2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 6: Rare Earths & Ionic Liquids
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 432 pages |
| ISBN: | 978-1-987820-08-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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THE INCREASE IN VISCOSITY AND SOLIDIFICATION ON COOLING AS A CONSEQUENCE OF OCCURRENCES OF ATOMIC QUANTUM EFFECTS
Valery Pavlov1; Alexei Potapov2;1URAL STATE MINING UNIVERSITY, Ekaterinburg, Russian Federation; 2INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 88
Topic: 11
Abstract:
Many metal production and refining processes are limited by transport properties of melts: diffusion, viscosity, ionic conductivity, etc. The molecular dynamics method demonstrates that in a conventional computer model, the "substance of the melt" has both kinetic and mechanical properties of a dense gas or simple fluid over all temperature range, including the area near absolute zero.
The rigid network of the melt or the crystal lattice is not formed at ordinary interactions of atoms and their classical motion, and, thus, the liquid solidification does not occur. In such model, the energy barriers EA, surmounted at atomic rearrangements, are relatively small compared to the thermal energy RTm, where Tm is the melting temperature.
The present work proposes a new model that considers the influence of occurring quantum effects on the melt solidification. This model naturally describes the solidification process, the appearance of stable and rigid crystal structures and large real activation energies (e.g., E ~ 40RTm) of transport properties. In this model, the increase in viscosity and solidification results from the increasing fraction of the quantum "freezing out" of atoms. The "frozen out" atoms are motionless because they are located on the zero energy level. Normally, the fixation of a few atoms is sufficient to form the rigid lattice. This fixation is equivalent to the loss of some atomic degrees of freedom.