摘要
邹家山铀矿床矿石有大量的磷灰石,含量与铀呈正相关性。系统研究磷灰石矿物学特征,并探讨其与铀成矿的关系,可以完善铀矿成矿原理,并为铀矿找矿提供一定的地球化学信息。本文对邹家山铀矿石及围岩开展了化学成分测试、电子探针分析和矿物自动分析(MAL)等研究,结果显示:①邹家山铀矿床P2O5含量与U、ΣREE、HREE、CaO、TiO2、烧失量呈显著正相关性,与SiO2、Al2O3、MgO、Na2O、K2O、LREE/HREE呈显著负相关性,与Fe2O3、MnO、LREE相关性不明显。②磷灰石占铀矿石总重量的2.18%,其颗粒相对铀矿物较大,为自形‒半自形晶结构。磷灰石分为2种:一种晶体破碎,有铀矿物伴生(粒径>10μm,主要为10~50μm,裂隙发育,矿物边缘呈港湾状);另一种磷灰石晶体自形且较完整,无铀矿物伴生(粒径>50μm,表面和边缘平整)。③磷灰石‒铀矿物连生体占总矿物的7.58%,磷灰石以氟磷灰石和氟碳磷灰石为主。磷灰石的Ca和P主要来源于围岩中的斜长石和黑云母;磷灰石形成矿物时消耗络阴离子,破坏铀酰络合物的平衡,同时磷灰石对(UO2)2+较强的吸附性促使铀矿物的形成。
The ores from the Zoujiashan uranium deposit contain a large amount of apatite,and the content of apatite is positively correlated with that of uranium.A systematic study of the mineralogical characteristics of apatite and its relationship with uranium mineralization will shed lights on uranium metallogeney and guide future uranium deposit prospecting.Chemical analysis,electron microprobe analysis and automatic mineral analysis of the uranium ores and surrounding rocks from the Zoujiashan uranium deposit showed that:(1)The P2O5 contents of the ores are positively correlated with those of U,ΣREE,HREE,CaO,TiO2 and LOI,negatively correlated with those of SiO2,Al2O3,MgO,Na2O,K2O and LREE/HREE,and irrelevant with that of Fe2O3,MnO and LREE.(2)The uranium ores consist of 2.18%apatite which commonly occurs as euhedral or subhedral crystals with grain-size larger than that of the uranium-bearing minerals.Two types of apatite can be recognized,i.e.,one type apatite is closely associated with uranium-bearing minerals,commonly heavily fractured and showing adsorption structure with sizes larger than 10μm;whereas the other type is unrelated to uranium-bearing minerals,and characterized by euhedral and relatively integrated crystals larger than 50μm in size,with flat surfaces and edges.(3)The intergrowth apatite-uranium minerals account for 7.58%of the ores,and the apatite consists mainly of fluorapatite and fluorocarbon apatite.We argue that Ca and P in apatite mainly come from decomposition of plagioclase and biotite,whereas the formation of apatite may consume anions such as F-and CO32-,and disturb the balance of uranyl complex which lead to the precipitation of uranium minerals.
作者
高海东
王运
邱林飞
胡宝群
王倩
李满根
郭福生
吴志春
周义朋
陈功新
孙占学
GAO Haidong;WANG Yun;QIU Linfei;HU Baoqun;WANG Qian;LI Mangen;GUO Fusheng;WU Zhichun;ZHOU Yipeng;CHEN Gongxin;SUN Zhanxue(School of Earth Sciences,East China University of Technology,Nanchang 330013,Jiangxi,China;Jiangxi Provincial Institute of Nuclear Geology(Jiangxi Nuclear Geological Bureau 266th Brigade),Nanchang 330038,Jiangxi,China;Beijing Research Institute of Uranium Geology,Beijing 100029,China;Chifeng Institute of Geology and Mineral Exploration and Development of Inner Mongolia,Chifeng 024000,Inner Mongolia,China)
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2020年第6期1113-1127,共15页
Geotectonica et Metallogenia
基金
国家自然科学基金项目(41472069、41572185)资助。
关键词
磷灰石
铀成矿
邹家山铀矿床
相山矿田
apatite
uranium mineralization
Zoujiashan uranium deposit
Xiangshan ore field
