries at temperatures up to 600°C and are used commercially at higher temperatures for batch-style minerals roasting processes. UniSA expect this project will develop molten salt technologies for reaction, separation and purification processes above 850°C.

Frank Bruno, associate research professor at UniSA, expanded the scope for the technology to other industries it could serve. He said: “The knowledge developed…can be adopted in other applications such as solar power plants, high temperature thermal energy storage, molten salt reactors, glass optical property modification and refining for other minerals.”

Centrex said it will use the technology to be the first commercial and cost-effective manufacturer of bulk potassium chloride fertiliser from potassium feldspar ore.

“[The project] will allow us to look at competing in the bulk fertiliser space for our globally unique large scale potassium feldspar deposit at Oxley, creating more long-term jobs in Australia’s currently struggling mining industry,” said Centrex CEO, Ben Hammond.

Centrex and its government partners have awarded UniSA A$464,000 (US$352,000) for work on the first two stages of the proposed three-stage research programme. Details of additional funding and the final timescale of the project will be decided at stage completions.