Removal of Vand Fe from spent denitrification catalyst by using oxalic acid:Study of dissolution kinetics and toxicity  

作　　者：Wenfen Wu Chenye Wang Xingrui Wang Huiquan Li 

机构地区：[1]CAS Key Laboratory of Green Process and Engineering,National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,Chinese Academy of Sciences,Beijing,100190,China [2]College of Chemical and Engineering,University of Chinese Academy of Sciences,Beijing,100049,China

出　　处：《Green Energy & Environment》2021年第5期660-669,共10页绿色能源与环境（英文版）

基　　金：The authors are grateful for the financial support of the National Natural Science Foundation of China(No.51574214).

摘　　要：The selective dissolution of V and Fe from spent denitrification catalyst(SDC)with oxalic acid was investigated to minimise their environmental effects.The dissolution kinetics of different elements from SDC by using 0.1–1.5 mol L^(-1) oxalic acid concentration was studied at 60℃–90℃.V and Fe were preferentially released(65%and 81%)compared with Al,Ti and W within 5 min due to the redox reactions of oxalic acid.The dissolved fractions of Fe,V,Al,Wand Ti increased with the increase of oxalic acid concentration and reaction temperature.The dissolution kinetic experiments were analysed and controlled diffusion with n<0.5 according to the Avrami dissolve reaction model(R^(2)>0.92).The Arrhenius parameters of the Ea values of Ti,W,V,Fe and Al from SDC with oxalic acid were 30,26,20,19 and 11 kJ mol^(-1),respectively.The obtained Avrami equation of V and Fe was successfully used to predict their leaching behaviour in oxalic acid.Toxicity characteristic leaching procedure revealed that the toxicity risk of Vand Fe metals from SDC after leaching with oxalic acid decreased to below 5 mg kg^(-1) residua.Overall,the leaching residua by oxalic acid indicated its safety for the environment.

关 键 词：Spent denitrification catalyst Oxalic acid Dissolution kinetic Avrami model 

分 类 号：X70[环境科学与工程—环境工程]