SALT EFFECT PARAMETER FROM TIE LINE CORRELATION CONSTANTS

The tie line correlation given by Eisen and Joffe for correlating the equilibrium data of salt-containing ternary liquid-liquid equilibrium systems, i.e. In(X(CB)/X(BB)) = a + bX(s) + (c + dX(s)) In(X(CA)/X(AA) ) is related to the Setschenow equation, i.e. In(X(CA)(o)/X(CA)) = k(s )X(SA) It is shown that the Setschenow constant or the salt effect par ameter k(s) can be obtained from the tie line correlation constants a, b, c and d and the salt concentration X(s): k(s) - A(100-X(s))/c+dX(s ) with A = b - ad/c + (d/c) In(X(CB)/X(BB)) Such calculated k(s) value s for various salts vary from 0.36 to 7.42 and are in accordance with those reported in the literature. The results show that, although the salt effect parameter decreases, the salt effect increases with increa se in salt concentration.