Laser Raman spectroscopy, minerals

Kauppinen T, Khajehzadeh N, Haavisto O (2014) Laser-induced fluorescence images and Raman spectroscopy studies on rapid scanning of rock drill core samples. Int J Miner Proc 132 26-33 Lamprecht G, Himan H, Snyman L (2007) Detection of diamond in ore using pulsed laser Raman spectroscopy. J Miner Proc 84 262-273... 

Lamprecht G, Himan H, Snyman L (2007) Detection of diamond in ore using pulsed laser Raman spectroscopy. J Miner Proc 84 262-273... 

The crystalline mineral silicates have been well characterized and their diversity of stmcture thoroughly presented (2). The stmctures of siHcate glasses and solutions can be investigated through potentiometric and dye adsorption studies, chemical derivatization and gas chromatography, and laser Raman, infrared (ftir), and Si Fourier transform nuclear magnetic resonance ( Si ft-nmr) spectroscopy. References 3—6 contain reviews of the general chemical and physical properties of siHcate materials. 

Thomas R. (2000) Determination of water contents of granite melt inclusions by confocal laser Raman microprobe spectroscopy. Am. Mineral. 85, 868-872. 

The possibilities of time-resolved laser based spectroscopies have been demonstrated, combining such techniques as luminescence, Raman, breakdown and second-harmonic generation. Radiometric sorting of minerals using LIBS was patented and apparatus for evaluation of phosphate rocks with elevated dolomite content has been developed and constructed. 

The Applications of Laser-induced Time-resolved Spectroscopic Techniques chapter starts with a short description of laser-induced spectroscopies, which may be used in combination with laser-induced luminescence, namely Breakdown, Raman and Second Harmonic Generation. The chapter contains several examples of the application of laser-based spectroscopies in remote sensing and radiometric sorting of minerals. The proljlem of minerals as geomaterials for radioactive waste storage is also considered. 

Individual and non-destructive chemical analysis of microscopic remnants enclosed in mineral grains has been proven possible by certain spectroscopic techniques such as Raman-, IR-, UV/visible- and Laser mass spectroscopy (Pflug, 1982)16>. 

Pasteris, J. D., B. Wopenka J. C. Seitz, 1988. Practical aspects of quantitative laser Raman microprobe spectroscopy for the study of fluid inclusions. Geoch. Cosmoch. Acta. 52 979-988. Petrichenko, 0. I., 1973. Methods of Study of Inclusions in Minerals of Saline Deposits. Naukova dumka, Kiev, p. 98 (in Ukrainian transl. In Fluid Inclusion Research Proc. COFFI, 12 214-... 

Lenz C, Nasdala L, Talla D et al (2015) Laser-induced REE " photoluminescence of selected accessory minerals - an advantageous artefact in Raman spectroscopy. Chem Geol Lupashko T, Tarashchan A, Kvasnytsya V et al (1996) Luminescence, EPR and morphology of diamond crystals from placer deposits. In Abstracts of third European meeting Spectroscopic Methods in Mineralogy , Kiev, 10-13 p 27... 

Another laser based technique, which may be used together with time-resolved luminescence, is Raman spectroscopy. It is very well known technique, which is widely used in mineralogy. Several reviews have been recently published mostly devoted to minerals (Dubessy et al. 1994 Nasdala et al. 2004 Smith and Dent 2005 Jasinevicius 2009 Dubessy et al. 2012 Panczer et al. 2012). Thus only the theoretical aspects which are the mostly relevant to our research devoted to the real time online quahty control of minerals will be considered. 

Over the past decade, Raman spectroscopy has continued to develop as a prime candidate for the next generation of in situ planetary instruments, as it provides definitive stmctural and compositional information of minerals in their natural geological context. A time resolved Raman spectrometer have been developed that uses a streak camera and pulsed miniature microchip laser to provide picosecond time resolution (Blacksberg et al. 2010). The ability to observe the complete time evolution of Raman and fluorescence spectra in minerals makes this technique ideal for exploration of diverse planetary environments, some of which are expected to contain strong, if not overwhelming, fluorescence signatures. In particular, it was found that conventional Raman spectra from fine grained clays. 

Sharma S, Lucey P, Ghosh M et al (2003) Stand-off Raman spectroscopic detection of minerals on planetary surfaces. Spectrochim Acta A 59 2391-2407 Singh J, Thakur S (2007) Laser-induced breakdown spectroscopy. Elsevier, Amsterdam Smith E, Dent G (2005) Modem Raman spectroscopy a practical approach. Wiley, Hoboken Steinfeld J, Wormhoudt J (1998) Explosives detection a challenge for physical chemistry. Ann Rev Phys Chem 49 203-232... 

Abstract world class unconformity-related U deposits occur in the Proterozoic McArthur Basin (Northern Territory, Australia) and Athabasca Basin (Saskatchewan, Canada). Widespread pre-to post-ore silicifications in the vicinity of the deposits, allow proper observation of paragenetically well-characterized fluid inclusions. We used a combination of microthermometry, Raman microspectroscopy and Laser Induced Breakdown Spectroscopy (LIBS), to establish the physical-chemical characteristics of the main fluids having circulated at the time of U mineralization. The deduced salinities, cation ratios (Na/Ca, Na/Mg) and P-T conditions, led to the detailed characterization of a NaCI-rich brine, a CaCl2-rich brine and a low-salinity fluid, and to the identification of mixing processes that appear to be key factors for U mineralization. 

Sedlachek A, Ray M, Wu M (2004) Application of UV Raman scattering to non-traditional standoff chemical detection. Trends Appl Spectrosc 5 19-38 Senesi G (2014) Laser-Induced Breakdown Spectroscopy (LIBS) applied to terrestrial and extraterrestrial analogue geomaterials with emphasis to minerals and rocks. Earth Sci Rev 139 231-267... 

LIBS additional advantage is that it is a laser-based technique, therefore easily combined with other laser spectroscopy techniques, such as time-resolved luminescence and gated Raman. Specifically for the mining industry, such spectroscopic combination would enable analyses of both elements and minerals with characteristic luminescence or Raman signals, while PGNAA and XRF can only analyze elements. 

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