A white solid was precipitated when ozone was introduced into the solution containing Al
2 (SO
4)
3 (NH
4)
2SO
4·24 H
2O as the starting material.
When ozone was introduced, pH of the solution decreased. The solid was identified as β-Al203.31120 by X-ray diffraction analysis.
The transition energy 4H from β-Al203.3 H2O to 77-Al203 was determined using commercial β-Al
2O
3·3H
2O (i) and β-Al
2O
3·3H
2O (ii) obtained in this study. The ΔH determined were about 23. 3 mcal/ mg for (i) and 21.3 mcal/mg for (ii), respectively.
Grain size distribution was determined, and the grain size of β-Al
2O
3·3H
2O (ii) was in the range of 0.3μm to 4. 0 μm. The grain having 0.3μm occupied about 30% and this distribution pattern in compared with the starting material did not change even they were calcined at the temperatures for production of η-or α-Al
2O
3.
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