QUT ePrints

Thermal decomposition of natural and synthetic plumbojarosites: Importance in 'archeochemistry'

Frost, Ray L., Wills, Rachael-Anne, Weier, Matt L., Musumeci, Anthony W., & Martens, Wayde N. (2005) Thermal decomposition of natural and synthetic plumbojarosites: Importance in 'archeochemistry'. Thermochimica Acta, 432(1), pp. 30-35.

View at publisher

Abstract

Plumbojarosite and argentoplumbojarosite were sources of lead and silver in ancient and medieval times. The understanding of the chemistry of the thermal decomposition of these minerals is of vital importance in 'archeochemistry'. The thermal decomposition of plumbojarosite was studied using a combination of thermogravimetric analysis coupled to a mass spectrometer. Three mass loss steps are observed at 376, 420 and 502 °C. These are attributed to dehydroxylation, loss of sulphate occurs at 599 °C, and loss of oxygen and formation of lead occurs at 844 and 953 °C. The temperatures of the thermal decomposition of the natural jarosite were found to be less than that for the synthetic jarosite. This is attributed to a depression of freezing point effect induced by impurities in the natural jarosite. Raman spectroscopy was used to study the structure of plumbojarosite. Plumbojarosites are characterised by stretching bands at 1176, 1108, 1019 and 1003 cm−1 and bending modes at 623 and 582 cm−1. Changes in the molecular structure during thermal decomposition were followed by infrared emission spectroscopy. The technique shows the loss of intensity in the hydroxyl stretching region attributed to dehydroxylation. Loss of sulphate only occurs after dehydroxylation. Lead is formed at higher temperatures through oxygen evolution.

Impact and interest:

15 citations in Scopus
Search Google Scholar™
18 citations in Web of Science®

Citation countsare sourced monthly from Scopus and Web of Science® 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 the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

Full-text downloads:

53 since deposited on 17 Jun 2009
12 in the past twelve months

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.

ID Code: 22535
Item Type: Journal Article
Additional URLs:
Keywords: Jarosite, Plumbojarosite, Dehydration, Dehydroxylation, Infrared Emission Spectroscopy, Thermogravimetric Analysis
DOI: 10.1016/j.tca.2005.04.001
ISSN: 0040-6031
Subjects: Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > ANALYTICAL CHEMISTRY (030100)
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Copyright Owner: Copyright 2005 Elsevier
Deposited On: 17 Jun 2009 23:14
Last Modified: 01 Mar 2012 11:45

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page