A preliminary study of reserve estimate and resource potential assessment of critical elements in the Jiaodong gold deposits, China

通过对大尹格庄和夏甸两个超大型金矿床的精金矿与尾矿砂中关键元素含量的分析,发现相对于华北克拉通地壳元素丰度,本次分析的稀贵元素Co、Rh、Ir和Ru,稀散元素Cd、Te和Se,稀有元素W和In均发生了不同程度的富集;特别是Te、Co和Cd超常富集达到伴生组分综合评价品位。根据伴生有用组分综合评价规范和金矿选矿报告相关参数,分别估算了金矿石和精金矿中可利用的关键金属矿产储量,其中夏甸金矿床内Te储量为69吨(精金矿中52吨)、Co储量为604吨(精金矿中413吨),大尹格庄金矿床内Cd储量为224吨(精金矿中206吨),这些均可直接回收利用。矿物学和矿物化学综合研究表明:Te主体以碲金矿、碲银矿、碲铋矿、碲铅矿和陈国达矿等独立矿物存在,与可见金密切共生;Co常以微量元素形式分布在金成矿早阶段的粗粒黄铁矿和磁黄铁矿中;Cd主要以类质同象的形式赋存于金成矿晚阶段的闪锌矿、黄铁矿和黄铜矿中。进一步通过对典型金矿床中黄铁矿原位和/或单矿物的Te与Co含量对比、并结合矿石中Co与Cd元素组成及其区域地球化学空间分布特征,综合约束了其超常富集特征与资源潜力,揭示新城、玲珑和寺庄金矿床及栖霞异常区分别有约2329吨、1035吨、1553吨和22790吨Co资源量,乳山、新城和焦家金矿床有约1529吨、126吨、216吨Te资源量,仓上、新立、三山岛、寺庄和新城金矿床、以及栖霞和招平北段异常区分别有约47.6吨、78吨、63.7吨、69吨、3564吨、7120吨和696吨Cd资源量;即胶东金矿集区具备近期被综合利用或作为未来潜在接替资源的Co、Te和Cd资源条件,且其展布区域广泛、资源潜力巨大。初步研究已显示胶东具有形成大型-超大型Cd、Te和Co矿床的资源条件,但关键金属资源的空间分布极不均一、其超常富集机理与规律尚不清楚,亟需深入研究。;Through analysis of critical element content in fine gold mine and tailing sands of the two super-large gold deposits of Dayingezhuang and Xiadian, it is found that relative to abundance of elements in crust of the North China Craton, rare and precious elements Co, Rh, Ir and Ru, scattered elements Cd, Te and Se, and rare elements W and In have all been enriched to different degrees; Especially, extreme enrichment of Te, Co and Cd has reached the comprehensive evaluation grade of associated components. According to comprehensive evaluation specifications of associated useful components and relevant parameters of gold beneficiation report, the available critical metal reserves in gold ores and fine gold mines were estimated respectively. The Te reserves in the Xiadian gold deposit are 69 tons (52 tons in fine gold mine), Co reserves are 604 tons (413 tons in the fine gold mine), and the Cd reserves in the Dayingezhuang gold deposit are 224 tons (206 tons in the fine gold mine), all of which can be directly recycled. Mineralogy and geochemistry studies show that Te mainly exists as independent minerals such as gold telluride, silver telluride, bismuth telluride, lead telluride and Chenguoda mineral, and they are closely associated with visible gold; Co is often distributed in the form of trace elements in the coarse-grained pyrite in the early stage of the gold mineralization; Cd mainly occurs in the sphalerite, pyrite and chalcopyrite in the late stage of gold mineralization in the form of isomorphism. Furthermore, by comparing the Te and Co content of pyrite in situ and/or single minerals in typical gold deposits, combined with the elemental composition of Co and Cd in the ore and its regional geochemical spatial distribution characteristics, the extreme enrichment characteristics are comprehensively restricted. The Xincheng, Linglong and Sizhuang gold deposits and the Qixia anomaly area have about 2329 tons, 1035 tons, 1553 tons, and 22790 tons of Co potential resources, respectively, and the Rushan, Xincheng and Jiaojia gold deposits have about 1529, 126, and 216 tons of Te resources, the Cangshang, Xinli, Sanshandao, Sizhuang and Xincheng gold deposits, and the Qixia and northern Zhaoping anomaly areas are about 47.6 tons, 78 tons, 63.7 tons, 69 tons, 3564 tons, 7120 tons and 696 tons of Cd resources, respectively; that is, the Jiaodong gold mining area has the Co, Te, and Cd resource conditions that are comprehensively utilized in the near future or as potential replacement resources in the future, and its spread area is wide and the resource potential is huge. Preliminary studies have shown that Jiaodong has the resource conditions for the formation of super-large Cd deposits, large-scale Te and Co deposits, but the spatial distribution of critical metal resources is extremely uneven, and its extreme enrichment mechanism and law are still unclear, and in-depth research is urgently needed.