燃煤飞灰中铁磁性物质及其形成机制

Ferromagnetic Substance in Coal-Fired Fly Ash and Its Formation Mechanism

运用穆斯堡尔谱仪对徐州烟煤和内蒙褐煤煤粉在高温沉降炉中燃烧产生的燃煤飞灰中含铁物相及其相对含量进行定性和定量分析,探讨燃烧温度和燃烧气氛对含铁物相相对含量的影响规律.结果表明,煤种、温度和燃烧气氛对燃煤飞灰中含铁物相的种类没有影响,而对含铁物相中铁的相对含量有一定的影响,其中所含磁性铁相成分也有所不同.燃烧温度升高,灰中硅酸盐玻璃体中铁的相对含量有一定程度的减少,而铁氧化物中铁的相对含量相应增加,其中赤铁矿中铁的相对含量增大较为明显.相同燃烧温度不同燃烧气氛下,煤种对燃煤灰样中含铁物相成分的影响相对较小.

The iron phases in ash samples of Xuzhou bituminous coal and Inner Mongolia lignite burned out in a hightemperature drop tube furnace have been qualitatively and quantitatively analyzed by means of Mssbauer spectroscopy.The influences of combustion temperature and atmosphere on iron-bearing components were investigated.Experimental results show that coal type,temperature and atmosphere in combustion have no effect on the types of the iron-bearing minerals formed but do affect their relative amounts.With the increase in temperature,the relative amounts of Fe2＋ and Fe3＋ glass phases decrease to some extent,while the relative amounts of iron oxidation phases increase correspondingly,among which the relative amount of hematite increases significantly.At the same combustion temperature and under different at-mosphere,coal type does not affect the content of iron-bearing components obviously.