Research On Occurrence Of The Organic Sulfur In Coke Coal Via Accelerated Solvent Extraction

Xinyu coke coal was separated to four group component, i.e. heavy components, lightcomponents, loose medium components and dense medium components, to research thedistribution regularities of organic sulfur in the coke coal. Adopting n-hexane, methanol,n-propanol and tetrachloroethylene as the solvents, we performed the fractional and multipleextraction of the coke coal and its group components via accelerated solvent extraction. Thedissolved matters were analyzed via GC/MS. The distribution and dissolution regularities ofsmall sulfide molecules were speculated with embedded structure model of coal. The undissolvedmatters of fractional extraction were analyzed via XPS to research the distribution regularities ofdifferent types of organic sulfur and to compare with the results from soxhlet extraction.98%of sulfur matters in the coke coal was organic, which mainly existed in heavycomponents of big molecules, and there were seldom organic sulfides in light components ofsmall molecules. The relative contents of organic sulfides in different group componentsdecreased as the following order: dense medium components> loose medium components>heavy components> light components. Thiophene-type sulfur was96%of organic sulfides in thecoke coal. With separating it as group components,78.6%,6.6%and8.1%of thiophene-typesulfur were distributed in heavy components，loose medium components and dense mediumcomponents, respectively. Performed fractional extraction of each group components,10%ofthiophene-type sulfur was dissolved in total. Meanwhile,76.4%,4.5%and2.8%ofthiophene-type sulfur were distributed in heavy components，loose medium components anddense medium components, respectively.There are three types of organic sulfides in Xinyu coaking coal and its group components,i.e. mercaptan-thioether, thiophene and sulfoxide, and mainly thiophene type. The Da,tofdissolved organic sulfides decreased as following order, dense medium components> loosemedium components> raw coal> heavy components. Polar and non-polar solvents dissolved theorganic sulfides in heavy components and dense medium components very well, respectively.Compared with Soxhlet extraction, accelerated solvent extraction showed a perfectdissolving capacity to the organic sulfides of small molecules in coke coal. There were8organicsulfides in n-hexane dissolving matters.