还原性气氛下熔渣中铁的富集及析出机理研究  

Study of iron enrichment &iron precipitation in molten slag under reducing atmosphere

作　　者：李寒旭[1] 李金知 张冬梅 熊金钰[1] 辛宇[1] 

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232001 [2]中安联合煤化责任有限公司,安徽淮南232001

出　　处：《中国矿业大学学报》2015年第1期144-150,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(21176003)

摘　　要：以Shell煤气化过程中产生的工业渣样(正常渣样和非正常渣样)和不同温度与还原性气氛下烧制的煤灰渣样(实验渣样)为研究对象,利用XRD,XRF,SEM-EDX研究了还原性气氛下熔渣中铁的富集及析出机理.结果表明:正常渣样组成稳定,主要为非晶态熔体;非正常渣样按矿物组成分为两类,一类以钙长石晶体为主,另一类以陨硫铁和铁单质为主.非正常渣中钙长石的生成与铁的富集和析出有内在联系;在相同还原性气氛下,随温度升高,钙长石晶体矿物相对含量增加,促进了含铁矿物的转化,导致Fe-S-O熔体的富集,进一步被还原成铁单质.在25%CO气氛1 200℃和50%CO气氛1 100℃的条件下熔体中均检测到了相对含量分别为0.44%和1.11%铁单质,验证了工业渣样的分析结果及析铁机理.The discharged slag sample（normal slag）in normal operation of Shell coal gasification process,slag lump（abnormal）in the process of slag blockage of Shell coal gasification in abnormal operation,and the slag samples of ZX coal ash derived from different temperature and reducing conditions were selected to investigate the mechanism of the iron enrichment ＆iron precipitation in molten slag under reducing atmosphere by X-ray fluorescence spectrometer（XRF）,X-ray diffractometer（XRD）and scanning electron microscope/energy dispersive X-ray spectrometer（SEM-EDX）,respectively.The results show that the normal discharged slag samples are mainly amorphous melt with stable ash chemical composition.The abnormal discharged slag samples could be classified into two categories by the crystalline mineral composition：one is mainly anorthite,and the other is mainly the troilite and iron.The formation of anorthite relates to the enrichment of Fe-S-O and iron-bearing minerals and precipitation of iron.The slag samples derived from different temperature and reducing conditions were prepared to prove the results of industrial slag samples.The results show that the relative content of anorthite in crystal minerals under same reducing atmosphere is increasing with temperature increment,which leads to the enrichment of Fe-S-O and the precipitation of iron.The iron isdetected under 25%CO atmosphere at 1 200℃and 50%CO atmosphere at 1 100℃,and the relative content of iron are 0.44% and 1.11% respectively.Experimental results validate the analysis results of industrial slag samples and iron precipitation process.

关 键 词：SHELL粉煤气化 铁富集 还原性气氛 析铁 

分 类 号：TQ546[化学工程—煤化学工程]