the behaviour of siderite rocks in an experimental imitation of pyrometamorphic processes in coal-waste fires: upper and lower silesian case, poland

Little is known of the influence of fluxes on the nature and the intensity of burning in coal-waste heaps. To gain some insight, two siderite samples, one each from coal-mining waste heaps in Upper- and Lower Silesian Coal Basins (Poland), were heated under identical conditions in a thermal chamber coupled to a powder X-ray diffractometer. Differences in the behaviour of siderite phase and the products of its decomposition, mainly magnetite, wüstite, and olivine, are discussed. The waste heaps sampled underwent self-heating and self-ignition catalysed by fluxes. Though the samples are unlikely to be truly representative of the Silesian basins, the heterogeneous behaviour they displayed on heating merits description and explanation, as siderite is an important widely known flux in pyrometamorphic processes.