鱼田堡煤微波/磁脱硫的穆斯堡尔谱研究

MOSSBAUER STUDY OF THE MICRO WAVE/MAGNETIC DESULFURIZATION OF YUTIANBAO COAL

用穆斯堡尔效应研究煤粒的微波脱硫,结果表明一半以上的硫铁矿FeS_2转变为中等磁性的非化学计量的磁黄铁矿Fe_(1-α)S(0<x≤0.125)和反铁磁性的陨硫铁FeS,从而大大增强了煤粒磁性脱硫的效果;没有氧化铁类物相的痕迹.经0.6T磁场再分离后,非磁煤粒中除少量FeS_2外,不再有Fe_(1-x)S、FeS和FeSO_4存在.计算得到两者的无机硫脱硫率分别为24%和91%.

The microwave/magnetic desulfurization is an attractive, novel and efficient physical method for coal cleaning. The Mossbauer spectrum of the coal sample after microwave irradiation shows that high-frequenoy selective heating of coal has transformed more than 50% nonmagnetic pyrite FeS2 into moderately magnetic pyrrhotite Fe1-xS (0<a≤0.125) which will enhance effectively magnetic separation of inorganic sulfur in coal, and into antiferro-magnetio troilite FeS. The ferrous sulfate FeSO4 of weathered products derived from FeS2 is probably oxidized first and then sulfidized. There are no traces of iron oxide in the spectrum.The magnetization enhancement of coal after microwave exposure is clear. Mossbaner spectra of magnetic separa ted samples show that there are no Fe1-xS, FeS and FeSO4 in the non-magnetic fraction, but there is a little of pyrite. Consequently, a majority of inorganic sulfur in the run-of-mine ooal has already been removed significantly.Calculations from the spectra of the abovementioned samples indicate that a 24 % reduction of inorganic sulfur in ooal after microwave treatment and a 91 % reduction after microwave irradiation/magnetic separation treatment have been obtained, respectively.