Utilisation of X-Ray computed microtomography for evaluation of iron sulphide distribution in roofing slate

0460700 - ÚGN 2017 RIV DE eng A - Abstract
Souček, Kamil - Daněk, T. - Vavro, Martin - Botula, J.
Utilisation of X-Ray computed microtomography for evaluation of iron sulphide distribution in roofing slate.
Geophysical Research Abstracts. Göttingen: European Geosciences Union, 2016. ISSN 1607-7962.
[EGU General Assembly. 18.04.2016-22.04.2016, Vienna]
Institutional support: RVO:68145535
Keywords : roofing slate * X-Ray computed microtomography * natural stone
Subject RIV: JQ - Machines ; Tools
http://meetingorganizer.copernicus.org/EGU2016/EGU2016-2779.pdf

Roofing slate represents a traditional natural stone used for centuries for roofing and other construction applications
in various types of buildings. Quality roofing slate must be primarily splittable into large, thin and waterproof
tiles. In addition, it must be stable in colour and resistant against weathering. The abundance of mineral phases that
weather easily or minerals that are long-term unstable has the effect of reducing the durability of slates in exterior
conditions. One of the most problematic rock components, which are in a larger or smaller extent present in almost
all slates, are iron sulphides, such as pyrite, marcasite or pyrrhotite. Under common atmospheric conditions,
these minerals tend to oxidise, which leads to the formation of limonite and sulphuric acid. As a consequence of
the origin of red-brown Fe oxyhydroxides, the undesirable colour changes of the slate may occur. But the most
serious problem which occurs during this process is the changes in volume. This can cause disintegration of slate
depending on the form of the iron sulphide occurrence.
The content and size distribution of iron sulphides in roofing slate is normally determined using the microscopic
analysis in transmitted light, combined with the observation in reflected light. For quantitative determination of
iron sulphides in slate, the X-Ray powder diffraction is also often used. The results of the microscopic and X-Ray
analyses need to be mutually compared and should not differ fundamentally.
This paper is focused on the assessing the possibility of application of the X-Ray computed microtomography
(CT) as a new complementary technique enabling the analysis of content and size (volume) distribution of
iron sulphides in roofing slate.
Permanent Link: http://hdl.handle.net/11104/0260714