Thermal analysis of halotrichites
Four halotrichites from different origins were analysed by thermogravimetric and differential thermogravimetric analysis. The halotrichites were analysed by powder X-ray diffraction and were phase pure. The chemical composition was analysed using EDX techniques. The formula of the halotrichite minerals were determined as halotrichite (Fe0.752+,Mg0.25)SO4.Al2(SO4)3.22H2O,apjohnite (Mn0.642+,Mg0.28,Zn0.08)SO4.Al2(SO4)3.22H2O, pickeringite (Fe0.222+,Mg0.78)SO4.Al2(SO4)3.22H2O, wupatkiite as (Co0.45,Fe0.552+)SO4.Al2(SO4)3.22H2O. Three low temperature decomposition steps a) between 0 and 44°C, 50 and 76°C, 72 and 88°C were attributed to dehydration. An additional dehydration step at around 317 to 330°C was confirmed by in-situ mass spectrometry. The higher temperature decomposition steps between 516 and 738°C are attributed to the decomposition of sulphate to sulphur dioxide and oxygen as confirmed by mass spectrometry. A comparison of the thermal decomposition of jarosites is made.
Impact and interest:
Citation countsare sourced monthly fromand 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 downloadsdisplays 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.
Repository Staff Only: item control page