Dehydration processes in borate minerals: pentahydroborite and nifontovite from Fuka Mine, Okayama Prefecture, Japan
| Autor: | Nenad Tomašić, Željka Žigovečki Gobac, Krešimir Furić, M. Rajić Linarić, Vladimir Bermanec |
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| Rok vydání: | 2010 |
| Předmět: |
Thermogravimetric analysis
Mineral 010504 meteorology & atmospheric sciences pentahydroborite nifontovite calcium borate thermal decomposition water content Thermal decomposition Inorganic chemistry Mineralogy chemistry.chemical_element 010502 geochemistry & geophysics medicine.disease 01 natural sciences Decomposition chemistry.chemical_compound chemistry Geochemistry and Petrology Differential thermal analysis medicine Dehydration Boron Calcium borate Geology 0105 earth and related environmental sciences |
| Zdroj: | Mineralogical Magazine. 74:1013-1025 |
| ISSN: | 1471-8022 0026-461X |
| DOI: | 10.1180/minmag.2010.074.6.1013 |
| Popis: | Data on the dehydration of pentahydroborite, CaB2O(OH)6·2H2O and nifontovite, Ca3B6O6(OH)12·2H2O from the Fuka mine, Japan are presented. Critical temperatures of the dehydration of the borates were determined by thermogravimetric analysis/differential thermal analysis measurements. The untreated mineral samples and their heating products were investigated by X-ray diffraction and Raman spectroscopy. Upon dehydration, both minerals decompose and undergo amorphization, and at greater temperatures crystallize as an orthorhombic calcium borate, CaB2O4 (Pnca). The dehydration paths of the two minerals are different, with nifontovite showing a greater resistance to decomposition and amorphization than pentahydroborite. Differences in the dehydration processes are related to the residuals of the water content and structural accommodation of the borate polyanion. |
| Databáze: | OpenAIRE |
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