GUANGZHOU, Jan. 23 (Xinhua) -- A group of Chinese researchers has revealed the dynamic formation process of gold nanoparticles on pyrite surfaces, according to a research article published on Thursday in the journal PNAS.
Their study shows that a unique "dense liquid layer" at the interface between pyrite and water acts as a "nano-factory," promoting the nucleation, growth and enrichment of gold even in fluids with extremely low gold concentrations, such as 10 parts per billion.
This finding offers a novel perspective for understanding gold ore formation from a diluted gold-bearing solution.
Pyrite-induced gold precipitation is a critical step in forming high-quality gold deposits, yet its interfacial dynamic mechanism had previously remained unclear. Past studies largely relied on post-reaction analyses, making it difficult to capture the instantaneous processes of gold precipitation.
In this latest research endeavor, the collaborative team led by Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, managed to observe the reaction between pyrite and low-concentration gold-bearing solutions in real time.
Results demonstrated that approximately 13 minutes after contact, a "dense liquid layer" formed around the pyrite. About 20 minutes later, gold nanoparticles began to appear within this layer, gradually increasing in number and size over time.
This observation provides key evidence for understanding how gold forms on pyrite-water interfaces.
These findings also challenge the traditional view that "gold primarily originates from deep hydrothermal fluids" and open new avenues for explaining nanoparticle-driven mineralization processes in nature. ■
