Mineral matter characteristics, sulfur

Fate of Sulfur in Feedstock - Mineral Matter Characteristics... 

Advanced physical cleaning techniques are expected to be more effective than older techniques (Feibus et al., 1986). And increased efficiency can be achieved by grinding the coal to a much smaller size consistency whereupon the coal will release more of the pyrite and other mineral matter. Thermal treatment can be used to reduce moisture and modify surface characteristics to prevent reabsorption. New coal-cleaning processes can remove more than 90% of the pyritic sulfur and undesirable minerals from the coal. 

Heterotrophic respiration fueled by the rain of organic matter from the surface ocean is ubiquitous in marine sediments. Its rate determines one of the important characteristics of the sedimentary environment the depth of redox horizons below the sediment-water interface. Heterotrophic respiration is the process by which carbon and nutrients are returned to the water column it is important in the marine fixed nitrogen and sulfur cycles and the accumulation of metabolic products sets the conditions for the removal of phosphorus from the oceans in authigenic minerals. A great deal of effort has been directed toward quantifying the rates, pathways, and effects of metabolism in sediments. 

The nature of the hydrocarbon and sulfur content is still not clear. However, calculations based on density data would seem to support earlier suggestions that the sulfur must be present as SO, or H O within the silica lattice. The optical characteristics of the mineral show that the organic matter occurs in films between the faces of the crystals. On the other hand, calculations based on the difference in densities of the original mineral and the pyrolyzed silica crystals show that the sulfur compounds at least must be within the crystal lattice. Kamb offers evidence (69) that the silica structure is a clathrate with SO,. HjO, and CH in the lattice analogous to the known 12 A gas hydrates of water, 6X 46HjO, where X is CH , H S, CO SOi, Cl, etc., and in fact the structure is the complete analogue of 6CI - H 0. 

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