Numerical Thermodynamic Model of the H2O–LiCl–CaCl2 Fluid System for a Temperature Range from –77 to +50°С

A numerical thermodynamic model of the H2O–LiCl–CaCl2 fluid system is proposed for a temperature range from –77 to +50°C using new parameters of temperature correlations of the Li, Ca, Cl ion interaction and corresponding solubility products within the Pitzer approach. A resulted phase diagram reflects eutectic point $$E^{{''}}$$ and peritectic points $$P_{1}^{{''}}$$ , $$P_{2}^{{''}}$$ , $$P_{3}^{{''}}$$ , $$P_{4}^{{''}}$$ , and $$~P_{5}^{{''}}$$ in the H2O–LiCl–CaCl2 ternary system, which are calculated on the basis of the model, and various phase boundaries of crystal hydrates and shows their compositions. The calculated eutectic point $$E$$ and peritectic point $$P$$ of the H2O–CaCl2 binary system and eutectic point $$E{{'}}$$ and peritectic points $$P_{1}^{'}$$ , $$P_{2}^{'}$$ , and $$P_{3}^{'}$$ of the H2O–LiCl binary system are also shown. The comparison of the calculated model characteristics of the eutectic and peritectic points in the binary subsystems and solubility of solid phases (salt crystal hydrates) is in agreement with experimental data.