Vanadium Precipitation Research Articles

Efficient Separation of Silicon and Vanadium by Sodium Roasting-Water Leaching from Vanadium Slag and CaV2O6 Preparation

Calcium vanadate (CaV2O6), a new product of vanadium precipitation, was obtained from vanadium slag by sodium roasting-water leaching and calcium precipitation. The separation behavior of vanadium and silicon in vanadium slag during sodium roasting and water leaching was systematically studied, and micro-morphology and valence migration behavior of vanadium and Fe in vanadium slag, roasting slag, and residue were revealed. The Na2CO3 was added to the vanadium slag at 20% mass fraction, roasted at 790 °C, and kept for 120 min, the roasted sample was added to the deionized aqueous solution with a liquid-solid ratio of (L/S) 5mL/g, and then heated at 90 °C for 60 min, 89.54% vanadium and 1.96% chromium were extracted. Sodium carbonate tends to combine with vanadium to form sodium vanadate, while silicon is easy to combine with Fe and Na to form acmite (NaFeSi2O6). When the molar ratio of N (Ca/V) is 0.6 and CaO, is added to adjust the pH of vanadium leaching solution to 6.7 ± 0.1 and precipitate 90 min at 90 °C, vanadium is precipitated in the form of CaV2O6 with a purity of 95.69%, under these conditions, the precipitation ratio is 95.03%.

Cyclic metallurgical process for extracting V and Cr from vanadium slag: Part I. Separation and recovery of V from chromium-containing vanadate solution

The separation and recovery of V from chromium-containing vanadate solution were investigated by a cyclic metallurgical process including selective precipitation of vanadium, vanadium leaching and preparation of vanadium pentoxide. By adding Ca(OH) 2 and ball milling, not only the V in the solution can be selectively precipitated, but also the leaching kinetics of the precipitate is significantly improved. The precipitation efficiency of V is 99.59% by adding Ca(OH) 2 according to Ca/V molar ratio of 1.75:1 into chromium-containing vanadate solution and ball milling for 60 min at room temperature, while the content of Cr in the precipitate is 0.04%. The leaching rate of V reaches 99.35% by adding NaHCO 3 into water according to NaHCO 3 /V molar ratio of 2.74:1 to leach V from the precipitate with L/S ratio of 4:1 mL/g and stirring for 60 min at room temperature. The crystals of NH 4 VO 3 are obtained by adjusting the leaching solution pH to be 8.0 with CO 2 and then adding NH 4 HCO 3 according to NH 4 HCO 3 /NaVO 3 molar ratio of 1:1 and stirring for 8 h at room temperature. After filtration, the crystallized solution containing ammonia is reused to leach the precipitate of calcium vanadates, and the leaching efficiency of V is >99% after stirring for 1 h at room temperature. Finally, the product of V 2 O 5 with purity of 99.6% is obtained by calcining the crystals at 560 °C for 2 h.

Separation and Recovery of Chromium from Solution After Vanadium Precipitation

The separation and recovery of chromium from solution after vanadium precipitation were investigated by deep removal of vanadium, hydrolysis precipitation of chromium, and preparation of chromium oxide. Hydrous oxide of trivalent iron is an effective deep vanadium remover and can be recycled. Under the most suitable conditions including hydrous oxide of trivalent iron addition with a Fe/V molar ratio of 4, reaction temperature of 60 °C, reaction time of 10 min, as well as the solution pH value of 3.0, the removal of vanadium reached 97.4%. Cr3+ and Mn2+ in solution can be separated through precipitation method. Under the conditions including solution pH value of 6.0, reaction temperature of 35 °C, and reaction time of 2 h, the precipitation of chromium was 96.6%. After deep remove manganese using sodium thiosulfate as the reducing agent, the well-crystallized Cr2O3 product with a purity of 99.1% was prepared. The manganese in the solution after chromium recovery can be recycled as an oxidant by hydrolysis precipitation and hydrogen peroxide oxidation.

