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针对氯化物体系中金的浸出反应进行热力学计算,分别绘制出Au-Cl-H2O体系电位-pH图、lg[Au(Ⅲ)]-pH图、lg[Cl-]-pH图,并分析了金氯化浸出过程的热力学影响因素。电位-pH图中存在着金氯络合物的稳定区域,在pH为中性或弱酸性并保持氧化电位高于0.9 V的条件下,金将以AuCl4-的形态浸出。AuCl4-的稳定性很差,易受氯化物浓度、AuCl4-浓度等热力学因素的影响。加大氯化物浓度或降低AuCl4-浓度,在热力学上有利于金的浸出。在保证金尽可能浸出的角度来说,热力学上最佳条件为pH 3.5～7.8、氧化电位高于0.9 V、氯化物浓度高于1 mol.L-1,AuCl4-浓度1×10-5～1×10-4mol.L-1。
According to the thermodynamic calculation of the gold leaching reaction in the chloride system, the potentials-pH diagram, lg [Au (Ⅲ)] - pH diagram and lg [Cl -] - pH chart of the Au-Cl- Thermodynamic Factors Affecting Gold Chlorination Leaching Process. There is a stable region of the gold chloride complex in the potential-pH diagram, which will leach out in the form of AuCl4- at pH values of neutral or weakly acidic and with an oxidation potential higher than 0.9 V. AuCl4- poor stability, susceptible to chloride concentration, AuCl4-concentration and other thermodynamic factors. Increasing the chloride concentration or reducing the AuCl 4 -concentration is thermodynamically favored for gold leaching. The best thermodynamic conditions were pH 3.5 ~ 7.8, oxidation potential higher than 0.9 V, chloride concentration higher than 1 mol.L-1 and AuCl4- concentration 1 × 10-5 ~ 1 × 10 -4 mol.L-1.