摘要
为了深入认识循环流化床(CFB)锅炉粉煤灰的组成特性,采集了山西平朔、河坡、宏光、国峰4个典型电厂CFB机组的飞灰和底渣,研究了其化学和物相组成特性及其随粒径的变化规律。结果表明:不同电厂CFB粉煤灰的粒径分布规律具有一定的相似性,飞灰的粒径范围较为集中,75%以上分布在96~109μm(140~160目)和61~80μm(180~240目);与飞灰相比,底渣的分布较为分散,各粒径范围的比例均在25%以下,从粒径筛分效果看,底渣比飞灰更易分选。飞灰的化学组成随粒径变化较小,底渣的化学组成随粒径的变化较为明显,底渣中SiO_2和Al_2O_3含量随着粒径减小而减少,CaO和SO_3含量则随着粒径减小而增加,Fe_2O_3和MgO含量基本不随粒径而变化。筛分后不同粒径飞灰之间矿物质种类区别不大,以石英、硬石膏和赤铁矿为主;底渣中以石英、硬石膏、氧化钙和赤铁矿为主,固硫产物硬石膏含量随粒径减小而增加,其更易分布在小粒径底渣中。
In order to understand the composition characteristics of circulating fluidized bed( CFB) boiler pulverized fuel ash,the fly ash and bottom slag of CFB units from four typical power plants in Pingshuo,Hepo,Hongguang and Guofeng of Shanxi Province were collected. The chemical and phase compositions of ash with different particle sizes were studied. The results show that the particle size distribution of CFB pulverized fuel ash from different power plants has some similarities. More than 75% of fly ash distributed between 96 109μm( 140160 mesh) and 6180 μm( 180240 mesh). Compared with fly ash,the distribution of bottom slag is relatively dispersed,and the proportion of each particle size range is below 25%. From the perspective of the particle size screening effect,bottom slag is easier to sort than fly ash. The chemical composition of fly ash varies little with particle size. The chemical composition of bottom slag is more pronounced with particle size. The contents of SiO2 and Al2O3 in the bottom slag decrease with decreasing particle size,and the contents of CaO and SO3 increase with decreasing particle size. The content of Fe2O3 and MgO does not change with particle size. After sieving,there is no significant difference in mineral species between fly ash of different particle sizes. Quartz,anhydrite and hematite are the main components; quartz,anhydrite,calcium oxide and hematite are the main components in slag,and anhydrite content increased with decreasing particle size,which indicating that the sulfur-fixed product is more easily distributed in small particle size bottom slag.
作者
单雪媛
马志斌
郭彦霞
程芳琴
SHAN Xueyuan;MA Zhibin;GUO Yanxia;CHENG Fangqin(State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources,Shanxi University,Taiyuan 030006,China;Institute of Resources and Environment Engineering,Shanxi University ,Taiyuan030005,China)
出处
《煤炭科学技术》
CAS
北大核心
2018年第11期232-238,共7页
Coal Science and Technology
基金
国家重点研发计划资助项目(2017YFB0603101)
NSFC-山西煤基低碳联合基金资助项目(U1610254)
山西省2016年度煤基低碳重大专项资助项目(MC2016-05)
关键词
粉煤灰
循环流化床
粒径分布
飞灰
底渣
pulverized fuel ash
circulating fluidized bed
particle size distribution
fly ash
bottom slag
