A further study of solid-liquid equilibrium for the NaCl-NH₄ Cl-H₂O system

Solid-liquid equilibrium (SLE) values were experimentally determined for the NaCl-NH₄ Cl-H₂O system in the temperature range from 293.15 to 333.15 K, using the flow-cloud-point method (Zhang et al., 1998, Journal of Chemical and Engineering Data, 43, 32-37). A judicially selected equilibrium constant of NH₄Cl, which is consistent with the available literature values, was used to determine a new Pitzer interaction parameter for pure NH₄ Cl. This new parameter, together with the Pitzer mixing parameters determined from correlating the experimental values obtained in this work and some of the literature values, could be used to extend SLE for this system from 273.15 to 373.15 K, satisfying the process simulation requirement involved in the production of soda. (C) 2000 Elsevier Science Ltd. All rights reserved.