Study of the behaviour of Au in oxide ores during thiosulfate leaching

该项目的目标是开发一种新的方法来研究硫代硫酸盐、复杂矿石样品和金之间的相互作用，以更好地理解在金提取的工业过程中发生的复杂行为，即浸出。为了研究硫代硫酸盐存在下金与矿物的相互作用，并研究硫代硫酸盐与金与矿物表面的相互作用，本文将制备一种新型环-金盘-矿物电极。电化学技术将用于研究金的浸出动力学，以及在不同矿物存在下阻碍浸出动力学的被动层的形成速度。然后将采用光谱技术来确定限制金浸出动力学的被动层的性质。使用这种环盘电极，我们将确定负责增加硫代硫酸盐氧化和被动层形成的矿物。这方面的知识是必不可少的矿石预处理方法的发展，减轻这些影响，提高金浸出动力学。为了比较确定每种添加剂在不同矿物存在下的作用，将对先前确定的几种增强金浸出的浸出剂溶液中的添加剂进行研究。本项目所收集的资料对于协助加拿大金工业，特别是巴里克黄金公司开发新的环境友好型金提取工艺至关重要。

The objective of this project is to develop a novel methodology to investigate the interactions between thiosulfate, complex ore samples and Au to better understand the complex behaviour that occurs during the industrial process of Au extraction called leaching. A novel ring-Au disk-mineral electrode will be fabricated to study Au and mineral interactions in the presence of thiosulfate and to study thiosulfate interactions with both Au and the mineral surface. Electrochemical techniques will be employed to study the Au leaching kinetics as well as the rate of formation of a passive layer that impedes the leaching kinetics in the presence of different minerals. Spectroscopic techniques will then be employed to identify the nature of the passive layer responsible for limiting the Au leaching kinetics. Using this ring-disk electrode we will identify the mineral(s) responsible for increased thiosulfate oxidation and passive layer formation. This knowledge is essential for the development of the ore pretreatment methodology mitigating these effects and increasing the Au leaching kinetics. Several additives to the lixiviant solution that have been previously identified to enhance Au leaching will be investigated in order to comparatively determine the role of each additive in the presence of different minerals. The information sought in this project will be essential for assisting the Canadian Au industry, specifically Barrick Gold Inc in development of new environmentally-friendly Au extraction processes.