17.熱処理に伴う石炭の凝集構造緩和

抄録

The effects of heating rate on the change in associated molecular structure of slightly-coking coal, Witbank coal, was investigated. Spin-spin relaxation phenomenon of the coal during heat treatment was observed using in-situ pulsed ^1H-NMR. A solid-echo pulse sequence was employed to monitor the variation of molecular mobility of coals. The echo signals obtained were deconvoluted into a set of a Gaussian and two Lorentzian decay, which represent the immobile, intermediate and mobile components, respectively. With rapid heating treatment up to 644K, mobile component in Witbank coal is varied not only quantitatively but also qualitatively. The variation might be result from the relaxation of associate structure induced by heat treatment. Since the molecular mobility were considered to have a close relation to the softening characteristics of coal, the improvement of coking phenomenon with rapid heating treatment can be attributed to the change in associated molecular structure of the coal. These results indicate that change in the associated macromolecular structure of coal has strongly affected with heating rate.