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CN-122012951-A - Method and system for removing impurity silicon in sodium vanadium solution

CN122012951ACN 122012951 ACN122012951 ACN 122012951ACN-122012951-A

Abstract

The invention belongs to the technical field of vanadium oxide extraction from vanadium slag, and relates to a method and a system for removing impurity silicon in sodium vanadium liquid. The method comprises the steps of S100, adjusting the pH value of the sodium vanadium solution, maintaining the pH value of a solution system to be 8.0-10.0, obtaining pretreated sodium vanadium solution, S200, heating the pretreated sodium vanadium solution, sequentially adding aluminum sulfate and chromium sulfate for carrying out Si deep removal reaction, obtaining reaction slurry, and S300, sequentially carrying out standing sedimentation and solid-liquid separation on the reaction slurry, thus obtaining purified vanadium solution. The use of the method according to the invention ensures that Si in solution is precipitated out without carrying Al in the double hydrolysis reaction of Al 3+ and SiO 3 2‑ by adding to the liquid system of vanadium sodium salt a low dose of aluminium sulphate, lower than the theoretical amount of Al 3+ salt for silicon removal.

Inventors

  • JIANG LIN
  • WU ZHENXIU
  • CHEN XIANGQUAN

Assignees

  • 攀钢集团攀枝花钢铁研究院有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. The method for removing the impurity silicon in the sodium vanadium solution is characterized by comprising the following steps of: s100, adjusting the pH value of the sodium vanadium solution, and maintaining the pH value of a solution system to be 8.0-10.0 to obtain pretreated sodium vanadium solution; s200, heating the pretreated sodium vanadium solution, and sequentially adding aluminum sulfate and chromium sulfate to carry out deep Si removal reaction to obtain reaction slurry; and S300, sequentially carrying out standing sedimentation and solid-liquid separation on the reaction slurry to obtain purified vanadium liquid.
  2. 2. The method for removing silicon impurity from a sodium vanadium solution according to claim 1, wherein in step S100, the solution pH is adjusted by adding H 2 SO 4 or introducing CO 2 gas into the sodium vanadium solution.
  3. 3. The method for removing silicon impurities from a vanadium sodium salt solution according to claim 1, wherein in step S200, the reaction temperature is controlled to be 50-90 ℃.
  4. 4. The method for removing silicon impurity from a vanadium sodium solution according to claim 1, wherein in step S200, a predetermined amount of aluminum sulfate and chromium sulfate are sequentially added to ensure that the molar ratio of chemical elements in the vanadium sodium solution is n (Si): n (Al): n (Cr) =1 (0.5 to 0.7): 0.02 to 0.07.
  5. 5. The method for removing silicon impurity from a vanadium sodium salt solution according to claim 1, wherein in step S200, the Si deep removal reaction is performed under stirring.
  6. 6. The method for removing silicon impurities from a vanadium sodium salt solution according to claim 5, wherein in step S200, the stirring reaction time is controlled to be 30-120 min.
  7. 7. The method for removing silicon impurities in a vanadium sodium salt solution according to claim 1, wherein in the step S300, the standing sedimentation time is controlled to be 4-12 hours.
  8. 8. The method for removing silicon impurity from a vanadium sodium salt solution according to claim 7, wherein in step S300, the settled reaction slurry is subjected to solid-liquid separation by plate-frame filtration.
  9. 9. The method for removing silicon impurity from a vanadium sodium salt solution according to claim 8, wherein in step S300, a filtrate and a residue are obtained after solid-liquid separation, the residue is washed with water, and a washing solution is incorporated into the filtrate to obtain a purified vanadium solution.
  10. 10. The system for removing the impurity silicon in the sodium vanadium solution is characterized by comprising the following components: The pretreatment module is used for adjusting the pH value of the sodium vanadium solution, and maintaining the pH value of a solution system to be 8.0-10.0 to obtain pretreated sodium vanadium solution; The reaction module is used for heating the pretreated sodium vanadium solution, and sequentially adding aluminum sulfate and chromium sulfate to carry out deep Si removal reaction to obtain reaction slurry; and the post-treatment module is arranged for sequentially carrying out standing sedimentation and solid-liquid separation on the reaction slurry to obtain purified vanadium liquid.

