白云鄂博矿床磁铁矿成分标型与深部富铁矿体预测  

Typomorphic characteristics of magnetite and prediction of deep ironrich orebody in the Bayan Obo ore deposit

作　　者：徐志豪 闫国英 杨宗锋[1,2] 王昭静 申俊峰[2] 张萌萌 李培培 徐渴鑫 XU Zhihao;YAN Guoying;YANG Zongfeng;WANG Zhaojing;SHEN Junfeng;ZHANG Mengmeng;LI Peipei;XU Kexin(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Beijing),Beijing 100083,China;Research Center of Genetic Mineralogy,School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Minging Research Institute of Baotou Steel(Group)Corp.,Baotou 014010,China)

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学(北京)地球科学与资源学院成因矿物学研究中心,北京100083 [3]包头钢铁(集团)有限责任公司矿山研究院(有限责任公司),内蒙古包头014010

出　　处：《地学前缘》2023年第2期426-439,共14页Earth Science Frontiers

基　　金：包头钢铁(集团)有限责任公司矿山研究院(有限责任公司)2021年A类重点项目“白云鄂博稀土-铌-铁资源矿物标型学研究(BGKY-ZH-2021-Z-017)”。

摘　　要：白云鄂博稀土-铌-铁矿床蕴藏着大量的铁资源,其中磁铁矿作为矿石矿物被广泛研究。磁铁矿的矿物标型特征可以指示矿床成因、成矿规律以及深部找矿,但磁铁矿标型矿物学尚未在白云鄂博矿床中普及与应用。本研究使用了22条勘探线全铁数据,利用扫描电镜能谱和电子探针的矿物微区成分测试方法,测试了覆盖600 m×600 m,纵深800 m范围内10条勘探线的45件样品,将白云鄂博矿床中的磁铁矿分为岩浆型和热液型,表明岩浆和热液在白云鄂博矿床中均形成或改造磁铁矿。结合磁铁矿温度计得知,岩浆型磁铁矿,尤其是高温磁铁矿富集的区域,矿床全铁成分更加富集,更容易形成富铁矿体,磁铁矿形成的温度为350~650℃。因此推测,12、13号线的深部东部方向有很大可能形成富铁矿体,可能在深部连接东矿,值得进一步研究与开采。The Bayan Obo rare earth-niobium-iron ore deposit contains a large amount of iron resources, among which magnetite has been widely studied as an ore mineral. Typomorphic characteristics of magnetite can be used to explore the genesis, metallogenic regularity and deep prospecting of the ore deposit, however, they have not been commonly studied in the Bayan Obo ore deposit. In this paper, the total iron data of 22 exploration lines were used, and mineral micro-zone composition testing was performed on 45 samples from 10 exploration lines covering 600 × 600 meters in area and 800 meters in depth, using energy dispersive spectroscopy(EDS) and electron probe(EPMA) methods. The Bayan Obo magnetite can be divided into magmatic and hydrothermal magnetites, indicating both are formed or modified in the ore deposit. Combined with thermometric data, it can be seen that wherever magnetites are enriched, the local total iron content is also higher, and iron-rich orebodies are easy to form at formation temperatures ranging between 350-650℃. Under such observation, deep iron-rich orebodies are likely to form in the eastern direction of Line 12 and 13 and may be connected to the eastern deep ore deposit, which is worthy of further research and exploitation.

关 键 词：白云鄂博矿床 磁铁矿 标型矿物 热液 岩浆 找矿 

分 类 号：P618.31[天文地球—矿床学]