Quantitative evaluation of materials by scanning electron microscopy

Abstract

QEM*SEM, or quantitative evaluation of materials by scanning electron microscopy, is a fully automated scanning electron microscope system that was designed and engineered by CSIRO in Australia for applications to the minerals industry. It is an integrated system in which the computer and its associated hardware and software control SEM operations. Minerals can be identified in point, linear or area scans. Depending on the type of scan, information is extracted from the data files and summarized in tables and graphs covering mineral abudances, associations, sizes, free surface area and the degree of liberation. In addition, area scans can be replayed on a graphics monitor to produce QEM*SEM mineral species maps.The QEM*SEM system consists of an International Scientific Instruments SX-40 scanning electron microscope with a specially designed sample chamber that permits 100 mm movement of the stage. The EDS units were designed for rapid collection of x-ray spectra and consist of four lithium drifted silicon detectors each with a separate preamplifier.