PNNL

The Science

Nickel (Ni) and cobalt (Co) are critical elements for modern technologies, with high-grade Ni and Co ores becoming increasingly scarce. Mafic and ultramafic deposits are low-grade, abundant alternatives to traditional Ni and Co ores. However, new methods that make Ni and Co extraction and recovery from these deposits economically viable are needed. Researchers used ab initio molecular dynamics simulations to identify how Ni and Co incorporate in forsterite (Mg₂SiO₄), common in mafic and ultramafic rocks. The results show that, of the two cation sites of forsterite (M1 and M2), Ni and Co incorporation in the M1 site is preferred. This preference is diminished in natural samples with low Ni/Co concentrations relative to literature data on more highly concentrated samples.

The Impact

Carbonation of silicate minerals like forsterite could improve the economic viability of Ni and Co extraction and recovery from low-grade ores by lowering ore-processing costs and helping the mining industry reach net-zero CO₂ emissions. This work identifies how forsterite incorporates Ni and Co with atom-level detail, beneficial information for scientists developing new extraction and recovery methods. These results will help researchers understand how silicate minerals like forsterite react with CO₂ during carbonation and guide efforts to improve Ni and Co extraction and recovery.

Summary

The deepening scarcity of high-grade recoverable ores of critical elements such as Ni and Co makes using low-grade—yet more abundant ores—increasingly attractive. Low-grade ores of Ni and Co are found in mafic or ultramafic deposits. These deposits are abundant in silicates that are reactive toward carbonation and thus of interest for durable carbon storage. A better understanding of the fate of Ni and Co during silicate carbonation is needed to design economically viable Ni and Co extraction and recovery methods. Researchers used ab initio molecular dynamics simulations to determine how Ni and Co incorporate in forsterite, a silicate mineral commonly found in mafic and ultramafic rocks. They demonstrate that the atomic-level distribution of Ni and Co incorporated in forsterite depends on their concentration. Ordering in incorporation sites weakens when Ni and Co are depleted. This work will help interpret the outcomes of silicate carbonation reactions and guide efforts to improve Ni and Co extraction and recovery methods.

PNNL Contact

Sebastien Kerisit, Pacific Northwest National Laboratory, Sebastien.Kerisit@pnnl.gov

Funding

This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences program, Chemical and Materials Sciences to Advance Clean Energy Technologies and Low-Carbon Manufacturing (FWP 80281). Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for the DOE by Battelle Memorial Institute under Contract DE-AC05-76RL01830. The simulations were performed using PNNL Research Computing and the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Biological and Environmental Research program and located at PNNL in Richland, WA.