Radiation- and self-ignition induced alterations of Permian uraniferous coal from the abandoned Novátor mine waste dump (Czech Republic)

In self-ignition-affected samples, the higher reflectance (1.31-1.71%), and values of Raman band disorder mirrored the intensity of burning processes. Organic matter samples located at unburnt- and burnt coal interfaces were composed of a mixture of coal macerals, char and solid bitumens. In the waste heap burning zone, coal and claystone were transformed to “clinkers” composed of plagioclase, pyroxenes, tremolite, hematite, magnetite, anatase, and aluminosilicate glass or to “paralava”, formed by porous cordierite and hematite. Organic components in the burnt-out zone were represented by small dense and massive coke particles with reflectance of 4.48%, fusinite with reflectance of 3.05% and rare coke droplets of solid bitumen (R = 1.90%). Only traces of phenanthrene and alkanes were identified in organic extracts of burnt-out rock.