Physicochemical properties and heavy metals leachability of fly ash from coal-fired power plant  

作　　者：Xiang Wei Han Baoping Zhou Dong Nzihou Ange 

机构地区：[1]School of Environment Science and Spatial lnforrnatics, China University of Mining & Technology, Xuzhou 221116, China [2]Centre RAPSODEE, Mines AIbi, University of Toulouse, Albi 81013, France [3]Xuzhou Institute of Technology, Xuzhou 221008, China d Beijing Puresino-Boda Environmental Engineering Co., Ltd., Beijing 100082, China

出　　处：《International Journal of Mining Science and Technology》2012年第3期405-409,共5页矿业科学技术学报（英文版）

基　　金：provided by the Europe-AsiaLink (No. CN/ASIA-LINK/010 94556);State Scholarship Fund of China Scholarship Council (No. 2010642035)

摘　　要：The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined： the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular par- ticles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fiuidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572~ and 497~, which levels might threaten the environment.The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular particles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fluidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572% and 497%, which levels might threaten the environment.

关 键 词：Fly ashPhysicochemical propertyLeachabilityHeavy metal 

分 类 号：TQ460.6[化学工程—制药化工] X770.5[环境科学与工程—环境工程]