作　　者： ; ; ; ;

机构地区： 南京大学环境学院污染控制与资源化研究国家重点实验室

出　　处： 《南京大学学报（自然科学版）》 2007年第3期329-334,共6页

摘　　要： 粉煤灰的矿物相组成对其资源化具有重要意义,它主要取决于燃料品种和燃烧过程.由于燃烧过程的差异,循环流化床锅炉(CFBC)内掺加高硫石油焦和煤混烧而排放的脱硫灰与煤粉炉粉煤灰在矿物相组成上具有较大差异.利用扫描电镜(SEM)、X-ray衍射(XRD)和傅立叶转换红外光谱(FT-IR)对CFBC掺高硫石油焦混烧脱硫灰的矿物相组成进行了研究,同时采用选择性溶解分离和重力分离的方法富集脱硫灰中的微量矿物,研究表明CFBC掺高硫石油焦混烧脱硫灰的矿物相组成以高α-石英、硬石膏和石灰含量为其主要特征,同时含有少量的方解石、莫来石、钙长石、钙铝黄长石、赤铁矿、硅酸二钙(2CaO.SiO2,C2S)、铝酸三钙(3CaO.Al2O3,C3A)、七铝酸十二钙(12CaO.7Al2O3,C12A7)及透辉石等矿物,可能含有少量玻璃相.如果样品在空气中存放时间较长,石灰吸收空气中的水分会导致羟钙石生成.而煤粉炉粉煤灰中的矿物主要为莫来石、石英和少量的赤铁矿,并含有大量的玻璃相. 　Mineral compositions of fly ash are very important for its reuse,and are dependent on the kind of fuel and the combustion process.The fly ash coming from a circulating fluidized bed combustor（CFBC） is very different from the coal ash from traditionally pulverized fuel firing due to many differences in their combustion processes,and thus these two kinds of coal ash have different mineral phases.The mineral compositions of the fly ash from CFBC cofiring coal and high-sulfur petroleum coke（CFBC fly ash） was investigated by SEM,XRD and FT-IR,with the use of the dissolution separation method and the gravity separation method for concentration of the minor phases.The results showed that the CFBC fly ash particles were irregular but the pulverized fly ash particles were often spherical.The major minerals present in the CFBC fly ash were α-quartz,anhydrite and lime,and the minor minerals iucluded calcite,mullite,anorthite,gehlenite,hematite,dicalcium silicate（C2S）,tricalcium aluminate（C3A）,twelve-calcium hepta-aluminate（C12A7） and diopside.There was a little glass phase in the CFBC fly ash.If the ash stored in the air for a long time,portlandite could be found in it due to water adsorption of lime.Nevertheless,many mullite and α-quartz crystalline phases and many glass phases existed in the pulverized fly ash.Anhydrite and lime existed in the CFBC fly ash because of the SO2-removing by limestone added in situ during combustion.And the reuse of the CFBC fly ash was generally dependent on the content of anhydrite and lime.

关 键 词： 循环流化床锅炉 脱硫灰 矿物相组成 重力分离

领　　域： [环境科学与工程]