摘要
熔融固化是目前危废焚烧灰渣处置的有效方法之一。为了能够有效地控制熔融过程中重金属元素的迁移,采用HSC Chemistry软件模拟研究了重金属元素As、Pb、Zn、Cu、Ni、Cr等在熔融过程中的物质变化历程,考察了不同气氛、温度、氯化物种类的影响。结果表明:在还原性气氛下,As、Pb几乎100%以As S(g)和Pb S(g)的形式挥发进入气相;Zn主要以气态金属挥发,1 500℃时90.8%的Zn进入气相;Cu、Ni、Cr与灰渣中的Fe2O3、Al2O3等形成不易挥发的化合物,几乎完全被熔渣固化。氧化性气氛有利于各重金属元素的固化,除46.47%的Pb以Pb Cl2(g)、Pb Cl(g)、Pb O(g)的形式挥发外,其余重金属元素均能被固溶在渣中。与灰渣中Na Cl相比,Ca Cl2不影响As、Cr的平衡形态分布,但能促进Pb、Zn、Cu、Ni以气态氯化物的形式挥发进入气相,不利于重金属元素的固化。
Vitrification is an effective way to dispose ash from hazardous waste incineration. In order to optimize heavy metals solidification, the migration characteristics of heavy metals in the vitrification process were studied by thermodynamic analysis. In this paper, the migration of heavy metals, such as As, Pb, Zn, Cu, Ni and Cr, were calculated under different atmospheres, temperatures and chloride species with HSC Chemistry software. The results showed that in reducing atmosphere, almost 100% of As and Pb were prone to volatilization in the form of As S（g） and Pb S（g）, and 90.8% of Zn was in the form of metal Zn at 1 500 ℃. Cu, Ni and Cr were almost completely solidified due to the existence of Fe2O3 and Al2O3, which could help to solidify heavy metals. In oxidizing atmosphere, all the heavy metals were prone to solidification except that, 46.47% of Pb was prone to volatilization in the form of PbCl2（g）, Pb Cl（g） and Pb O（g）. Compared with Na Cl in the ash, the addition of CaCl2 did not affect the migration of As and Cr, but on the other hand, it can help Pb, Zn, Cu and Ni to volatilize into gas phase in the form of chlorides.Therefore, the existence of CaCl2 was harmful for the solidification of heavy metals.
作者
胡明
虎训
邵哲如
程易
徐鹏程
HU Ming;HU Xun;SHAO Zheru;CHENG Yi;XU Pengcheng(China Everbright Group Post-Doctoral Scientific Research Workstation,Beijing 100033,China;Department of Chemical Engineering,Tsinghua University,Beijing 100084,China;Everbright Envirotech（Nanjing）Ltd.,Nanjing 211102,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2018年第9期2672-2679,共8页
Chinese Journal of Environmental Engineering
关键词
焚烧灰渣
熔融处理
重金属元素
热力学平衡分析
bottom slag and fly ash
mehing process
heavy metals
thermodynamic equilibrium analysis
