摘要
明确燃煤过程中重金属迁移特性对其减排具有重要的意义。本文采用US EPA Method 29烟气重金属取样方法,在管式炉实验台上考察了气氛(空气、40%O_(2)/60%CO_(2))、温度(700、900、1100℃)对燃煤过程中重金属As、Cr、Se迁移特性的影响。分别采用BCR、HJ/T 299-2007研究了煤中重金属的化学赋存形态和浸出毒性。结果表明:As、Cr、Se分别主要分布在飞灰、底渣、飞灰和烟气中。温度升高有利于As的挥发和在飞灰中富集。空气气氛下,温度升高有利于Cr在飞灰中富集。富氧气氛下,温度升高导致Cr在飞灰和烟气中的分布先增加后减小。As、Cr、Se在煤中分别以残渣态、残渣态、可氧化态+残渣态为主。赋存形态和浸出比例满足水/酸溶态和可交换态<浸出比例<水/酸溶态和可交换态+可还原态。
Clarifying the migration and transformation characteristics of heavy metals in coal combustion is significant to reduce its emission from coal combustion. In this paper, In this paper,the US EPA Method 29 flue gas heavy metal sampling method was used to investigate the effect of atmosphere(air, 40%O_(2)/60%CO_(2)) and temperature(700, 900, 1100℃) on the migration characteristics of heavy metal(As, Cr, Se) during the coal combustion on the tube furnace test bench.The chemical occurrence forms and leaching toxicity of heavy metals in coal were studied by BCR and HJ/T 299-2007, respectively. The results show that that As, Cr and Se are mainly distributed in fly ash, bottom slag, fly ash and flue gas, respectively. Increasing the temperature favors the volatilization of As and its enrichment in fly ash. Under the air atmosphere, the increase of temperature is beneficial to the enrichment of Cr in the fly ash. In the oxygen-enriched atmosphere, the distribution of Cr in fly ash and flue gas increases firstly and then decreases with the increase of temperature. As, Cr, and Se are mainly in residual state, residual state, oxidizable state+residual state in the coal, respectively. Occurrence form and leaching ratio satisfy that of water/acid soluble state and exchangeable state.
作者
赵士林
梁鑫
纪富
王林伟
张思琦
孙志强
ZHAO Shilin;LIANG Xin;JI Fu;WANG Linwei;ZHANG Siqi;SUN Zhiqiang(School of Energy Science and Engineering,Central South University,Changsha 410083,China;Huaibei Shenwan Power Generation Co.,Ltd.,Huaibei 235000,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2022年第8期2111-2118,共8页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.52006245)
湖南省科技创新计划资助项目(No.2021RC4006)。
关键词
煤燃烧
重金属
迁移转化
赋存形态
浸出毒性
coal combustion
heavy metal
migration and transformation
occurrence form
leaching toxicity
