Variations In Compositions And Superficiality Response Mechanism Of Extracted Coals With Different Macrolithotypes

The different macrolithotypes were extracted by different organic solvents to dissolve organic matter and micro-molecular compound,which caused profound changes in composition,characteristic functional groups,structural parameters and superficiality.The variation characteristics such as composition,structure and superficiality before and after improvement by organic solvents were compared and studied by means of modern measurement technology further.Then the solvent extraction of different macrolithotypes by different solvents were explored from microcosmic level,for the use of classification,processing,utilization and coal chemical industry of in different macrolithotypes,while providing reference for coal structure and wettability research and clean coal utilization.Coal samples with different macrolithotypes,collected coking coal from Pingdingshan two mine and meagre coal from Huoerxinhe mine,were separated them into the vitrain,the clarian,and the durian,and treated with organic solvents such as tetrahydrofuran,carbon disulfide,acetic,acid acetone,and n-hexane.Based on the chromatography,Fourier transform infrared spectroscopy,and contact angle measuring instrument,composition of the extracts,the main characteristic functional groups and the contact angles of the coal before and after the extraction were determined,and the variation characteristics of the composition and the superficiality in different macrolithotypes before and after extraction were discussed.The results show that:?1?Extraction yield of the vitrain is the highest,followed by the clarian,and the lowest is the durian.Extraction yields of THF and CS₂ solvents for coal samples are higher,followed by acetone and HAc,while n-hexane is the lowest,and extraction yield of coking coal is significantly higher than meagre coal;?2?The hydrocarbon contents in the extraction decrease in the sequence of the vitrain,the clarian,and the durian,whereas the non-hydrocarbon components increase correspondingly,and the hydrocarbons/non-hydrocarbons decrease in turn.More asphaltene is extracted from the coal samples under THF,but more saturated hydrocarbon is extracted under CS₂ and acetone.In all the solutions treated to the coal,the fatty hydrocarbon and oxygenic functional groups of the vitrain decrease most obviously,whereas the aromatic structure of the durian is the highest.The reduction of oxygen enrichment is the most obvious for CS₂,the most obvious decrease of aliphatic hydrocarbon structure is acetone,while the hydrogen-bond hydroxyl,phenols groups and fatty hydrocarbon are strong extracted by THF.?3?After organic solvent extraction,the water-coal contact angle of different macrolithotypes increases,while the surface tension decreases,the hydrophilic smaller,and the wetting ability is weakened.THF and CS₂ are the most obvious change on the superficiality of coal samples,and reduce significantly between the surface tension and the wettability.The wettability of coking coal is significantly stronger than meagre coal.