石炭の二硫化炭素‐ピリジン混合溶媒抽出物および残さ炭の性状

Abstract

The extractions of Shin-yubari and Zao Zhuang (China) coals with carbon disulfide-pyridine mixture, which gives high extraction yields at room temperature, were done and chemical natures of the extracts and residual coals obtained are compared with those from Soxhlet extraction with pyridine.For Shin-yubari coal the extraction yields are almost same (40%) in the both procedure and the extracts were fractionated to oil, asphaltene and preasphaltene, respectively. The preasphaltene from the extract with the mixture has higher molecular weight and aromaticity (fa) and lower FIX, the degree of substitution (σ) and condensation (Hau/Ca) from that from the Soxhlet extraction, while there is no substantial difference in nature of the oils and also the asphaltenes.The quantities of volatile matter of the residual coals are found to be almost same in the both procedures, but crucible swelling numbers and Roga indexes, a measure of the caking property, were higher for the residual coals from the extractions with the mixture. The similar result for the caking properties was obtained in the extractions of Zao Zhuang coal. Heat treatments of the residual coals from the extraction with the mixture, at 110°C, the temperature of Soxhlet extraction, in the presence of pyridine were found to reduce the swelling numbers and Roga indexes. This result suggests that one of the reasons for the decrease of the caking properties in the Soxhlet extraction may be chemical or physical change such as an increase of porosity, of the non-extractable part of the coal.