Dustiness index

The concept of a dustiness index was proposed to enable comparison among dust-producing capacities of different bulk materials, such as coal. Dustiness estimation methods were developed with a view to establishing relative dustiness indices (BOHS, 1985 Upton et al., 1990 Lyons and Mark, 1994 Vincent, 1995 Breum et al., 1996). The objective is to provide criteria for the selection of products that will lead to less dust emissions. It is important to note, however, that different dustiness methods will produce different rank orderings. 

Dust removal from mine workings and coal preparation plants is an important aspect of safety (Chapters 5 and 6) and there have been constant attempts to improve dust removal technology (Henke and Stockmann, 1992). As the techniques have been developed, the predictability of how coal will behave, in terms of the dust produced, under certain conditions has also been sought. The dustiness index of coal is a means of determining the relative values which represent the amount of dust produced when coal is handled in a standard manner. 

For the test method, a 50 lb sample of coal is placed on a slide plate in a metal cabinet of prescribed size. When the plate is withdrawn, the sample falls into a drawer and, after 5 s, two slides 

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Grindability Dustiness index Relative amount of work needed to pulverize coal Amount of dust produced when coal is handled... 

Hardness/abrasiveness Friability GrindabiUty Dustiness index Thermal properties Calorific value Heat capacity Thermal conductivity Plastic/agglutinating Agglomerating index Free swelling index... 

Cubic Foot Weight of Crushed Bituminous Coal Drop Shatter Test for Coal Dustiness, Index of, of Coal and Coke Fusibility of Coal Ash... 

DIN 5599-2 (1999) Standardised Single-Drop Dustiness Apparatus to Generate a Dustiness Index of Fillers and Pigments. Deutsches Insitut fur Normung, BerUn, Germany, www2.din.de. 

Some synonyms in the Alphabetical index are followed by bracketed notations. These notations provide additional clarifying information about the entry such as composition, modifications to the agents (e.g., thickened, dusty, binary), or a note for historical context. For example, "White Star" was a gas blend that was employed by the British in World War I consisting of 50% phosgene and 50% chlorine. The entry appears as ... 

In Equation (9.6), x is the direction of flux, nt [mol m-3 s 1 ] is the total molar density, X [1] is the mole fraction, Nd [mol m-2 s 1] is the mole flux due to molecular diffusion, D k [m2 s 1] is the effective Knudsen diffusion coefficient, D [m2 s 1] is the effective bimolecular diffusion coefficient (D = Aye/r), e is the porosity of the electrode, r is the tortuosity of the electrode, and J is the total number of gas species. Here, a subscript denotes the index value to a specific specie. The first term on the right of Equation (9.6) accounts for Knudsen diffusion, and the following term accounts for multicomponent bulk molecular diffusion. Further, to account for the porous media, along with induced convection, the Dusty Gas Model is required (Mason and Malinauskas, 1983 Warren, 1969). This model modifies Equation (9.6) as ... 

Discuss the procedure used for making a survey of dust conditions in an industrial plant. What is meant by index of dustiness ... 

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