Recovery of the Vanadium and Tungsten from Spent SCR Catalyst Leach Solutions by Hydrometallurgical Methods#

Abstract

In new millennium, wide-reaching demands for selective catalytic reduction (SCR) catalyst have been increased gradually in new millennium. SCR catalyst can prevent the NO x emission to protect the environment. In SCR catalyst the main composition of the catalyst is typically TiO 2 (70~80%), WO 3 (7~10%), V 2 O 5 (~1%) and others. When the SCR catalysts are used up and disposed to landfills, it is problematic that those should exist in the landfill site permanently due to their extremely low degradability. A new advanced technology needs to be developed primarily to protect environment and then recover the valuable metals. Hydrometallurgical techniques such as leaching and liquid-liquid extraction was designed and developed for

Phase Equilibria and Phase Diagram of the Quaternary NaOH–Na3VO4–Na2WO4–H2O System at 278.15 K to 353.15 K

“…The use of a selective catalytic reduction (SCR) catalyst has become the most effective means of reducing nitrogen oxide (NO x ) emissions from stationary segments around the world because of strengthened regulatory trends and emerging environmental issues. − The most widely used SCR catalyst, the V 2 O 5 –WO 3 /TiO 2 system, , contains a considerable amount of valuable metals (7–10 wt % of WO 3 , 0.5–1.5 wt % V 2 O 5 , and 70–80 wt % TiO 2 ) . This system shows excellent catalytic properties, such as a wide operating temperature window and high denitration rate …”