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在含金碳酸盐矿床的表生交代作用中,形成的风化流体倾向于碱性,因此,不适于金呈氯的络合物迁移的媒介,而在这种矿床中次生金的再活化常可归因于金与含硫配体的络合作用。通过可靠的热动力学计算,金、银分别在Au—S—O_2—H_2O和Ag—S—O_2—H_2O体系中的溶解度与金和硫代硫酸盐及二硫化物配体络合物的形成有关。最稳定的络离子是Au(S_2O_3)2~(3-)(当fO_2>10~(60))和Au(HS)_2~-(当fO_2<10~(60)),它们存在于中性或碱性溶液中。类似于金,银在中等氧化环境中形成一个稳定的硫代硫酸盐络离子Ag(S_2O_3)2~(3-),在还原、碱性介质中形成二硫化物络离子AgHS~D和Ag(HS)_2~-。在强氧化的中性或酸性溶液中,由于AgS_2O_3~-、Ag~+和AgSO_4~-络离子的形成,使Ag的溶解度增高。然而,胶态的、晶质的及呈合金态的金和银与0.1molNaS_2O_3溶液反应没有显示各自独立的溶解度。以金为例,其在0.1molNa_2S_2O_3溶液中的溶解度由于银的硫代硫酸盐络离子及合金态的银的存在而增高,这种性质可能与形成混合金属络离子(Au,Ag)(S_2O_3)2~(3-)有关。在巴布亚新儿内亚的Wau地区,碳酸盐矿床氧化代中次生金的性质和矿物组合与早期硫作为硫代硫酸盐络离子的再活化是一致的。这里的次生金是粗大结晶的,与50～75at％(原子百分此)的银组成合金,富集于潜水面上,并与二氧化锰共生于氧化带中。
In the superficial metanation of gold-bearing carbonate deposits, the weathering fluids formed tend to be alkaline and, therefore, unsuitable for the mediator of gold-chloride complex migration, whereas reactivation of secondary gold in this deposit Often attributable to the complexation of gold with sulfur-containing ligands. Through the reliable calculation of thermodynamics, the solubility of gold and silver in Au-S-O 2 -H 2 O and Ag-S-O 2 -H 2 O systems and the formation of gold and thiosulfate and disulfide ligand complexes related. The most stable complex ions are Au (S_2O_3) 2 ~ (3 -) (when fO_2> 10 ~ (60)) and Au (HS) _2 ~ Or alkaline solution. Similar to gold and silver, a stable thiosulfate complex ion Ag (S 2 O 3) 2 ~ (3-) is formed in a moderate oxidative environment, forming disulfide complex ions AgHS ~ D and Ag HS) _2 ~ -. In strongly oxidized neutral or acidic solutions, the solubility of Ag increases due to the formation of AgS_2O_3 ~ -, Ag ~ + and AgSO_4 ~ - ions. However, the reaction of colloidal, crystalline and alloying gold and silver with 0.1 mol NaS 2 O 3 solution did not show independent solubility. Taking gold as an example, its solubility in 0.1molNa_2S_2O_3 solution increases due to the presence of silver thiosulfate complex ions and alloying silver, which may be related to the formation of mixed metal complex ions (Au, Ag) (S_2O_3) 2 ~ (3-) related. In the Wau region of Papua New Guinea, the nature and mineral assemblage of the secondary metaplasia in the carbonate deposits is consistent with the reactivation of early-stage sulfur as the thiosulfate complex ion. The secondary gold here is coarse crystalline, and 50 ~ 75at% (atomic percent) of silver alloy, enriched in the diving surface, and manganese dioxide symbiosis in the oxidation zone.