云南北衙金铁氧化矿金银赋存状态与选冶回收研究  

Au-Ag Properties and Beneficiation of Beiya Au-Fe Oxidized ore Deposit in Yunnan Province, China

作　　者：蒋英 邱显扬 梁冬云 李波 王成行 Jiang Ying;Qiu Xianyang;Liang Dongyun;Li Bo;Wang Chenghang(Guangdong Provincial Key Laboratory of Development&Comprehensive Utilization of Mineral Resources,State Key Laboratory of Rare Metals Separation and Comprehensive Utilization,Guangdong Institute of Resources Comprehensive Utilization,Guangzhou 510650,China)

机构地区：[1]广东省资源综合利用研究所稀有金属分离与综合利用国家重点实验室广东省矿产资源开发和综合利用重点实验室

出　　处：《稀有金属》2019年第9期974-986,共13页Chinese Journal of Rare Metals

基　　金：广东省科学院高端领军人才培育培养专项项目(2017GDASCX-0301);广东省科学院创新人才引进资助专项项目(2017GDASCX-0838);广东省自然科学基金项目(2017A030310555)资助

摘　　要：通过光学显微镜(OM)观察,采用扫描电镜能谱仪(EDS)、电子探针(EPMA)及矿物自动检测仪(MLA)等分析技术,结合电子探针元素面扫描分布,对云南北衙地表金铁氧化矿的矿物组成、金银矿物嵌布特征、金银平衡分配以及赋存状态进行了系统研究,并优化了选矿工艺流程及选矿回收指标。研究结果表明,矿石中的金以独立矿物形式为主,少量以微细粒包裹体或吸附态形式赋存于载体矿物褐铁矿中。通过细磨,嵌布于其载体矿物中的绝大部分金粒可单体解离。矿石中银的赋存状态较复杂,其主要载体矿物为铅硬锰矿与褐铁矿,除少量呈独立显微银矿物外,绝大多数银为不可见银。独立显微银矿物主要有自然银、螺状硫银矿、角银矿、硫锑银矿等,可通过细磨获得解离。不可见银主要以类质同象形式赋存于铅硬锰矿中,其次为褐铁矿,很难直接氰化浸出,只能通过破坏载体矿物的晶体结构才能加以回收。在金银赋存状态研究基础上,采用"粗磨-弱磁选-强磁选-分流物料分别提取金银"新选矿工艺流程,金、银、铁回收率分别由88.15%, 30.26%和27.15%提高至93.05%, 74.34%和70.86%。Multiple technics including optical microscope(OM), scanning electron microscope(SEM) energy dispersive spectrometer(EDS), electron probe micro-analyzer(EPMA) and Mineral Liberation Analyzer(MLA) were used to study the mineral composition, dissemination characteristics and occurrences of gold and silver in the Beiya oxidized ore deposit in Yunnan Province, China. A new mineral processing flowsheet based on this study was developed and the recovery index was improved as well. The results showed that gold in the ore mainly occurred as independent minerals, in addition to a small amount of gold occurring as micro-inclusion or adsorbed state. The major gold-bearing mineral was limonite. Most of gold in the carrier mineral could be dissociated by fine grinding. The occurrence of silver was complicated and it was mainly hosted by coronadite and limonite. Only small amounts of silver occurred as independent, micron-scale silver minerals in the host minerals. The majority of silver was scattered in the host minerals and could not be observed. The independent silver minerals could be dissociated by fine grinding, but for the silver primarily occurring in the form of isomorphism in coronadite, and subordinately limonite, it could only be recovered by destroying crystal structure of the carrier minerals. Based on this study, a new mineral processing process of "coarse grinding-low intensity magnetic separation-high intensity magnetic separation-leaching separately" was adopted. Using the new processing flowsheet, the comprehensive recovery rate of gold, silver and iron were increased from 88.15%, 30.26% and 27.15% to 93.05%, 74.34% and 70.86%, respectively.

关 键 词：氧化矿 金 银 赋存状态 选矿工艺流程 

分 类 号：TD953[矿业工程—选矿]