摘要
对掺煤混烧的流化床焚烧飞灰熔融过程中重金属在气相(吸收率)中和固相(固定率)中的分布进行了研究,并采用HNO3—NaOH2级吸收方式对气相重金属进行了吸收。结果表明,CaO/SiO2(摩尔比)对重金属的迁移行为有重要影响,CaO/SiO2降低,Cd、Pb固定率总体呈上升趋势;2级吸收对气相重金属的吸收有限,大部分重金属主要溶解在HNO3吸收液中,但NaOH吸收液对Cr的吸收效果好于HNO3吸收液;氯对重金属的挥发有重要影响,当重金属以氯化物形式存在时,其挥发受到SiO2的限制,随着SiO2含量增加,挥发率降低。
The heavy metal distribution in solid residue and dust gas during the melting treatment of fluidized bed incinerator fly ash was analyzed, and the HNO3-NaOH two-stage adsorption was employed for adsorbing the heavy metal from the dust gas of melting furnace. The results showed that the CaO/SiO2 ratio of fly ash greatly affected the heavy metal behavior. The content of Cd, Pb and Zn in solid residue was increased with the decreasing of CaO/SiO2. Two-step absorption presented limited capability of heavy metal adsorption, most of adsorbed heavy mental was found in HNO3 absorbing liquid. While the adsorption of Cr in NaOH absorbing liquid was more than that in HNO3 absorbing liquid. The content of SiO2 could enhanced the stabilization of heavy metallic oxide but prevent the volatilization of its chloride.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2009年第8期16-19,共4页
Environmental Pollution & Control
基金
国家自然科学基金资助项目(No.50606028)
