.rbcl-nacl/kcl-roh-h <sub> 2 </ Sub> O Quaternary System Multi-temperature Phase Behavior Of (r = Ch <sub> 3 </ Sub>, Ch <sub> 3 </ Sub> Ch <sub> 2 </ Sub>, Ch <sub> 3 </ Sub> Ch <sub> 2 &l

The reserves of rubidium is rare and scattered in nature, so it is been called the rare alkali-metal, but the application is wide in such fields as ion rocket engine, information technology, nuclear energy, and space technologies. Accordingly, the study of separation and purification of these metals could be extremely siginficance because of the contradictions of scatterance and widely application. The aim of the study about the alkali-metals and mixed solvents was not only to provide the plenty of basic data for the applied research, but also to develop the solution chemistry.This experiment work mainly includes three sections: the first part is the review; the second one is the experimental one; the third one is the discussion of the study.In the review, the basic knowledge of rubidium and their compounds were introduced firstly. Then we present the investigation of inorganic salts-mixed solvent systems and the importance is paid on the systems of alkali metal and alkali earth metal salts.In the second part, we introduce the technology and the way of the experiment. The semi-micro phase equilibrium apparatus as well as the corresponding technology of the sample withdrawing and the analysis have been used to study the equilibrium phase behavior of the systems. We study the equilibrium phase behavior of the quaternary systems NaCl+RbCl+CH₃OH/C₂H₅OH /1-C₃H₇OH/2-C₃H₇OH+H₂O at 15℃, 25℃, 35℃and the quaternary systems KCl+RbCl+1-C₃H₇OH/2-C₃H₇OH+H₂O at 25℃. We investigated the solubility, density and refractive index for the methanol and ethanol systems. More over, we investigated the liquid-liquid equilibrium phase data that used the "cloud point" and "tie-line" methods.In the third part, we had discussed the study of the different systems. In the all systems, the methanol and ethanol systems are the systems that without dividing by layer. The other systems are the ones that dividing by layer. For the methanol and ethanol systems, we have fitted the experimental data of the solubility, density and refractive index with different equations and the results are reasonable. We also have drawed the phase diagrams of the systems on the study. For the propanol systems, we have drawed the completely phase diagram. What's more, we have fitted the binodal data by the five-parameter equation lnw₁=A+Bw₂^0.5+Cw₂+Dw₂²+Ew₂³, at the same time, we also have correlated the tie line data by the modified Eisen-Joffe equation lg(w₁/w₄)_or = (α₁ +β₁ 100(w₃)_aq +(γ₁+δ₁ 100(w₃)_aq)×lg(w₁/w₄))_aq + (λ₁ +η₁ 100(w₃)_aq)×(lg(w₁/w₄)aq) ², then we give the parameters of the two equations as well as the standard deviations. The results are satisfactory. At the last, we made an explanation for the mechanism of the liquid-liquid equilibrium.