Coal mineral characteristics

HASTiE ET AL. Alkali Vapor Transport Coal Mineral Characteristics... 

Analysis on the factors characteristics of coal miners safety behavior based on trajectory crossing... 

O Gorman, J.V. and Walker, P.L. 1971. Mineral characteristics of some American coals. Fuel, 50 135. 

Although filtratioa rates can be much faster with flocculants, the final cake moisture is often higher ia a flocculated cake (60—63). Ia coatrast, usiag flocculants optimized for filtration, coal, and other mineral slurries can be dewatered to moisture contents significantly lower than the untreated cake (64—68). The advantages of rapid filtration rates can also be preserved. Flocculants that provide better filtration tend to form floes having the foUowiag characteristics (65) ... 

Three West Virginia coals were supplied by the West Virgmia Geological Survey (WVGS). The particular coals were chosen on the basis of rank, petrographic composition, and mineral matter content The coals were limited to the bituminous rank since these coals are the most amenable to the NMP solvent extraction process and are mdigenous to the Appalachian region. Some of the coal characteristics are listed in Table 2. 

Perhaps the most important components of reactor solids are those that are generated during processing rather than those that are derived from inert minerals (quartz, clays) and macerals (fu-sinites, etc.) in the feed coal (74). The retention of these formed materials is more difficult to predict from the characteristics of the feed and, hence, control in liquefaction processes. 

A thorough understanding of the chemical and mineralogical composition of CCPs is necessary for proper management of these materials. This chapter will cover (1) the composition of coal (2) the formation of CCPs (3) the physical, chemical, and mineralogical characteristics of CCPs (4) characterization of North American fly ashes (5) hydrated minerals in fly ash/ water pastes (6) sulphur scrubbing products and (7) environmental impact of CCPs. 

As a result of the well-documented environmental concerns posed by coal combustion, and the disposal of CCPs, a large body of research has focused on characterizing the mechanisms of mobilization and attenuation of trace elements in coal and its ash. Based on their reported distribution in the solid phases of both source coals and coal ash, knowledge of the thermal transformations that occur to major mineral constituents during coal combustion, and a limited number of studies that have identified discrete solid phases of trace elements, a conceptual model of the chemical and mineralogical characteristics of trace elements in coal ash has been developed. 

The flotation process is applied on a large scale in the concentration of a wide variety of the ores of copper, lead, zinc, cobalt, nickel, tin, molybdenum, antimony, etc., which can be in the form of oxides, silicates, sulfides, or carbonates. It is also used to concentrate the so-called non-metallic minerals that are required in the chemical industry, such as CaF2, BaS04, sulfur, Ca3(P03)2, coal, etc. Flotation relies upon the selective conversion of water-wetted (hydrophilic) solids to non-wetted (hydrophobic) ones. This enables the latter to be separated if they are allowed to contact air bubbles in a flotation froth. If the surface of the solids to be floated does not possess the requisite hydrophobic characteristic, it must be made to acquire the required hydrophobicity by the interaction with, and adsorption of, specific chemical compounds known as collectors. In separations from complex mineral mixtures, additions of various modifying agents may be required, such as depressants, which help to keep selected minerals hydrophilic, or activators, which are used to reinforce the action of the collector. Each of these functions will be discussed in relation to the coordination chemistry involved in the interactions between the mineral surface and the chemical compound. 

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