Recovery of manganese from the mother liquor after vanadium precipitation during vanadium extraction with calcified roasting and acid leaching process

Recovery of manganese from the mother liquor after vanadium precipitation during vanadium extraction with calcified roasting and acid leaching process

Vanadium Recovery from the Waste Sludge of the Lime–Sulfuric Acid Processing of Converter Slag

The results of studying the vanadium recovery from the waste sludge of the manufacture of vanadium pentoxide V2O5 using the lime–sulfuric acid technology are discussed. Vanadium mainly exists in the sludge in three following forms: acid-soluble as manganese vanadate, unrecoverable in calcium silicates, and unrecovered as incompletely oxidized vanadium spinelides in the coarse fraction of the sludge. Low-temperature (20–40°C) sulfuric acid leaching of the sludge for complete recovery of acid-soluble vanadium, which is achieved at pH 0.75–0.8, is studied. Various variants of vanadium precipitation from a sulfuric acid solution are examined. The preliminary purification of the solution from impurities makes it possible to produce pure (≥99.4%) vanadium pentoxide during the precipitation of vanadium in the form of ammonium polyvanadate.

Ammonium vanadate/ammonia precipitation for vanadium production from a high vanadate to sodium ratio solution obtained via membrane electrolysis method

Vanadium is an important strategic metal and has been widely applied in a multiple of industries. However, the current process for the production of vanadium compounds suffers from the generation of a significant amount of high salinity ammonium containing wastewater due to the mixing of sodium salts, ammonium salts, and acid during vanadium precipitation operation. In order to avoid the generation of wastewater at source, a clean and recyclable V2O5 production process was proposed and investigated in this study. Using NH4VO3 and NH3·H2O as precipitants, (NH3)2·3V2O5·H2O and (NH3)2·V2O5·H2O were obtained by precipitation of vanadate (VxOyn−) from a high vanadate to sodium (V/Na) molar ratio acidic solution obtained via membrane electrolysis method, avoiding the generation of wastewater or solid waste. After calcination, high purity V2O5 product could be obtained. The vanadium precipitation process was investigated using ICP, XPS, SEM, XRD techniques, and the precipitation rate was investigated using solution conductivity method. Critical precipitation parameters such as excessive coefficient, solution temperature, solution V/Na molar ratio and solution pH were examined in detail. The results showed that increase the excessive coefficient, solution temperature and solution V/Na molar ratio, as well as reduce the solution pH would be beneficial for obtaining high purity vanadium products (≥99.9% V2O5). Optimum parameters were obtained at the V/Na molar ratio of 2.58, the excessive coefficient of 2, and the solution temperature of 363 K. The vanadium products obtained using both precipitants have a similar purity (more than 99.9%), however, due to a higher degree of hydrolysis reaction, the NH4VO3 precipitation method showed a higher VxOyn− precipitation rate (66.36%) in comparison with the NH3·H2O precipitation method (38.76%), indicating that the first method was superior. Based on this, a complete process with zero waste emission for V2O5 production was designed. The methods proposed and the results obtained from this study could provide fundamental information for the design of cleaner vanadium production process.

Cleaner extraction of vanadium from vanadium-chromium slag based on MnO2 roasting and manganese recycle

MnO2 roasting was proposed as a suitable roasting method for vanadium extraction from vanadium-chromium slag (V–Cr slag). Acid leaching and vanadium precipitation were carried out for the recovery of vanadium, then V2O5 was prepared. Manganese in the vanadium wastewater could be precipitated and recycled to the next roasting processes. The effects of roasting temperature and the amount of MnO2 on the phase evolution, along with elements distribution and leaching behaviors were discussed by XRD, SEM and leaching experiments. Two methods of manganese recycle were provided and evaluated. Results show that during MnO2 roasting, the stable vanadium spinel was oxidized and combined with Mn2O3, which was the decomposition product of MnO2 to form the acid-soluble manganese vanadate Mn2V2O7. Chromium, on the other hand, was combined with iron to generate the acid-insoluble (Fe0.6Cr0.4)2O3. After leaching the samples roasted at 850 °C in a molar ratio n(MnO)/n(V2O3) of 1.75 with acid at a pH value of 2.5, 89.48% of vanadium and 81.15% of manganese was leached due to the dissolution of Mn2V2O7, while only 0.15% of chromium and 0.02% of iron could be extracted simultaneously, improving the separation efficiency of vanadium with other impurities in V–Cr slag. V2O5 of 99.14% purity was produced after precipitating vanadium and ammonium vanadate roasting. As the highlight stage during MnO2 roasting, manganese could be recycled by precipitating with CO2 in an alkaline environment or precipitating directly with the addition of NH3·H2O. The products of precipitation were MnCO3 and Mn3O4 respectively, which could be both transformed into Mn2O3 before the combination of vanadium and manganese, which is consistent with the reaction during MnO2 roasting.

