Why do you always need to keep good stirring in the process of mixed acid nitrification?

The mixed acid nitration method also has the following characteristics: ① Nitrate or nitrated product is liquid at the reaction temperature and insoluble in waste sulfuric acid, so the waste acid after nitration can be recovered by layered method; ② The amount of nitric acid is close to the theoretical amount or the excess is not much, and the concentrated waste sulfuric acid can be used to prepare mixed acid, that is, the consumption of sulfuric acid is very small; ③ Mixed acid nitration is a heterogeneous process, which requires the nitration reactor to be equipped with a good stirring device to make the acid phase fully contact with the organic phase; ④ The composition of mixed acid is an important factor affecting nitrification ability, and the nitrification ability of mixed acid is expressed by sulfuric acid dehydration value (DVS) or nitrification activity factor (FNA). DVS is the calculated mass ratio of sulfuric acid to water in waste sulfuric acid after nitric acid in mixed acid is completely nitrated to produce water. FNA is the mass percentage concentration of sulfuric acid in waste acid calculated after nitric acid in mixed acid is completely nitrated to generate water. High DVS or FNA indicates strong nitrification ability. For each specific nitrification process, the mixed acid composition, DVS or FNA should be determined by experiments.