The invention discloses a method for preparing beta-
menadione by using a compound emulsifier, which comprises the following steps: step 1, uniformly mixing high-molecular-weight alkanol and high-molecular
alkyl sodium sulfonate to obtain the compound emulsifier; step 2, mixing beta-methylnaphthalene, water and a compound emulsifier to form an
emulsion; step 3, mixing
sodium dichromate with
chromic anhydride, adding the mixture into water, and adding
sulfuric acid to adjust the concentration of
hexavalent chromium so as to form an oxidation solution; and 4, dropwise adding the oxidation liquid into the
emulsion, carrying out a curing reaction on the reacted material, filtering, washing, and carrying out centrifugal
dehydration to obtain the beta-
menadione product. The invention has the following beneficial effects: the
emulsion can be uniformly dispersed, the stability is better, the
reaction speed with materials is high, the temperature range of reaction control is wider, and the
side reaction is less; meanwhile, the compound emulsifier is better in stability and basically does not react with the
oxidizing agent in the later period, the reaction process is more stable and continuous, and the obtained beta-
menadione material is high in purity.