The invention discloses a method for preparing high-purity 
vanadium pentoxide by low-temperature chlorination of high-
calcium and high-
phosphorus vanadium slag. The method includes the six processes of (1) an oxidation 
granulation process, (2) a low-temperature chlorination process, (3) a dust collection and 
elution process, (4) a rectification and purification process, (5) an oxidation powderingprocess, and (6) a 
tailings oxidation process. In this method, an additive is added in the oxidation 
granulation process, so that 
calcium in the 
vanadium slag is converted into a 
silicate phase or analuminosilicate phase, and the loss of flow caused by a large amount of 
calcium chlorination is avoided. In the low-temperature chlorination process, 
carbon monoxide is used as a 
carbon source to decrease the chlorination temperature and prevent the loss of flow caused by the melting of calcium and 
magnesium chlorides. In the oxidation powdering process and the 
tailings oxidation process, the recycling of 
chlorine gas is realized by blowing 
oxygen-enriched air. The method for preparing high-purity vanadium 
pentoxide by low-temperature chlorination of high-calcium and high-
phosphorus vanadium 
slag is suitable for the high-calcium and high-
phosphorus vanadium slag and has the advantages of being good in selectivity, low in 
reaction temperature, having no loss of flow, being environment-friendly, and high in added value of products.