Nanometallogeny: The role of the nano-effect in the enrichment, migration and mineralization of rare element, rare earth element and precious metal deposits

Jet Yin, Luc English, Hongyun Shi

geosciences to better understand what is perhaps the most economically important field in geology: the enrichment, migration and deposition of mineral deposits. Ore-bearing fluids and ore particles behave differently at the nano-scale compared to the more familiar macro-scale. Nanometallogenic processes have been used to explain the mechanism in which rare elements with extremely low abundance in the earth's crust, such as Te, Ga, In, Re and Rh, are enriched into mineral deposits. The nano effect influences the formation of mineral deposits in a number of ways. The physical properties of rocks and minerals alter at nano-scale. The physical-chemical properties of ore-bearing fluids changes within nanopores and micro-fractures with open spaces less than 100 nanometers. The dielectric constant and hence the solubility of ore-bearing ionic compounds in water is reduced in nanopores compared to macroscopic conditions so that ore metals precipitate and aggregate to form nano-ore deposits. The nano-effect can also be seen in the formation of supergene mineral enrichment. The weathering and oxidation of rocks to saprolite and soil involves the alteration of many primary rock forming minerals to nano-porous clay, providing an ideal environment for the enhanced migration and precipitation of ore metals. By drawing on the latest research on nanomaterials and other related technologies across disciplines the nascent field of Nanometallogeny is allowing us to re-examine the role of fluids in the formation of mineral deposits and challenge some of the fundamental concepts of mineral geology.