Abstract
In order to obtain the basic data for processing the bittern produced from the brine made by evaporation with ion exchange membrane, it is necessary to examine the existence of the chemical formula of the double salt composed of potassium chloride and calcium chloride.
It has so far been reported by Lightfoot and Assarsson that only one double salt exists in the system of KCl-CaCl2-H2O·Lightfoot has reported of 2 KCl-CaCl2-H2O, while Assarsson has reported of KCl·CaCl2·
However, after the authors examined their reports, they found the inconsistence:(1) KCl·CaCl2 has been reported to exist at 50°C and 2 KCl·CaCl2·2 H2O at 75°C, and (2) the both reports have mentioned the equilibrium values of the solution of each double salt at 95°C.
From the results of our residual method and X-ray diffraction, the authors reached the conclusion that only KCl·CaCl2existed as the bouble salt of potassium and calcium chloride.
