Revised equations for determining the critical properties of NaCl-H2O system

Revised equations for determining the critical properties of NaCl-H2O system were fitted on the previous critical data of NaCl-H2O solutions. They are T = 374e(0.02267S+0.00004277S2) , P = 221e(0.04156S+0.1 160S1/2) and V = 3.11e(-0.23594 Psi+0.002837 Psi 2) where T, P, V and S are the critical temperature, critical pressure, critical volume and the salinity of NaCl-H2O solution with the units of degrees C, bar, cm(3)/g and weight percent of NaCl respectively, and Psi=ln(S+1). These equations are valid for the salinities up to 36.6% NaCl by weight and temperatures up to 900 degrees C, which are adequate for the study on the mechanism of supercritical geofluids taking part in the hydrothermal metallic mineralization.