A promising method to recover spent V₂O₅–WO₃/TiO₂ catalyst: treatment by vanadium–titanium magnetite sintering process

Abstract

A large number of spent selective catalytic reduction (SCR) denitration catalysts are produced after the ultra-low emission transformation of coal-fired power plants in China. According to the China’s “Directory of National Hazardous Wastes (Version 2021)”, these spent vanadium–tungsten–titanium catalysts are classified as “HW50” hazardous waste, and their disposal and utilization processes have been strictly controlled. Thus, an effective and low-cost technique was developed to treat and utilize these spent SCR catalysts by the vanadium–titanium magnetite sintering process. Effects of adding spent SCR catalysts on the sintering production process and product quality indexes of sinter were studied. The results showed that adding spent SCR catalysts can improve the sintering granulation and green feed permeability, thereby increasing the productivity and flame front speed. When the addition proportion of spent SCR catalysts is less than 1 wt.%, the performance indexes of the finished sinter are basically equal to those of the finished sinter without adding spent SCR catalysts. Further increasing the proportion of spent SCR catalysts to 2.0 wt.% results in a decrease in product quality indexes, which could be attributed to the increase in perovskite content in the finished sinter.