Abstract
The Au-SiO2 and Sn-SiO2 complexes have been experimentally calibrated at varying temperature, silica concentration and pH:
Compared with Au-Cl, Au-HS and Sn-OH complexes, AuH3SiO4 and Sn(H3SiO4)4 complexes can be recognized as the dominant transport forms in Si-bearing solutions under pH and Eh conditions of general interest. The decrease of SiO2 concentration and oxygen fugacity would reverse the direction of dissolution-complexing reactions, resulting in the precipitation of gold and silica, as well as cassiterite and silica. This study illustrates the significance of SiO2-complexation in hydrothermal solutions for gold, tin and other metallizations.
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This research project was granted jointly by the National Natural Science Foundation of China (Grant No. 49373181) and the Open Lab. of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences.
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Fan, W., Wang, S., Tian, Y. et al. Complexation of Si in hydrothermal systems. Chin. J. of Geochem. 20, 201 (2001). https://doi.org/10.1007/BF03166140
DOI: https://doi.org/10.1007/BF03166140