Extraction Of Vanadium Research Articles

Fusion–Extraction Technique of Vanadium(III) Using Ammonium Phosphate Salt as Flux

This study presents an alternative fusion method for sample dissolution and extraction of vanadium from an inorganic (V2O3) compound and mineral ore sample (AMIS 0501) using phosphate salts as flux. Complete sample dissolution was achieved at 800 °C within ±20 min using both the sodium and ammonium phosphate flux. The precipitation of vanadium was subsequently achieved after the fusion of the sample using ammonium phosphate flux, and no precipitate was obtained using sodium phosphate flux. The differences in cations between the two fluxes (NH4+ and Na+) influenced the precipitation of vanadium. The XRD analysis of the precipitate from V2O3 using ammonium phosphate showed a monoclinic structure of vanadium (III) tris(metaphosphate) (V(PO3)3) compound, which belonged to the Ic space group with lattice parameters a = 10.6071, b = 19.0871 and c = 9.4230. A remarkable vanadium recovery of 98% was obtained from inorganic compounds, V2O3, and up to 70% from the AMIS mineral ore sample using the ammonium phosphate flux method. The vanadium precipitates from AMIS contained Fe (20.97%) and Ti (44.97%), which occurred as impurities in the recovery of vanadium using the ammonium phosphate flux method.

Heterotrophic Bioleaching of Vanadium from Low-Grade Stone Coal by Aerobic Microbial Consortium.

Bioleaching is a viable method that assists in increasing the vanadium output in an economical and environmentally friendly manner. Most bioleaching is conducted by pure cultures under autotrophic conditions, which frequently require strong acidity and produce acid wastewater. However, little is known about heterotrophic bioleaching of vanadium by mixed culture. This study investigated the bioleaching of vanadium from low-grade stone coal by heterotrophic microbial consortium. According to the results, vanadium was efficiently extracted by the employed culture, with the vanadium recovery percentage in the biosystem being 7.24 times greater than that in the control group without inoculum. The average vanadium leaching concentration reached 680.7 μg/L in the first three cycles. The kinetic equation indicated that the main leaching process of vanadium was modulated by a diffusion process. Scanning electron microscopy revealed traces of bacterial erosion with fluffy structures on the surface of the treated stone coal. X-ray photoelectron spectroscopy confirmed the reduction of the vanadium content in the stone coal after leaching. Analysis of high-throughput 16S rRNA gene sequencing revealed that the metal-oxidizing bacteria, Acidovorax and Delftia, and the heterotrophic-metal-resistant Pseudomonas, were significantly enriched in the bioleaching system. Our findings advance the understanding of bioleaching by aerobic heterotrophic microbial consortium and offer a promising technique for vanadium extraction from low-grade stone coals.

Phase transformation mechanism of boiler ash roasted with sodium salt for vanadium extraction

Phase transformation mechanism of boiler ash roasted with sodium salt for vanadium extraction

Simultaneous Extraction of Gold and Vanadium From Vanadium and Carbon-Rich Refractory Gold Minerals by Chlorination Roasting

Simultaneous Extraction of Gold and Vanadium From Vanadium and Carbon-Rich Refractory Gold Minerals by Chlorination Roasting

Separation of vanadium and tungsten in roasting‐acid leaching solutions of the spent selective catalytic reducing denitration catalyst by co‐extraction using hydroxyoxime extractant‐quaternary ammonium salt extractant LIX984–N263 extractant

