Migration Mechanism Of The Trace Elements On The Microwave Retorting Of Oil Shale

The release of the harmful trace elements endangered human health andenvironment during the exploitation and utilization of oil shale. Controlling therelease of these harmful trace elements has been a new forward field in the pollutioncontrol. The typical harmful trace elements in the oil shale are mercury (Hg), arsenic(As), lead (Pb), and etc, although these elements' content of oil shale is very low, theirdischarge amount is astonishing because of the great amount exploitation andutilization and deficient control methods. So the pollution cannot be ignored.In order to research the migration mechanism of the trace elements during oilshale microwave retorting, identify the extraction methods by X-ray diffractionanalysis in Huadian oil shale, the trace elements content in the four-layer oil shale ofHuadian Dachengzi mine was determined using inductively coupled plasma massspectrometry(ICP-MS) in different microwave retorting working conditions.The results demonstrated that except effect of the occurrence characteristics andgeochemical properties, the final temperature and microwave power had some effecton the migration mechanism of the trace elements. In the same microwave power, thesemi-coke yield decrease as the increase of the final temperature; and in the samefinal temperatur the semi-coke yield increase with the increase of the microwavepower.Except Cd, the volatilization rate of the other seven elements increase with theincrease of the terminal temperature of the microwave retorting, the volatilization rateof the other seven elements decrease with the increase of the microwave power of themicrowave retorting. The volatilization rate is the largest, and all states of Cd are notstable. The contents of exchangeable state, carbonate state, iron-manganese oxidestate, sulfide state and organic matter state of the most trace elements in our researchdecrease as the increase of the terminal temperature of the microwave retorting, the residue state of the most trace elements are relatively stable, they decrease as theincrease of the terminal temperature of the microwave retorting. The contents ofexchangeable state, carbonate state, iron-manganese oxide state, sulfide state andorganic matter state of the most trace elements decrease as the increase of themicrowave power, the contents of residue state of the most trace elements increase asthe increase of the microwave power. The final temperature and microwave powerhad some effect on the migration mechanism of the trace elements.