Semi-anthracite

Moj pyrograms of a high-volatile bituminous coal (E), a low-volatile bituminous coal (F) and a semi-anthracite (G). 

Explosibility of semi-anthracite, low-volatile bituminous-coal, and medium-volatile bituminous-coal dusts. U. S. Bur. Mines Rept. Investigations 3489. 

The present authors found another pyrolysis mechanism leading to optical anisotropy (10), in which no definite liquid phase was observable during the carbonization. In some carbonaceous substances, such as semi-anthracite coal, optical anisotropy over broad regions develops promptly at certain temperatures from the highly viscous stage. The component layers appear to be stacked, and are rearranged by heat-treatment to show optical anisotropy. Such a mechanism can be called the "preordered layer-transformation mechanism". 

Four different types of coal were used for the alkylation tests (Figure 2) a high volatile coal with 34.4X (volatile matter), a medium volatile coal with 24.2%, a low volatile coal with 19.4% and a semi-anthracite with 14.4%. 

It seems that the medium volatile coal remains unchanged. Cleaving and condensing effects probably balance each other. The extractablllty of the low volatile coal Is however Increased, especially by hydrogen fluoride at 80 C. The semi-anthracite Is essentially unaffected by such treatements because of Its highly condensed aromatic structure. 

The coals were reacted with hexadecene and the extractablll-tles of the reaction products were determined. The results are shown In Figure 4. The extractabllltles of the low and medium volatile coal were Increased significantly by this reaction. 68% of the low volatile coal and 65% of the medium volatile coal were extracted with pyridine. The extractablllty In chloroform and benzene, too. Increased to 50 and 30% respectively. The high volatile coal and the semi-anthracite showed no essential Increase of extractablllty. 

Names anthracite, semi-anthracite coal, bituminous coal CAS 8029-10-5... 

Anthracitic Meta-anthracite Anthracite Semi anthracite ... 

About 10% of the world s ammonia production is based on coal, coke, or lignite. About half of the coal-based capacity is in the People s Republic of China where there are over 1,000 small plants with capacities ranging from 3,000 to 10,000 tpy [39]. It was reported that 1,100 small coal-based ammonia plants were built between 1966 and 1974 and 100 more per year were being added in 1975 [40]. The technology of one of these plants has been described [41]. The feedstock was lump anthracite or semi-anthracite although it was r ported that briquetted coal or lower grade coal was used... 

As coalification proceeds in geological time with loss of hydrogen (as methane), the hydrogen bonding within bituminous coals is replaced by carbon-carbon covalent bonds causing the fusibility of the bituminous coals to decrease to zero as found in the semi-anthracites and anthracites (Figure 2.24). 

The HHV of coals increases from low rank (<24 MJ/kg(waf) for lignite B) continuously to higher rank achieving a maximum ( =37.3MJ/kg(waf) around 85-90 wt%(waf) carbon for low-volatile bituminous coals or semi-anthracite). 

Smith, I. (1971) The kinetics of combustion of pulverized semi-anthracite in the temperature range 1400-2200K. Combustion and Flame, 17 (3), 421-428. 

Poor adaptability to changing fuel. Minimum temperature operable, (lignite 690°C, Sub-bituminotis coal 750 C, Semi-anthracite, 800°C) depends on coed reactivity. 

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