A REVIEW OF SULPHUR IN COAL: WITH SPECIFIC REFERENCE TO THE TELKWA DEPOSIT, NORTH-WESTERN BRITISH COLUMBIA
The Jura-Cretaceous coal seams of the Currier, Mist Mountain, &thing and Gates formations generally formed in delta or strand plain environments with little marine influence. The sulphur contents of coal from these formations is therefore generally low, nearly always less than I % and often less than 0.5 %. Coalbearing formations of the Cretaceous Nanaimo and Skeena groups were deposited in coastal areas with more marine influence. Consequently sulphur contents are more variable and tend to be higher. It is therefore important to study aspects of sulphur in Cretaceous coal seams such as the seams in the Skeena Group at Telkwa (Figure I).
Control of different pyrite forms on desulfurization of coal with bacteria
Abstract The present paper entails the role of different pyrite forms during desulfurization of Nagaland coals of north-east India. This coal contains a considerable quantity of pyrite which occurs in various forms like framboidal, disseminated, cavity and fissure fillings, massive replacement and discrete grains. The discrete pyrite grains show strong affinity with liptinite and inertinite macerals while rest of the forms show low to moderate correlation with different macerals. The correlation between different pyrite forms and desulfurization reveals that the coal samples rich in disseminated pyrite have undergone minimum desulfurization followed by framboidal pyrite rich coal samples. These pyrite forms probably caused difficulty in desulfurization due to their small size, complicated structure and their highly scattered occurrences. The maximum removal was observed in samples rich in cavity and fissure filling pyrite.
On the use of the Hardening Soil Small Strain model in geotechnical practice
This article highlights the importance of using advanced constitutive soil models in numerical modelling as daily geotechnical practice. In this context, the Hardening Soil (HS) model is presented as the most advanced soil model implemented in the ZSoil finite element code. The article recalls the basic features of the HS model and it explains their role in numerical simulations. The role of pre-failure non-linear behaviour of soils is also discussed. An application of the HS model is illustrated on typical geotechnical problems such as retaining wall excavation, tunnel excavation and undrained loading followed by consolidation.