Method for removing sulfate radicals and hydrogen sulfate radicals when preparing sodium molybdate from molybdenum-containing waste catalyst through tertiary amine extraction method

The invention relates to a method for removing sulfate radicals and hydrogen sulfate radicals when preparing sodium molybdate from a molybdenum-containing waste catalyst through a tertiary amine extraction method. The method comprises the following steps that alkalified oxidation roasting, water leaching filtration, phosphorous removal by a chemical precipitation method, tertiary amine and a kerosene solution are adopted to treat the molybdenum-containing waste catalyst under a faintly acid condition to extract a molybdenum-sodium hydroxide solution and re-extract and concentrate crystal sodium molybdate product. According to the method, a dilute sodium hydroxide solution is used for eluting a molybdenum-loaded organic phase, which can reduce the sulfate radicals of the molybdenum-loaded organic phase to 1.96 g/L from 10.82 g/L before elution with the elution rate of 81.88%. After the molybdenum-loaded organic phase is diluted through a dilute alkali liquor, an alkali liquor is used for reextraction to obtain