British coal seams

Samples Studied. From British Seams. The suite of samples was collected and separated by the Coal Survey of the National Coal Board under the direction of Dr. G. W. Fenton, and the authors are indebted to Dr. Fenton for the gift of the samples. The suite consisted of the vitrinites, spore-rich exinites, fusinites and, in one case, the micrinite from five British coal seams of Carboniferous age together with the vitrinites from two coals of higher rank from which it was impracticable to separate the other macerals. The exinites were separated by float-and-sink methods from selected black durain bands, as also... 

Inorganic Matter in British Coals. Part 3 The Composition of Carbonate Minerals in the Coal Seams of the East Midlands Coalfields, J. Inst. Fuel (1970) 43, (354), 229-233. ... 

In the subsurface, arsenic may readily accumulate in coal. Specifically, groundwater percolating through volcanic deposits may leach arsenic and transfer it to underlying coal beds during or after coalification. Contact metamorphism and any associated hydrothermal fluids are other processes that sometimes locally enrich arsenic in coal seams. At a site in British Columbia, a Cretaceous bituminous coal seam was contact metamorphosed by a mafic dike. The contact temperatures were about 700-900 °C, which could volatilize arsenic and/or dissolve it into associated hydrothermal fluids. The arsenic was then transported and deposited into cooler sections of the seam (Yudovich and Ketris, 2005), 163. 

Goodarzi F. (1988) Elemental distribution in coal seams at the Fording coal mine, British Columbia, Canada. Chem. Geol. 68, 129-154. 

Whereas in some British pits there is practically no silica associated with the coal seam, those in Somerset and Dean Forest (Gloucestershire) include Pennant rock, a highly siliceous sandstone (Meik-LEjOHN 1960). Hart and Aslett (1942) concluded that the incidence of pneumoconiosis was somehow related to the hardness or rank of coal. Thus the disease was more present in the anthracite (hard--high rank) than in the bituminous or steam coal (soft-low rank) pits. 

To help miners visualize the invisible strata above the immediate roof, in-struction manuals and training texts also include diagrams. The diagram in Fig. 6.3, for example, shows a cross sectional view of a mine entry and an idealized picture of the strata or rock layers above the coal seam in the mine. Pillars of coal on either side of the entry provide walls or columns of support that help prevent roof falls. According to this diagram, the immediate roof of the mine shifts or resettles in response to the tremendous forces or pressures from the weight of the overburden (the mountain above the immediate roof) w hen a layer of rock or coal is removed. The British diagram in Fig. 6.4, on... 

Considerations of process simplicity as well as economy suggest that the waste heat produced by the fuel cell (about 0.25 kW per kW of net electrical DC output) should be fed back to thermally decompose the raw coal feed. This requires that the cell produce sufficient heat at a sufficiently high temperature to effect thermal decomposition within a time span that is short compared with that of electrochemical conversion. Fig. 8 (after Howard, 1981) reproduces data underlying Dryden s correlation (Dryden, 1957) for many British and American coal seams and shows the extent of decomposition (relative to that at prolonged pyrolysis at 1000°C) as a function of temperature and time. The reference to 1000 C is useful, as the yields observed at this temperature approach those of higher temperature asymptote. Also in Fig. 8 is the data from Anthony et al. (1975) taken after various exposure intervals between 0.1 and 14400 s, showing that devolatilization is 90% complete in the range of 5-20 s. 

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