AbstractThis study presents a synergistic extraction and recovery of vanadium and tungsten by mixed extractants (LIX984 and N263) from an acid leaching solution which was obtained from spent denitrification catalysts by chlorination heat treatment and acid leaching. Through thrice counter‐flow extraction, 99.5% V and 99.7% W were extracted, while 3.0% Fe, 2.9% Ti, 2.1% P, and 3.3% Mg were co‐extracted at a LIX984:N263 volume content of 22.0%, the phase ratio of 2.5 and the mother liquor's pH of 2.5. Then, at 0.80 mol/l NaOH and a phase ratio of 1, 99.9% tungsten and 99.1% vanadium were stripped from the organic phase to the aqueous phase. Subsequently, the aqueous phase's tungsten of 99.3% and vanadium of 98.1% were separated as calcium tungstate and ammonium metavanadate, respectively. In contrast, the residual solutions containing tungsten and vanadium can be returned to the following purification separation process to recover the valuable metals from the solution. Roasting converts the precipitated calcium tungstate and ammonium metavanadate to V2O5 and WO3 products. In addition, the thermodynamic analysis found the separation and recovery of tungsten and vanadium from the acid leach solution with LIX984:N263 to be an exothermic process. This method can be effectively extended for the separation of vanadium and tungsten from spent denitrification catalysts by the proposed process and validates the conclusion that metals with similar properties can be extracted using a mixture of extractants.

High efficient vanadium extraction from vanadium slag using an enhanced acid leaching-coprecipitation process

Vanadium slag (VS) is a by-product of vanadium titanium magnetite BOF steelmaking process and becomes an important material for vanadium products preparation. Sodium roasting-water leaching is a mainstream process for industrial production, but the water leaching residue (WLR) usually remains 1.0 wt% to 3.0 wt% V2O5, which still has value for recycling extraction of vanadium. In this research, a two-stage leaching process was proposed for high efficient vanadium extraction. The first stage leaching was sodium roasting-water leaching for vS and the second stage leaching was sulfuric acid leaching for WLR. As a result, the total leaching efficiency of vanadium can reach as high as 98.52%, which was 7.72% higher than that of conventional water leaching efficiency of vanadium (90.80%). The mechanism analysis indicates that the CaNaFe2Si4O12 and NaFeSi2O6 water-insoluble phases formed and covered on (Mn,Fe)(V,Cr)2O4 spinel surface during roasting, hindering vanadium oxidation and dissolution. The structures of wrapping phases and spinel can be effectively destroyed by acid leaching, releasing vanadium in WLR. By using hydrolytic precipitation of iron ions in acid leachate, 99.78% of vanadium can be recovered as V-Fe precipitation slag, which contains 6.83 wt% V2O5 and can be cycled back to sodium roasting process. The V-Fe slag belongs to amorphous precipitation, illustrating that residual vanadium in WLR can be changed to unstable compound by acid leaching and hydrolysis precipitation, which makes vanadium easier to extract during sodium roasting-water leaching process. This research has the advantages of enhanced reuse of V resource in the WLR, achieving a high V recovery. The short process has a strong adaptability and can provide technical support for efficient V extraction from vS.

Experimental Study on Vanadium Extraction from Refractory Vanadium Ore

Experimental Study on Vanadium Extraction from Refractory Vanadium Ore

Crystal Transformation of Sericite during Fluidized Roasting: A Study Combining Experiment and Simulation

Fluidized roasting is an efficient method to promote vanadium extraction from V-bearing mica in shale. In this study, the transformation behavior of V-bearing sericite during fluidized roasting was explored by combining experimental detections and density functional theory (DFT) calculations. TG-MS, XRD, FTIR, and SEM-EDS were used to investigate the characteristics of the roasted sericite samples. The crystal parameters of V-bearing sericite were calculated with Materials Studio. The results showed that dehydroxylation was the main reaction during roasting, which occurred between 650 °C and 960 °C. After being roasted at 900 °C for 2 h, hydroxyls were completely removed. The calculation results show that −OH was removed between the metal ions in the sericite O-layer, which turned the hexa-coordinate of V3+, Al3+, and Fe3+ into pentacoordinate. Through electronic rearrangement, the bond lengths between two ions connected by −OH were shortened from 0.18~0.20 nm to 0.17 nm. However, some chemical bonds were grown, which indicates that they are weaker and easier to transform. In addition, twisted six-membered rings were formed with obvious angle changes on the (0 0 1) surface. Furthermore, Mulliken’s overlap populations of some V-O, Al-O, and Fe-O were decreased. Therefore, dehydroxylation is a determining factor in the destruction of sericite crystals during fluidized roasting, which also promotes vanadium release from shale.

