QEMSCAN creates phase assemblage maps of a specimen surface scanned by a high-energy accelerated electron beam along a predefined raster scan pattern. Low-count energy-dispersive X-ray spectra (EDX) are generated and provide information on the elemental composition at each measurement point. The elemental composition in combination with back-scattered electron (BSE) brightness and x-ray count rate information is converted into mineral phases. QEMSCAN data includes bulk mineralogy and calculated chemical assays. By mapping the sample surface, textural properties and contextual information such as particle and mineral grain size and shape, mineral associations, mineral liberation, elemental deportment, porosity, and matrix density can be calculated, visualized, and reported numerically. Data processing capabilities include combining multiple phases into mineral groups, resolving mixed spectra (boundary phase processing), image-based filtering, and particle-based classification. Quantitative reports can be generated for any selected number of samples, individual particles, and for particle classes sharing similar compositional and/or textural attributes, such as size fractions or rock types.
Sample types and preparation
QEMSCAN is routinely employed in the analysis of rock- and ore-forming minerals. Sample preparation requirements include a level, dry specimen surface, coated with a thin electrically conductive layer (e.g. carbon). The sample must be stable under high vacuum conditions and the electron beam, typically 15 to 25 kV. Common sample types include 30 mm resin-impregnated blocks of drill cuttings and ore, thin sections of drill core and rocks, as well as soil samples. Very small particles such as atmospheric dust have been measured on carbon tape or filter paper. Coal samples are generally mounted in carnauba wax, providing sufficient contrast to allow for separation of the sample from the mounting medium, and subsequent measurement of coal and macerals.
QEMSCAN consists of proprietary software package iDiscover which consists of four software modules:
Datastore Explorer - Data management module
iMeasure - Measurement module, SEM and EDS control
iExplorer - Data processing and classification tools, mineral database management, reports
SIP editor - phase identification protocol
QEMSCAN consists of five customisable measurement modes
1980s New digital hardware and software developments by CSIRO allowed for automated analysis of multiple samples, creation of particle images form which mineralogy, texture and metallurgical parameters can be extracted and quantified.
1990s Light element X-ray detectors are introduced improving the mineral identification. The Julius Kruttschnitt Mineral Research Centre at the University of Queensland develop the Mineral Liberation Analyzer (MLA) expert software.
2001CSIRO announces intention to commercialise QEMSCAN.
2003 Intellection Pty Ltd. is founded to develop, market and sell QEMSCAN technology solutions.
2009FEI Company announces the acquisition of selected assets from Intellection Pty Ltd., including the QEMSCAN technology.
2010, June. Ammtec completes the first "on site" analysis, utilising an "R" series QEMSCAN, at an oil well drilling site in Sumatra, RI.
Sep.1, 2010press release on version 5.0 iDiscover software including a new Spectral Analysis System capable of identifying 72 elements for improved complex mineral composition discrimination.
Oct. 19, 2011press release on introduction of QEMSCAN WellSite analysis solution, field-tested on onshore and offshore oil platforms in collaboration with mudlogging service providers and oil & gas companies, including Halliburton, Oil Search Limited and Maersk.
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^Pirrie, D., Power, M.R., Rollinson, G.K., Wiltshire, P.E.J., Newberry, J., Campbell, H.E. 2005. Automated SEM-EDS (QEMSCAN) Mineral Analysis in Forensic Soil Investigations: Testing Instrumental Reproducibility. In:K. Ritz et al. (eds.) Criminal and Environmental Soil Forensics, 84, 10, 411-430, Springer Science doi:10.1007/978-1-4020-9204-6_26
^Knappett, C., Pirrie, D., Power, M.R., Nikolakopoulou, I., Hilditch, J., Rollinson, G.K. 2005. Mineralogical analysis and provenancing of ancient ceramics using automated SEM-EDS analysis (QEMSCAN): A pilot study on LB I pottery from Akrotiri, Thera. Journal of Archaeological Science, in pressdoi:10.1016/j.jas.2010.08.022
^Schrader, C.M., Rickman, D., Stoeser, D., Wentworth, S.J., Botha, P.W.S.K., Butcher, A.R., McKay, D., Horsch, H., Benedictus, A., Gottlieb, P. 2008. Analysis of Lunar Highland Regolith Samples from Apollo 16 Drive Core 64001/2 and Lunar Regolith Simulants - An Expanding Comparative Database. NASA Technical Report, MSFC-2144abstract
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Automated Mineralogy Resources - Online repository for journal papers, conference abstracts, published reports and theses on SEM-EDS based automated mineralogy and petrography applications