Sulfoarsenide Complexes of Gold in Hydrothermal Solutions in the Formation of Gold Ore Deposits (Thermodynamic Modeling)

摘要

The composition and conditions of the formation of gold sulfoarsenide complexes were studied by means of the solution of inverse problems of physicochemical modeling on the basis of the SELEKTOR software, with the computer analysis of the experimental data on Au dissolution in the presence of orpiment at 200-300℃and 1 kbar pressure. It was shown that sulfoarsenide complexes of gold formed in sulfurous-ars-enious metalliferous hydrothermal solutions quantitatively prevailed in acidic and near-neutral solutions in the presence of As. The stability of the H_2AuAsS_3~0 sulfoarsenide complex and of its AuAsS_2~0 deprotonated analogue depends on the concentration of arsenic in the system, just as the ratio of sulfoarsenide and hydrosulfide complexes of gold. The productive metalliferous generations of sulfides in pyrite-arsenopyrite parageneses are deposited involving gold sulfoarsenides.