Aluminum speciation and equilibria in aqueous solution: I. The solubility of gibbsite in the system Na-K-Cl-OH-Al(OH) sub 4 from 0 to 100C

Journal Article · Sat Feb 29 23:00:00 EST 1992 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(92)90047-M· OSTI ID:7278378

Wesolowski, D J ^[1]

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1. Oak Ridge National Lab., TN (United States)

The solubility of gibbsite, Al(OH){sub 3}, has been measured in a large number of solutions in the system Na-K-Cl-OH-Al(OH){sub 4} from 6.4 to 80C and 0.01 to 5.0 molal ionic strength. These results have been coupled with selected literature data and modeled using the Pitzer ion interaction treatment. An eight-parameter expression is derived for the molal concentration quotient of the reaction Al(OH){sub 4}{sup {minus}} {r reversible} Al(OH){sub 3} + OH{sup {minus}} in this system from which the equilibrium constant at infinite dilution, log K{sub 4}, and the stoichiometric molal activity coefficient ratio, log ({gamma}OH{sup {minus}}/{gamma}Al(OH){sub 4}{sup {minus}}), can be evaluated over the range 0-100C and 0-12 molal ionic strength at 1 bar with a precision of approximately {plus minus}0.02 log units. Standard thermodynamic properties of the reaction at 25C and 1 bar are log K{sub 4} = 1.143 {plus minus} 0.006, {Delta}H{degree} = {minus}22.5 {plus minus} 0.3 kJ/mol, {Delta}S{degree} = {minus}54 {plus minus} 1 J/K/mol, and {Delta}C{sub p}{sup 0} = {minus}148 {plus minus} 6 J/K/mol. From these quantities and the standard thermodynamic properties of gibbsite, the values of {Delta}G{sub f}{sup 0}, {Delta}H{sub f}{sup 0}, and S{sup 0} of (Al(OH){sub 4}{sup {minus}}){sub (aq)} at 25C and 1 bar are computed to be {minus}1305.6 {plus minus} 1.2 kJ/mol, {minus}1500.6 {plus minus} 1.5 kJ/mol, and 111.4 J/K/mol, respectively. Approximate values of the pure electrolyte parameters {beta}{sup 0}, {beta}{sup 1}, and C{sup {phi}} for NaAl(OH){sub 4} and KAl(OH){sub 4} as well as the mixing parameters for aluminate ion with OH{sup {minus}}, OH{sup {minus}} + Na{sup +}, and OH{sup {minus}} + K{sup +} are also obtained.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7278378
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 56:3; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

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ABSORPTION SPECTROSCOPY
ALKALI METAL COMPOUNDS
ALUMINIUM
ALUMINIUM COMPOUNDS
ALUMINIUM HYDROXIDES
AQUEOUS SOLUTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
CHROMATOGRAPHY
COHERENT SCATTERING
DATA
DIFFRACTION
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
ENTHALPY
ENTROPY
EQUILIBRIUM
EXPERIMENTAL DATA
FOURIER TRANSFORMATION
FREE ENTHALPY
GEOCHEMISTRY
GIBBSITE
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
INFRARED RADIATION
INTEGRAL TRANSFORMATIONS
ION EXCHANGE CHROMATOGRAPHY
METALS
MINERALS
MIXTURES
NUMERICAL DATA
OXIDE MINERALS
OXYGEN COMPOUNDS
PHASE STUDIES
PHYSICAL PROPERTIES
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
RADIATIONS
SCATTERING
SEPARATION PROCESSES
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SOLUBILITY
SOLUTIONS
SPECIFIC HEAT
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
THERMODYNAMIC PROPERTIES
TRANSFORMATIONS
X-RAY DIFFRACTION