X-CT引导的矿物赋存状态及微区表征研究

Study on mineral occurrence states and microzone characterization guided by X-CT

在常规岩矿鉴定过程中普遍存在对岩芯内部构造、矿物分布等缺乏了解的问题。X射线断层扫描(X-CT)作为一种无损分析测试手段,近年来在地球科学领域备受关注。以相山火山岩型和沙特碱性花岗岩型岩芯样品为研究对象,采用X-CT对岩芯中高密度矿物的形貌、空间分布等参数进行表征。通过对X-CT测定数据的解析,可以快速准确地获得目标重矿物在岩芯中的空间位置。依据X-CT给出的目标矿物所在岩芯中的空间相对位置,引导传统制靶工艺制备目标区域的靶样,联用扫描电子显微镜(SEM)和激光烧蚀电感耦合等离子体质谱仪(LA-ICP-MS)进行微区表征,获得了岩芯中稀土矿物和含铀矿物的空间赋存状态以及微区特定元素分布信息。由于预先采用X-CT对目标矿物及对应微区进行空间位置标定,使得制靶效率和选点准确度得到有效提高。

There is a general lack of understanding of the internal structure and mineral distribution of the cores in the process of conventional rock and ore identification.As a non-destructive analysis and testing method,X-CT has attracted much attention in the field of earth science in recent years.Taking the core samples of Xiangshan volcanic rock type and Saudi Arabia alkaline granite type as the research object,and using X-CT to characterize the morphology,spatial distribution and other parameters of highdensity minerals in the cores.The spatial position of the target heavy mineral in the cores can be quickly and accurately obtained by analyzing the X-CT data.According to the relative spatial position of the target minerals in the cores provided by X-CT,traditional target preparation techniques are guided to prepare target samples in the target area.Microzone characterization is performed using scanning electron microscopy(SEM)and laser ablation inductively coupled plasma mass spectrometry(LA-ICPMS)to obtain the spatial occurrence states of rare earth minerals and uranium-containing minerals in the rock core,as well as the distribution information of specific elements in the microzonea.Due to the preuse of X-CT to locating the spatial position of the target minerals and corresponding microzone,the efficiency of target preparation and the accuracy of point selection have been effectively improved.