The invention relates to a method for preparing
vanadium pentoxide from
sulfuric acid leach liquor of stone
coal vanadium ore, particularly a method for preparing high-purity
vanadium pentoxide from
sulfuric acid leach liquor of low-
impurity-content stone
coal vanadium ore. The method is characterized by sequentially comprising the following steps: (1) extracting leach liquor, which is obtained by leaching stone
coal vanadium ore with
sulfuric acid, to remove impurities; (2) carrying out back extraction on sulfuric acid to carry an organic phase; (3) oxidizing the back extraction liquor; (4) carrying out
hydrolysis to precipitate vanadium; and (5) calcining the vanadium precipitate
slag to obtain the vanadium
pentoxide. Compared with the traditional technique, by using oxydol, persulfuric acid and the like as oxidants in the
oxidation process, the method provided by the invention can avoid introducing other
impurity cations, thereby ensuring the purity of the product vanadium pentoxide. Compared with the traditional
ammonium-salt vanadium-
precipitation technique, the method provided by the invention saves the alkali consumption required by
neutralization. The purity of the prepared vanadium pentoxide is up to 99.9%, and the
recovery rate of vanadium is up to above 98%; and meanwhile, the invention can implement no
pollution and cyclic utilization of the back extraction agent.