Phase Behavior of the System UO₂SO₄-CuSO₄-H₂SO₄-H₂O, at Elevated Temperatures.

Abstract

pounds of water and 0.6 pound of methyl ethyl ketone, the other containing 99.4 pounds of methyl ethyl ketone and NOMENCLATURE Ffluid phase existing above critical pressure of ethylenesolvent binary at temperature of diagram L =* single liquid phase existing over entire range of watersolvent compositions, usually at low ethylene concentrations Lj * water-rich or more dense liquid phase La = solvent-rich or less dense liquid phase Pl * low pressure, about 1 to 5 atm.

Visual and in situ Raman spectroscopic observations of the liquid–liquid immiscibility in aqueous uranyl sulfate solutions at temperatures up to 420°C

“…Unlike previous observations [9,11], the liquid-liquid immiscibility was found to be fairly stable in aqueous UO2SO4 solutions because no precipitates were observed in all the investigated samples at temperatures up to 420 ºC. To investigate the possible changes in the thermodynamic properties of the UO2SO4-H2O system, Yang and…”

“…The phase behaviors of 1.04 mol/kg UO2SO4 in the optical cell were illustrated Since liquid-liquid immiscibility is undesirable in homogenous reactors using UO2SO4 (H2O/D2O) solutions as fuels [10], many experimental observations were carried out to describe the phase boundaries of the two immiscible liquids under saturation pressures or hydrostatic pressures [9,12]. As shown in Fig.…”

“…It should be noted that no precipitate was formed in this case, even though the temperature reached the supercritical point of water. Among these sulfate-water systems, the UO2SO4-H2O system has been studied for a long time because the liquid-liquid phase separation temperature constitutes the upper limit for the operation of aqueous homogeneous reactors [8][9][10][11][12]. For example, Marshall and coworkers observed the liquid-liquid immiscibility at elevated temperatures and pressures (280-450 ºC, 7.5-180 MPa) [12].…”

In situ observations of liquid–liquid phase separation in aqueous ZnSO4 solutions at temperatures up to 400 °C: Implications for Zn2+–SO42− association and evolution of submarine hydrothermal fluids

“…Unlike previous observations [9,11], the liquid-liquid immiscibility was found to be fairly stable in aqueous UO2SO4 solutions because no precipitates were observed in all the investigated samples at temperatures up to 420 ºC. To investigate the possible changes in the thermodynamic properties of the UO2SO4-H2O system, Yang and Pitzer conducted theoretical calculations at temperatures close to the critical temperature of the liquid-liquid immiscibility [27].…”

Phase Equilibria in Binary and Ternary Hydrothermal Systems

“…Such thermostat can be a stirred air bath (Kracek, 1931a,b,c;Akhumov and Vasil'ev, 1936;Bergman and Kuznetsova, 1959;Huang et al, 1985;Wang and Chao, 1990;Brown et al, 2000, etc. ) or liquid thermostat with low-melting salt mixtures (LiNO 3 (30 mass %), NaNO 3 (14 mass %), KNO 3 (56 mass %) (T melt = 113 °C) or NaNO 3 (46 mass %), KNO 3 (54 mass %) (T melt = 222 °C) (Clark et al, 1959;Barton et al, 1961;Connolly, 1966, etc. ) or with silicone oil (Pryor and Jentoft, 1961;Sinke et al, 1985).…”