Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation

Details Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation

Oct 1981

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1981gecoa..45.1733s&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 45, Issue 10, pp.1733-1741

Computer Science

1

Scientific paper

A quasi-chemical model for illites has been derived, and local electrostatic balance has been added to a random regular solution site-mixing model for illites ( , 1979). Each model assumes similar order-disorder conditions for both the end-members micas and the solid solution. Thermodynamic properties of illites predicted by the random, electrostatic, and quasi-chemical models are compared as a function of composition. For natural illite compositions, molar entropies of mixing in the electrostatic model are about 1 entropy unit less than those in the random model. Intermediate values are given by the quasi-chemical model. Each model predicts an increased entropy of mixing in dominantly trioctahedral illites as compared to dioctahedral illites. Each model also predicts destabilization of trioctahedral illites using absolute molar exchange energies greater than 2 RT / Z x , where Z x is the number of adjacent cation interactions per site in the X th site class. The most negative free energies of mixing are predicted by the quasi-chemical model. Intermediate values predicted by the random model are apparently the result of error cancellation due to overestimation of both the entropy and enthalpy of mixing.

Affiliated with

Also associated with

No associations

Rating

Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation 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 Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refinements in a site-mixing model for illites: local electrostatic balance and the quasi-chemical approximation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1469169