The occurrence forms and mechanisms of Zn in cerussite: Based on LA-ICP-MS and first principles

Both the test and simulation results indicate that Zn is easy to grow on the surface of cerussite. Therefore, during the growth of cerussite crystals, zinc in ore-forming fluids primarily exists in an adsorbed form on the crystal growth surfaces. Based on the stability phase diagram of lead compounds, the optimal conditions for the growth and development of cerussite are observed within the pH range of 6 to 10 and redox potentials (Eh) ranging from −0.28 eV to +0.82 eV. As the crystals continue to grow, zinc accumulates predominantly in the growth zoning interstices of cerussite. During the simulation process, we assumed that the zinc species was Zn 2+ , and ignored the factors that may affect the adsorption process, such as solvent effect, temperature, oxygen fugacity change and diversity of zinc species, and mainly considered the adsorption of Zn by surface atoms. It has been shown that the adsorption of zinc on the surface of cerussite is mainly carried out by ion exchange mechanism. • Experimental results demonstrate that Zn exhibits distinct growth zonation patterns along the crystallographic growth surfaces of cerussite. • DFT simulations reveal Zn tends to adsorb on the growth surfaces of cerussite, rather than incorporating through isomorphic substitution or interstitial insertion into the crystal lattice. • Integrated experimental analyses and DFT simulations elucidate zinc incorporation mechanisms during cerussite crystallization, establishing a novel multiscale methodology. This study aims to elucidate the occurrence mechanism of Zn in cerussite (PbCO 3 ) and to provide fundamental insights into zinc’s solid-phase behavior in mineral systems. The occurrence forms of Zn are studied by LA-ICP-MS tests and density functional theory (DFT) calculations, with a simplified model assuming Zn 2+ as the primary species. The results indicate that the occurrence of Zn in cerussite primarily occurs through an ion-exchange mechanism on surface, not dominated by isomorphism or interstitial atoms. It is a good explanation of why Zn is mainly distributed on the growth surface of cerussite in LA-ICP-MS tests. Although the calculations do not consider more complex physicochemical conditions, the proposed model provides a new perspective for elucidating the occurrence mechanism of Zn in cerussite. By combining DFT calculations and LA-ICP-MS experimental data, we have revealed the interaction patterns between Zn and the mineral surface, Zn mainly has strong adsorption interaction with O on the surface. This study bridges the gap between theoretical simulations and geochemical observations, it may clarify the occurrence of Zn in carbonate-rich environments. Future work could focus on improving the adsorption model’s accuracy by incorporating solvent effects, temperature dependence, and more complex species behavior. These advancements are expected to deepen mechanistic insights into zinc mineralization.