Preparation of electrolyte for vanadium redox flow battery from sodium-polyvanadate precipitated wastewater

In order to reduce pollution from wastewater and recycle the valuable metal in the vanadium precipitation process, sodium polyvanadate precipitated wastewater was utilized to prepare an electrolyte for the vanadium redox flow battery after two-stage purification via solvent extraction, which removed most of the impurities, especially Mn. The concentration of impurity ions was less than 10 ppm, as obtained by using inductively coupled plasma-optical emission spectroscopy, and the electrolyte obtained from the wastewater complied with the Chinese national standard. The method applied herein can simplify the preparation process compared to the conventional method and avoid ammonia nitrogen pollution. Electrochemical analysis showed that the properties of the prepared electrolyte were similar to those of the standard electrolyte. From the charge/discharge test, the energy efficiency and coulombic efficiency of the electrolyte reached nearly 90% of those of the standard electrolyte, which indicates that the electrolyte prepared from wastewater has the potential for commercial applications.

Influence of Vanadium Microalloying on Isothermal Transformation Behavior of Eutectoid Steel

Abstract—The influence of vanadium as a microalloying element on the austenite decomposition behaviors and microstructure transformation of eutectoid steel were studied during isothermal cooling. Vanadium dissolved in γ matrix exhibited a negative effect on austenite decomposition to pearlite microstructure and led to a decrease in the lamellar spacing. Moreover, the results indicated that the dissolved vanadium segregated toward austenite grain boundaries and suppressed the formation of grain boundary ferrite. However, the precipitation of vanadium during the isothermal process led to a decrease in vanadium dissolved in matrix that indirectly promoted transformation to pearlite. The precipitates could act as nucleus for pearlite formation, which also accelerated the transformation. The lamellar spacing of pearlite increased as a result of carbon consumption of precipitates. The addition of nitrogen remarkably accelerated the transformation, because the chemical driving force for VN formation was significantly larger.

Cleaner production of ammonium poly-vanadate by membrane electrolysis of sodium vanadate solution: The effect of membrane materials and electrode arrangements

In this study, we put forward a clean and complete process of V2O5 production from vanadium-containing solutions. It features membrane electrolysis for V/Na separation and AMV precipitation. With the aid of membrane electrolysis, the vanadium and sodium in the leaching solution can be directly separated using membrane-electrolysis. Meanwhile, the NaOH in the cathode chamber can also be recycled for vanadium slag decomposition. The electrolysis systems and membrane types have been investigated. It was found that 3-chamber electrolysis was much more energy efficient than the traditional 2-chamber electrolysis, while F8080 membrane showed a better separation efficiency than N117, CMI7000, LF0014 membrane. The main electrolysis parameters were also investigated, and it appeared that high current density and electrolyte temperature, as well as low initial cathodic NaOH concentration were beneficial for the separation efficiency. Under the optimum electrolysis conditions the electricity consumption of producing 750 kg V2O5 and 1000 kg NaOH and was 2151 kW h, with a current efficiency of 92.9%. During the vanadium precipitation process, NH4VO3 was used as precipitant for the first time, avoiding the introduction of impurity ions, such as Cl−, SO42− or Ca2+, realizing zero waste generation by source. A low-sodium medium product of (NH4)2V6O16 was precipitated at pH between 2 and 4. The commercial quality V2O5 product could be obtained by calcination and the ammonium slat was recycled for precipitation. This method can achieve the clean production of V2O5 with no wastewater or solid waste generated through the whole process.

Cleaning method of vanadium precipitation from stripped vanadium solution using oxalic acid

Adding ammonium salt to the stripped vanadium solution followed by calcination is the most commonly used vanadium precipitation method in the vanadium industry. However, the problem of ammonia waste water and waste gas emission in this process urgently needs to be solved. To avoid the ammonia emissions and utilize the sodium ion, a hydrothermal method was used to precipitate NaV2O5 by stripped vanadium solution. Under optimal conditions of a pH of 4.0, a time of 10 h, a temperature of 220 °C, and a molar ratio of oxalic acid to vanadium of 0.50, a NaV2O5 product with 99.83% of purity and 98.79% of vanadium precipitation rate was obtained. In view of crystal form, microscopy and granularity changes of products, a rational reaction and growth mechanism is put forward and that is condensation (oxolation and olation)-intercalation-reduction and self-assembly. The sodium in the stripped vanadium solution also can be utilized in this study. In short, one-step vanadium precipitation of NaV2O5 via hydrothermal process is an innovative, cleaning and efficient method, and it will also play a great role in NaV2O5 synthesis.