Evaluation of Variables Determining Leaching Efficiency in Vanadium Extraction Using Alkali Roasting

Evaluation of Variables Determining Leaching Efficiency in Vanadium Extraction Using Alkali Roasting

Utilization of titanium nanocomposites as prospective materials for recycling of vanadium (V) from waste solutions

Vanadium (V) is widely used, especially in nuclear reactors, and recycling vanadium from waste has become a high priority. In this study, three titanium nanocomposites, polyacryl/TiO2 (PAA/TiO2), polyacryl-16, 16-dimethylheptadecan-1-amine/TiO2 (PAA-PJMT/TiO2) and polyacryl-ethylenediamine-tetraacetic acid/TiO2 (PAA-EDTA/TiO2), were synthesized by free radical polymerization in order to extract vanadium (V) from waste solution through cross linking into polymeric matrix. FTIR, SEM, TEM, EDX, particle size distribution, and porosity measurements are used to characterize the synthesized titanium nanocomposites. Several factors, such as pH, contact time, metal ion concentration, sorbent dose, and temperature, were studied in order to optimize V (V) sorption onto the synthesized titanium nanocomposites. After 60 min, the monolayer sorption capacities of VO2+ on PAA/TiO2, PAA-PJMT/TiO2 and PAA-EDTA/TiO2 at pH = 4 and 298 K are 120.3, 201.2 and 231.5 mg g−1, respectively. The kinetic mechanism of the reaction was discovered to be pseudo 2nd order, as well as VO2+ sorption is an endothermic and spontaneous process. Polymer degradation occurs in the prepared nanocomposites at 1 M H2SO4, and vanadium can be recovered with 96.5, 98.6, and 98.8% efficiencies for PAA/TiO2, PAA-PJMT/TiO2 and PAA-EDTA/TiO2, respectively, in the presence of the dissolved Ti(IV). The pH is increased to pH = 7 in order to precipitate Ti(IV) ions and separate it from recovered vanadium cations.

Investigation on separation principle of vanadium and chromium among Fe2VO4-CaO-FeCr2O4 system: Simplify and simulate calcification roasting process of vanadium-chromium slag

The competitive reaction of vanadium and chromium with calcium additives, along with the formation mechanism of calcium vanadate and calcium chromate are the central issue to the efficient separation and extraction of vanadium and chromium from vanadium-chromium slag (V-Cr slag) by calcification roasting. In this study, Fe2VO4 and FeCr2O4 were synthesized to simulate the vanadium chromium spinel in V-Cr slag; then, the reaction mechanism of Fe2VO4-CaO-FeCr2O4 powder system was studied by XRD, SEM and leaching experiments. Results showed that calcium vanadate and calcium chromate are generated after roasting Fe2VO4-CaO system and FeCr2O4-CaO system individually. In Fe2VO4-CaO-FeCr2O4 system, as n(CaO)/n(V2O3) is 2, vanadium exists in the form of Ca2V2O7 while almost all Cr2O3 from the decomposition of FeCr2O4 reacts with Fe2O3 to continuously form solid solution with more FeCr2O4 adding. After leaching, the addition of FeCr2O4 has no obvious effect on the leaching ratio of vanadium, and the leaching ratio of chromium decrease with FeCr2O4 adding. Consequently, 94.03% of vanadium and 0.15% of chromium are leached with n(CaO)/n(V2O3)/n(Cr2O3) of 2/1/1.03 at 900 °C. When n(CaO)/n(V2O3) is 4, Fe2VO4 is oxidized and calcified gradually to form Ca2V2O7 and Ca3V2O8 with increasing roasting temperature. A small amount of CaCrO4 is generated owing to the calcification of chromium, and most chromium still exists in the form of solid solution. The reaction result of Cr2O3 and Fe2O3 is the superposition of solid solution reactions with different degrees. Increasing the roasting temperature can significantly reduce the chromium leaching ratio. All above would provide a theoretical support for the calcification roasting process from V-Cr slag.

