1464
CHEKRYSHKIN et al.
CONCLUSIONS
l h–1
(1) With increasing polarization force of the cations,
the oxidation ability of chloride ions in melts of zinc,
calcium, and barium chlorides increases, whereas the
catalytic effect of vanadium pentoxide on this process
decreases.
l h–1
(2) The oxidation of chloride ion in a molten zinc
chloride is the zero-order reaction, limited by the diffu-
sion of oxygen above 550°C.
Fig. 4. The relative amount of chlorine νCl2/νV O5 (mole/mole)
released from the МCl2–10 wt % V2O5 systems2vs. the polariza-
tion force of the chloride cation ze/rMz+.
(3) The size of the zinc oxide particles obtained by
ZnCl2 oxidation changes in the range 50–700 nm, which
is due to high temperature of the experiment and its long
time.
larization force is lower than of barium cation, whereas
the effect of vanadium pentoxide on its oxidation ability
with respect to chloride ions is lower too (Fig. 3, curve 4).
This is accounted for by the low deformation ability of
its electronic shells.
ACKNOWLEDGMENTS
The study was partially supported by the Program
of the Presidium of the Russian Academy of Sciences
“The Synthesis and Separation of Nanosized Metal Ox-
ide Powders in Chloride Melts” (project no. 18) and by
the Russian Foundation for Basic Research (project no.
10-03-00187a).
Metal oxides possess higher melting temperatures than
corresponding chlorides. Also, they have low solubility
in chlorides. Therefore, in halide melts they will be in
the form of a precipitate, because their density is higher
than that of oxides. For example, the density of ZnO is
5.7 and that of ZnCl2, 2.91 g cm–3 [16]. In this case, the
oxide particles formed will be stabilized (solvated) with
molten metal chlorides, which gives hope to obtain highly
dispersed oxide powders.
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RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 83 No. 8 2010