摘要
该文对煤燃烧过程中痕量元素排放的国内外研究现状进行了综述。描述了煤中痕量元素的含量分布 ,并大致按含量的不同将它们分为 4类 ,即 >5 0 μg/g ,10 - 5 0 μg/ g ,1- 10 μg/ g ,<1μg/ g ;总结了燃烧气体与固体产物中痕量元素的形态、分布与富集特性 ,包括飞灰中痕量元素的尺寸分布、痕量元素在亚微米级微细颗粒中的富集、易挥发痕量元素的气相排放、煤及燃烧废物中痕量元素的迁徙及浸洗特性等 ;阐明了燃烧过程中痕量元素形态转变的机理是 :高温下蒸发的金属在下游低温区成核或凝结 ,这些元素与飞灰颗粒一道形成悬浮烟雾 ,上述已蒸发组分向固态或液态形式的转变决定了痕量元素最终的变形和分布行为 ;最后 ,文中简单介绍了痕量元素的控制方法和技术并探讨了痕量元素研究的若干方向。
In this paper, an overview of trace elements research in coal combustion process is presented. Several important aspects are described. The occurrences of trace elements in coal are introduced. Four main groups of trace element content level, say,>50μg/g, 10\|50μg/g,1\|10μg/g, and <1μg/g can be drawn. Trace elements partitioning in emission streams, enrichment in submicron particles, vaporization and emission in flue gas, and the mobility and leaching behavior of trace elements in coal and combustion waste are summarized. The mechanisms of trace elements transformation during combustion are illustrated as following: the vaporized metals at high temperature near the combustion flame will subsequently nucleate or condense at lower temperature downstream. These metals form a suspended aerosol along with particles. The conversion of vaporized components into various solid and/or liquid forms is the key factor influencing the final trace elements transformation/partitioning behavior. Finally, current trace elements emission control technologies are briefly introduced. Research needs are identified and potentially promising research topics on trace elements emission are discussed.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2001年第10期33-38,共6页
Proceedings of the CSEE
基金
国家重点基础研究专项经费资助项目(G19990 2 2 2 12 0 5 )~~
