Thermal decomposition of syngenite, K2Ca(SO4)2.H2O
Kloprogge, J. Theo, Ding, Zhe, Martens, Wayde N., Schuiling, Roelof D., Duong, Loc V., & Frost, Ray L. (2004) Thermal decomposition of syngenite, K2Ca(SO4)2.H2O. Thermochimica Acta, 417(1), pp. 143-155.
The thermal decomposition of syngenite, K2Ca(SO4)2.H2O, formed during the treatment of liquid manure has been studied by Thermal Gravimetric Analysis, Differential Scanning Calorimetry, high temperature X-ray diffraction and Infrared Emission Spectroscopy. Gypsum was found as a minor impurity resulting in a minor weight loss due to dehydration around 100 degrees Celsius. The main endothermic dehydration and decomposition stage of syngenite to crystalline K2Ca2(SO4)3 and amorphous K2SO4 is observed around 200 degrees Celsius. The reaction involves a solid-state recrystallization, while water and the K2SO4 diffuse out of the existing lattice. The additional weight loss steps around 250 and 350 degrees Celsius are probably due to presence of larger syngenite particles, which exhibit slower decomposition due to the slower diffusion of water and K2SO4 out of the crystal lattice. A minor endothermic sulphate loss around 450 degrees Celsius is not due to the decomposition of syngenite or its products or of the gypsum impurity. The origin of this sulphate is not clear.
NOTE: files in separate file
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.
|Item Type:||Journal Article|
|Keywords:||differential scanning calorimetry, infrared emission spectroscopy, sulphate double salt, syngenite, thermogravimetry, mass spectroscopy|
|Subjects:||Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > INORGANIC CHEMISTRY (030200)|
|Divisions:||Past > QUT Faculties & Divisions > Faculty of Science and Technology|
|Copyright Owner:||Copyright 2004 Elsevier|
|Copyright Statement:||Reproduced in accordance with the copyright policy of the publisher: This journal is available online.|
|Deposited On:||13 Oct 2005|
|Last Modified:||09 Jun 2010 12:23|
Repository Staff Only: item control page