CaO对烟气中砷的形态和分布的影响  

Effect of CaO on the speciation of arsenic in flue gases

作　　者：王泉海[1] 刘迎晖[1] 张军营[1] 邱建荣[1] 郑楚光[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《环境科学学报》2003年第4期549-551,共3页Acta Scientiae Circumstantiae

基　　金：教育部骨干教师资助项目 ( 2 2 0 2 );国家自然科学基金资助项目 ( 5 0 176 0 15 )

摘　　要：采用热力平衡分析方法研究了在一个大气压下 ,130 0K— 4 0 0K温度范围里痕量元素砷在煤燃烧过程的形态及分布以及添加剂CaO对砷的形态和分布的影响 .为探讨规律 ,研究的系统只考虑煤中的主量元素和砷 .分析结果表明 ,在煤燃烧和气化的高温区域里 ,大部分的砷元素蒸发以一氧化砷的形式存在于气相中 ,随着温度的降低 ,一氧化砷将发生化学反应生成固相As2 O5和As2 S2 .CaO可以大大地增强砷元素的沉积趋势 ,烟气中CaO的含量越大 。The species and distribution of arsenic in flue gas of coal combustion and the effect of CaO on the speciation of arsenic were studied using chemical thermodynamic equilibrium calculation approach. The system studied is a simplified system which only cencerns the main elements in coal and arsenic. The results showed that in the high temperature zone of coal combustion and gasification, AsO(g) is the thermal stable form. when taperature decreases,AsO reacts with other components in the flue gases and form solid As 2O 5 and As 2S 2. CaO can greatly improve the deposition of arsenic. when the content of CaO in flue gases is greater, the temperature zone of Ca\-3(AsO\-4)\-2 as the main form of arsenic is wider.

关 键 词：CAO 烟气 砷 形态 分布 影响 环境污染 痕量元素 煤 气化 燃烧 

分 类 号：X701[环境科学与工程—环境工程]