Laboratory of Physical Chemistry of Metallurgical Melts, Institute of Metallurgy of Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia:

A. A. Vostryakov, Senior Researcher
E. A. Pastukhov, Head of Laboratory, e-mail: past@imet.mplik.ru
N. I. Sidorov, Senior Researcher
V. P. Chentsov, Senior Researcher

In the recent years, a serious interest to experimental researches of hydrogen application has been shown in remelting processes for metals refinement. Together with hydrogen permeability of metallic membranes, such situation is the reason of the carried out analysis of impurities removal from liquid Ta, Zr, and Nb in refining processes. Hydrogen and iron diffusion factors in tantalum, zirconium and niobium melts are calculated using the molecular dynamics method. Molecular dynamics calculation results are compared to literary data on impurities removal from Ta, Zr and Nb melts in plasma-arc melting with hydrogen applying, as well as in electron beam melting and vacuum-arc melting processes. Electric field affect to tantalum diffusion factor is more intensive than the same affect to iron diffusion factor. Hydrogen increases the iron diffusion factor in higher degree than electric field. Application of molecular dynamics method to liquid zirconium refinement made it possible to estimate the limiting stage of the process, as well as electric field affect and ironing impurity content to its diffusion factor D_Fe in liquid zirconium. Rate of iron evaporation from Ta and Zr melts is calculated, taking into account initial iron concentration in electron beam melting and plasma-arc melting with hydrogen presence, and in vacuum-arc melting. The calculation results have shown, that iron impurities removal rate is approximately proportional to iron diffusion factors up to the middle stage of melting. The obtained results can be used for further researches development of dependence of physical and chemical properties temperature for liquid metals and alloys in high temperature region.

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