We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Physicochemical and Thermochemical Study of Ettringite.
- Authors
Ogorodova, L. P.; Gritsenko, Yu. D.; Kosova, D. A.; Vigasina, M. F.; Melchakova, L. V.; Ksenofontov, D. A.; Dedushenko, S. K.
- Abstract
The paper presents results of a physicochemical study of ettringite, natural calcium hydrosulfoaluminate Ca6Al2(SO4)3(OH)12⋅26H2O, from N'Chwaning, Kalahari, South Africa, by X-ray powder diffraction, IR and Raman spectroscopy, thermal analysis, and calorimetry. The thermal transformation of ettringite has been studied using IR and Raman spectroscopic data. The enthalpies of the stepwise dehydration of the mineral were measured on a NETZSCH DSC 204 F1 (Germany) differential scanning calorimeter. The enthalpy of formation of ettringite from elements ΔfH0(298.15 K) = −17 525 ± 40 kJ/mol was determined using a CETARAM (France) high-temperature heat-flux Calvet microcalorimeter by the method of melt solution calorimetry. The enthalpy of formation of Fe-dominant analogue of ettringite Ca6Fe2(SO4)3(OH)12⋅26H2O was estimated at −16 649 ± 59 kJ/mol.
- Subjects
KALAHARI Desert; SOUTH Africa; ETTRINGITE; HEAT of formation; X-ray powder diffraction; THERMAL analysis; THERMOCHEMISTRY; RAMAN spectroscopy
- Publication
Geochemistry International, 2021, Vol 59, Issue 12, p1188
- ISSN
0016-7029
- Publication type
Article
- DOI
10.1134/S0016702921100050