Poster (EARTH)

[PE1-080] Recovery of Valuable Metals from Spent SCR Catalysts

○IN MING LIN¹, Shen Yun Hwei¹ (1. National Cheng Kung University)

Keywords:SCR, leaching, ion exchange, asenic

The research on the recovery and reuse of valuable molybdenum and
vanadium in waste denitrification catalyst with MoO3-V2O5 / TiO2 as
the main component was discussed. And to explore the effect of leaching
vanadium and some arsenic on the arsenic concentration of the
subsequent products by acid leaching.
The purpose of this study is to recover valuable metals from spent SCR
catalysts by chemical precipitation and ion exchange. First, using
Na2SO3 and H2SO4 solution leaching to make vanadium and arsenic
dissolved in the liquid phase. Second, baking the residual solid phase
with NaOH, then leaching in hot water to make molybdenum dissolved in
liquid phase. Third, using ion exchange method to recover the pure
vanadium and molybdenum product. Research results were as following:
1. 0.2g of Na2SO3 mixed with 5g spent SCR catalysts, and leaching
with 100mL 1N H2SO4 at 90℃ for 4hr, resulted in the extraction of 67%
V and 24% As.
2. After filtering, 30g of solid phase was mixed with 21g NaOH, baked
at 450℃ for 2hr and then leached with 100 mL water at 90℃ for 2hr,
resulted in a leachate with concentrations of 1900 ppm Mo, 82 ppm V
and 116 ppm As.
3. Using ion exchange method, pure vanadium and molybdenum
product were obtained.