石炭の黒鉛化と灰分の触媒作用

Abstract

Raw and deashed coals, phenol-folmaldehyde resin and petroleum pitch with and without ash components were heat-treated to 1200, 2000 and 2800°C. The heat-treated products were observed and examined by TEM and X-ray diffraction to clarify the graphitization of them and the effect of minerals on the one.Taiheiyo coals have micropore phase in which carbon layers in 5-6 nm thick surround the pore less than 5-6 nm in diameter. The micropore phase is originally of no graphitization, however in favor of minerals for it. Taiheiyo coal heat-treated at 2800°C also has macropore, lamella and mesopore phases formed from the micropore phase by the catalysis of indigeneous mineral matters.Microtextures of Yubari and Cerro coals are substantially lamella phase which shows the preferred orientation of carbon layer stacks, although Cerro coal is considerably higher degree of graphitization than Yubari one. Ash components locally interfered with the graphitization of both coals to produce small amount of macropore and mesopore phases.Mesopore phase begins to appear at relatively temperatures lower than other phases when minerals are contained in coal. It is considered that the phase will be formed in the steps of solution-precipitation between carbon and minerals such as iron or iron carbide containd . And macropore and lamella phases might be formed at temperatures higher than 2000 t by the SiC formation and decomposition.