9. Additional selected topics relevant to the physical chemistry of high temperature processes
Aim: to give a description of the physico-chemical basis for a number of high temperature processes and systems relevant to the synthesis, properties and performance of materials interesting for technological applications.
The preceding topics represent in a sense the “core” of high temperature chemistry based mainly on equilibrium thermodynamics, phase diagrams, thermodynamic data and their use in materials problems and, to a lesser extent, kinetics. This section contains a selection of additional “special” topics useful to illustrate a number of both classical and innovative processes of technological interest, where high temperature conditions and materials behaviour play an important role. The list reported here is not intended to be comprehensive. Indeed, there are so many temperature-dependent properties that are relevant to high-temperature physico-chemical behaviour of inorganic materials that could be selected for teaching in a course or part of a course dedicated to HTMC. These include: defects in solids and thermodynamics of defects, solid state diffusion, nucleation and growth, kinetics of phase transformation, which are typical of solid state chemistry and physics and are usually addressed in specific courses, basic or advanced, of solid state chemistry and physical chemistry of materials; others, such as thermophysical and thermomechanical properties traditionally pertain more to the field of materials engineering and are not explicitly considered here. In teaching a lecture course, some of the special topics described in the following may be selected as optional.
9.1 Pyrometallurgical processes
Aims: To describe the physico-chemical basis of some high temperature processes of materials, such as extraction and recovery of metals from ores, and metal refinement.