The molar enthalpy of dehydration of cordierite

Journal Article · · American Mineralogist; (United States)

OSTI ID:7006403

Carey, J W ^[1]; Navrotsky, A ^[2]

---

1. Harvard Univ., Cambridge, MA (United States)
2. Princeton Univ., NJ (United States)

The molar enthalpy of dehydration of hydrous cordierite (Mg[sub 2]Al[sub 4]Si[sub 5]O[sub 18][center dot] nH[sub 2]O) was determined by transposed temperature drop calorimetry. Six samples ranging from 0 to 0.84 H[sub 2]O per formula unit were examined. The observed enthalpy of dehydration is a linear function of H[sub 2]O content indicating an ideal enthalpy of mixing for H[sub 2]O in cordierite. The molar enthalpy of dehydration is 41.8 [plus minus] 1.6 kJ/mol at the reference conditions 25 C, 1 bar, and gaseous H[sub 2]O. This value is the same as the molar enthalpy of vaporization for water (40.9 kJ/mol) within experimental uncertainty and is considerably less than that found for the dehydration of zeolites (61-84 kJ/mol).

• DOE Contract Number: AC02-83ER13096; FG02-87ER13799; FG02-85ER13437
• OSTI ID: 7006403
• Journal Information: American Mineralogist; (United States), Journal Name: American Mineralogist; (United States) Vol. 77:9-10; ISSN AMMIAY; ISSN 0003-004X
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
152002* -- Geothermal Data & Theory-- Properties of Minerals & Rocks
58 GEOSCIENCES
580000 -- Geosciences
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CALORIMETRY
DEHYDRATION
ENTHALPY
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IRON COMPOUNDS
MAGNESIUM COMPOUNDS
MATERIALS
MINERALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
ZEOLITES