金、铀、硅溶解性状的实验研究

EXPERIMENTAL STUDY ON DISSOLUTION BEHAVIOUR OF An, U AND Si

在ＰＨ２Ｏ为１５０ＭＰａ，ｐＨ为１０的Ｎａ２ＣＯ３溶液中混合花岗岩的金、铀、硅溶解实验表明，温度３５０—４００℃时有利于金的溶解，２００—３００℃时有利于铀溶解，而硅的溶解随温度的增加呈线性增长。在ＰＨ２Ｏ为１５０ＭＰａ，３５０℃状态下，铀、硅的溶解随Ｎａ２ＣＯ３浓度的增加而增加。当用ＨＣｌ调节Ｎａ２ＣＯ３溶液的ｐＨ值时，金偏向溶于碱性介质，铀偏向溶于酸性介质。在ＰＨ２Ｏ为１５０ＭＰ。，３５０℃不同的碱性溶液中，金与硫化物、氯化物，铀与碳酸盐或碳酸盐－硫化物关系密切，表现金的亲硫性和铀的亲氧性。“焙烧”实验表明，构造、岩浆活动等热事件对金、铀、硅溶解起促进作用。

The results of the dissolution experiments on An,U and Si in migmatitic granite in water solution of Na2CO3 at PH2O(150MPa) and PH(10) show that t (350-400℃) and t (200-300℃) are favourable for the dissolution of gold and uranium respectively. The solubility ofSt is positively proportionally increasing with the rising of temperature. The dissolution of Uand SiO2 at PH2O(150 MPa) and t (350℃ ) increases with the increasing of Na2CO3 concentration. While using HCl to adjust the PH values of the Na2CO3 solution, Au tends to be dissolved in alkaline media and U in acidic media. In various alkaline solutions at PH2O (150MPa) and t (350℃). Gold is closely related with sulfide and chloride, and uranium with carbonate or carbonate-sulfide, showing the chalcophile affinity of gold,and lithophile affinity ofuranium respectively. The roasting experiments indicate that heating events such as the magmatic and tectonic activities may accelerate the dissolution of An,U and SiO2.