Method for recovering molybdenum catalyst values and use of said values in the recycling of said catalyst

A process for regenerating as a molybdic ester, a molybdenum catalyst used in synthesizing a vicinal alkane diol having four or five carbon atoms per molecule by contacting in an aqueous medium butene or methyl-butene, an alkane hydroperoxide which forms an alcohol as reduction product, and a catalyst which consists essentially of the reaction product of molybdic acid or ammonium molybdate with a vicinal alkanediol having four or five carbon atoms per molecule;

• separating the products of the reaction by distillation to isolate any unreacted olefin, said alcohol, said diol, and with the distillation bottoms said catalyst;
• comprising the steps of:
• a. taking at least a portion of said bottoms and reacting ammonia with the molybdenum content thereof to form ammonium molybdate;
• b. separating said ammonium molybdate from at least any organic phase of the reaction mixture resulting from step (a);
• c. reacting an aqueous solution of said ammonium molybdate with an amount of said diol to convert said ammonium molybdate to the corresponding molybdic ester precipitate with released ammonia being recycled to step (a).
• d. separating said precipitate from the reaction mixture of step (c) and recycling it as at least a portion of the catalyst for said synthesizing process.