Purification of V2O5 and its application in all-vanadium redox flow batteries

V2O5 was prepared using chemical impurity removal agents (CaCl2, MgCl2, and Al2(SO4)3) in impurity removal methods and hydrolytic precipitation of vanadium with industrial grade ammonium vanadate as raw material, and then, VOSO4 electrolyte was prepared with the V2O5. The results show that the purity of V2O5 prepared by hydrolytic precipitation of vanadium is higher than that of the V2O5 prepared by chemical impurity removal agents (CaCl2, MgCl2, and Al2(SO4)3) via impurity removal methods, and new impurities (such as Ca, Mg, or Al) are introduced with the latter methods. The electrochemical performance of the VOSO4 electrolyte was evaluated through cyclic voltammetry and AC impedance tests. The experimental results show that the VOSO4 electrolyte created with V2O5 prepared via hydrolytic precipitation of vanadium have the best electrochemical performance. The VOSO4 electrolytes prepared with V2O5, created using a chemical impurity removal agent (MgCl2 or Al2(SO4)3) via impurity removal methods also have better electrochemical activities because of the higher purity of V2O5, although new impurities, such as Mg and Al, are introduced. The introduction of Ca impurity via the use of the chemical impurity removal agent CaCl2 is not beneficial for the electrochemical performance of the VOSO4 electrolyte, although a higher purity of V2O5 was achieved. Moreover, the all-vanadium redox flow battery with the electrolyte using V2O5 prepared via hydrolytic precipitation of vanadium exhibites the best cycling stability and charging and discharging performance with the capacity increasing by approximately 9% compared with that of the unpurified electrolyte.

Selective vanadium extraction from vanadium bearing ferro-phosphorus via roasting and pressure hydrogen reduction

A novel process involving roasting with additives, water leaching, and vanadium precipitation by high-pressure hydrogen reduction is proposed to selectively extract vanadium from vanadium-bearing ferro-phosphorus. The optimum conditions of roasting and leaching are obtained as follows: roasting temperature of 850 °C, Na2CO3 dosage of 30 wt%, CaCO3 dosage of 30 wt%, roasting time of 1 h, leaching time of 2 h and a leaching liquid–solid ratio of 1 mL/g. A V2O3 product having a purity of 99.92% is precipitated from the leaching solution by a high-pressure hydrogen reduction. The total recovered vanadium is up to 92.3%. X-ray diffraction (XRD) analysis of the raw ore, roasted ore, and leaching residue shows that the additive of Na2CO3 during roasting can react with the vanadium-bearing compounds and transform it into water-soluble NaVO3, while the additive of CaCO3 can solidify phosphorus-bearing and chromium-bearing compounds into non-water-soluble phosphates of Ca3(PO4)2 and Cr3(PO4)2. Moreover, the iron-bearing compounds are converted into non-water-soluble Fe2O3 and Na3Fe2(PO4)3. Thus, vanadium can be selectively extracted through the subsequent water leaching and high pressure hydrogen reduction process. Compared with the traditional process, this process is more efficient and environmentally friendly owing to the high recovery of vanadium, the non-used roasting additive of sodium chloride and the adopted eco-friendly vanadium precipitation method.

An environmentally friendly hydrothermal method of vanadium precipitation with the application of oxalic acid

During the traditional metallurgical process of vanadium (V), an ammonium salt is often employed as the precipitator to form an ammonium vanadate, which converted into V2O5 in the subsequent calcination. Due to the restriction of ammonia emissions by the Chinese government, the vanadium-bearing shale industry in China urgently needs to find out a new environmentally friendly vanadium precipitation method. As the widely used method in the synthesis of VO2, hydrothermal reduction with oxalic acid was firstly introduced into vanadium precipitation in this study. Several factors that affect the vanadium precipitation were studied in the batch tests, such as initial reaction pH, temperature, time, and n(H2C2O4·2H2O)/n(V(V)). A product with 99.53% purity of VO2(B) and 99.47% extent of vanadium precipitation was obtained under the optimized reaction conditions: initial reaction pH of 0.80, time of 8 h, temperature of 493 K, and n(H2C2O4·2H2O)/n(V(V)) of 1.00. Raman spectroscopy, inductively coupled plasma with optical emission spectrometry (ICP-OES) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) were also carried out to characterize the product and the results indicated that the product was pure VO2(B) in the form of nanorods. The reaction mechanism of VO2 prepared from stripped vanadium solution is put forward and the transformation of V from stripped vanadium solution to VO2 is proposed as: VO2+ → VO2(C2O4)− → VOC2O4 → VO2. Overall, the present hydrothermal method of vanadium precipitation with the application of oxalic acid has the characteristics of environmentally friendly, short process, simple and efficient.

