함탄층(含炭層) 내의 chiastolite-shale의 개발(開發) 이용(利用)에 관(關)한 연구(硏究)

The Research on the Exploitation and Utilitization of Chiastolite bearing shale in the Coal bearing strata

The chiastolite bearing shale was known to occur in various coal fields in South Korea among which the Kangneung coal fields is the most outstanding in quality and quantity of chiastolite. The chiastolite occurs mostly in black shales of Sadong formation and little in shales of Hongjom and Kobangsan formations, and is most abundant in the footwall coaly shales of the Sadong coal seams. The chiastolite has been proved to be thermal contact product of the high aluminous shale that comes into contact with Kangneung granite. The distribution of chiastolite in the Kangneung coal field is irregular. The eastern part of the region contains more chiastolite than that of western part. It is believed that the difference of the grade is due to the intensity of metamorphism. The grade of chiastolite in the shale varies from few percent up to as high as 60 % in volume, and the minable reserve of the chiastolite is estimated about 4,700,000 tons. This reserves is rather concentrated in few localities such as in Jiam Mine, Jungrim Mine, Sir 1 Hang in the Whasung Mine, the second and third sections of Kangneung Mine and Umbuelri district. The chemical composition of chiastolite bearing coaly shale is $SiO_2$, 35.0%; $Al_2O_3$, 27.0%; $Fe_2O_3$, 0.29%.