Description

Method and system for removing impurity silicon in sodium vanadium solution Technical Field The invention belongs to the technical field of vanadium oxide extraction from vanadium slag, and relates to a method and a system for removing impurity silicon in sodium vanadium liquid. Background The vanadium titano-magnetite adopts a blast furnace ironmaking-converter vanadium extraction process to obtain vanadium slag, and the vanadium slag is a main raw material for extracting vanadium. In the current industrial application of vanadium extraction from vanadium slag, sodium-modified vanadium extraction is a common process for vanadium oxide production, and the industrial productivity of the sodium-modified vanadium extraction is about 70%. The process for extracting vanadium by sodium treatment of vanadium slag mainly comprises the working procedures of sodium salt roasting, water leaching, solution purification, vanadium precipitation, melting sheet, reduction and the like. In the sodium vanadium solution obtained by water leaching, si and P are common impurity elements, and the impurity P can form a stable complex H 7[P(V2O5)6 with vanadium in the subsequent acid ammonium salt vanadium precipitation process, so that the vanadium precipitation rate and the vanadium product quality are affected, and the industrial solution purification process mainly aims at removing the impurity P. For Si impurity in the sodium vanadium solution, the Si impurity is not removed independently, because the influence of Si with a certain concentration on the acid ammonium salt vanadium precipitation process is not great, vanadium oxide products meeting common quality requirements can be obtained, such as Si content less than or equal to 0.25% in V 2O5 98.0.0-F and Si content less than or equal to 0.20% in V 2O5 98.0.0-P in YB/T5304-2017. However, in the fields of vanadium catalysts, aerospace-grade vanadium-aluminum alloys, all-vanadium redox flow batteries and the like, high-purity vanadium oxide is required to be used as a raw material, and higher requirements are put forward on the content of Si impurity, for example, powder V 2O5 99.8.8-A in certain enterprise standards requires that the content of Si is less than or equal to 0.015 percent, and 99.8-B requires that the content of Si is less than or equal to 0.02 percent. Therefore, in order to realize the high-value utilization of vanadium resources and obtain high-purity vanadium oxide, impurity silicon needs to be removed before vanadium precipitation. At present, chemical precipitation method removal technology is mostly adopted for separating and removing impurity silicon in sodium vanadium solution, and comprises an aluminum salt precipitation method, a magnesium salt precipitation method, a hydrolysis precipitation method and the like. Patent CN120230925A discloses a method for selectively desilicating alkaline vanadium liquid, wherein pre-prepared magnesium-aluminum hydrotalcite is introduced into the alkaline vanadium liquid, pH is not required to be regulated, silicon can be selectively adsorbed, desilication residues are desorbed and then recycled as desilication agents, and sodium silicate-containing solution can be used for preparing sodium silicate products. Patent CN119637935A discloses a production method of low-silicon low-aluminum sheet vanadium pentoxide, wherein steam is adopted to heat vanadium liquid in the Si removal process, then concentrated sulfuric acid and aluminum sulfate are sequentially added to obtain purified vanadium liquid, and the mass percentage of silicon and aluminum in the sheet vanadium pentoxide obtained by subsequent precipitation and melting is less than or equal to 0.05%. Patent CN117737486a discloses a desilication method of alkaline vanadium liquid, which comprises mixing alkaline vanadium liquid and meta-aluminate solution, adjusting pH value of the mixed solution, and obtaining purified liquid and desilication slag through solid-liquid separation. Patent CN102477493B discloses a method for removing silicon and phosphorus from a sodium-modified vanadium extraction leaching solution, which adopts soluble magnesium salt, ammonium salt and soluble aluminum salt to cooperatively remove silicon and phosphorus impurities. Patent CN117004834a discloses a preparation method and application of a silicon removing agent for vanadium liquid, wherein Mg 2+ silicon removing agent is prepared in non-silicon vanadium liquid by electrolyzing Mg sheets, the pH value is adjusted by adding solid HVO 3、Na3VO4、NaVO3, the silicon removing agent can react with the silicon vanadium liquid to form Mg x(SiO3)y, and then heating precipitation is performed. Patent CN101709376B discloses a purifying method of alkaline vanadium leaching solution, magnesium nitrate is added into alkaline vanadium leaching solution, and the alkaline vanadium leaching solution is stirred uniformly and settled by standing, so as to obtain purified clear liquid, the purifying effect