Hydrotalcite

Formula : Mg4Al2O7:10H2O

Family: 
LDH
Space group: 
Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3m
Dana class: 
16b.6.2.1 (16b)Carbonates - Hydroxyl or Halogen (16b.6) Dana Type (16b.6.2) Sjorgrenite-Hydrotalcite Group (Hydrotalcite subgroup:Rhombohedral)
High temperature: 
Stability ofHydrotalcite at low temperature cannot be dismissed.
Geological context: 
Found associated with serpentinite rocks. Cement phases

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
 V°
cm3·mol-1
 ΔGºf
J·mol-1
 ΔHºf
J·mol-1
 Sº
J·mol-1·k-1
 CP
J·mol-1·K-1
443.332 227.360 (Ref.: 97tay) Taylor H.F.W. , 1997 Cement Chemistry, 2nd. Ed., Thomas Telford, London. -6407255 (Ref.: 10bbla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Thermodynamic data assessment for phases other than C-S-H. Cement and Concrete Research, 40, p. 1360-1374. -7219687 (Ref.: Internal calculation) 512.960 (Ref.: 10bbla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Thermodynamic data assessment for phases other than C-S-H. Cement and Concrete Research, 40, p. 1360-1374. 556.15 (Ref.: 10bbla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Thermodynamic data assessment for phases other than C-S-H. Cement and Concrete Research, 40, p. 1360-1374.
CP(T) = a + b·T + ·c·T-2 (T in Kelvin)
a
J·mol-1·K-1
 b * 103
J·mol-1·K-2
 c * 10-5
J·K·mol-1
 Maier Kelley Ref.
556.15 0.00 0.00 (Ref.: 10bbla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Thermodynamic data assessment for phases other than C-S-H. Cement and Concrete Research, 40, p. 1360-1374.
Reaction properties

Hydrotalcite + 14H+ ⇌ 2Al+3 + 4Mg+2 + 17H2O

298.15 K, 1 bar log10K: 73.76 ΔH°r:-584223 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K 83.20 73.76 63.14 53.74 44.75 37.73 31.92 26.76
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-2490.176972 -0.363272 159288.385312 894.670677 -6739560.722151