///Based on the calculations, the importance of the above organic complexes in the transport of thallium in low temperature hydrothermal solutions up to 100℃ was evaluated. According to EQ3/6 calculations, at 75℃, under reducing conditions (ΣH2S stable) and in the geologically reasonable pH range, free Tl+ accounts for about 55% of total thallium, TlHS0 for about 10%, and the above thallium complexes with organic ligands for the balance with TlCit2-as a dominant species. At the same temperature and under oxidizing conditions (ΣSO4 stable), free Tl+ accounts for about 55% of total thallium, and the above thallium organic complexes for the rest. At 100℃, under reducing conditions and again in the geologically reasonable pH range, free Tl+ accounts for about 20% of total thallium, TlHS0 for about 20%, and the thallium organic complexes for the rest. At 100℃ and under oxidizing conditions, free Tl+ accounts for about 30% of total thallium, and the thallium organic complexes for the rest. It is thus concluded that thallium organic complexes, especially with TlCit2-as a dominant player, could play an important role in the solubilization and transport of thallium in low temperature hydrothermal solutions.
