| 腐殖酸与铅锌相互作用的实验地球化学 |
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| 引用本文：.1995.Experimental geochemistry of interaction between hymid acids and Pb2+ (Zn2+)[J].Mineral Deposits,14(4):362~368 |
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| 基金项目:生物成矿作用和低温地球化学重点基金项目 |
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| 中文摘要:腐殖酸是沉积有机质的主要成分。实验证明，腐殖酸对铅锌离子具有强烈的富集能力。通过替代反应初步确定了腐殖酸与Pb、Zn之间几种结合方式及各种结合方式所占数量和比 例；证实富啡酸 (F. A.) 和胡敏酸 (H. A.) 与Pb2+、Zn2+之间形成了两大类络合物：一类其稳定常数小于EDTA-Pb (Zn)络合物；另一类稳定常数大于EDTA-Pb (Zn) 络合物。根据F. A. 与Zn2+反应过程中氢离子释放量，可估算络合物生成量；溶液pH值及成熟程度，对有机质结合Pb(Zn)的能力有重要影响。溶解有机质、腐殖酸和单宁酸的存在对方铅矿晶面发育具有控制作用。 |
| 中文关键词:腐殖酸 络合物 双源层 |
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| Experimental geochemistry of interaction between hymid acids and Pb2+ (Zn2+) |
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| Abstract:Laboratory studies were made on the interactions between humic acids and Pb2+ (Zn2+). The experiment results show that humic acids tend strongly to combine with Pb2+and Zn. Under the conditions of pH 5 ~ 8, 0.02 mol/L CaCl2 and 0.1% humic acid and fulvic acid in the solution, 40%～94% lead and zinc ions in the solution are combined with organic matter; high pH condition can promote complexation of humic acids and Pb2+ (Zn2+). The reaction between humic acids and Pb2+ ( Zn2+) has double character of coordinate chemistry and colloid chemistry. More than 67 % of total lead (zinc) ions combining with humic acids exist in the form of fulvic acid-Pb complex, and 32% Pb in the form of ion-exchange and ion-adsorpion. During the complexation, equivilent Ht is released. The experimental results also suggest that at least two kinds of complexes are formed in the reaction between humic acids and Pb2+ (Zn2+), with their stability constant being higher and lower than that of EDTA-Pb(Zn) complexes respectively. The capacity of organic matter for combining with metals is related to pH value of solution and maturity of organic matter. Tabular and thin-tabular galena crystals were identified in the solution of tannic or humic acids. |
| keywords:humid acids, complex, dual-source bed |
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