石灰对高温烟气中重金属的吸附特性研究  

HEAVY METALS'ABSORPTION BY LIMES AT HIGH TEMPERATURE INCINERATION FLUE GAS

作　　者：魏芃[1] 陈德珍[1] 徐科[1] 

机构地区：[1]同济大学热能与环境工程研究所,上海200092

出　　处：《能源环境保护》2005年第3期16-20,23,共6页Energy Environmental Protection

基　　金：国家自然科学基金项目(50006009);上海市青年科技启明星项目(01QF14040)资助

摘　　要：研究了常用的酸性气体吸收剂石灰在600℃和800℃下对焚烧烟气中常见的四种重金属Cd,Pb,Zn和Cu的吸附效果。实验中采用重金属的氯化物作为蒸发源将重金属挥发到烟气中,吸收剂在流化床中对烟气中的重金属进行吸收。实验结果表明石灰类吸收剂在600℃和800℃时对四种重金属均有一定的吸附效果,其中Cd和Pb容易被吸附,而Zn难以被吸附。所试验的三种石灰吸收剂中,CaCO3对重金属的吸附能力相对较差,特别是对Cd和Pb;而普通Ca(OH)2的吸附能力最强。为了提高高温烟气净化残渣的质量,600℃及以上的高温下宜使用CaCO3和改性Ca(OH)2作酸性气体的吸收剂。In this paper three kinds of limes which are common absorbents for acidic gases are used to absorb four kinds of typical heavy metals occurring in the incineration flue gases,namely,Cd,Pb,Zn and Cu under the temperatures of600℃and800℃.In the laboratory chlorides of four heavy metals were evaporated to formvapor in the flue gas and then the heavy metal vapors were absorbed in the fluidized-bed reactor with limes as absorbents.The experimental results showed that under600℃and800℃,the four kinds of heavy metals can be absorbed to different levels.Cd and Pb are relatively easier to be absorbed,while Zn is most difficult to be absorbed under the conduction of high temperatures.Of the three tested limes,CaCO 3 was the worst one to work as heavy metal abˉsorbent,especially for Cd and Pb;while common Ca(OH) 2 was the most effective one.In order to improve the quality of flue gas ashes(including fly ash,reacted and un-reacted absorbents)modˉified Ca(OH) 2 and CaCO 3 were suggested as absorbents for high temperature flue gas scrubbing.

关 键 词：重金属 石灰 吸附 高温 烟气净化 残渣 

分 类 号：X701[环境科学与工程—环境工程]