Recent developments in the recycling of spent selective catalytic reduction catalyst in South Korea

Abstract

Spent selective catalytic reduction (SCR) catalyst installed in power and incineration plants is used to convert nitrogen oxide (NOx) gas to nitrogen (N2) gas. Currently, most spent SCR catalyst in South Korea is eventually discarded in landfills. Recently, a novel and efficient recycling process has been developed to recover tungsten (W), vanadium (V) and titanium (Ti) from spent SCR catalyst. In this process, after soda-melting reactions between the spent SCR catalyst and sodium carbonate (Na2CO3) at 1273 K, hydrometallurgical treatments were carried out for the production of high-purity products, such as 99.3% sodium tungstate (Na2WO4), 99.3% vanadium oxide (V2O5) and 99.6% titanium dioxide (TiO2). On the basis of the fundamental investigation of this novel recycling process, process scale-up has been attempted to establish a commercial process. In this paper, recent developments in the recycling process for spent SCR catalyst and the results obtained using the scaled-up process will be discussed. Therefore, this study will provide a practical method for the recovery of W, V and Ti from spent SCR catalyst.