Computational Modeling in Pyrometallurgy: Part I

Pyrometallurgy is the subtle art and science of using high temperatures to process raw materials into valuable products. This is performed in several key stages, including pre-treatment, chemical reactions, separation of product and waste streams, and product refining. The interior of pyrometallurgical vessels in all stages is an extreme and hazardous environment, with process temperatures well in excess of 1000 C. As a result, it is a uniquely challenging subject for experimental study and measurement, and in many cases the task of improving our fundamental understanding and engineering knowledge of pyrometallurgical processes falls solely to mathematical, numerical, and computational models of the various phenomena at work. When developing such models, the level of complexity present in the governing physics and chemistry is, however, a formidable obstacle. It is not uncommon for a single pyrometallurgical unit operation to exhibit behavior related to simultaneous heat transfer and thermal radiation, multiphase and free surface fluid flow, phase thermodynamics and thermochemistry, solid–liquid–gas phase changes, flow and motion of granular media, electromagnetic stirring and heating effects, transonic and supersonic flow, thermo-mechanical cycling and material fracture, and many others. Strong coupling between these different phenomena generally mean that they cannot be studied in isolation and must be solved as part of integrated multiphysics models. Additionally relevant behavior may occur over an extremely broad range of length and time scales, from micrometers to tens of meters and from milliseconds to days.* Such complexity has historically made it very difficult indeed to develop efficient numerical algorithms for the study of pyrometallurgy using computational modeling methods. However, sustained increases in available computer power combined with new advances in both computational hardware and software are for the first time starting to give us a glimmer of insight into this most intractable of engineering challenges. In this special topic, we present nine papers that highlight those computational modeling advances.