Search

CN-121990606-A - Method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate

CN121990606ACN 121990606 ACN121990606 ACN 121990606ACN-121990606-A

Abstract

The invention provides a method for preparing high-purity vanadium pentoxide by dissolving ammonium vanadate and removing impurities, which comprises the steps of adding a vanadium-containing intermediate into a magnesium salt-carbonate composite reaction system for reaction to obtain a vanadium-containing solution, adding a impurity removing agent into the vanadium-containing solution for reaction to obtain a vanadium-containing purifying liquid, adding a complexing agent and an ammonium salt into the vanadium-containing purifying liquid, cooling for reaction to obtain a vanadium-precipitating product ammonium metavanadate, drying the vanadium-precipitating product ammonium metavanadate, and calcining to obtain vanadium pentoxide. The method adopts a magnesium salt-carbonate composite reaction system to realize the re-dissolution of vanadium, prepares ammonium metavanadate through impurity removal and complex crystallization, and then obtains the vanadium pentoxide product with the purity of more than 99.5 percent through calcination, thereby solving the technical problems of longer technological process and high production cost in the existing technology for preparing the high-purity vanadium product through dissolving chemical impurity removal.

Inventors

  • WANG JINPENG
  • WANG SHIWEI
  • JIANG LIN

Assignees

  • 攀钢集团攀枝花钢铁研究院有限公司

Dates

Publication Date
20260508
Application Date
20260318

Claims (10)

  1. 1. The method for preparing the high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate is characterized by comprising the steps of adding a vanadium-containing intermediate into a magnesium salt-carbonate composite reaction system for reaction to obtain a vanadium-containing return solution, adding an impurity removing agent into the vanadium-containing return solution for reaction to obtain a vanadium-containing purifying liquid, adding a complexing agent and an ammonium salt into the vanadium-containing purifying liquid, cooling for reaction to obtain a vanadium-precipitating product ammonium metavanadate, and drying and calcining the vanadium-precipitating product ammonium metavanadate to obtain the vanadium pentoxide.
  2. 2. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 1, wherein the vanadium-containing intermediate is selected from one of ammonium metavanadate and ammonium polyvanadate.
  3. 3. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 1, comprising the following steps: Step 1, adding magnesium salt and carbonate into a solvent, and uniformly stirring to form a magnesium salt-carbonate composite reaction system; Step 2, adding the vanadium-containing intermediate into the magnesium salt-carbonate composite reaction system, uniformly stirring, heating to 75-95 ℃, and reacting until the vanadium-containing intermediate is completely dissolved to obtain the vanadium-containing return solution; Step 3, maintaining the temperature of the vanadium-containing return solution at 75-95 ℃, adding the impurity removing agent into the vanadium-containing return solution, and carrying out solid-liquid separation after reacting for 15-60 min to obtain the vanadium-containing purifying liquid and impurity removing slag; step 4, adding the complexing agent into the vanadium-containing purifying liquid, and after stirring uniformly, adding the ammonium salt to form vanadium-containing liquid; Step 5, cooling the vanadium-containing liquid to 5-35 ℃, and carrying out solid-liquid separation after stirring reaction to obtain the vanadium-precipitating product ammonium metavanadate and vanadium-precipitating liquid; And 6, drying the ammonium metavanadate which is the vanadium precipitation product, and heating to 500-600 ℃ in an oxidizing atmosphere, and carrying out heat preservation and calcination to obtain the vanadium pentoxide.
  4. 4. The method for preparing high-purity vanadium pentoxide by dissolving ammonium vanadate according to claim 3, wherein in the step 1, the magnesium salt is at least one selected from magnesium oxide, magnesium hydroxide and magnesium chloride, and the addition amount of the magnesium salt is 0.5-4 g/L based on the volume of the solvent.
  5. 5. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 4, wherein in the step 1, the carbonate is at least one selected from ammonium carbonate and ammonium bicarbonate, the adding amount of the carbonate is 25-40 g/L based on the volume of the solvent, and the solvent is deionized water or distilled water.
  6. 6. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 3, wherein in the step 3, the impurity removing agent is at least one selected from aluminum sulfate, aluminum chloride, ferric sulfate and ferric chloride, and the adding amount of the impurity removing agent is 0.1-1 g/L based on the volume of the vanadium-containing return solution.
  7. 7. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 3, wherein in the step 4, the complexing agent is at least one selected from ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid and hydroxyethyl ethylenediamine triacetic acid, and the adding amount of the complexing agent is 0.1-0.5 g/L based on the volume of the vanadium-containing purifying liquid.
  8. 8. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 3, wherein in the step 4, the ammonium salt is at least one selected from ammonium carbonate and ammonium bicarbonate, and the adding amount of the ammonium salt is 8-12 g/L based on the volume of the vanadium-containing purifying liquid.
  9. 9. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 3, wherein in the step 5, the stirring reaction time is 6-7 hours.
  10. 10. The method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate according to claim 3, wherein in the step 6, the oxidizing atmosphere is an air atmosphere or an oxygen atmosphere, and the heat preservation calcination time is 2-3 h.

