A system and method for preparing high-purity vanadium pentoxide powder by chlorination

Abstract

The invention belongs to the field of chemical industry and metallurgy, and provides a system and a method for preparing high-purity vanadium pentoxide powder through a chlorination method. Accordingto the method, an industrial grade vanadium oxide is converted into vanadium oxytrichloride by using fluidization chlorination; two-stage dust removing and four-stage leaching are performed to obtaincrude vanadium oxytrichloride; and the crude vanadium oxytrichloride is subjected to two-stage rectification, catalytic oxidation and calcination treatment to obtain the high-purity vanadium pentoxidepowder. According to the present invention, the too high furnace temperature can be prevented by spraying the vanadium oxytrichloride mud into the chlorination fluidized bed; by arranging the horizontal porous inner member in the catalytic oxidation fluidized bed, the generation of large gas bubbles can be inhibited, and the reaction efficiency can be improved; and the system and the method haveadvantages of strong raw material adaptability, no pollution wastewater emission, low production energy consumption, low operation cost, stable product quality and the like, are suitable for the large-scale industrial production of high-purity vanadium pentoxide powder with more than 4N, and have good economic and social benefits.

Description

technical field [0001] The invention belongs to the fields of chemical industry and metallurgy, and particularly relates to a system and method for preparing high-purity vanadium pentoxide powder by a chlorination method. Background technique [0002] Vanadium pentoxide is one of the important industrial vanadium products, widely used in the production of alloy additives such as ferrovanadium and vanadium nitride, as well as catalysts, colorants and cemented carbide additives. With the continuous development of new energy technologies, the demand for high-purity vanadium pentoxide (purity above 3N5) is increasingly strong in the battery industry, including all-vanadium redox flow batteries (VRB) with good large-scale energy storage performance and vanadium for electric vehicles Acid-based lithium-ion batteries, etc. However, the existing industrial technology can usually only prepare vanadium pentoxide with a purity of 2N5 (that is, the product specified in HGT3485-2003), w...

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Problems solved by technology

This patent has the following deficiencies: (1) Similar to the aforementioned research by Iowa State University in the United States, this patent actually only provides the principle process of chlorination and lacks specific operable solutions. For example, the chlorination method includes boiling Chlorination includes molten salt chlorination, and molten salt chlorination and boiling chlorination are completely different chlorination methods; for another example, it is proposed to use "rotary kiln, fluidized furnace, fluidized furnace, shaft furnace And multi-hearth furnace" and other reactors actually cover almost all the commonly used mainstream reactors in the field of metallurgical industry, but different reactors have very different requirements for raw materials. The shaft furnace can only handle "coarse" particles larger than 8mm. When using "fine particles", pelletizing and pre-sintering treatment are required, and boiling chlorination is generally suitable for processing fine particles, so for a specific vanadium raw material, it cannot be directly applied to rotary kilns, fluidized furnaces, fluidized fluidized furnaces, shaft furnaces and Reactors such as multi-hearth furnaces; besides, "fluidized furnace" and "fluidized fluidized furnace" are essentially the same, but they are called differently; it can be seen that because the operation methods and conditions of these reactors are very different, only the principle flow is given Can't implement in fact; (2) vanadium oxychloride is passed into ultrapure aqueous solution and hydrolyzed, because vanadium pentoxide is very easily dissolved in hydrochloric acid solution, the precipitation recovery rate of vanadium is too low; When HCl concentration is greater than 6.0mol / In the hydrochloric acid solution of L, when vanadium pentoxide is dissolved, reduction will occur to generate VOCl 2 , release chlorine gas simultaneously, and this will further reduce the precipitation recovery rate of vanadium; Precipitation and washing process will certainly produce a large amount of vanadium-containing hydrochloric acid solution, be difficult to realize comprehensive treatment effectively; (3) vanadium oxychloride is directly passed into ammoniacal solution Ammonium salt precipitation is carried out in the precipitation washing process, and there is also a large amount of ammonia nitrogen wastewater generated during the precipitation washing process, which is difficult to deal with and easily causes environmental pollution.

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