Oral Presentation Crystal36-AXAA Conference 2026

Developing carbon-negative nickel and cobalt production from ultramafic tailings using synchrotron X-ray techniques (144455)

Jessica L Hamilton 1 , Zhen Wang 2 3 , Maximillian Mann 2 , Jing Hu 2 , Jahangir Ahmad 2 , Andrew Frierdich 2 , Connor C Turvey 2 4 , Arif Hussain 4 , Annah Moyo 4 , Sasha Wilson 4 , Dan Su 5 , Phil Renforth 5
  1. Australian Synchrotron, ANSTO, Clayton, VIC, Australia
  2. School of Earth Atmosphere & Environment, Monash University, Clayton, VIC, Australia
  3. School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia
  4. Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
  5. School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, United Kingdom

Nickel and cobalt are critical metals used for energy generation and storage technologies. However, their extraction from laterite ores typically require high pressures and temperatures which incur high energy inputs and carbon emissions. Here, we target ultramafic tailings (such as from diamond, nickel, chrysotile mines) with a dual-purpose ore processing scheme to reverse emissions and produce carbon negative nickel and cobalt.1,2

Acid leaching of ultramafic rocks strips labile elements (e.g. Mg, Ca) which can be reacted with CO2 to permanently trap carbon in a mineral form. At the same time, trace nickel and cobalt are mobilised by the acid treatment and can be precipitated with iron as artificial laterites. Nickel and cobalt can then be extracted from the artificial laterites at ambient pressure, temperature, and circumneutral pH, via the addition of aqueous Fe(II).3

X-ray Absorption Spectroscopy (XAS) is used to determine the proportion of nickel and cobalt associated with different mineral hosts throughout this process, providing essential information for optimising metal recovery. While nickel measurements are routine, cobalt speciation in these iron-rich materials has historically been challenging because the X-ray fluorescence energies of cobalt and iron overlap, and iron is present at concentrations orders of magnitude higher, making the cobalt signal difficult to resolve. Using a crystal spectrometer at the Australian Synchrotron XAS beamline, we can now collect high-energy-resolution fluorescence-detected (HERFD) measurements that effectively eliminate interference from iron fluorescence. This enables cobalt speciation (and EXAFS analysis) in iron-rich materials for the first time.4

Here, we present synchrotron XAS and X-ray Fluorescence Mapping (XFM) measurements of nickel and cobalt during the formation of artificial laterites and demonstrate how these measurements are being used to optimise metal extraction in our process.3,4 The results highlight the role of synchrotron techniques as an enabling tool for the development and scale-up of carbon-negative nickel and cobalt production, supporting the progression of this technology from laboratory studies to field-scale trials.

  1. 1. Hamilton, J. L., Wilson, S., Morgan, B., Harrison, A. L., Turvey, C. C., Paterson, D. J., Dipple, G.M. & Southam, G. (2020). Accelerating mineral carbonation in ultramafic mine tailings via direct CO2 reaction and heap leaching with potential for base metal enrichment and recovery. Economic Geology, 115(2), 303-323.
  2. 2. Su, D., McBride, A.L., Pereira, R.J.L., Yaddala, J., Turvey, C.C., Hussain, A., Moyo, A., Hamilton, J.L., Wang, Z., Mann, M., Hu, J., Lammers, L., Wilson, S., Frierdich, A.J., Van der Spek, M. and Renforth, P. (2025) Net negative carbon dioxide nickel mining examined through prospective technoeconomic assessment. Research Square [Preprint]. Available at: https://doi.org/10.21203/rs.3.rs-8049102/v1
  3. 3. Wang, Z., Mann, M., Hamilton, J.L., Turvey, C.C., Hussain, A., Wilson, S., Su, D., McBride, A.L., Renforth, P., Lammers, L.N. and Moyo, A. (2025). Artificial Laterite from Acid Leaching of Ultramafic Rocks: Mobilization, Enrichment, and Extraction of Critical Metals. Environmental Science & Technology, 59(38), 20829-20841.
  4. 4. Wang, Z., Mann, M., Hamilton, J. L., Wykes, J. L., & Frierdich, A. J. (2024). Comparison between Co (II) and Ni (II) cycling at goethite-water interfaces: Interplay with Fe (II)-catalyzed recrystallization. Geochimica et Cosmochimica Acta, 384, 128-139.