Process for producing methacrylic acid catalyst for producing a catalyst for methacrylic acid production, the production method of methacrylic acid

A process for preparing a catalyst for producing methacrylic acid by vapor phase catalytic oxidation of methacrolein with molecular oxygen, or a solution containing (i) at least molybdenum (Mo), phosphorus (P) and vanadium (V) the slurry preparing a (I solution), (ii) preparing a solution or slurry (II solution) containing ammonium radical, (iii) the solution I or II was either of the liquid (PR solution) of It was charged to the vessel (a tank), the other of the liquid to the liquid surface area contiguous with 0.01 to 10% of the area to the total area of ​​the liquid surface of the PR liquid which is charged to the tank a a step (LA solution) was charged to prepare a liquid I II liquid mixture, and characterized in that it comprises a (iv) the step of drying and firing the solution or slurry containing a catalyst precursor comprising all the catalyst components to a predetermined atom at a predetermined atomic ratio Method for producing a non-methacrylic acid production catalyst.