The Behaviour of Siderite Rocks in an Experimental Imitation of Pyrometamorphic Processes in Coal-Waste Fires: Upper and Lower Silesian Case, Poland

Abstract

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.

An <em>In-Situ</em> Mössbauer Study of the High-Temperature Behavior of Siderite under Reduction Conditions

“…Siderite crystallizes in the trigonal crystal system and is rhombohedral in shape, typically with curved and striated faces, and the color of siderite ranges from yellow to dark brown or black, the latter being due to the presence of manganese [9]. This carbonate is an important mineral that finds application in various industries and has gained commercial importance over the years [10]; for example, it is one of the primary sources of iron in Europe [11], in petroleum drilling fluids as a scavenger for H2S and in processes for making ferrous catalyst materials [12][13][14] or in the combustion of the coast [15,16].…”

Thermal Decomposition of Siderite and Characterization of the Decomposition Products under O2 and CO2 Atmospheres

“…Siderite is the primary mineral, the formation of which governs the ore-forming process [6,7]. Due to its high iron content and light smelting, it plays an important role in steel production [8,9], in petroleum drilling fluids as a scavenger for H 2 S, and in processes for making ferrous catalyst materials [10][11][12] or in the combustion of the coal [13,14]. Siderite is a well-characterized mineral [2,7,[15][16][17][18], and the thermal decomposition and oxidation of this material have been a topic of considerable interest because of both its commercial importance and scientific questions.…”