Study on the Process of Sulfuric Acid Leaching Vanadium of Waste SCR Catalyst

摘要

In this paper, the hydrometallurgical method is used, Na2SO3 is used as the reducing agent, and the vanadium in the waste SCR catalyst is leached with sulfuric acid solution at one time. After obtaining the optimal leaching conditions, two stages of countercurrent leaching are used to further increase the leaching rate of vanadium in the waste SCR catalyst. The main component of the remaining undissolved solid is TiO2, so that TiO2 is separated to obtain a crude titanium tungsten powder product. The optimal process conditions were determined through experiments: leaching temperature 80?C, leaching time 60 min, sulfuric acid concentration 8%, liquid-solid ratio 5:1, and sodium sulfite concentration 7% (relative to the catalyst amount). The vanadium leaching rate is 79.74%, and the two-stage countercurrent leaching improves the leaching rate by about 9%.