Carbonaceous matter, association with

Coking n In the running of copals, or sweating of asphal-tums, and other materials, which naturally contain a proportion of infusible dirt or mineral matter, this extraneous matter is likely to escape the action of the stirrer. As a consequence, any organic matter associated with it is liable to be overheated, and carbonization occurs. This ultimately results in the formation of carbonaceous lumps, and it is then said to have coked. 

Ores which are associated with carbonaceous matter which reabsorbs dissolved gold. 

Chemical oxidation reactions and radical-induced hydrophobic-to-hydrophilic aging processes tend to increase the water solubility of OAs and, therefore, are thought to enhance the activity of atmospheric OAs as cloud condensation nuclei (CCN). As discussed by Gysel et al. (2004), at 75-90% of relative humidity (RH) the inorganic fraction dominates the water uptake (59-80%). Nevertheless, under the same conditions of RH, between 20% and 40% of total particulate water is associated with water-soluble organic matter. More data concerning the multiphase aerosol and cloud processes, as well as the chemical reactivity of carbonaceous aerosol components, have been compiled in the reviews of Jacobson et al. (2000), Kanakidou et al. (2005), and Poschl (2005) (and references therein). 

As was to be expected, atmospheric pollution was found to be greatest in the winter, reaching a maximum in December. The occurrence of the maximum in December seemed to be associated with unusually cold Decembers in the two winters studied, and it is possible that the peak would occur normally in January. The winter months showed about twice as much pollution as the summer months. This excess was particularly evident for carbonaceous matter and sulfur. 

Nearly all the metasedimentary rocks entering into the make-up of the BIF contain free carbonaceous matter, and its typical association with the argillaceous (shaly) component of the rocks is observed. Let us examine some typical examples. 

As a result of these exchange reactions, the gas phase in equilibrium with the siderite + magnetite association will be a complex mixture of H2O, CO2, CO, H2, and CH4, the relative amounts of which depend on temperature, total pressure, presence or absence of graphite (carbonaceous matter), and oxygen fugacity. 

The relationship between the concentration of an element in "whole" coal and the ash content can be used as a guide to the affinity of that element for, or incorporation in, the mineral matter or the carbonaceous material. If the concentration of an element increases with increasing ash content that element is presumed to be associated with the inorganic species that form ash, or in other words may be said to have an inorganic affinity. If the concentration shows no correlation with ash content, that element would be said to have an organic affinity. Linear least squares correlation coefficients were calculated for the concentrations of 39 elements... 

There can also be a flammability limit associated with dust clouds. The flammability limits of combustible dusts are reported as the minimum explosion concentrations. The upper explosion limits for dust clouds have not been determined due to experimental difficulties. In the fourteenth edition of the Fire Protection Handbook [National Fire Protection Association (NFPA), Boston, MA, 1975], numerous results from the U.S. Bureau of Mines reports are listed. These results were obtained with dusts 74 fim or smaller. It should be noted that variations in minimum explosive concentrations will occur with change in particle diameter, i.e., the minimum explosive concentration is lowered as the diameter of the particle decreases. Other conditions which affect this limit are sample purity, oxygen concentration, strength of ignition source, turbulence, and uniformity of the dispersion. The NFPA tabulation is most extensive and includes data for dusts from agricultural materials, carbonaceous matter, chemicals, drugs, dyes, metals, pesticides, and various plastic resins and molding compounds. Except for metal... 

Gentry et al. (1976) have recently shown, on the basis of isotopic analyses, that uranium introduction may have occurred far more recently than was previously supposed. However, they find also that, in some instances, the uranium was introduced before coalification was complete since the haloes have been compressed with the coal as it increased in rank. These results are consistent with laboratory and field work by Szalay (1964) who showed that the insoluble humic acids in peat are capable of concentrating uranium from very dilute solutions in natural waters. Sorption occurs as uranyl humate , the process following the normal kinetics of the Langmuir adsorption equation. (Where uraninite occurs in association with peat or other carbonaceous matter, the uranium may thus have been initially sorbed as a uranyl compound which was later reduced to uraninite.)... 

The phosphorites consist of carbonate-fluorapatite mixed with varying amounts of quartz silt, clay minerals, calcite, dolomite, chert and carbonaceous matter. Most of the phosphate occurs as pellets with amounts of oolites, intraclasts, scales, phosphatic shells and replaced skeletal grains. The pellets are cemented with dolomite, calcite, phosphate or, rarely, chert. Some phosphorite beds are composed of phosphate mud. There is a general decrease in size and abundance of intraclast fragments and an increase in carbonaceous content in the phosphorite beds toward the west. These characteristics, plus the close association of phosphorites with cherts and... 

A characteristic of old diesel engines was black soot in their exhausts caused by the combustion process itself in which very small atomized droplets of fuel burning in hot compressed air left an unbumt core of fine carbon particles onto which other species in the exhaust gas adsorbed [26-28]. The total particulate matter emissions of diesel exhaust are comprised of three main components. One component is the solid carbonaceous fraction, which is the visible soot emissions commonly associated with diesel exhaust A second component is the soluble organic fraction (SOF). The SOF can exist either as a vapor or as an aerosol depending of the temperature of the diesel exhaust These liquids arise from imbumed or partially burned diesel fuel or lubricating oil swept from the cylinder walls of the engine [29]. 

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