Electrolytical properties of solutions of lithium hydroxide at high temperatures and pressures

Abstract

This paper presents experimental and calculated data on dissociation constants and specific and molar (limiting) electric conductivity of aqueous and vapor solutions of LiOH at concentrations ranging from 7.24 × 10−7 to 3.34 × 10−1 mol/kg and temperatures ranging from 298.15 to 646.65 K on the saturation line. To extend the capabilities of estimating the physico-chemical processes at lithium water chemistry under conditions of high temperatures, the graphical dependence of the specific conductivity of aqueous solutions of LiOH on concentration and temperature is given, which shows the advisability of determining concentration from a specific conductivity in the region of a maximum of curves describing the dependence of the specific conductivity on temperature. The values of pH and pOH of solutions of LiOH within the indicated range of concentrations and temperatures have been calculated. It is shown that on dosing LiOH solutions into the boiler water at concentrations from 7.24 × 10−7 to 8.7 × 10−6 mol/kg the values of pH for LiOH and H2O are virtually the same at the temperature of 553 K, which scarcely affects the formation of protective lithium-ferrite film. Five relationships for calculating pH at different values of concentration and specific conductivity of LiOH solutions on isotherms ranging from 373.15 to 616.35 K have been worked out.