焚烧飞灰水泥窑共处置过程As的迁移特征  

Characteristics of arsenic migration in MSWI fly ash during co-processing with a cement kiln

作　　者：王雷[1] 金宜英[2] 聂永丰[2] 李润东[1] 

机构地区：[1]沈阳航空航天大学辽宁省清洁能源重点实验室,沈阳110036 [2]清华大学环境科学与工程系,北京100084

出　　处：《环境科学学报》2011年第2期407-413,共7页Acta Scientiae Circumstantiae

基　　金：国家科技支撑计划项目(No.2009BAC64B06);辽宁省创新团队项目(No.2008T150)~~

摘　　要：为了明确焚烧飞灰水泥窑共处置过程中As的迁移特性,对大量国外工业水泥窑As的监测数据进行了统计分析,研究As或Cl输入总量对As迁移特性的影响.同时,采用CHEMKIN软件对水泥窑煅烧过程中As的物相进行热力学模拟,并使用水泥回转窑系统的简化模型讨论了窑灰循环对As迁移的影响.结果表明,焚烧飞灰中As的酸可提取态、可还原态和可氧化态所占的比例分别为28.55%、20.72%和65.33%.焚烧飞灰水泥窑共处置过程中Cl对As的物相影响很小,水泥原料煅烧产生的CaO与As发生反应生成稳定的固态Ca3(AsO4)2,从而抑制了As的挥发.水泥窑共处置过程中As的一次固定率较高,可达65%,焚烧飞灰替代原料后,窑灰和熟料中的As含量增加缓慢,窑灰循环有助于熟料中As固定率的增加.The migration characteristics of arsenic during the co-processing of municipal solid waste incinerator （MSWI） fly ash in a cement kiln were investigated. Emission data of arsenic from the cement kilns which co-processed waste materials were analyzed statistically to investigate the effect of total arsenic input and total chloride input. An equilibrium analysis of arsenic was performed using the thermodynamic equilibrium software CHEMKIN. A simplified model of cement kiln was used to investigate the effect of kiln dust circulation on the migration characteristics of arsenic. The results show the exchangeable,water and acid-soluble phase,the easily reduced phase and the oxidizable phase of arsenic in MSWI fly ash were 28.55%,20.72% and 65.33% respectively according to the BCR sequential extraction procedure. CaO has a dramatic effect on the thermodynamic behavior of arsenic,while chloride has little effect. Because the main component of the cement raw meal is CaCO3,which generates a large amount of CaO after decomposition,it reacts with arsenic to form stable Ca3（AsO4）2. The ＂single stabilization rate＂ of arsenic was approximately 65% during the sintering process. The model calculation show the As concentration increased in both kiln dust and clinker after the substitution of cement raw meal with MSWI fly ash at 1%. Kiln dust circulation increased the stabilization of As in clinker.

关 键 词：焚烧飞灰 水泥窑共处置 砷 迁移 热力学模拟 CHEMKIN 窑灰循环 

分 类 号：X705[环境科学与工程—环境工程]