Hydration Analysis and the Expansion of Relative Activity Coefficients

2000 ◽  
Vol 65 (12) ◽  
pp. 1833-1838
Author(s):  
Jaroslav Nývlt

Of correlation methods for solubility in ternary systems, the method of expansion of relative activity coefficients and the hydration analysis are based on the thermodynamic condition of phase equilibria. Both of them require only reliable solubility data in the ternary system and corresponding binary systems. Correlation parameters of both of these methods are interrelated and the methods are compared on the system K2SO4-H2SO4-H2O at 50 °C.

1994 ◽  
Vol 59 (9) ◽  
pp. 1911-1921 ◽  
Author(s):  
Jaroslav Nývlt ◽  
Jitka Eysseltová

Hydration analysis, which enables information on ionic processes in saturated solutions to be derived from solubility data in ternary systems, was applied to the interpretation of solubility interaction constants from the relative activity coefficient expansion. A close relationship was found between the hydration analysis parameters and the solubility interaction constants characterizing the relative activity of solute, which extends our insight into the ionic behaviour of the system studied by using the values of the interaction constants.


The liquid-vapour equilibrium of the system methane-ethylene has been determined at 0, -42 , -78, -88 and -104° C over a wide range of pressures and the results are shown on a pressure-composition-temperature diagram and by a series of pressure-composition curves. The liquid-vapour equilibrium of the ternary system methane-ethane-ethylene has been determined at -104, -78 and 0° C. Values for the two binary systems methane-ethane and methane-ethylene and for the ternary system methane-ethane-ethylene are shown on a composite pressure-composition diagram.


2017 ◽  
Vol 898 ◽  
pp. 1036-1041
Author(s):  
M.H. Rong ◽  
S.D. Lin ◽  
Jiang Wang ◽  
H.Y. Zhou ◽  
G.H. Rao

Ternary intermetallic compounds with rare earth elements and transition metals in the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems show interesting magnetic properties. As key sub-binary systems of the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems, the information of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems are indispensable to explore the RE-Mn-X (X=Si, Ge, Sn etc.) alloys with better magnetic properties. In this work, the experimental data of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems in the published literature were reviewed. Based on the available experimental information, thermodynamic calculation of phase equilibria of the Mn-RE (RE=Nd, Gd, Dy) binary systems was performed using the CALPHAD method. As a result, further experimental investigation and thermodynamic optimization would be still necessary in order to develop the self-consistent and compatible thermodynamic database of the RE-Mn-based alloy systems.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2396 ◽  
Author(s):  
Jinfa Liao ◽  
Hang Wang ◽  
Tzu-Yu Chen

The phase equilibrium of the Ni–Al–La ternary system in a nickel-rich region was observed at 800 °C and 1000 °C using scanning electron microscopy backscattered electron imaging, energy dispersive X-ray spectrometry and X-ray diffractometry. The solubility of Al in the Ni5La phase was remeasured at 800 °C and 1000 °C. Herein, we report a new ternary phase, termed Ni2AlLa, confirmed at 800 °C. Its X-ray diffraction (XRD) pattern was indexed and space group determined using Total Pattern Solution (TOPAS), and the suitable lattice parameters were fitted using the Pawley method and selected-area electron diffraction. Ni2AlLa crystallizes in the trigonal system with a space group R3 (no. 146), a = 4.1985 Å and c = 13.6626 Å. A self-consistent set of thermodynamic parameters for the Al–La and Ni–La binary systems and the Ni–Al–La ternary system includes a Ni2AlLa ternary phase, which was optimized using the CALPHAD method. The calculated thermodynamic and phase-equilibria data for the binary and ternary systems are consistent with the literature and measured data.


2017 ◽  
Vol 1142 ◽  
pp. 62-68
Author(s):  
Xiao Long Chen ◽  
Jiang Wang ◽  
Tai Li Chen ◽  
Mao Hua Rong ◽  
Guang Hui Rao ◽  
...  

The Fe-RE (RE=Gd, Tb, Dy, Lu) binary systems with the experimental data of phase equilibria and thermodynamic properties in the published literature were reviewed firstly. Based on available phase equilibria data and thermodynamic data, the Fe-RE (RE=Gd, Tb, Dy, Lu) binary systems were assessed thermodynamically using the CALPHAD method. As a result, further experimental investigations and thermodynamic calculations would be both required in order to develop thermodynamic database of the RE-Fe-B ternary systems, which is very useful to study the relations between alloy compositions, microstructure and magnetic properties of novel Nd-Fe-B-based permanent magnets.


1973 ◽  
Vol 51 (7) ◽  
pp. 1032-1040 ◽  
Author(s):  
R. C. Kerby ◽  
J. R. Wilson

The phase equilibrium relationships of several vanadate systems have been studied by a combination of differential thermal analysis (DTA) and X-ray powder diffraction methods. All systems studied were eutectic in nature. The liquidus temperatures of the sodium vanadates were found to depend on the oxygen partial pressure for sodium oxide concentrations between 1.0 and 36 mol%. This effect was not observed for the ferric vanadate, chromic vanadate or magnesium vanadate systems. The solid–liquid phase equilibria for the ternary vanadate systems V2O5–Na2O–Fe2O3, V2O5–Na2O–Cr2O3, and V2O5–Na2O–MgO were measured by determining the temperature–composition data for various quasi-binary systems within each ternary system. Liquidus temperatures between 500 and 700 °C were found for those compositional ranges containing greater than 40 mol% V2O5 and between 10 and 60 mol% Na2O. The liquidus temperatures decreased with increasing oxygen partial pressure over much of the same compositional range.


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