Abstract: The purity of potassium metavanadate in products being over 99.5% was prepared through alkali dissolving for im- purity removing，ammonium concentration removal，and solventing-out crystallization，with ammonium metavanadate as raw material.The technological principles of the manufacturing process were analyzed.The effects of pH，ammonium removal tem- perature，and vanadium concentration on the compositions of potassium metavanadate were investigated，and the technologi- cal conditions for solventing-out crystallization were also discussed.Results showed that the pH of alkali dissolving for impurity removing and the pH of concentrated terminal point were the main influence factors for the quality of potassium metavanadate. The optimum process conditions for preparation of potassium metavanadate were as follows：alkali dissolving for impurity removing pH was 9~10，ammonium removal temperature was 95 ℃，concentrated terminal point pH was 7.5~8.5，mass con- centration of total vanadium for concentrated terminal point was 180 g/L，volume ratio of solventing-out agent to solution was 1∶1，and crystallization period 30 min.And the results showed that the mass concentration of residual vanadium in filtrate was less than 3.0 g/L，and the yield of vanadium was over 98%.

Key words: potassium metavanadate, ammonium metavanadate, alkali dissolving for impurity removing, solventing-out crys-
tallization