A cleaner and efficient process for extraction of vanadium from high chromium vanadium slag: Leaching in (NH4)2SO4-H2SO4 synergistic system and NH4+ recycle

A cleaner and novelty leaching medium, (NH4)2SO4-H2SO4 synergistic system was introduced into the leaching process for extracting vanadium efficiently after calcification roasting with high chromium vanadium slag (HCVS), and then V2O5 was prepared after precipitation and roasting. The effects of leaching and precipitation conditions were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). 93.45% vanadium and 0.24% chromium were leached when the calcification roasted sample was leached in the (NH4)2SO4-H2SO4 synergistic system at 20 °C for 60 min with a liquid–solid ratio (L/S) of 10, achieving the efficient separation of vanadium and chromium in HCVS. The optimal (NH4)2SO4-H2SO4 synergistic system was composed with 250 g/L (NH4)2SO4 and 3.75 mol/L H2SO4, the amount of H2SO4 was 1 mL in every 30 mL leaching system. The introduction of (NH4)2SO4 provided much NH4+, which could promote the acid leaching reaction. 99.75% vanadium was precipitated further from vanadium-containing leaching liquid when heating the liquid at 60 °C for 60 min after adjusting the system pH at 8.0, and the deposit was ammonium polyvanadate (NH4)2V6O16. Then, V2O5 with a purity of 95.71% was prepared after roasting, and recovery rate of vanadium from HCVS was higher than 93%. After precipitation, the supernatant containing a large amount of NH4+ could be recycled as the new leaching medium with some (NH4)2SO4 adding according to NH4+ loss after vanadium precipitation. This process achieved the efficient extraction of vanadium from HCVS and provided a new thinking for the leaching process based on the (NH4)2SO4-H2SO4 synergistic system.

An Environment-Friendly Process Featuring Calcified Roasting and Precipitation Purification to Prepare Vanadium Pentoxide from the Converter Vanadium Slag

Converter vanadium slag is a byproduct of the iron making process when the vanadium titanomagnetite is used as iron raw material. A cleaner process including calcified roasting, dilute acid leaching, precipitation purification, vanadium precipitation with ammonium salt, followed by thermal decomposition was proposed to extract vanadium resource from this slag. And then vanadium pentoxide with purity over 98% was prepared, which can be used as additives for high strength low alloy steel production. A total vanadium recovery beyond 80% was achieved in this whole process. Since no sodium and potassium salt was introduced, wastewater generated was closed-circulating after removing the enriched impurities of P, Si, Ti and Cr with adding powder CaO. The content of V2O5 in residues after vanadium extraction was lower than 1.2 wt.%, while other valuable metals like Fe, Mn, Cr and Ti were concentrated. With no alkaline metal salts added in this process, the metal resources of Fe, Mn, Cr and Ti in the residues were more feasible to be recovered with pyrometallurgy processes.

Efficient extraction and separation of vanadium and chromium in high chromium vanadium slag by sodium salt roasting-(NH4)2SO4 leaching

