A method for preparing low-silicon vanadium pentoxide from vanadium-chromium-silicon solution

Abstract

A method for recycling and preparing low-silicon high-purity vanadium pentoxide (V2O5) from a mixed solution containing vanadium, chromium and silicon. The method comprises the following steps: firstly, silicon is removed from a solution containing vanadium, chromium and silicon using an amphoteric metal salt and / or an alkali metal salt, then other introduced impurities are removed by adjusting the pH value, and solid-liquid separation is performed; the vast majority of the vanadium is selectively extracted into an organic phase using a primary amine extraction system, the vanadium in the vanadium-rich organic phase is stripped using an alkaline solution containing an ammonium salt, and ammonium metavanadate precipitates out, and a water phase, after stripping has been performed, is filtered or centrifuged to obtain a high-purity ammonium metavanadate solid, and after washing and drying, calcination is performed at a certain temperature to obtain a brick-red substance, V2O5, having a purity of more than 99.9% and a silicon content of less than 0.007%. No interlayer is formed in the extraction-stripping process.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy or wastewater treatment, and relates to a method for preparing low-silicon V 2 o 5 The method, especially relates to a kind of preparation low silicon high purity V from vanadium chromium silicon solution 2 o 5 process flow. Background technique [0002] Vanadium is a non-ferrous metal and a very important strategic resource. Vanadium pentoxide (V 2 o 5 ) is an important oxide of vanadium and is also the most widely used oxide. The scope of application has expanded from metallurgy, chemical industry and other industries to aerospace, electronics industry, electrochemistry, etc. 2 o 5 The market demand is increasing, the V 2 o 5 The purity requirements of vanadium are also getting higher and higher, especially the development of vanadium redox flow batteries and vanadium aluminum alloys, which put forward higher requirements for the purity of vanadium and the content of impurity silicon in h...

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Problems solved by technology

Related technologies such as CN101121962 adopt operations such as extraction, stripping, and precipitation of vanadium to fully reclaim the vanadium chromium in the vanadium chromium solution, but the purity of its product vanadate can only reach 99.5%

CN103540745A uses amines to extract the heteropolyacid in the vanadium solution to purify the vanadium solution, add ammonium salt to precipitate vanadium and calcined to obtain vanadium pentoxide with a purity greater than 99.9%, but the raw material liquid requires the formation of phosphorus molybdenum tungsten, silicon molybdenum tungsten and other heteropolyacids for impurity removal, but it is no longer suitable for other vanadium-chromium solutions that are difficult to form heteropolyacids

[0006] CN102849795A uses crude ammonium metavanadate as raw material to produce high-purity V 2 o 5 , not only the raw materials are limited, but also the operation is repetitive and complicated, which is not conducive to popularization and application

CN102923776A also uses crude ammonium metavanadate as raw material, and obtains 99.95% V 2 o 5 , but its requirements for equipment are relatively high, and the initial investment is relatively large

[0008] In the current reports, there are few low-silicon and high-purity V 2 o 5 process, so find a suitable process flow, low-cost preparation of low-silicon high-purity V 2 o 5 Urgent need to solve

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