
TY  - JOUR
A1  - Bear, IJ 
T1  - The influence of vapour pressure on the formation of anhydrous zirconium sulphates
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1969
VL  - 22
IS  - 5
SP  - 875
EP  - 889
KW  - 
UR  - https://doi.org/10.1071/CH9690875 
N2  - The anhydrous products resulting from the dehydration of Zr(SO4)2,4H2O in external atmospheres of controlled H2SO4 and SO3 partial pressures consist of three polymorphs, two of which, &#947;- and &#946;-Zr(SO4)2, are metastable and equilibrate to the stable phase, &#945;-Zr(SO4)2.     The rates of decomposition of these anhydrous sulphates to cubic ZrO2 have been measured and activation energies for the processes calculated. From these data the vapour pressure-temperature diagram for the anhydrous region of the ZrO2-SO3-H2O system has been delineated. This shows the existence range of &#947;-Zr-(SO4)2 lies within that of &#946;-Zr(SO4)2 while both lie within that of the stable &#945;-phase.     The function of physical factors, such as particle and sample size and heating technique, in controlling phase formation during dehydration in air is interpreted in terms of the vapour pressure- temperature diagram. 
ER  -