Description

Method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate Technical Field The invention relates to the technical field of chemical industry, in particular to a method for preparing high-purity vanadium pentoxide by dissolving and removing impurities from ammonium vanadate. Background The main difficulty in the preparation of the high-purity vanadium oxide is the efficient and low-cost removal process of impurities, and the impurity content in the vanadium pentoxide product with the purity of 99.5 percent and above is generally required to be lower than 0.01 weight percent due to the higher control requirement on the impurity content level, which means that the stability and the easy implementation of the impurity removal process are also important constraint links in the production of the high-purity vanadium. The existing vanadium pentoxide purification technology for realizing production and application is an alkali-dissolution impurity-removal technical route, and has the advantages of simple operation and low equipment requirement, but multi-stage alkali dissolution-precipitation operation is often needed for achieving the impurity-removal effect, the process flow is long, the medicament consumption is large, the vanadium yield is low, the wastewater treatment capacity is large, the production cost is directly high, and the application development of high-purity vanadium products is limited. At present, the main technology for preparing the high-purity vanadium oxide is still to use crude vanadium such as vanadium pentoxide or industrial-grade vanadate product as raw materials to produce the high-purity vanadium product, dissolve the crude vanadium to obtain vanadium-containing solution, remove impurities and purify the solution, remove impurity types including Al, si, P, fe, mn, ca, cr, K, na and the like, precipitate vanadium again in the purified vanadium solution to obtain ammonium metavanadate with higher purity, and finally calcine the ammonium metavanadate to prepare the vanadium pentoxide product. The method is characterized in that sodium hydroxide, ammonia water, ammonium carbonate, sodium carbonate and the like are used as solvents for dissolution, alkaline vanadium liquid is obtained, sulfuric acid is used for dissolving vanadium pentoxide and then reducing the vanadium pentoxide, acidic tetravalent vanadium solution is obtained, and then the acid tetravalent vanadium solution is subjected to impurity removal and purification, wherein the impurity removal and purification process mainly comprises the steps of extraction impurity removal technology, ion exchange resin impurity removal technology and chemical impurity removal technology such as lanthanum salt, strontium salt, magnesium salt and calcium salt and the like, and the impurity removal technology is used for removing impurities, and has great differences in terms of impurity types and product requirements, wherein the impurity removal effect of the extraction and ion exchange impurity removal technology is generally better, impurity ions can be controlled to be below 30ppm, but the process flow is complex, and the medicament cost is high. Aiming at the pH value of the solution and the impurity types, the vanadium precipitation process can adopt an alkaline ammonium salt vanadium precipitation technology and an acidic ammonium salt vanadium precipitation technology to respectively prepare ammonium metavanadate and ammonium polyvanadate products. The preparation method of the high-purity vanadium pentoxide disclosed by CN 106241873B comprises the steps of preparing a dissolution solution by using an ammonium metavanadate crude product, adding sodium hydroxide and sodium carbonate into the dissolution solution, adjusting the pH value of the dissolution solution to 8.5-9.0, adding a purifying agent into the dissolution solution with the pH value adjusted, carrying out solid-liquid separation to obtain a filtrate, adding ammonium chloride into the filtrate to obtain an ammonium metavanadate precipitate, washing and dehydrating the precipitate to obtain ammonium metavanadate crystals, and calcining the ammonium metavanadate crystals at 500-550 ℃ for 2-2.5 hours to obtain the vanadium pentoxide, wherein the purifying agent is a mixture comprising one or more of magnesium chloride and calcium chloride, and the pH value of the purifying agent is 4-5. According to the prior art, impurity ions can be removed rapidly and effectively by adopting impurity removal measures combining a physical method and a chemical method, and the purity of the final product vanadium pentoxide can be improved effectively. However, the purifying agent in the prior art adopts magnesium chloride/calcium chloride, and ammonium metavanadate is washed for precipitation by adopting an ammonium chloride washing liquid, so that accumulated residues of chloride ions and magnesium ions/calcium ions in a system are easily