Rapid Identification Methods on the Characteristic Information of the Micro-zone in Common Rocks and Minerals by Laser Ablation Spectroscopy

Laser Ablation Spectroscopy (LAS) is an attractive potential geochemical analysis technique for real-time, online, non-destructive determination of the elemental compositions of any substances (solid, liquid, or gas). A small LAS system with the emission spectrum from 200 nm to 800 nm was set up and applied to analyze 150 kinds of common standard rocks and minerals under normal atmospheric conditions, to obtain the LAS spectra of these specimens. The characteristic information of the micro-zone in the standard samples (micrograph,mineral components,characteristic spectra of LAS) was collected to construct the database. The related software to rapidly identify and classify the samples based on the database was designed using a mathematical processing approach. The LAS spectra were simplified by smoothing and extracting the characteristic peaks. The unknown rocks and minerals were identified by comparing the characteristic peaks in the database of the LAS spectra. In this study,the LAS system combined with the identification database highlighted the potential for 'geochemical fingerprinting’, thereby laying the foundation for real time or in-field rapid identification of the characteristic information of the micro-zone in rocks and minerals, in order to provide technical support for ore exploiting, mining and mineral processing.