Temperature programmed decomposition of thorium oxalate hexahydrate

被引：28

作者：

Dash, S ^{[1
]}

Krishnan, R ^{[1
]}

Kamruddin, M ^{[1
]}

Tyagi, AK ^{[1
]}

Raj, B ^{[1
]}

机构：

[1] Indira Gandhi Ctr Atom Res, Dept Atom Energy, Met & Mat Grp, Kalpakkam 603102, Tamil Nadu, India

来源：

JOURNAL OF NUCLEAR MATERIALS | 2001年 / 295卷 / 2-3期

关键词：

D O I：

10.1016/S0022-3115(01)00481-0

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Temperature programmed decomposition (TPD) of thorium oxalate hexahydrate (TOH) was studied by evolved gas analysis-mass spectrometry (EGA-MS), thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). The microcrystalline solid exhibited sequential dehydration. The anhydrous compound yielded amorphous phase Th(CO3)(2) upon CO release arising out of the bond cleavage. The Th(CO3)(2) phase transformed to nano-crystalline thoria upon decomposition through an oxycarbonate intermediate. The mechanism underlying Various conversion stages exhibited control by random nucleation, diffusion and phase boundary interface motion. From the fractional extent of decomposition data, Arrhenius factors like activation energy and pre-exponential factors were evaluated. Based on these studies, a chemical pathway is proposed for the entire decomposition process. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：281 / 289

页数：9

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