The invention discloses a method for recovering
vanadium,
potassium and
silicon from a waste
vanadium catalyst. The method comprises the following steps: firstly, leaching the waste
vanadium catalyst in water, and leaching in a reductic acid, wherein the total
leaching rate of vanadium is greater than or equal to 95.0%, separating the
silicon from vanadium and
potassium transferred to a leaching solution in a form of a leaching
slag; preparing liquid
sodium silicate to recover
silicon from the leaching
slag by alkali
dissolution; separating the vanadium from
potassium in the leaching solution in an extraction manner; preparing potassium sulphate to recover potassium from a
raffinate phase in an evaporative
crystallization manner; and preparing vanadium
pentoxide from an extract phase by the procedures of re-extraction,
molybdenum precipitation,
calcination and the like. Meanwhile, the vanadium in the extract phase and the
raffinate phase is larger in distribution ratio, and does not react with other
metal impurities such as iron and the like due to excellent selectivity of an extraction agent TOA on vanadium, other
metal impurity ions such as iron and the like do not need to be removed in advance, and the vanadium can be directly extracted. Thus, a part of edulcoration procedures are reduced, the
raw material consumption is saved, and a high-purity product of vanadium can be directly prepared. By adopting the method disclosed by the invention, not only can the vanadium, potassium and silicon in the waste vanadium catalyst be comprehensively recovered, but also the targets of turning the waste into treasure and protecting the environment are achieved.