Patent ID: 9731285
Date: 2017-08-15
CPC Classifications: B01J,C07C,Y02P

Claim:
1. A process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of: (i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively, (ii) spray drying the raw material mixture to obtain catalyst precursor particles, (iii) classifying the catalyst precursor particles having a mean particle diameter of from 45 to 65 μm in which a content of the precursor particles having a particle diameter of 25 μm or less is 8% by mass or less, and (iv) pre-stage calcining the classified catalyst precursor particles in an inert gas atmosphere, wherein the pre-stage calcining is carried out continuously at a temperature from 250 to 400° C., to produce pre-stage calcined catalyst precursor particles having a reduction ratio of 8-12%, (v) main calcining the pre-stage calcined catalyst precursor particles in an inert gas atmosphere, wherein the main calcining is carried out continuously at a temperature from 550 to 800° C.