Method for producing vanadium pentoxide by roasting vanadium slag

Abstract

The invention discloses a method for producing vanadium pentoxide by roasting vanadium slag. An addition amount of an additive is determined according to the difference between the content of vanadium in the vanadium slag and the amount of impurities, and a proportioning parameter of the additive is further optimized, thus the treatment of a subsequent process is convenient. According to the method for producing the vanadium pentoxide by the roasting the vanadium slag, disclosed by the invention, the influence of SiO2 and Fe on the conversion ratio of clinkers is reduced by regulating the proportion of salt to alkali; the addition amount of the alkali is reduced when the content of the SiO2 is increased, and the addition amount of the salt is increased; and the method is beneficial to reducing of the generation amount of sodium silicate and increasing of the generation amount of sodium vanadate, and additive proportioning parameters are optimized by aiming to high contents of silicon and iron in the vanadium slag. According to the method disclosed by the invention, a suitable high-silicon high-iron vandadium slag roasting method and a corresponding additive proportion are promotedpertinently, thus the conversion ratio of the clinkers is largely increased, the product yield is remarkably increased and the unit consumption of the vanadium slag is remarkably reduced.

Description

technical field [0001] The invention relates to a vanadium slag oxidation and sodium roasting process, in particular to a method for producing vanadium pentoxide by roasting high-silicon and high-iron vanadium slag. Background technique [0002] At present, vanadium slag roasting mainly uses sodium oxide roasting and water leaching to extract vanadium to produce vanadium pentoxide. The additives for vanadium slag oxidizing and sodium roasting are mainly industrial salt and soda ash. The grade of vanadium slag is low, and the roasting temperature of vanadium slag with high silicon and iron content is not suitable to be controlled, and the conversion rate fluctuates greatly. The ratio of the existing vanadium slag additives is mainly adjusted according to the vanadium content and impurity content of the vanadium slag, the amount of the additive is determined according to the vanadium slag grade data in the plant, and the salt-alkali ratio is adjusted when the iron and silicon...

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Problems solved by technology

With SiO 2 The higher the content, the spinel structure in the slag is not complete, the particles are fine, it is not conducive to the extraction of vanadium, the yield of vanadium is low, and the SiO 2 During the firing process, it is easy to form low-melting glass with additives, and the charge will appear liquid phase prematurely, making the charge sticky, agglomerated, and large kiln rings, which hinder the oxidation of vanadium and the formation of soluble sodium vanadate

The metallic iron in the vanadium slag is currently the main factor affecting the roasting of the vanadium slag. The metallic iron is preferentially oxidized and decomposed before the vanadium, which generates a large amount of heat, causing the temperature of the preheating zone to be too high. Small balls seriously affect the conversion rate, which is generally 77-80%

[0003] In summary, the existing vanadium slag roasting method is limited to the roasting method of vanadium slag with high grade, silicon content and low iron content, so it is necessary to develop a vanadium slag roasting method with high silicon content and high iron content

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