Abstract:
Datong coal was pulverized to 0.074 mm and dried at 105 ℃, then oxidized with hydrogen peroxide under mild condition. Both raw and oxidized coal were extracted with methanol/tetrahydrofuran (THF) mixed solvents under ultrasonic irradiation, then the extracts were analyzed by GC/MS so as to study the difference of extracting between raw and oxidized coal. The result indicates that the extraction yields of oxidized coal were higher than those of raw coal at the test conditions and the extraction yield increased with increasing THF concentration. The components of the four extracts were different from each other, indicating that chemical components of extracts can be changed by both oxidation and THF content in mixed solvent. But the compounds in all the four extracts were mainly hydrocarbons. In addition, coal particles were supernatant through formation of coal powder-extract-solvent colloid, therefore, filtration must be taken in coal extraction under ultrasonic irradiation.