银在含氨基酸热液中的物理化学行为

PHYSICOCHEMICAL BEHAVIORS OF SILVER IN HYDRO THERMAL SOLUTION CONTAINING AMINO ACIDS

考虑到银主要富集在中低温热液阶段，同时考虑到成矿溶液中氨基酸的存在及其不同类型，对含银矿物样品在中性、碱性和酸性氨基酸热液中的物理化学行为分别进行了实验研究。结果表明，含有酸性氨基酸（谷氨酸）的热水溶液，比仅含ＮａＣｌ的热卤水、含碱性氨基酸（赖氨酸）和中性氨基酸（氨基乙酸和氨基丙酸）的热水溶液，更有利于银的活化和迁移。实验同时表明，银与各氨基酸形成的易溶配位化合物的稳定性受到温度的强烈影响。在２５℃左右，是银－氨基酸配位化合物稳定存在的最适宜温度条件；在１００℃以上，随温度的逐渐升高，银在含氨基酸热液中的溶出量明显减少。表明银－氨基酸的配位化合物强烈地分解，而使银得以更多地沉积。银在含氨基酸热液中的这种物理化学行为，和铅在含有酸性氨基酸（谷氨酸）、铜在含有碱性氨基酸（赖氨酸）热液中的活化。

According to the probable existence of amino acids in ore forming solution and the presence of different types of amino acids, the authors performed a model experimental study on the behaviors of ore sample containing silver in the hydrothermal solution which is contained by neutral amino acids (glycine and alanine), acidic amino acid (glutamic acid) and alkaline amino acid (lysine) respectively. The result of study shows that the role of the hydrothermal solution containing amino acids in the activation and migration of silver or the stability of readily soluble coordination compounds formed by amino acids with silver is not only related to the types of amino acids, but also affected obviously by temperature. As to the activation and migration of silver, the hydrothermal solution containing acidic amino acid (glutamic acid) is more favourable than those containing NaCl, neutral amino acids (glycine and alanine), and alkaline amino acid (lysine). It indicates that the silver glutamic acid coordination compound is more stable and easily dissoluble than the other silver amino acids coordination compounds. Whithin the range of 25￣200℃, the dissolution amount of silver in the hydrothermal solution containing various amino acids decreases with the increase of temperature from 25℃ to 200℃. The dissolution amount of silver may reach to its maximum at about 25℃. This indicates that the temperature of 25℃ seems to be the most suitable temperature for the existence and migration of silver amino acids coordination compounds. But when the temperature is above 100℃ the coordination compounds will be obviously decomposed, leading to the precipitation of silver. This is very similar to the migration and deposition of lead in hot brine containing acidic amino acid (glutamic acid) and copper in hot brine containing alkaline amino acid (lysine).