Ore mineralogy of the heap leaching field of the Dexing copper deposit and geochemistry of Cu and associated elements
GAO Zhi-rui;ZHAO Yuan-yi;CAO Chong;CHANG Yu-hu;Institute of Mineral Resources, CAGS/MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences;Tianjin Center,China Geological Survey;China University of Geosciences (Beijing);
The Dexing copper deposit is one of the famous porphyry copper deposits characterized by low grade and multi-elements in China. In the past years, only the Cu element was recovered, and the other elements, such as Re, Co, Au and Ag, were hardly considered in the heap leaching process. In this study, XRD, SEM and EDS,EMPA, ICP-MS analysis and phase analysis were conducted to study mineral composition variations, modes of occurrence and spatial distribution regularity of associate elements in order to put forward the feasible evaluation on comprehensive utilization in this paper. The main conclusions are as follows: Au mainly occurs as native gold; Ag occurs as both simple substance and compounds; Co mainly occurs as isomorphs; Mo and Re elements have no economic value in the heap leaching field due to their very low content. However, recovery of Co element in the acid water reservoir can possess important economic value with its higher content of 19 g/t and its higher leaching rates of 73%. Au and Ag are just potential resources with the much lower leaching rates and the lower average content of 0. 1 g/t and 0. 39 g/t, respectively. Besides, the further study should be performed with regard to recycling rutile due to its rich content and its average particle size of 20 μm.