Thermal behaviour of natural and synthetic iron precipitates from mine drainage

0429128 - ÚACH 2015 RIV HU eng J - Journal Article
Pulišová, Petra - Máša, B. - Michalková, E. - Večerníková, Eva - Maříková, Monika - Bezdička, Petr - Murafa, Nataliya - Šubrt, Jan
Thermal behaviour of natural and synthetic iron precipitates from mine drainage.
Journal of Thermal Analysis and Calorimetry. Roč. 116, č. 2 (2014), s. 625-632. ISSN 1388-6150. E-ISSN 1588-2926
R&D Projects: GA MŠMT 7AMB12SK155
Institutional support: RVO:61388980
Keywords : Thermogravimetry * Differential thermal analysis * X-ray diffraction analysis * Acid mine drainage * Iron precipitates * Precipitation with urea
Subject RIV: CA - Inorganic Chemistry
Impact factor: 2.042, year: 2014

TG-DTA, MS detections and XRD were used to characterize thermal behaviour of iron precipitates from acid mine drainage prepared by precipitation with urea and natural iron precipitates sampled from sludge bed (settling pit Sedem A3/4ien and old abandoned adit Hodrua, mining area Banska tiavnica, Slovakia). The high-resolution transmission electron microscopy and scanning electron microscopy (SEM) techniques were used to characterize the surface microstructure and shape of the synthesized and sampled iron precipitates. The SEM micrographs of the iron precipitates (natural and precipitated with urea) show that the samples had formed into agglomerates, probably due to attractive forces of quite large surface area. During heating of the all samples up to 200 A degrees C, physically adsorbed water was removed. On further heating in the range from 250 to 350 A degrees C in natural iron precipitates, the less stable forms (goethite, ferrihydrite, and schwertmannite) transform to more stable forms like hematite. In case of synthetic samples, the transformation runs in two steps: first in the range from 250 to 350 A degrees C, and second in the range from 600 to 750 A degrees C.
Permanent Link: http://hdl.handle.net/11104/0234304