Method for regeneration of exhaust gas treatment catalyst, and exhaust gas treatment cataylst produced using the method

An exhaust gas treatment catalyst regenerated by a method of regenerating an exhaust gas treatment catalyst having ash adhering to a surface thereof, the exhaust gas treatment catalyst regenerated by performing:

• a used catalyst crushing step of crushing the exhaust gas treatment catalyst that has been used;
• a separating step of separating the crushed exhaust gas treatment catalyst into coarse pieces having a size exceeding a threshold size S and fine particles having a size not larger than the threshold size S;
• a used catalyst pulverizing step of pulverizing the separated coarse pieces into a fine powder;
• a molding step of molding the pulverized fine powder as a raw material into an exhaust gas treatment catalyst;
• a precursor calcining step of calcining a molded precursor of the exhaust gas treatment catalyst;
• a newly-made catalyst crushing step of crushing the exhaust gas treatment catalyst that has been newly made;
• a slurrying step of slurrying the crushed newly-made exhaust gas treatment catalyst;
• a slurry coating step of coating a surface of a base obtained by the calcination in the precursor calcining step with the slurry liquid;
• and
• a coating calcining step of calcining the base coated with the slurry liquid at a higher temperature than a calcination temperature during production of the crushed newly-made exhaust gas treatment catalyst, wherein
• the threshold size S has a value not smaller than 0.105 mm.