A novelty process based on sodium salt roasting-(NH4)2SO4 leaching was proposed to extract vanadium and chromium in high chromium vanadium slag (HCVS). V2O5 and Cr2O3 was then prepared. The effects of roasting and leaching conditions on vanadium and chromium extraction behavior were studied systematically and completely. Vanadium precipitation conditions and chromium reduction conditions were optimized further. 94.6% vanadium and 96.5% chromium were extracted when HCVS and Na2CO3 were mixed in the molar ratio of n(Na2CO3)/n(V2O3+Cr2O3) of 2.5, then leached in 30g/L (NH4)2SO4 solution. 94.8% vanadium was precipitated as ammonium polyvanadate (APV) just by adjusting the leaching liquid pH at 4.5, almost all chromium was remained in liquid, achieving the efficient separation of vanadium and chromium. Chromium was then recovered by reduction and precipitation. More than 99% chromium was reduced when Na2S2O5 was added in m(Na2S2O5)/m[Cr(VI)] above 3. By roasting the deposits of vanadium and chromium respectively, 91.49% V2O5 and 89.89% Cr2O3 were obtained. The supernatant after vanadium and chromium extraction containing NH4+ could be recycled as the new leaching medium with some new (NH4)2SO4 added, which greatly reduced the discharge of ammonia-nitrogen wastewater and made the whole process more environmentally friendly.

Preparation of Vanadium Oxides from a Vanadium (IV) Strip Liquor Extracted from Vanadium-Bearing Shale Using an Eco-Friendly Method

In the traditional vanadium precipitation process, the use of ammonium salts can produce serious pollution problems from the ammonia waste-water and the ammonia gas generated during the processing. In this reported study, an eco-friendly technology was investigated to prepare vanadium oxides from a typical vanadium (IV) strip liquor, obtained after the hydrometallurgical treatment of a vanadium-bearing shale. Thermodynamic analysis demonstrated that VO(OH)2 could be prepared as a precursor over a suitable solution pH range. Experimental results showed that by adjusting the pH to around 5.6, at room temperature, 98.6% of the vanadium in the strip liquor was formed into hydroxide, in 5 min. After obtaining the VO(OH)2, it was washed with dilute acid to minimize the level of impurities. VO2 and V2O5 were then produced by reacting the VO(OH)2 with air or argon, in a tube furnace. The XRD analyses of the products showed that VO2 had been produced in air and V2O5 had been produced in argon. The purity of the VO2 was 98.82% after calcining for 2 h at 550 °C, in argon flow, at a rate of 50 mL/min. It was found that the purity of the V2O5 was 98.70%, using the same reaction conditions in air. Compared to the traditional precipitation method that uses ammonium salt, followed by calcination, this proposed method is eco-friendly and employs less quantities of reagents and energy, and two types of products can be produced. Consequently, this process could promote the sustainable development of the vanadium chemical industry.

Improved All-Vanadium Redox Flow Batteries using Catholyte Additive and a Cross-linked Methylated Polybenzimidazole Membrane

Through controlling the cross-linking and thickness of low-cost methylated polybenzimidazole anion exchange membranes and by using imidazolium chloride as a catholyte additive, we improved the energy efficiency at a current density of 100 mA cm–2 for all-vanadium redox flow batteries (RFBs) to 82%, compared to 76% with a Nafion 212 membrane and 67–78% for previously reported polybenzimidazole membranes with standard electrolyte. Moreover, thermal stability analysis of the charged catholytes, by direct observations of vanadium precipitation and variable temperature 51V nuclear magnetic resonance, confirmed an optimized content of 0.16 M of the electrochemically inert additive in 1.6 M vanadium solution, consistent with the electrochemical data. The imidazolium chloride additive with such a low concentration is sufficient to induce interaction with vanadium species in catholyte. This explains the improved electrolyte stability and enhanced cycling efficiency.

Precipitation of vanadium using ammonium salt in alkaline and acidic media and the effect of sodium and phosphorus

Two kinds of precipitation processes: ammonium salt precipitation of vanadium in alkaline media and ammonium salt precipitation of vanadium in acidic media from the stripping solution of N235-P507 synergistic extraction system were investigated. Both of them were found to be feasible for the high-efficient and selective extraction of vanadium from vanadium-bearing shale combined with N235-P507 synergistic extraction system. During the ammonium salt precipitation of vanadium in alkaline media, the crystal of sodium vanadates formed in the vanadium precipitate and the purity of the V2O5 product was affected when Na was 23 g/L. The vanadium precipitate was washed by 2% NH4Cl solution after ammonium salt precipitation of vanadium in alkaline media and high quality product contained 98.431% V2O5 was obtained by the calcining of refined vanadium precipitate. During the ammonium salt precipitation of vanadium in acidic media, Na had no significant effect while P had a great impact on the precipitation rate and purity of V2O5 product. After P was removed by MgSO4, the precipitation rate of vanadium was more than 99% and purity of V2O5 product was 99.761% by the ammonium salt precipitation of vanadium in acidic media.