Extraction of vanadium from black shale by novel two-step fluidized roasting process

A novel two-step fluidized roasting (TSFR) process was explored to promote vanadium extraction from black shale. The phase transformation, micromorphology, and pore structure during the conditional experiment were investigated by XRD, FTIR, SEM-EDS, and BET. The results showed the optimal conditions of first-step roasting were 650 °C, 60 min, and 30% O 2, and second-step roasting was 950 °C, 75 min, and 21% O 2 . The vanadium leaching rate (TSFR) reached 68.54% which increased by 39.28% than raw ore and 13.54% than original NaCl roasting. Furthermore, 95.89% carbon was removed in first-step roasting. It avoided the spontaneous combustion and sintering of black shale when it was directly roasted at high temperature. Dolomite and kaolinite were decomposed. Second-step roasting made V-bearing sericite dehydroxylation. This destroyed the sericite lattice and promoted the release of V 3+ . Therefore, this study is expected to have guiding significance for the efficient and green development of vanadium extraction. • A two-step fluidized roasting (TSFR) process was used for vanadium extraction. • The V leaching rate of 68.54% was obtained from the refractory stone coal by TSFR. • The transformation of mineral phase and microstructure was analyzed. • The lattice damage of V-bearing sericite promoted the release and dissolution of V 3+ .

Enhancing effect of vanadium releasing efficiently from lattice in black shale by thermal activation

With the increasing demand for vanadium, the extraction technology of vanadium from strategic black shale has been widely valued. Vanadium mainly exists in muscovite of shale, and the extraction of vanadium requires the consumption of a large amount of acid. In industry, thermal activation is usually used to promote the dissolution of vanadium from muscovite. But the enhancing effect of thermal activation for releasing vanadium from lattice is unclear. In this study, the phase transition of black shale after thermal activation was described. Then the difference in lattice dissolution and vanadium migration were analyzed by quantum chemical simulations. From the atomic level, thermal activation caused a lattice expansion of vanadium-bearing muscovite (VM) through dehydroxylation reaction. Moreover, thermal activation can promote the replacement of K+ by H+, the removal of structural oxygen of tetrahedron and the coordination reaction of F- with central vanadium of octahedron in the acid leaching process.

Rapid Vanadium Extraction from Roasted Vanadium Steel Slag via a H2SO4-H2O2 System: Process and Mechanism.

A H2SO4–H2O2 system was developed to enhance the efficacy of vanadium extraction from roasted vanadium steel slag. The optimum parameters and the behavior of vanadium extraction were investigated systematically. When 1 mL of H2O2 per gram of vanadium slag was added to a leaching mixture at 50 °C, along with 30% H2SO4, 80.5% of vanadium extraction was achieved within 15 min. However, without H2O2, only 58.5% of vanadium extraction was achieved at the same leaching time. The H2SO4–H2O2 system facilitated the dissolution of metallic ions in a short time and then triggered the production of strong oxidizing substances, such as HO• and O2–•, via the Fenton reaction and Fenton-like reaction. Subsequently, the low-valence vanadium, existing in the leaching solution or located on the surface of the particle, was converted to pentavalent vanadium by strongly oxidizing substances, such as H2O2 and its derivatives HO• and O2. The complex oxides on the surface of the particle were destroyed, after which the vanadium inside the particle was gradually exposed to the acid leaching solution. The vanadium was oxidized to pentavalent vanadium, which then entered the leaching solution. Finally, a pathway of vanadium extraction via the H2SO4–H2O2 system was proposed to gain insight into rapid vanadium leaching.

