Study on Release and In-situ Fixation of SO2 During Preheating Oxidation Roasting Process of High-sulfur Iron Ores
Preheating oxidation roasting of low magnetic refractory high-sulfur iron ore before reduction roasting can ef-fectively desulphurize and obtaining low-sulfur iron ore concentrate.In order to solve the problem of desulfurization more effi-ciently and economically,it is very important to study the mechanism of sulfur migration,release and fixation during roasting process.The effects of roasting temperature and gas flow rate on the release of SO2 were investigated using hematite samples containing 2%sulfur.And the phase composition and SO2 release mechanism of calcined clinker were analyzed by X-ray dif-fraction(XRD).It was shown that the sulfur-fixation efficiency of CaO with the addition of 20%reached 77.10%;The adsorp-tion energy of SO2 on the surface of CaO(100)to be-74.856 kcal/mol and an electron transfer of 0.284 e were calculated by DFT;Density of states analysis revealed the reaction mechanism:a greater degree of electron transfer between the sulfur at-om and the oxygen atom on the CaO surface,and a strong chemical bond was formed.The results provide a basic theory for the transformation of desulphurization from end control to process control.
high-sulfur iron oreSO2 releaseoxidizing roastingsulfur fixation
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