Octava, CSIRO “bioleaching” tests point to critical minerals extraction

Octava Minerals has received promising early-stage results from CSIRO tests of a “bioleaching” process of ore samples from its Byro rare earths and lithium project in Western Australia’s Gascoyne region.

The company aims to develop a cost-effective and environmentally sustainable extraction method for critical minerals from Permian black shale at the project using “biomining” or “bioleaching” as a low-cost solution. 

The biomining process, which uses microbes to leach metals from ores, has already been used overseas for large-scale extraction of metals from sulphidic deposits, including nickel, copper and cobalt. 

The national science agency’s stage one testwork focused on identifying, enriching and adapting a range of iron- and sulphur-oxidising microorganisms best suited to the Byro ore. The microbes are commonly used in biomining to extract valuable metals from complex mineral systems. 

Octava says the CSIRO’s mixed bioculture readily adapts to the Byro samples, demonstrating strong cell growth, ferrous iron oxidation and acid generation – which are all key indicators of the leaching medium’s bioleaching potential.

The project has now progressed to stage two, which will test the adapted cultures to see which of them best extract critical and battery metals from the Byro polymetallic ore samples, including rare earth elements, lithium, zinc, vanadium, rubidium, scandium and potassium.

Octava Minerals managing director Bevan Wakelam said: “There is no shortage of critical mineral projects worldwide, but the key driver is extracting the metals at low cost. That’s why we have chosen a staged approach at Byro, with early metallurgy to better understand what we have.”

The 555-square-kilometre Byro project spans two granted exploration licences. Located 220 kilometres southeast of Carnarvon, it stands to benefit from the region’s existing infrastructure, including proximity to the Geraldton port and the North West Gas Pipeline and may gain access to future green energy developments proposed by the WA government.

The region’s geology is also highly prospective. The Byro sub-basin hosts Permian black shales, which are globally recognised for their potential to contain enriched polymetallic deposits. Octava believes these shales have acted as a metal sink, concentrating significant volumes of rare earths, lithium and base metals.

The microorganisms used in biomining, or bioleaching derive energy by oxidising iron and sulphur compounds in ore. Finland’s Terrafame mine, was the world’s first large-scale biomining operation to recover multiple metals from polymetallic black shale. Notably, mining majors BHP, Rio Tinto and Denison Mines are now all involved in biomining.

In the biotechnology sector, California-based firm Blue Evolution has launched the first United States-based platform, Orca Minerals, using cultivated seaweed to regeneratively bio-mine rare earths and critical minerals from seawater. Start-up company AlkaLi Labs is using microbes to pull critical minerals from industrial waste streams to provide new, low-impact, sustainable sources to meet the world’s growing demands for electrification and green hardware. Its first project will target lithium produced in wastewater from US oil and gas infrastructure.

Octava’s broad exploration strategy is focused mostly on new energy metals. The company’s portfolio includes antimony, lithium, rare earths and gold projects, which are strategically located in prospective parts of WA. 

The company aims to de-risk Byro early, then build a robust technical foundation before advancing to large-scale development. It already has a native title agreement in place for the project.

If the bioleaching process proves successful, the platform could provide Octava with a competitive edge in an intensifying global race for critical minerals. The company’s early investment in innovative extraction technologies could position it as a leader in the next generation of low-cost, sustainable mining operators.

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au