Structural Properties of Concentrated Aqueous Solutions of Lithium Chloride Near the Critical Point of Water as Calculated by the Integral Equation Method

Abstract

The integral equation method was used to study structure formation in concentrated aqueous solutions of lithium chloride in the near-critical region (P = 20 MPa, T = 298-623 K). It is found that when the LiCl–H₂O system passes from a concentrated state to a melt-like one ($LiCl{\kern 1pt} :{\kern 1pt} 8H_{2} O \to {\kern 1pt} LiCl{\kern 1pt} :{\kern 1pt} 6H_{2} O{\kern 1pt} \to {\kern 1pt} LiCl{\kern 1pt} :{\kern 1pt} 4H_{2} O{\kern 1pt} \to {\kern 1pt} LiCl{\kern 1pt} :{\kern 1pt} 3H_{2} O$), some of its structural characteristics change oppositely depending on temperature, leading to anomalous structural properties of the most concentrated solution. Analyzing the temperature dependence of coordination numbers we established the temperature range and the steps of structural changes in the LiCl–H₂O system.