Hyperenrichment of gold in pyrite induced by solid-state transportation

Abstract The hyperenrichment of gold is critical for the formation high-grade deposits in orogenic systems, where enrichment can reach several percent. However, many details on nature mechanism remain unclear. Here we show a “self-purification” model that could explain from nanoparticles to veinlets deformed pyrite. three-dimensional spatial relationship and coexistence indicate direct transformation former latter solid-state. Theoretical evaluation reveals this involves thermodynamically favorable self-purification process. We thus propose deformation/thermo drives transport towards pyrite through atomic diffusion. This deformation/thermo-driven applicable any nano-gold-bearing explains how solid-state effectively concentrate very high grade. Similar mechanisms may have broad implications both ore-forming beneficiation processes.