Clean and efficient extraction of vanadium from vanadium slag: Effect of manganese on the phase composition and vanadium extraction process

Manganese in vanadium slag plays an important role in the clean and efficient extraction of vanadium, attributed to the effect of manganese content on the phase of vanadium slag and the synergistic effects between manganese and roasting additives during the roasting process. In this study, remelting and crystallization method were used to prepare vanadium slag with different MnO mass fractions. The aforementioned effects were examined using XRD, SEM, and roasting-leaching experiments. The results show that manganese in vanadium slag always occupies the lattice of iron and forms (Mn, Fe)(V, Cr)2O4 and (Fe, Mn)2SiO4. With the increasing MnO content, the diffraction peaks of both spinel and olivine shift to a small angle due to the lattice distortion. Moreover, the MnO content has a greater influence on olivine than on spinel. Mn2V2O7 and Ca2V2O7 are the main vanadates of blank roasting and calcification roasting using n(CaO)/n(V2O3) of 2, respectively. During calcification roasting with n(CaO)/n(V2O3) less than 2, calcium vanadate and manganese vanadate coexist in the roasted samples. During leaching, the vanadium leaching rate shows a completely opposite trend after blank roasting and calcification roasting using n(CaO)/n(V2O3) of 2 as the MnO content increases. By reducing the amount of the added calcium salt, the vanadium leaching rate increases slightly compared with that in the case of n(CaO)/n(V2O3) is 2.0, which fluctuates between 83% and 86%. Furthermore, around 30% of manganese in vanadium slag transforms the vanadium-bearing phase and is further transferred to the leaching solution when reducing the amount of calcium salt properly.

Two-stage cyclic ammonium sulfate roasting and leaching of extracting vanadium and titanium from vanadium slag

Compared with traditional sodium or calcification roasting process for vanadium extraction from raw vanadium slag (V-slag), ammonium sulfate (AS) roasting could reduce about 470 °C roasting temperature and avoid Cl2, HCl, sodium-containing waste-water and waste gypsum discharging. To reduce the amount of AS added in vanadium extraction process, an efficient AS two-stage cyclic roasting and acid leaching process was proposed. The result of TG analysis indicates V-slag could be decomposed in 275–380 °C using AS roasting process. Using 2.03:1 total mass ratio of AS to V-slag, 90.86% V and 80.54% Ti could be extracted after 380 °C roasting for 30 min and 8% initial concentration of H2SO4 leaching at 70 °C for 100 min. XRD analysis indicates V-containing spinel phase in the 1st stage leaching residue would be efficiently decomposed by the cyclic two-stage roasting and leaching process. Furthermore, the valence of V(III) in raw V-slag was not changed after the 1st AS roasting stage, but a part of V(III) in the 1st leaching residue was oxidized to V(V) after 2nd roasting process.

Distribution behavior of vanadium and titanium between hot metal and high titanium slag relevant to HIsmelt smelting condition

The HIsmelt process is well suited for smelting vanadium-titanium magnetite and has significant potential. In this paper, the vanadium and titanium distribution behavior at 1450 °C in the basicity range of 0.3–1.2 during HIsmelt smelting vanadium titano-magnetite was investigated experimentally for the first time. According to thermodynamic calculations combined with experimental validation, lower C content increases the activity coefficients of vanadium and titanium in the metal. Higher basicity decreases the activity coefficients of TiO2 and SiO2 in the slag, improves the distribution ratio of vanadium and titanium. Increasing C content and reducing basicity could increase the content of vanadium in the metal and TiO2 in the slag, which is favorable to vanadium extraction and titanium recovery. Furthermore, the V and Ti content in the hot metal increased significantly with rising smelting temperature. Higher smelting temperatures promote vanadium distribution into hot metal but not titanium distribution into slag. Finally, The Si and Ti distribution ratios have a positive connection according to the fitted models.

