Pitzer Model Based Study of CsX-NiX2-H2O (X = Cl, Br) Systems at 298.15 K

1996 ◽  
Vol 61 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Christomir Christov
Keyword(s):  
Thermodynamic Functions ◽  
Interaction Model ◽  
Pitzer Model ◽  
Solubility Diagrams ◽  
Model Based ◽  
Solubility Products ◽  
Ternary Parameters ◽  
Ion Interaction Model ◽  
Good Agreement

The Pitzer ion-interaction model was used for simulating the CsX-NiX2-H2O (X = Cl, Br) systems at 298.15 K. The necessary thermodynamic functions (binary and ternary parameters, thermodynamic solubility products) were calculated and the theoretical solubility diagrams plotted. A very good agreement was found between the calculated and observed data.

Thermodynamic Study of the CuCl2-MCl2-H2O Systems (M = Mg, Co) at 298.15 K

1996 ◽  
Vol 61 (4) ◽  
pp. 507-511 ◽  
Author(s):  
Christomir Christov
Keyword(s):  
Thermodynamic Functions ◽  
Interaction Model ◽  
Thermodynamic Study ◽  
Interaction Parameters ◽  
Solubility Diagrams ◽  
Solubility Products ◽  
Ion Interaction Model ◽  
Good Agreement

The Pitzer ion-interaction model was used for a simulation of the CuCl2-MCl2-H2O (M = Mg, Co) systems at 298.15 K. The necessary thermodynamic functions (binary and ternary ion-interaction parameters and thermodynamic solubility products) were calculated and the theoretical solubility diagrams plotted. A very good agreement was obtained between the calculated and observed data.

Study of the Conversion of CaSO4 to CaCO3 within the CaSO4 + Na2CO3 = CaCO3 + Na2SO4 Four-Component Water-Salt System

1995 ◽  
Vol 60 (12) ◽  
pp. 2107-2111 ◽  
Author(s):  
Dimitar Trendafelov ◽  
Christomir Christov ◽  
Christo Balarew ◽  
Aneta Karapetkova
Keyword(s):  
Free Energy ◽  
Calcium Sulfate ◽  
Interaction Model ◽  
Sea Salt ◽  
Salt System ◽  
Molar Gibbs Free Energy ◽  
High Dispersity ◽  
Water Salt ◽  
Solubility Products ◽  
Ion Interaction Model

The Pitzer ion-interaction model was employed to predict the conversion in the title quaternary water-salt system. The thermodynamic solubility products (Ks0) were determined and the conversion of CaSO4 to CaCO3 in the CaSO4 + Na2CO3 = CaCO3 + Na2SO4 system was predicted. The standard molar Gibbs free energy ∆rG0 of the conversion reaction was calculated to be -23.62 kJ mol-1. A 98% degree of conversion of CaSO4 was achieved by using calcium sulfate isolated from sea salt production waste brines. Suitable conditions were found for obtaining CaCO3 exhibiting a high dispersity and whiteness.

Solubility Prediction for the Reciprocal Quaternary System (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15 K Using Pitzer Ion-Interaction Model

2012 ◽  
Vol 549 ◽  
pp. 437-440 ◽  
Author(s):  
Shi Qiang Wang ◽  
Ya Fei Guo ◽  
Tian Long Deng
Keyword(s):  
Quaternary System ◽  
Salt Lake ◽  
Interaction Model ◽  
Linear Regression Method ◽  
Solubility Prediction ◽  
Temperature Dependent ◽  
Solubility Predictions ◽  
Multiple Linear Regression Method ◽  
Ion Interaction Model ◽  
Salt Lake Brine

Solubilities of the reciprocal quaternary system (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15K were calculated using Pitzer and its extended HW model. The values of the Pitzer single-salt parameters β(0), β(1), β(2)and Cφfor LiCl, MgCl2, Li2SO4, and MgSO4, the mixed ion-interaction parameters θLi,Mg, θCl,SO4, ψLi,Mg,Cl, ψLi,Mg,SO4, ψLi,Cl,SO4and ψMg,Cl,SO4, and the Debye–Hückel parameter Aφin the system at 273.15K were derived either temperature-dependent equation or through fitting solubility data of the ternary system by multiple linear regression method. Based on the Jänecke indexes, the phase diagram was plotted. This study affords the necessary parameters for solubility predictions of complicated systems and establishes a theoretical basis for the separation of these valuable minerals from salt lake brine.

Comments on the Urban Spatial-Interaction Model Based on the Intervening-Opportunities Principle

1979 ◽  
Vol 11 (5) ◽  
pp. 527-539 ◽  
Author(s):  
Irena Chudzyńska ◽  
Z Słodkowski
Keyword(s):  
Mathematical Model ◽  
Spatial Interaction ◽  
Interaction Model ◽  
Spatial Interaction Model ◽  
Model Based ◽  
Number Of Equilibria ◽  
Intervening Opportunities

A mathematical model of urban spatial interaction based on the intervening-opportunities principle is discussed and its equilibria are studied. It is shown that, under natural assumptions, the number of equilibria is finite, and a mathematical criterion for distinguishing the equilibrium corresponding to reality is given.

scholarly journals A Deformation Dipole Model for Crystals: Application to NaCI

1983 ◽  
Vol 36 (6) ◽  
pp. 897 ◽  
Author(s):  
DD Richardson ◽  
J Mahanty
Keyword(s):  
Lattice Dynamics ◽  
Theoretical Calculations ◽  
Ion Pairs ◽  
Dipole Model ◽  
Model Based ◽  
Good Agreement

We present a deformation dipole model based on theoretical calculations of induced moments in ion pairs. The model is generally applicable and in this paper is applied to the calculation of the lattice dynamics of NaCI. Only a few parameters are required to give good agreement with experiment. Limitations of the approach are discussed.

scholarly journals The Physical and Thermodynamic Functions of Borides

2017 ◽  
Vol 18 (1) ◽  
pp. 58-63
Author(s):  
N.Yu. Filonenko
Keyword(s):  
Free Energy ◽  
Physical Properties ◽  
Thermodynamic Functions ◽  
Point Of View ◽  
Energy Potential ◽  
High Temperature Expansion ◽  
Temperature Dependences ◽  
Function Calculation ◽  
First Time ◽  
Good Agreement

In the paper the physical properties and thermodynamic functions of borides Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr) are studied with accounting for fluctuation processes. We use the microstructure analysis, the X-ray structural and the durometric analyses to determine the physical properties of alloys. In the paper it is determined the phase composition and physical properties of borides. In this paper for the first time it is determined the thermodynamic functions of borides using the Hillert and Staffansson model with accounting for the first degree approximation of high-temperature expansion for the free energy potential of binary alloys. We obtain the temperature dependences for such thermodynamic functions as Gibbs free energy, entropy, enthalpy and heat capacity Ср along with their values at the formation temperature for Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr). The approach under consideration enables to give more thorough from the thermodynamic point of view description of borides formed from the liquid. The outcomes of the thermodynamic function calculation for borides are in good agreement with experimental data and results of other authors.

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