Method for preparing high-purity ammonium molybdate from low-grade molybdenum material

The invention relates to a method for preparing high-purity ammonium molybdate from a low-grade molybdenum material. The method comprises the following steps that the low-grade molybdenum material issubjected to oxygen pressure leaching with sodium hydroxide, filtration, dephosphorization through a chemical precipitation method, molybdenum extraction through tertiary amine and a kerosene solutionunder weak acidic conditions, ammonium hydroxide reverse extraction and ammonium molybdate concentration crystalline. According to the method for high-purity ammonium molybdate from the low-grade molybdenum material, hydrogen sulfate loaded organic phase can be reduced from 12.15 g/L before elution to less than 0.5 g/L, and the elution rate is greater than 95%; and the actual amount of ammonia under the optimum elution condition is 1.3 times of the theoretical amount, the washing liquor end point pH value is 3.5 to 4.0, the effect that the molybdenum elution rate is less than 2% while the elution rate of hydrogen sulf