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(2) There is no thermodynamic support to the contention that Na would not be removed <br />from solution. <br />The second refutation is a simple thermodynamic observation. On page 5 of the report, several <br />possible reactions involving Na' are discussed as potential mechanisms for reducing Na-content <br />of water. These ion exchange reactions are <br />2NaA1Siz06•HZO+CaZ =Ca(AISiZ06)Z•HZO+2Na' <br />2NaAlSr206•HZO+MgZ =Mg(A1Sr206)•Hz0+2Na <br />Mgr +Na-Clay=2NaZ +Mg-Clay <br />Cat +Na-clay=2Na'+Ca-clay <br />The statement is made that the Edwards Portal spring water could not be "in-mine fault water" <br />because no plausible mechanism exists for reducing the Na content of water between the in-mine <br />faults and the Edwazds Portal spring because the loss in Na would require reverse ion exchange. <br />That ignores the equilibrium constant of the reaction, mathematically described by the Gibbs <br />Free Energy G in the following equation: <br />OG ~~• _ -RTInKa <br />where the (G) is a function of temperature and the equilibrium constant KQ of the reaction. <br />Using the 4th mineral reaction listed above, in which Na is exchanged for Ca in a clay, <br />Cat +Na-clay=2Na'+Ca-clay <br />the equilibrium constant is the activity of the reaction products divided by that of the reactants. <br />Symbolically, <br />R a °(aNa)~(ae~g~my)~(a,Ng)(aNo~my) <br />The activity (a) is essentially the concentration of each of those reaction constituents (Na, Ca, <br />Na-clay and Ca-clay). The K, term is a constant for the temperature, so the proportions of <br />each participant in the reaction adjust to maintain equilibrium concentrations at the temperature <br />at which the reaction is occurring. Thai is, if the Na-concentration of the system in which the <br />reaction is going on is very high, the reaction is effectively "driven" to the left, taking Na from <br />solution and replacing Ca on the clay, thus removing Na ions from the water in place of calcium. <br />