Studying the leaching mechanism of spent SCR catalyst with different leaching agents (NaOH, H2SO4, HCl and HNO3) using DFT calculations

Strategy and Technical Progress of Recycling of Spent Vanadium–Titanium-Based Selective Catalytic Reduction Catalysts

“…Wet Recovery. Wet recovery involves the use of leaching agents to break the bonds between V, W, and O in the catalyst, mainly affecting the bonding of V−O 2 , W−O 4 , and W− O 2 , 88 thereby removing the components V 2 O 5 and WO 3 from the carrier. Depending on the leaching agent, wet recovery can be divided into acid leaching, alkaline leaching, and new leaching methods adapted to the environment.…”

“…Accordingly, acid leaching targets the extraction of V, and the current process mostly uses inorganic acids such as HCl, H 2 SO 4 , and HNO 3 but also organic acid reagents such as oxalic acid for leaching. Nie et al 88 identified the leaching mechanisms of NaOH, H 2 SO 4 , HCl, and HNO 3 for V and W and compared to their leaching capacities using DFT calculations and experimental studies. The leaching experiment was carried out under the conditions of different inorganic acid solutions with a concentration of 5 mol/ L, a solid−liquid ratio of 1:20 g/mL, a temperature of 80 °C, and a time of 8 h. The order of leaching capacity and leaching rate of inorganic acid solutions for V decrease in the order H 2 SO 4 (69.0%) > HCl (52.5%) > HNO 3 (42.2%), and W was almost not leached under these conditions.…”

“…Accordingly, acid leaching targets the extraction of V, and the current process mostly uses inorganic acids such as HCl, H 2 SO 4 , and HNO 3 but also organic acid reagents such as oxalic acid for leaching. Nie et al . identified the leaching mechanisms of NaOH, H 2 SO 4 , HCl, and HNO 3 for V and W and compared to their leaching capacities using DFT calculations and experimental studies.…”

Leaching Vanadium from the Spent Denitration Catalyst in the Sulfuric Acid/Oxalic Acid Combined Solvent

“…9,10 Currently, the common methods for extraction V from spent denitration catalysts include alkaline leaching, 11 sodium roasting, 12 and single-acid leaching. 13 Among these methods, alkaline leaching is known for its high alkali consumption and wastewater generation, while sodium roasting causes high energy consumption. 14 The single-acid leaching method, on the other hand, could be further classified into inorganic acid leaching and organic acid leaching.…”

“…Numerous studies on the extraction and purification of V from spent denitration catalysts have been carried out. , Currently, the common methods for extraction V from spent denitration catalysts include alkaline leaching, sodium roasting, and single-acid leaching . Among these methods, alkaline leaching is known for its high alkali consumption and wastewater generation, while sodium roasting causes high energy consumption .…”