9303814 Hovis This research project will focus on energies of mineral processes. Aspects of particular interest include the energies of mixing in ternary feldspars and the nepheline- kalsilite system as determined by investigating the enthalpies and volumes of K-Na mixing, the Gibbs energies and entropies of mixing for nepheline-kalsilite as yielded by phase equilibrium (solvus) measurements, the dependence of enthalpies and volumes of mixing, normally assumed to be constant with T and P, on these variables, and the energies associated with other mineral processes such as order- disorder in orthopyroxenes and exsolution in alkali feldspars. The major techniques to be utilized include solution calorimetry, drop calorimetry, and room- and high- temperature x-ray powder diffraction.
