In new perspective areas of science and technology, as e.g. technology of
semiconductors, microelectronics, optoelectronics, technology of
superconductive materials, vacuum technology, nuclear metallurgy, space
metallurgy and technology, materials, metals and their special alloys and
compounds of a high chemical purity with defined physical and structural
parameters and specific utility properties are required. The
subject "Fundamentals of Metallurgy of Pure Metals" deals with methods of
refining and preparation of high purity substances and the stress is laid not
only on a high degree of chemical purity attainable by means of chemical and/or
hydrometallurgical physicochemical methods, e.g. sorption, extraction,
crystallization from aqueous solutions, electrolysis, but also by means of
pyrometallurgical methods, such as crystallization from melts, evaporation,
condensation and transport reactions, electrotransport, diffusion separation of
substances, removing of gases from melts as well as refining of metals in
vacuum. When preparing high purity metals by means of crystallization refining
methods, zone melting and directional crystallization, which are principal
methods of preparation of defined high purity metals, even in the single
crystal form, a controlled redistribution of admixtures and impurities present
in the basic substance occurs on the melt-crystal phase interface.