A KINETIC-STUDY OF THE THERMAL DEHYDRATION OF CALCIUM SULFITE HEMIHYDRATE

被引：10

作者：

ANDERSON, C

GALWEY, AK

机构：

[1] QUEENS UNIV BELFAST,SCH CHEM,BELFAST BT9 5AG,ANTRIM,NORTH IRELAND

[2] QUEENS UNIV BELFAST,CTR QUESTOR,BELFAST BT9 5AG,ANTRIM,NORTH IRELAND

来源：

CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE | 1992年 / 70卷 / 09期

关键词：

D O I：

10.1139/v92-312

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

An isothermal kinetic study of the dehydration of orthorhombic calcium sulphite hemihydrate is reported: CaSO3 . 1/2H2O(s) --> CaSO3(s) + 1/2H2O(g) Fractional reaction (alpha)-time curves exhibit the sigmoid shape characteristic of nucleation and growth reactions proceeding in the solid state. Yield-time data exhibit a very satisfactory obedience to the Avrami-Erofe'ev (n = 2) equation [-1n(1 - alpha)]1/2 = kt Rate studies were concerned with the temperature interval 573-673 K and the calculated activation energy was 173 8 kJ mol-1, showing the hydrate to be thermally relatively stable. The mechanism of dehydration is discussed and reference is made to the dehydration of calcium hydroxide with which it shows close similarities.

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页码：2468 / 2475

页数：8

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