石炭の炭化初期段階に関する研究 (XXIII)
赤外吸収スペクトル (4) (加熱炭について)
1970 年 49 巻 12 号 p. 898-907
詳細
1970 年 49 巻 12 号 p. 898-907
The infrared spectra of the heat treated coals, prepared by heating 7 different ranks of Japanese coal at temperatures of 200∼500°C were measured by KBr method. Spectra changes began mostly at the temperature range of 300∼400°C; the lower the rank of the original coal is, the earlier the changes began.
In general, increasing the heat treatment temperature resulted in increasing the optical densities of the absorption bands at 3030, 1600 and 870∼750 cm-1 with some reversals beyond the temperature of 450°C, and decreasing those at 2920, 1450 and 1380 cm-1.
From the informations obtained, some inferences were drawn as that there should be significant differences in structure and behavior of the condensed aromatic ring amongdifferent ranks of coal; the absorption band at 1600 cm-1 had a close connection with aromatic carbon content at least for the heat treated coals, and that the natural coalification might develop at temperatures lower than 450°C.
The structural assignment for the 1260 cm-1 band remained controversial. Also worthy of note was the rectilinear correlation between the optical density of the 3030 cm-1 band and the arithmetical sum of those of the bands at 870, 820 and 750 cm-1.
