Effects of copper ions on dissolution mechanism of marmatite

The dissolution mechanism of marmatite in the presence of Cu2+ was intensively studied by experiments and density functional theory (DFT) calculations. Leaching experiments showed that Cu2+ accelerated marmatite dissolution at high temperatures (above 55 degrees C), but the trend was reversed at low temperatures (below 45 degrees C), which may be because the reaction mechanism between Cu2+ and marmatite changed from surface adsorption to bulk substitution with increasing temperature. The substitution reaction caused more zinc atoms in the marmatite crystal lattice to be released and enhanced the electrochemical reactivity, while the adsorption of copper ions at low temperatures would passivate marmatite, thus inhibiting the reaction process. DFT calculations showed that the energy of the substitution reaction was more negative than that of the adsorption reaction at high temperatures, which further verified the proposed mechanism.

Automated summary

The dissolution mechanism of marmatite in the presence of Cu2+ was studied using experiments and density functional theory (DFT) calculations. The experiments showed that Cu2+ accelerated marmatite dissolution at high temperatures and reversed the trend at low temperatures. DFT calculations further verified the proposed mechanism by showing that the energy of the substitution reaction was more negative than that of the adsorption reaction at high temperatures.