Klaus Hack

FactSage Thermochemical Software and Databases

Abstract This paper presents a summary of the FactSage thermochemical software and databases. FactSage was introduced in 2001 and is the fusion of the FACT-Win/F∗A∗C∗T and ChemSage/SOLGASMIX thermochemical packages that were founded over 25 years ago. The FactSage package runs on a PC operating under Microsoft Windows® and consists of a series of information, database, calculation and manipulation modules that enable one to access and manipulate pure substances and solution databases. With the various modules one can perform a wide variety of thermochemical calculations and generate tables, graphs and figures of interest to chemical and physical metallurgists, chemical engineers, corrosion engineers, inorganic chemists, geochemists, ceramists, electrochemists, environmentalists, etc. In this article emphasis is placed on the calculation and manipulation of phase diagrams. However the reputation of FactSage has been established mainly in the field of complex chemical equilibria and process simulation where the software has unique capabilities. Some of these capabilities are also shown in this paper.

CHEMSAGE : A COMPUTER PROGRAM FOR THE CALCULATION OF COMPLEX CHEMICAL EQUILIBRIA

An extensive computer program called ChemSage, based upon the SOLGASMIX Gibbs energy minimizer, is presented together with several examples which illustrate its use. ChemSage was designed to perform three types of thermochemical calculations in complex systems involving phases exhibiting nonideal mixing properties. These are the calculation of thermodynamic functions, heterogeneous phase equilibria, and steady-state conditions for the simulation of simple multistage reactors. The thermodynamic functions module calculates specific heat, enthalpy, entropy, and Gibbs energy with respect to a chosen reference state for a given phase and, if this phase is a mixture, the partial properties of its components. Chemical equilibrium calculations can be made for a system which has been uniquely defined with respect to temperature, pressure (or volume), and composition. One of these quantities may also be replaced by an extensive property or phase target,e.g., for the calculation of adiabatic and liquidus temperatures, respectively.

Use of Thermodynamic Data to Determine Surface Tension and Viscosity of Metallic Alloys

During the last three decades, various thermodynamic databases have been compiled to be applied mainly to the calculation of phase diagrams of alloys, salts, and oxides. The accumulation and assessment of thermodynamic data and phase-equilibrium information to establish those databases is sometimes called the CALPHAD (calculated phase diagram) approach. The CALPHAD approach has been recognized as useful in various aspects of materials science and engineering. In addition to the use of thermodynamic databases for the calculation of phase diagrams, it would be very desirable to apply them to the calculation of other physicochemical quantities, such as surface tension. By doing this, not only can the Utility of databases be enlarged, but also a deeper understanding of the physical properties in question can be reached. On the basis of the concepts just mentioned, we have applied those thermodynamic databases to the calculation of the surface tension of liquid alloys and molten ionic mixtures. In these calculations, we have applied Butlers equation for the surface tension of liquid alloys. In addition, we have modified Butlers equation to be extended to molten ionic mixtures by considering the relaxation structure in the surface. These approaches will lead us to develop a multifunctional data-bank System that will be widely applicable in the evaluation of physicochemical properties of liquid alloys and molten ionic mixtures from thermodynamic data. In this article, we explain some physical modeis for the surface tension and viscosity of liquid alloys and molten ionic mixtures, in which thermodynamic data can be directly applied to evaluate these physical properties. In addition, the concept for the just-mentioned multifunctional thermodynamic data-bank System will be described by demonstrating the simultaneous calculation of phase diagrams, surface tension, and viscosity of some alloys used for new, Pb-free soldering materials.

The thermochemistry library ChemApp and its applications

Abstract ChemApp is a thermochemical software library which enables the user to perform thermochemical calculations across a wide spectrum of applications by providing an easily programmable interface to complex equilibrium calculation techniques for multicomponent, multiphase chemical systems. ChemApp is described, and an overview of selected application examples from areas such as metallurgy, gas phase and aqueous chemistry, combustion technology, corrosion, geochemistry, and more is given.

Calculation of surface tension of liquid BiSn alloy using thermochemical application library ChemApp

The surface tension of liquid Bi-Sn alloys has been calculated using the thermochemical application library ChemApp and thermodynamic data, which are usually applied to calculate various thermodynamic functions and phase equilibria, in a program, ChemSurf, for the calculation of surface tension.

A THERMODYNAMIC EVALUATION OF THE IRON-ZINC SYSTEM

Experimental thermodynamic properties and phase equilibrium data have been used in deriving a thermodynamically consistent analytical description of the thermochemical properties and phase diagram of the Fe-Zn system. A set of coefficients is used to describe the conventional Gibbs free energy of the pure components and stoichiometric intermetallic compounds and the excess Gibbs energies of the solution phases are given. Thermodynamic and phase boundary values calculated with these coefficients agree well with experimental data within experimental error.

SimuSage – the component library for rapid process modeling and its applications

Abstract SimuSage is an innovative software tool for process simulation and flowsheeting tasks. Based on ChemApp and its rigorous Gibbs energy minimizing technique, it provides a library of components for the development of highly customized process simulation models. The SimuSage concept is described, and a number of examples from typical application areas such as metallurgy, combustion technology, and other industrial high-temperature processes involving inorganic chemistry are introduced.

A thermodynamic evaluation of the Ba-Cu-Y System

Abstract Experimental thermodynamic and phase equilibrium measurements in the binary systems Ba-Cu, Ba-Y and Cu-Y, together with experimental information on the miscibility gap in the ternary system Ba-Cu-Y, have been evaluated with the aid of the ‘Lukas optimization program’. The resulting set of coefficients allow phase equilibria and thermodynamic values to be reproduced within satisfactory limits.

Setting kinetic controls for complex equilibrium calculations

Publisher Summary This chapter discusses setting kinetic controls for complex equilibrium calculations. Many methods exist that cover only the kinetic aspects of a stoichiometric reaction and how it proceeds in time. Only a few attempts have been made so far to link equilibrium aspects of multi-component systems with kinetic inhibitions or even single reaction rates. None of these has led to a generally applicable link between the terms used in reaction kinetic equations and the Gibbs energy minimization method available for general equilibrium calculations. Mostly, dedicated solutions for special cases have been established. The image component method, although practical, is not fully consistent thermodynamically when used for solution phases. The chapter describes a method that combines multi-component multi-phase equilibrium thermodynamics with reaction kinetics.

IV.7 – Production of metallurgical-grade silicon in an electric arc furnace

Publisher Summary This chapter describes the production of metallurgical-grade silicon in an electric arc furnace. Metallurgical-grade silicon is produced in an electric arc furnace. The chapter, schematically, illustrates the process of production of metallurgical-grade silicon in an electric arc furnace. Quartz sand and carbon are fed in appropriate proportions through the top and liquid silicon is extracted at the bottom. The temperature in the production zone is approximately 2200 K. It is achieved through an electric arc burning between a graphite electrode and the metal bath. Hot gases are produced in the bottom zone of the reactor during the formation of silicon under the input of energy from the electric arc. These gases flow upward as a convective flux. On their way up, heat exchange with condensed matter falling downward takes place. If quartz is permitted to react freely with carbon in a system at a given total pressure and temperature, a different type of calculation must be carried out. All phases possible must be considered for set values of temperature, total pressure, and system composition. In particular, all possible gas species have to be introduced into the calculation.