Early success sees Chatham Rock Phosphate moving to the next phase of research with CSIRO to evaluate bioleaching as a means of extracting rare earth elements from its North-West Queensland phosphate deposits.

The CSIRO work program was commissioned by Chatham’s Australian company Pacific Rare Earths.

Stage 1 involved culturing microbes potentially suitable for biomining, with encouraging results, Chatham said.

The first step saw the successful enrichment of natural microbes present in three geologic horizons within Korella, Korella North and Korella South sites in North-West Queensland.

Under controlled lab conditions, the native microbes were cultured and demonstrated three orders of magnitude cell growth over a period of four days.

Additional subculturing of the cultures was conducted to further enrich native microbes.

Subject to continued success for the balance of the Stage 1 preparatory phase, Chatham said it would commit to the series of longer duration bioleaching tests.

“These encouraging results continue to reinforce our confidence in continuing our work with CSIRO in Stage 2 of the biomining program,” Chatham Rock Phosphate chief executive officer Chris Castle said.

The company acquired the Korella phosphate and rare earths mining lease and assets, about 150km south-east of Mount Isa, in 2021.

It subsequently added an area known as Korella South and in August expanded its phosphate ground in North-West Queensland with the addition of the Korella North tenement.

Chatham Rock Phosphate is looking to develop a stand-alone 5Mtpa phosphate/fertiliser export facility at the Port of Townsville.