• Ribeiro, Joana
• Ward, Cr
• Suarez Ruiz, I.
• Flores, D.

Abstract

The environmental risks associated with coal mining activities include, among others, the production of solid wastes. Selfburning coal waste piles may present serious potential environmental and human health hazards. The geological characterization of waste materials in self-burning waste piles is essential in order to identify the related negative impacts and to further contribute to their mitigation. The main goal of this study is to identify the mineralogical composition of burning or already burnt and unburned coal waste material from self-burning anthracite waste piles and the changes attributed to the combustion process. X-ray powder diffraction was used for the determination of the mineralogical composition of relevant coal waste materials. The results show that illite+mica and quartz are the main constituents of the unburned material, together with minor proportions of muscovite, kaolinite, chlorite, pyrophyllite, anatase, gypsum, and rutile. However, other minerals, such as mullite, cristobalite, hematite, jarosite, anorthite, were identified in burning/burnt waste samples. The formation of these minerals is attributed to the combustion process, and suggests that they may have reached temperatures of at least 1000ºC. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP

Topics

• impedance spectroscopy
• mineral
• combustion
• mullite
• gypsum