神华煤灰掺混木屑灰在O_2/CO_2气氛下的烧结特性

Sintering characteristic of Shenhua coal ash blending with saw dust ash in O_2/CO_2 atmosphere

利用CCD监测系统和自制烧结探针研究神华煤灰掺混不同比例的木屑灰在O_2/CO_2气氛下的烧结特征,实时在线监测灰块在烧结时的形状特征.结果表明:掺混木屑灰对混合灰块的高度影响较少,而对横截面积影响较大.当木屑灰比例为0、25%、50%、75%和100%时,相应的高度收缩率分别为0.127、0.119、0.134、0.124和0.136,而横截面积收缩率则分别为0.125、0.150、0.074、0.117和0.164.各灰块在烧结探针上经过烧结处理后,其横截面都具有三层层状结构,且每层的颜色和烧结程度都不同.利用XRD技术对每层的矿物质分布进行分析,结果表明:对于掺混不同比例的生物质灰,其混合灰块的矿物质种类和含量都有很大变化,尤其是最外层.对各灰块的层状结构进行SEM分析,发现掺入木屑灰后,灰块最外层孔状结构变小.同时,加入掺混木屑灰能够使得灰块最外层的横截面结构光滑致密.

CCD monitoring system and sintering probe were applied to investigate the sintering characteristic of Shenhua coal ash blending with saw dust ash in oxy-fuel combustion atmosphere（O_2/CO_2）.The shape of ash samples was observed online by the CCD monitoring system.The results reveal that the effect of the blending ratio of saw dust ash on the height of ash sample was not evident.Nevertheless,the blending ratio of saw dust ash affects the cross-sectional area of ash sample significantly.The height shrinkage rates of the ash samples were 0.127,0.119,0.134,0.124 and 0.136,which corresponding to 0%,25%,50%,75% and 100% of saw dust ash in blend ash.And the corresponding area shrinkage rates were0.125,0.150,0.074,0.117 and 0.164,respectively.Meanwhile,results indicate that all the residue ashes are characterized by three layer structures with different colors and sintering degrees.The XRD analysis results show that the blending ratio of saw dust ash in the blend ash influence the types and content of mineral in the residue ashes,especially for the outer most layer.The SEM analysis results reveal that the blending saw dust ash in blend ash can give rise to the smaller of pore structures in the outer most layer.In addition,the saw dust ash can make the matrix of the outer most layer more smooth and compact.