Australia's national science agency CSIRO has set itself a five-year deadline to hand industry a working blueprint for CO2 mineralization, after core flooding tests on several hundred Australian rock samples overturned assumptions about what makes the storage method succeed.

"In five years, if everything checks out, we should be able to hand industry a blueprint—this is how to do carbon mineralization in Australia," Dr. Lionel Esteban, a petrophysicist in CSIRO's Energy Research Program, told Carbon Herald.

The program matters for the carbon removal supply chain because it targets a storage route that converts CO2 into solid carbonate minerals rather than keeping it as a gas or supercritical fluid under pressure — the approach used in conventional carbon capture and storage, which carries leakage risks back to the atmosphere.

What did the rock tests actually show?

Esteban's team floods core samples of Australian ultramafic rocks under conditions simulating shallow reservoirs: roughly 500 m depth, 50 bar pressure, and 60°C. They track the reaction through imaging, geochemical analysis, and petrophysical measurement.

The results rewrote the working assumptions. Cracks and pores, long expected to govern fluid penetration, proved secondary. Mineralogy emerged as the main factor.

The mineral composition of the formation and how far it has already been altered by hydration drive mineralization, with temperature also critical — higher temperatures lower the kinetic barriers to reaction, improve ion mobility, and help reactive minerals dissolve. At the cool shallow depths CSIRO is targeting, the researchers stress that kinetic drag must enter the design calculation.

In short: what the rock is made of matters more than how easily fluid moves through it.

Why is permeability the sticking point?

Australia has abundant mineral-rich volcanic formations, but their geological characteristics differ significantly from those in Iceland, where Carbfix achieved carbon mineralization within two years by injecting CO2-saturated water into highly permeable basalt.

"Over the past three years, we have examined several hundred samples from Australian volcanic formations. None reached a permeability of 0.1 millidarcy, making conventional large-volume CO₂ injection challenging," Esteban said.

"However, our laboratory findings suggest that these older, tighter formations could still be suitable for mineralization. Natural fractures may provide pathways for CO2-rich fluids, while the surrounding rock offers the reactive minerals needed for carbonate formation."

Australian mineralization will therefore likely require engineering, particularly to improve injectivity. The country, on Esteban's reading, may already possess many of the required geological ingredients.

Who is doing what?

The assessment runs on three parallel tracks:

• Bulk experimental characterization — Dr. Lionel Esteban's core flooding program, simulating shallow reservoir conditions and measuring the reaction as it happens.
• Pore-scale imaging — Senior Research Scientist Dr. Mihaela Grigore uses neutron scattering rather than conventional imaging to follow fluid movement and reaction at the level of individual pores and mineral grain boundaries.
• Hydromechanical modelling — Dr. Saeed Salimzadeh studies what mineralization does to the host rock once it begins.

The program is phased. Mapping and laboratory validation come first, followed by site selection and pilot design, in which CO2 will be injected and monitored. If verification passes, the output becomes a model to guide future commercial projects.

What happens next?

The research sits alongside CSIRO's broader roadmap work on novel carbon dioxide removal in Australia, and against a background of ongoing debate over leakage risk in conventional CO2 storage.

The verdict now rests on a single technical hurdle: injectivity in tight Australian formations. If Esteban's engineers can crack it, the five-year clock runs to a blueprint; if not, the permeability problem stays exactly where several hundred samples left it.