Eco-friendly chromium recovery from hazardous chromium-containing vanadium extraction tailings via low-dosage roasting

The Cr recovery from the Cr-containing tailings of vanadium extraction always generates large amounts of hazardous wastewater sludge and solid waste. This work proposed an eco-friendly Cr recovery method based on low-dosage soda roasting for a new kind of Cr-containing tailing, the Mg-based tailing. The low dosage of soda ensures the targeted conversion of Cr-bearing phases in the Mg-based tailing during roasting and minimizes the soda roasting of accompanying phases other than Cr-bearing phases, leading to the minimization of waste discharge. In the optimal condition of low-dosage soda roasting-water leaching, the Cr extraction efficiency is as high as 93.25 %; from the leach liquor, the Cr2O3 product is obtained by Na2S reduction, precipitation, and calcination with total Cr recovery of 92.93 %. For Cr extraction, the soda dosage has been reduced by 20 % while the production rates of hazardous sludge, leach residue, and CO2 have been reduced by 30 %, 18 %, and 20 %, respectively. This work exemplifies the control of targeted phase conversion to minimize hazardous wastes, which provides a novel strategy for eco-friendly resource utilization of hazardous tailings.

Effect of CaO on the Phase Evolution of Vanadium Slag during Crystallization and Roasting–Leaching Processes for Selective Extraction of Vanadium

In this paper, the effects of CaO on the phase evolution mechanism of vanadium slag during slagging, direct roasting, and (NH4)2CO3 leaching processes are investigated. Results indicate that with the increase in CaO content, vanadium is always concentrated as (Fe, Mn, Mg)V2O4 in spinels, part of titanium is concentrated and transformed into CaTiO3, and phosphorus is concentrated in 3CaO·P2O5 (C3P) and transformed into n·2CaO·SiO2-3CaO·P2O5 (nC2S-C3P). During the direct roasting process, a part of the vanadium-containing spinel phase oxidizes and reacts with Ca2SiO4 to produce calcium vanadate (Ca3V2O8, Ca10V6O25, and Ca2V2O7), which is soluble in (NH4)2CO3 aqueous solution. However, a part of the vanadium-containing spinel phase is oxidized and decomposed to vanadium oxides (V2O5 and V6O13), which are insoluble in (NH4)2CO3 aqueous solution. This is not beneficial for vanadium extraction using (NH4)2CO3 aqueous solution. In addition, (NH4)2CO3 aqueous solution can restrain the leaching of C3P from the nC2S-C3P solid solution in the directly roasted vanadium slag with high CaO content.

Solvent extraction of vanadium with D2EHPA from aqueous leachate of stone coal after low–temperature sulfation roasting

The solvent extraction of vanadium from aqueous solution after the leaching of stone coal vanadium ore following low–temperature sulfation roasting was enabled by di-(2-ethylhexyl)phosphoric acid (D2EHPA). Firstly, the effects of main factors on vanadium extraction and iron removal were investigated. Secondly, density function theory (DFT) simulations using the DMol3 module (GGA/PW91) were conducted to elucidate the interactions between D2EHPA and vanadium, which concluded that the phosphoric acid oxygen atom formed a coordination bond with vanadium atoms to achieve the solvent extraction of vanadium. D2EHPA molecules also dimerized to form a cyclic chelate complex with vanadium, which contributed to the solvent extraction of vanadium. Lastly, the solution chemical behavior of the vanadium in the organic phase after extraction with D2EHPA was analyzed. After reduction and neutralization pretreatments, VV (VO2+) was reduced to VIV (VO2+), which could be more strongly coordinated by D2EHPA over the pH range of 1–4.03, while FeIII was reduced to FeII, which was not coordinated as strongly by D2EHPA, minimizing the amount of iron extracted from the aqueous leachate into the organic phase by D2EHPA. The vanadium extraction efficiency increased as the initial pH of the leachate increased, but the formation of VOSO4 at pH > 2.5 hampered the extraction of vanadium.