A perturbed hard‐sphere, corresponding states model for liquid metal solutions

Abstract

Molecular thermodynamics is used to develop a new model for the prediction of the thermodynamic properties of liquid metal mixtures. It combines corresponding states theory with a perturbed hard sphere model to predict successfully, without adjustable parameters, a variety of mixture properties from pure component properties for simple eutectic mixtures. SCOPEThe use of liquid metals as solvents for chemical processes is becoming increasingly'important, making it essential to have a valid and useful method for the prediction of the thermodynamic properties of liquid metal solutions. Previous research had applied modern statistical mechanical methods to pure liquid metals and separate work had successfully used corresponding states theory for pure liquid metal properties. The goal of this work was to combine the theory of correspond-ing states with a perturbed hard-sphere representation of the liquid to correlate and predict both pure component and mixture properties for liquid metal solutions. Currently, the state of the art in molecular thermodynamics permits excellent design methods for typical organic reactions and separation processes; such a method as proposed here, if successful, would extend the same advantages to high-temperature, liquid metal solvent processes. CONCLUSIONS AND SIGNIFICANCEA statistical mechanical description of the liquid state is combined with the practical empiricism of classical thermodynamics to give a workable theory for the thermodynamic behavior of liquid metal mixtures. The resulting model is of practical value for thermodynamic calculations in metallurgical processes involving liquid metals and liquid metal mixtures. In this formulation, a three-parameter theory of corresponding states, based an hard-sphere perturbation theory, isused to The American Institute of Chemical Engineers. 1981.ing states, based on hard-sphere perturbation theory, is used to correlate the thermodynamic properties of pure liquid metals; the resulting expressions are extended to the prediction of thermodynamic properties of multicomponent liquid metal mixtures. The extension to solution behavior for mixtures is accomplished without the use of adjustable parameters.The model is also used to predict quantitatively solid-liquid equilibria and liquid-liquid partial miscibility for binary metal mixtures. The treatment is applicable to multicomponent systems exhibiting either positive or negative deviations from ideal solution behavior, including partial miscibility, but is not applicable to mixtures exhibiting intermetallic compound formation.

Nonideal behavior in liquid metal solutions. 1. Physical theory model

“…Clearly if gE data exist at one temperature, even if they are fragmentary, these may be used to evaluate AZ by the usual fitting techniques (Prausnitz et al, 1980). Fortunately for liquid metal mixtures, there exists virtually always a phase diagram showing a eutectic point, and this is so-to-speak a "free" datum which almost always is available and can easily be used to evaluate a mixture parameter (Paulaitis and Eckert, 1981).…”

“…These calculations have been applied to a few systems only, mainly liquid alkali alloys, and have not been extended to a wide category of metallic solutions. Paulaitis and Eckert (1981) proposed a physical model which combined corresponding-states theory with a perturbed hard-sphere representation for predicting mixture properties. Another model based on an electron theory which includes both structure-dependent and structureindependent contributions has been developed by Cox (1979).…”

In Honor of Charles A. Eckert

“…Chuck and his students have also done important work on the molecular thermodynamics of liquid metal solutions. [50][51][52][53][54] Chuck Eckert's research accomplishments have earned him numerous awards. In 1971 he was appointed a Guggenheim Foundation Fellow, and shortly thereafter, in 1973, he received the AIChE's Allan P. Colburn Award, for the application of molecular thermodynamics to chemical kinetics.…”

“…This is a key quantity for separations involving a dilute solute, as is the case in many environmental problems. Chuck and his students have also done important work on the molecular thermodynamics of liquid metal solutions. − …”