Novel Leaching Process of Vanadium and Tungsten from Spent SCR Catalyst at Normal Temperature and Pressure

doi:10.12068/j.issn.1005-3026.2022.03.015

Abstract

Abstract: Based on SEM-EDS and XPS， a novel two-stage leaching process of spent SCR(selective catalytic reduction) catalyst under normal temperature and pressure was proposed. Box-Behnken design(BBD)was used to study the effects of various factors and their interactions on the leaching of vanadium and tungsten， then，the optimal process parameters were obtained and the leaching mechanism was studied. The results showed that: during the two-stage leaching process， the order of influence factors on the leaching rate is temperature >time>leaching agent concentration in the first stage(vanadium extraction process) and temperature>leaching agent concentration>time in the second stage(tungsten extraction process). In the first stage， when the NaOH concentration is 0.5mol·L^-1and reacts at 60℃ for 10min， the vanadium leaching rate is(61.40±0.24)%. In the second stage， when the NaOH concentration is 2.5mol·L^-1and reacts at 90℃ for 50min， the tungsten leaching rate is(55.73±0.22)%. Vanadium in the spent catalyst exists in the form of V₂O₃， VOSO₄ and V₂O₅， and reacts with NaOH to form soluble vanadate. A small part of V₂O₃ and V₂O₅ are dissolved after forming VOSO₄.

Key words: spent SCR catalyst; Box-Behnken design; SEM-EDS; XPS

CLC Number:

X705

LIU Na-na， XU Xin-yang， CHEN Xi， LIU Yuan. Novel Leaching Process of Vanadium and Tungsten from Spent SCR Catalyst at Normal Temperature and Pressure[J]. Journal of Northeastern University(Natural Science), 2022, 43(3): 414-423.

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