Method for recovering denitrating catalyst
AssigneeMitsubishi Jukogyo Kabushiki Kaisha
InventorsYoshiaki Obayashi, Shigeaki Mitsuoka
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Abstract
A method for recovering a denitrating catalyst which is characterized by washing, with an aqueous oxalic acid solution, the used tungsten-titania or the tungsten-titania-vanadium denitrating catalyst which dust components have adhered to or have accumulated on and in which an SO.sub.2 -oxidizing power has thus risen; impregnating the catalyst with a tungsten compound; and drying and calcining the thus treated catalyst.
Claims3
A method for recovering used tungsten-titania denitrating catalyst in which SO.sub.2 -oxidizing power has risen due to adhesion or accumulation of dust components, the method comprising washing said used denitrating catalyst with an aqueous oxalic acid solution having a concentration of 0.1 to 5.0 wt % at a temperature within the range of about 20.degree. C. to 100.degree. C.;
- impregnating said catalyst with a tungsten compound;
- and drying and calcining said catalyst.
A method for recovering used tungsten-titania-vanadium denitrating catalyst, comprising washing said catalyst with water or an aqueous dilute inorganic acid solution;
- further washing said catalyst with an aqueous oxalic acid solution having a concentration of 0.1 to 5.0 wt % at a temperature within the range of about 20.degree. C. to 100.degree. C.;
- impregnating said catalyst with a tungsten compound;
- and drying and calcining said catalyst.
Dependencies are inferred from the claim text.