Other
Scientific paper
Aug 1986
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986gecoa..50.1667m&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 50, Issue 8, pp.1667-1677
Other
9
Scientific paper
Determinations of the aqueous solubilities of kaolinite at pH 4, and of five smectite minerals in suspensions set between pH 5 and 8, were undertaken with mineral suspensions adjusted to approach equilibrium from over- and undersaturation. After 1,237 days, Dry Branch, Georgia kaolinite suspensions attained equilibrium solubility with respect to the kaolinite, for which K eq = (2.72 ± 0.35) × 10 7 . The experimentally determined Gibbs free energy of formation ( G f ,298 0 ) for the kaolinite is -3,789.51 ± 6.60 kj mol -1 . Equilibrium solubilities could not be determined for the smectites because the composition of the solution phase in the smectite suspensions appeared to be controlled by the formation of gibbsite or amorphous aluminum hydroxide and not by the smectites, preventing attempts to determine valid G f 0 values for these complex aluminosilicate clay minerals. Reported solubility-based G f 0 determinations for smectites and other variable composition aluminosilicate clay minerals are shown to be invalid because of experimental deficiencies and of conceptual flaws arising from the nature of the minerals themselves. Because of the variable composition of smectites and similar minerals, it is concluded that reliable equilibrium solubilities and solubility-derived G f 0 values can neither be rigorously determined by conventional experimental procedures, nor applied in equilibriabased models of smectite-water interactions.
Helmke Philip A.
Jackson Marion L.
Klnniburgh D. G.
May Howard M.
No associations
LandOfFree
Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-892697