In-situ investigation of melting characteristics of waste selective catalytic reduction catalysts during harmless melting treatment  

作　　者：Hao ZHOU Yu-jian XING Jia-nuo XU Ming-xi ZHOU 

机构地区：[1]State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China [2]Institute for Thermal Power Engineering,Zhejiang University,Hangzhou 310027,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2021年第3期207-221,共15页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by the National Key Research and Development Program of China (No. 2018YFB0604104)。

摘　　要：Selective catalytic reduction(SCR) catalyst waste is a hazardous solid waste that seriously threatens the environment and public health.In this study,a thermal melting technology is proposed for the treatment of waste SCR catalysts.The melting characteristics and mineral phase transformation of waste SCR catalysts blended with three different groups of additives were explored by heating stage microscopy,thermogravimetric analysis/differential scanning calorimetry(TG/DSC) analysis,thermodynamic simulation,and X-ray diffraction(XRD) analysis;heavy metal leaching toxicity was tested by inductively coupled plasma-atomic emission spectrometry(I CP-AES) analysis.The results indicated that the melting point of waste SCR catalysts can be effectively reduced with proper additives.The additive formula of 39.00% Fe2 O3(in weight),6.50% CaO,3.30% SiO2,and 1.20% Al2 O3 achieves the optimal fluxing behavior,significantly decreasing the initial melting temperature from 1223℃ to1169℃.Furthermore,the whole heating process of waste SCR catalysts can be divided into three stages:the solid reaction stage,the sintering stage,and the primary melting stage.The leaching concentrations of V,As,Pb,and Se are significantly reduced,from 10.64,1.054,0.195,and 0.347 mg/L to 0.178,0.025,0.048,and 0.003 mg/L,respectively,much lower than the standard limits after melting treatment,showing the strong immobilization capacity of optimal additives for heavy metals in waste SCR catalysts.The results demonstrate the feasibility of harmless melting treatments for waste SCR catalysts with relatively low energy consumption,providing theoretical support for a novel method of disposing of hazardous waste SCR catalysts.

关 键 词：Waste selective catalytic reduction(SCR)catalyst Thermal melting treatment Melting characteristics ADDITIVES Heating stage microscope Leaching toxicity 

分 类 号：X70[环境科学与工程—环境工程]