Pyrosim Software

Pyrosim is a general-purpose computer program for the steady-state simulation of pyrometallurgical processes. One of the primary strengths of the program is its built-in capability to calculate multi-component multi-phase equilibria, along with the automatic performance of energy-balance calculations. This predictive ability allows the program to simulate novel processes rather accurately. An empirical modelling capability also allows the program to match known parameters of existing processes.

The program was originally developed in 1985, with the purpose of simulating processes for the production of raw stainless steel. However, the program's structure was kept very general to allow other processes to be simulated. The program has been successfully applied to the processing of ferroalloys, metal carbides, base metals, precious metals, and refractory metals. The program has also been used for the study of various pyrometallurgical pretreatment options, such as preheating and prereduction, as well as processes involving combustion. Pyrosim has also recently been used successfully to model the plasma-arc treatment of waste materials such as lead blast-furnace slag and electric-arc furnace dust, processes inherently complex because of the number of chemical elements involved.

Processes involving furnaces, fluidized beds, and rotary kilns have been modelled by Pyrosim. The program provides process models to describe heating, chemical equilibrium, and multi-stage equilibrium with staged removal of a product stream. Bypass streams, entrainment of metal in slag (for example), and simple recycle loops are easily handled. Energy-controlled calculations (where the final process temperature has to be calculated) can also be performed for all models. Where appropriate, some of the models also provide a significant quantity of derived information, such as the liquidus temperature, viscosity, and basicity of slags, as well as gas ratios and degrees of reduction.

A recent addition to Pyrosim is a general empirical model (Pyrobal), which complements the existing predictive models. There are times when the user may wish to use certain known facts about the process being modelled, in preference to the information provided by the predictive models. The remaining process variables are then calculated from a set of simultaneous linear equations, and an energy balance can then be carried out. The specifications allowed by the program are of two types: namely ratios between pairs of species or percentages of species in a particular stream. A value can be specified for the mass ratio or molar ratio of any species in any stream to any other species in any other stream. For example, the molar ratio between CO and CO2 in the gas can be specified, as can the mass ratio between S in the slag and S in the metal, or the mass ratio between TiO2 in the slag and Ti in the metal. Alternatively, the user can specify the mass percentage of any species in any stream. For example, the content of C in the metal can be specified as having a particular value. Streams containing only one element, such as solid carbon, for example, are also easily accommodated using this model.

A utility program called Pyromake is supplied with the software, to allow the user to construct a simulation disk (or directory) containing only the chemical species of interest. By means of a simple selection from a list of species on the screen, a database containing all the relevant thermodynamic data is automatically constructed. This simple-to-use utility program allows the user to set up a stand-alone Pyrosim system containing all chemical species of interest. The built-in process models can then be used on the systems of your choice. Energy balance calculations are also performed automatically.

The latest version of the program (v1.56) supports large systems (typically up to 100 feed materials, 100 species in the system, 60 species per equilibrium phase, and 30 elements). Features recently added to the program are the automatic calculation of elemental analyses of all product streams (also showing slags in terms of the simple oxides) and the provision of a table showing the distribution of elements between phases.

The Pyrosim program runs on personal computers using the MS-DOS or Windows operating systems. There are no special hardware requirements needed to run the program, although 640 kb of memory and a math coprocessor are recommended. Version 1.56 of Pyrosim is available for purchase from the Pyrometallurgy Division, Mintek. The author of the program may be contacted by electronic mail at

Full paper describing Pyrosim software

Thermo software

Pyrosim User's Manual

Pyrosim users around the world

Instructions for using DOSbox to run Pyrosim in Windows 7 or 8

Copyright © 1996-2011, Rodney Jones,, Randburg, South Africa (Last updated on 2 August 2011)

Pyrometallurgy Division, Mintek, 200 Malibongwe Drive, Private Bag X3015, Randburg, 2125, South Africa
Phone: +27-11-709-4602       Fax: (086) 512-5877