کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1696388 1519124 2009 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mineralogical transformations of calcareous rich clays with firing: A comparative study between calcite and dolomite rich clays from Algarve, Portugal
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Mineralogical transformations of calcareous rich clays with firing: A comparative study between calcite and dolomite rich clays from Algarve, Portugal
چکیده انگلیسی

Mineralogical transformations during firing of two extremely calcareous clays, one calcite and other dolomite rich, and relatively poor in silica were studied. Original clays were mineralogical and chemically characterized with X-ray diffraction (XRD) and X-ray fluorescence (XRF). Firing of both clays was carried out in the temperature range 300–1100 °C under oxidizing conditions and the mineralogical transformations were investigated with XRD, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy associated with energy dispersive X-ray spectroscopy (SEM-EDS).Important compositional differences in the neoformed phases were observed between calcite and dolomite rich clays. In the Ca-rich clay the assemblage gehlenite + wollastonite + larnite was observed. In the Mg(Ca)-rich clay the reaction products included akermanite, diopside, monticellite, forsterite, periclase and spinel.XRD and SEM-EDS showed the presence, in both clays, of a potassium–calcium sulfate in samples fired between 900 and 1100 °C.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Clay Science - Volume 42, Issues 3–4, January 2009, Pages 345–355
نویسندگان
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