摘要
为了实现稻壳的资源化利用以及垃圾飞灰的无害化处理,以不同煅烧条件制得的稻壳灰作为中温热处理垃圾飞灰稳固化重金属的添加剂.采用X射线衍射、扫描电子显微镜以及BCR逐级提取法,探究不同的煅烧温度和时间下制得的稻壳灰对飞灰重金属稳固化的影响.研究结果表明:煅烧温度为500℃时,处理样中Pb和Zn的浸出质量浓度均随稻壳煅烧时间的延长逐渐降低;当煅烧温度在600~800℃时,Pb和Zn的浸出质量浓度均随着稻壳煅烧时间的延长先降低后升高.稻壳煅烧条件对稻壳灰的反应活性以及稳固化重金属效果有重要影响.经稻壳灰热处理后新生成Fluorellestadite相(Ca10(SiO4)3(SO4)3F2)和Ca3SiO5等,此类晶体结构有利于实现对重金属的包裹;热处理后飞灰的重金属中不稳定的酸溶态转化为稳定的可氧化态和残渣态,从而实现飞灰重金属的稳固化.
To realize both resource utilization of rice husk and harmless treatment of municipal solid waste incineration(MSWI)fly ash,the rice husk ash obtained under different combustion conditions was adopted as the additive for the stabilization of heavy metals in MSWI fly ash using intermediate-temperature thermal treatment.The effects of the combustion temperature and time of the rice husk on the stabilization of heavy metals in MSWI fly ash were investigated by X-ray diffraction,scanning electron microscopy and European Community Bureau of Reference(BCR)sequential extraction procedure analysis.The results show that when the combustion temperature is 500℃,the leaching concentrations of Pb and Zn in the thermal treatment samples decrease with the extension of combustion time.However,with the temperature ranging from 600℃to 800℃,the leaching concentrations of Pb and Zn decrease firstly and then increase.The combustion conditions of rice husk exact an important effect on the reactivity of rice husk ash(RHA)and the stabilization efficiency of heavy metals.Fluorellestadite phase(Ca10(SiO4)3(SO4)F2)and Ca3SiO5 beneficial to the encapsulation of heavy metals,are formed after thermal treatment with the addition of rice husk ash into MSWI fly ash.The thermal treatment at the intermediate-temperature facilitates the conversion of unstable acid-soluble state in heavy metals to stable oxidizable state and residual state thus realizing the stabilization of heavy metals in MSWI fly ash.
作者
刘斌
吴新
李军辉
谭锦涛
王开
梁财
Liu Bin;Wu Xin;Li Junhui;Tan Jintao;Wang Kai;Liang Cai(Key Laboratory of Energy Thermal Conversion and Process Control of Ministry of Education, Southeast University, Nanjing 210096, China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第3期522-529,共8页
Journal of Southeast University：Natural Science Edition
基金
国家重点研发计划资助项目(2018YFB0605102).
关键词
垃圾飞灰
稻壳灰
制备条件
热处理
重金属稳固化
municipal solid waste incineration(MSWI)fly ash
rice husk ash
combustion conditions
thermal treatment
stabilization of heavy metals
