德兴铜矿堆浸场矿石矿物学、Cu伴生元素地球化学特征及意义

Ore mineralogy of the heap leaching field of the Dexing copper deposit and geochemistry of Cu and associated elements

德兴铜矿是我国乃至世界著名的低品位多金属岩型铜矿之一。多年来,德兴铜矿在低品位矿石堆浸过程中只对Cu元素进行回收,而对Re、Co、Au、Ag等伴生元素研究甚少。本文采用X射线衍射、扫描电镜与电镜能谱、电子探针以及ICP-MS等方法对德兴铜矿杨桃坞与祝家村堆浸场低品位矿石进行测试分析,研究了低品位矿石矿物组成变化、重要共伴生元素的赋存状态与空间分布规律,并对其进行了综合利用的可行性评价。研究结果表明,Au主要以自然金形式存在,Ag以单质和化合物两种形式存在,Co主要以类质同像形式存在;Re与Mo含量很低,无利用价值;Co元素含量相对较高,均值19 g/t左右,浸出率为73%,因此回收酸性水库中的Co元素可能具有重大经济价值;杨桃坞堆浸场Au平均含量0.10 g/t,几乎无浸出;Ag平均含量0.39 g/t,浸出率较低,可作为一种潜在资源。此外,堆浸场中金红石含量较丰富,平均粒度20μm左右,估算储量达460万吨,有必要对其回收性开展深入研究。

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.