Micrograph, electron 8 coal

Plate 1. Scanning Electron Microscope and Optical Microscope Micrographs of selected char from oxidised A series coals, la., char produced from fresh coal, lb., char from coal oxidised for 17 days. Ic., char from coal oxidised for 112 days. V, devolatilisation vent., M, mechanical damage. 

Fig. 4. Plerospheres in coal combustion fly ash. The large pleiosphere in the centre of the field of view has broken open to reveal smaller nests of plerospheres and cenosphcres inside. Transmission electron micrograph courtesy of Dr. E. E. Lachowski.

Fig. 2. Scanning electron micrograph of typical coal fly ash particles.

Fig. 6. Scanning electron micrograph of moderate-Ca Class-C lignite fly ash (from Fort Union coal).

Fig. 7. Scanning electron micrograph of high-Ca Class-C subbituminous fly ash (from Powder River Basin coal).

Figure 1. Electron micrograph of an ultrathin section of a dull attrital layer (durain) in a high volatile A bituminous (hvab) coal. V—vitrinitey E—exinite, M—granular micrinite. X 10,500...

Figure 6. Electron micrograph of a replica of granular micrinite in vitrain in hvab coal.

Figure 10. Electron micrograph of an ultrathin section of exinite in hvab coal. X 42,000...

With increasing rank, the differences between macerals become progressively smaller in electron as in light microscopy. Exinite in particular becomes difficult to distinguish in medium volatile coals, and could not be positively identified in the electron micrographs of low volatile bituminous coals so far examined. Similarly, the laminate structure of vitrinite described above could not be observed in low volatile bituminous coals. 

Figure 10.8 Milk lipid globule membranes released by churning of washed globules and collected by ultracentrifugation retain densely staining coal material along one face of the bilayer membrane. As seen in this electron micrograph of glutaraldehyde and osmium tetroxide-fixed material, the...

Figure 7. Scanning electron micrograph of fracture surface of coke from Chinese Shuang Ya coal, CR 502 (See Ref. 30).

In addition to those minerals associated with the granular constituent, there are numerous submicron-sized minerals that are intimately mixed with other coal macerals. A typical example can be seen in Figure 11, which is a TEM micrograph of vitrinite, where the circular aperture identifies the region from which the electron diffraction pattern, shown in the inset, was obtained. The mineral, which was identified as kaolinite, appears to have been deposited as plates parallel with the coal bedding, based upon an analysis of the diffraction pattern. Also present in these coals is the clay mineral illite, which can be distinguished from kaolinite by both EDX and SAD analyses, lllites contain potassium (K)... 

Fig. 9 Scanning electron micrograph of pyrite particle in Prince coal following pyrolysis.

Figure 4, Secondary electron micrograph of semicoke from Pittsburgh No, 8 coal...

Figure 5, Transmitted electron micrograph of semicoke from Lower Kittanning coal after heating to 500°C,...

---